-- ============================================================================
-- 1. Configuration & Constants
-- ============================================================================
local APP_VERSION_TEXT = "v1.0.2"

local CONFIG = {
    CLOUD_URL = "ws://stabadmin.fse-media.group",
    API_URL = "http://stabadmin.fse-media.group",
    SYNC_INTERVAL = 30,
    AUDIO_BASE = "Audio/",
    AUDIO_STATION = "Audio/Station/",
    DISK_AUDIO_BASE = "disk/Audio/",
    DISK_AUDIO_STATION = "disk/Audio/Station/",
    AUDIO_VOLUME = 3,
    DEBUG = true
}

local dfpwm = require "cc.audio.dfpwm"

local COLORS = {
    INFO = colors.white,
    WARN = colors.yellow,
    WARNING = colors.yellow,
    ERROR = colors.red,
    DEBUG = colors.cyan,
    SUCCESS = colors.green
}

-- ============================================================================
-- 2. State Management
-- ============================================================================
local State = {
    ws = nil,
    stationName = "Unknown",
    stationCode = "UNK",
    stationPlatform = "1",
    registered = false,
    stationList = {}, 
    currentTrain = nil,
    logs = {},
    logScrollOffset = 0,
    audioRx = nil,
    audioQueue = {},
    currentPlaying = nil,
    currentPriority = -1,
    interruptSeq = 0
}

-- ============================================================================
-- 3. Peripherals Setup
-- ============================================================================
local Peripherals = {}

function Peripherals.init()
    -- Station Peripheral
    Peripherals.station = peripheral.wrap("back", "train_station") 
        or error("Train station peripheral required on 'back'")
    -- Monitors
    local monitors = { peripheral.find("monitor") }
    if #monitors == 0 then error("At least one monitor is required") end
    -- Assign monitors
    Peripherals.primaryMonitor = monitors[1]
    Peripherals.primaryMonitor.setTextScale(0.5)
    -- Speakers
    Peripherals.speakers = { peripheral.find("speaker") }
end

-- ============================================================================
-- 4. Utility Functions
-- ============================================================================
local Utils = {}

function Utils.log(level, message)
    local timestamp = os.date("%H:%M:%S")
    local entryText = string.format("[%s][%s] %s", timestamp, level, message)
    local entry = { level = level, text = entryText }
    table.insert(State.logs, 1, entry)
    if #State.logs > 100 then table.remove(State.logs) end
    
    -- If user is scrolling history, increment offset to stay on same items
    if State.logScrollOffset > 0 then
        State.logScrollOffset = math.min(State.logScrollOffset + 1, math.max(0, #State.logs - 1))
    end
end

function Utils.getStationCode(name)
    if not name then return nil end
    name = tostring(name)
    
    local code = nil
    local codeInParens = name:match("[%[%(]([%w%d%-%/%s]+)[%]%)]")
    if codeInParens then
        local firstPart = codeInParens:match("[^/]+")
        if firstPart then
            code = firstPart:match("^%s*(.-)%s*$")
        end
    end

    if not code then
        code = name:match("[%w%d]+%-[%w%d]+") or name:match("[%a]+[%d]+")
    end

    if not code then
        local cleanName = name:match("^%s*(.-)%s*$"):lower()
        if State.stationList and State.stationList[cleanName] then 
            code = cleanName 
        end
    end

    if code then
        return tostring(code):lower() -- Always return lowercase for consistent comparison
    end
    return nil
end

function Utils.getPlatformNumber(name, default)
    if not name then return default end
    local p = name:match("[Pp]latform%s*([%d]+[a-zA-Z]?)") or name:match("[Tt]rack%s*([%d]+[a-zA-Z]?)")
    if p then return p end
    return name:match("([%d]+[a-zA-Z]?)$") or default
end

function Utils.getBroadcastStationCode(name)
    if not name then return "UNK" end
    name = name:match("^%s*(.-)%s*$")
    name = name:gsub("%s+", "_")
    if name == "" then return "UNK" end
    return name
end

function Utils.isSameTrain(id1, id2)
    if not id1 or not id2 then return false end
    if id1 == id2 then return true end
    
    -- Consist Car Match: "CK 1 01" vs "CK 1 02"
    local function getConsist(id)
        local clean = id:gsub("^%[.-%]%s*", "")
        local p = {}
        for s in clean:gmatch("%S+") do table.insert(p, s) end
        if #p >= 2 then
            if #p[1] <= 4 and tonumber(p[2]) then
                return p[1] .. " " .. p[2]
            end
        end
        return p[1] or clean
    end

    local c1 = getConsist(id1)
    local c2 = getConsist(id2)
    if c1 == c2 then return true end

    -- Fuzzy match: remove type prefix and compare content
    local _, name1, num1 = Utils.parseTrainId(id1)
    local _, name2, num2 = Utils.parseTrainId(id2)
    
    -- If both have numbers, compare name and number
    if num1 ~= "" and num2 ~= "" then
        return name1 == name2 and num1 == num2
    end
    
    -- Fallback to comparing just the main content/name
    return name1 == name2
end

function Utils.parseTrainId(trainId)
    if not trainId then return "unknown", "" end
    
    -- Generic match: [Type]Content
    local typeStr, content = trainId:match("^%[(.-)%](.+)$")
    
    if typeStr then
        -- Check for Express types
        if typeStr == "Ltd.Exp" or typeStr == "Express" then

            local name, num = content:match("^(.+) No%.(%d+)$")
            if name then
                return "express", name, num
            else
                return "express", content, ""
            end
        elseif typeStr == "Local" then
             return "regular", "Local", content
        else
             return "regular", typeStr, content
        end
    end
    
    return "unknown", "Unknown", trainId
end

function Utils.getDestination(schedule)
    if not schedule then return "Unknown" end
    -- Handle both wrapped and unwrapped schedule structure
    local entries = schedule.entries or (type(schedule) == "table" and schedule)
    if not entries or type(entries) ~= "table" then return "Unknown" end
    
    
    if #entries == 0 then
        local count = 0
        for _ in pairs(entries) do count = count + 1 end
        if count > 0 then

            local list = {}
            for k, v in pairs(entries) do
                local n = tonumber(k)
                if n then list[n] = v end
            end
            entries = list
        end
    end

    local dest = "Unknown"
    local maxIdx = 0
    for k, _ in pairs(entries) do
        if type(k) == "number" and k > maxIdx then maxIdx = k end
    end


    for i = 1, maxIdx do
        local entry = entries[i]
        if entry then
            local inst = entry.instruction
            if inst then
                if inst.id == "create:destination" then
                    dest = (inst.data and inst.data.text) or inst.text or dest
                end
                
                if inst.id == "create:station" then
                    local sName = (inst.data and inst.data.text) or inst.text
                    if sName then
                        dest = sName 
                    end
                end
            end
        end
    end
    
    return dest
end

function Utils.getBaseName(name)
    if not name then return "" end
    name = tostring(name):lower()
    name = name:gsub("%s*[Pp]latform%s*[%d%a]+", ""):gsub("%s*[Tt]rack%s*[%d%a]+", "")
    name = name:gsub("%s*[%[%(].-[%]%)]%s*", " ")
    name = name:gsub("%s+%d+$", "")
    return name:match("^%s*(.-)%s*$")
end

function Utils.isFuzzyMatch(str, pattern)
    if not str or not pattern then return false end
    str = tostring(str):lower():match("^%s*(.-)%s*$")
    pattern = tostring(pattern):lower():match("^%s*(.-)%s*$")
    
    if str == pattern then return true end
    
    -- 1. Handle Create Mod Wildcards (*)
    if pattern:find("*") then
        local p = pattern:gsub("([%^%$%(%)%%%.%[%]%+%-%?])", "%%%1")
        p = p:gsub("%%%*", ".*")
        local ok, res = pcall(function() return str:match("^" .. p .. "$") end)
        if ok and res then return true end
    end
    
    -- 2. Base name comparison
    local b1 = Utils.getBaseName(str)
    local b2 = Utils.getBaseName(pattern)
    if b1 ~= "" and b2 ~= "" then
        if b1 == b2 then return true end
        -- Substring match for base names
        if #b1 >= 4 and #b2 >= 4 then
            if b1:find(b2, 1, true) or b2:find(b1, 1, true) then
                return true
            end
        end
    end
    
    -- 3. Alphanumeric only comparison
    local a1 = str:gsub("[^%w%d]", "")
    local a2 = pattern:gsub("[^%w%d]", "")
    if a1 ~= "" and a2 ~= "" and (a1 == a2 or a1:find(a2, 1, true) or a2:find(a1, 1, true)) then
        return true
    end

    return false
end

function Utils.getStopTime(schedule, stationName)
    if not schedule or not schedule.entries or not stationName then return nil end
    
    local target = tostring(stationName):lower():match("^%s*(.-)%s*$")
    if target == "" then return nil end
    
    local targetCode = Utils.getStationCode(target)
    local targetBase = Utils.getBaseName(target)
    local targetAlpha = target:gsub("[^%w%d]", "")

    Utils.log("DEBUG", string.format("STATION TARGET: '%s' (Code: %s, Base: %s, Alpha: %s)", target, tostring(targetCode), targetBase, targetAlpha))

    local function extractTime(data)
        if not data then return nil end
        local val = tonumber(data.value) or tonumber(data.seconds) or tonumber(data.s) 
                 or tonumber(data.time) or tonumber(data.duration) or tonumber(data.delay)
        local unit = tonumber(data.time_unit) or tonumber(data.unit) or 1 
        if val then
            if unit == 0 then return val / 20
            elseif unit == 1 then return val
            elseif unit == 2 then return val * 60
            end
            return val
        end
        local ticks = tonumber(data.ticks) or tonumber(data.tick)
        if ticks then return ticks / 20 end
        return nil
    end

    local function findTimeInConditions(conditions)
        if not conditions then return nil end
        for i, item in ipairs(conditions) do
            if type(item) == "table" then
                local cid = tostring(item.id or ""):lower()
                if cid:find("delay") or cid:find("wait") or cid:find("idle") or cid:find("pause") then
                    local s = extractTime(item.data)
                    if s and s > 0 then 
                        Utils.log("DEBUG", string.format("Found Time in Condition [%d]: %.1fs (ID: %s)", i, s, cid))
                        return s 
                    end
                end
                for k, sub in pairs(item) do
                    if type(sub) == "table" then
                        local s = findTimeInConditions({sub})
                        if s then return s end
                    end
                end
            end
        end
        return nil
    end

    local maxIdx = 0
    if schedule.entries then
        for k, _ in pairs(schedule.entries) do
            if type(k) == "number" and k > maxIdx then maxIdx = k end
        end
    end
    
    Utils.log("DEBUG", string.format("--- Schedule Scan Start (MaxIdx: %d) ---", maxIdx))
    
    local matchFoundIndex = nil

    for i = 1, maxIdx do
        local entry = schedule.entries[i]
        if entry then
            local function scanRecursive(obj, depth)
                if depth > 5 or not obj then return false end
                for k, v in pairs(obj) do
                    if type(v) == "string" then
                        local entryText = v:lower()
                        local entryCode = Utils.getStationCode(entryText)
                        local entryAlpha = entryText:gsub("[^%w%d]", "")
                        local entryBase = Utils.getBaseName(entryText)
                        
                        Utils.log("DEBUG", string.format("  [%d] SCAN '%s': '%s' (Code: %s)", i, k, entryText, tostring(entryCode)))

                        local isMatch = (target == entryText)
                            or (targetCode and entryCode and targetCode == entryCode)
                            or (targetAlpha ~= "" and entryAlpha ~= "" and (targetAlpha == entryAlpha or targetAlpha:find(entryAlpha, 1, true) or entryAlpha:find(targetAlpha, 1, true)))
                            or (targetBase ~= "" and entryBase ~= "" and (targetBase == entryBase or targetBase:find(entryBase, 1, true) or entryBase:find(targetBase, 1, true)))
                            or Utils.isFuzzyMatch(target, entryText)

                        if isMatch then
                            Utils.log("DEBUG", string.format("  >>> MATCH FOUND AT ENTRY %d (via field '%s')", i, k))
                            return true
                        end
                    elseif type(v) == "table" then
                        if scanRecursive(v, depth + 1) then return true end
                    end
                end
                return false
            end

            if scanRecursive(entry, 0) then
                matchFoundIndex = i
                local s = findTimeInConditions(entry.conditions)
                if s then 
                    Utils.log("DEBUG", string.format("  >>> TIME RESOLVED FROM CONDITIONS: %.1fs", s))
                    return s 
                end
                
                if entry.instruction and entry.instruction.data then
                    local s = extractTime(entry.instruction.data)
                    if s then 
                        Utils.log("DEBUG", string.format("  >>> TIME RESOLVED FROM INSTRUCTION: %.1fs", s))
                        return s 
                    end
                end
                
                break 
            end
        end
    end

    if matchFoundIndex then
        Utils.log("DEBUG", string.format("  >>> Station matched at [%d], scanning ahead for time...", matchFoundIndex))
        for i = matchFoundIndex + 1, maxIdx do
            local entry = schedule.entries[i]
            if entry then
                local isOtherStation = false
                local function checkIsStation(obj, depth)
                    if depth > 2 or not obj then return false end
                    for k, v in pairs(obj) do
                        if type(v) == "string" then
                            local lk = tostring(k):lower()
                            if lk:find("text") or lk:find("station") or lk:find("destination") then return true end
                        elseif type(v) == "table" then
                            if checkIsStation(v, depth + 1) then return true end
                        end
                    end
                    return false
                end
                if checkIsStation(entry, 0) then break end

                local s = findTimeInConditions(entry.conditions)
                if s then 
                    Utils.log("DEBUG", string.format("  >>> TIME FOUND AT LATER ENTRY [%d]: %.1fs", i, s))
                    return s 
                end
                if entry.instruction and entry.instruction.data then
                    local s = extractTime(entry.instruction.data)
                    if s then 
                        Utils.log("DEBUG", string.format("  >>> TIME FOUND AT LATER INSTRUCTION [%d]: %.1fs", i, s))
                        return s 
                    end
                end
            end
        end
    end

    Utils.log("DEBUG", "--- Scan End: No Time Resolved ---")
    return nil
end

-- ============================================================================
-- 5. Audio System
-- ============================================================================
local Audio = {}

function Audio.createStream()
    local chunks = {}
    local finished = false
    local stream = {}
    
    stream.push = function(chunk)
        if type(chunk) ~= "string" then return end
        table.insert(chunks, chunk)
        os.queueEvent("audio_chunk")
    end
    
    stream.finish = function()
        finished = true
        os.queueEvent("audio_chunk")
    end
    
    stream.read = function()
        while #chunks == 0 do
            if finished then return nil end
            os.pullEvent("audio_chunk")
        end
        return table.remove(chunks, 1)
    end
    
    return stream
end

function Audio.loadStationList()
    State.stationList = {}
    if not fs.exists("list.txt") then 
        Utils.log("WARN", "list.txt not found")
        return 
    end
    
    local file = fs.open("list.txt", "r")
    if file then
        local count = 0
        local line = file.readLine()
        while line do
            line = line:gsub("%s+$", "") -- Trim trailing \r\n and spaces
            if line ~= "" then
                local codes, files = line:match("^([^=]+)==(.+)$")
                if codes and files then
                    local list = {}
                    for f in files:gmatch("[^,]+") do
                        local cleanName = f:match("^%s*(.-)%s*$"):gsub("%.wav$", ""):gsub("%.dfpwm$", "")
                        if cleanName ~= "" then
                            table.insert(list, cleanName)
                        end
                    end
                    
                    -- Map all codes to this list
                    local allCodes = {}
                    for code in codes:gmatch("[^/]+") do
                        local cleanCode = code:match("^%s*(.-)%s*$"):lower()
                        if cleanCode ~= "" then
                            table.insert(allCodes, cleanCode)
                            State.stationList[cleanCode] = list
                        end
                    end
                    
                    if #allCodes > 1 then
                        local fullRawCode = codes:match("^%s*(.-)%s*$"):lower()
                        State.stationList[fullRawCode] = list
                        local dashCode = table.concat(allCodes, "-"):lower()
                        State.stationList[dashCode] = list
                    end
                    count = count + 1
                end
            end
            line = file.readLine()
        end
        file.close()
        Utils.log("INFO", string.format("Station list loaded: %d entries", count))
    end
end

function Audio.enqueueDfpwm(dfpwmData)
    if type(dfpwmData) ~= "string" or #dfpwmData == 0 then return end
    Audio.enqueueItem({ audioData = dfpwmData, audioFormat = "dfpwm", priority = 1 })
end

function Audio.enqueueItem(item)
    if type(item) ~= "table" then return end
    item.audioData = item.audioData or item.dfpwmData
    item.audioFormat = tostring(item.audioFormat or (item.dfpwmData and "dfpwm") or "dfpwm"):lower()
    if type(item.audioData) ~= "string" and type(item.audioData) ~= "table" then return end
    item.priority = tonumber(item.priority) or 0
    local idx = 1
    while idx <= #State.audioQueue do
        local p = tonumber(State.audioQueue[idx].priority) or 0
        if item.priority > p then break end
        idx = idx + 1
    end
    table.insert(State.audioQueue, idx, item)
    os.queueEvent("audio_queue")
end

function Audio.stop(mode, flushBelow)
    State.interruptSeq = State.interruptSeq + 1
    if State.audioRx and State.audioRx.stream then
        pcall(State.audioRx.stream.finish)
    end
    State.audioRx = nil
    if Peripherals.speakers then
        for _, sp in ipairs(Peripherals.speakers) do
            pcall(function()
                if type(sp.speakStop) == "function" then sp.speakStop()
                else sp.stop() end
            end)
        end
    end

    if mode == "all" then
        State.audioQueue = {}
    elseif flushBelow ~= nil then
        local minP = tonumber(flushBelow) or 0
        local kept = {}
        for _, it in ipairs(State.audioQueue) do
            local p = tonumber(it.priority) or 0
            if p >= minP then table.insert(kept, it) end
        end
        State.audioQueue = kept
    end

    os.queueEvent("audio_interrupt", State.interruptSeq)
end

local function shouldStop(playSeq)
    return State.interruptSeq ~= playSeq
end

local function waitForInterruptibleDelay(playSeq, seconds)
    local timer = os.startTimer(seconds)
    while true do
        local ev = { os.pullEvent() }
        if ev[1] == "audio_interrupt" and tonumber(ev[2]) and tonumber(ev[2]) >= playSeq then
            return false
        end
        if ev[1] == "timer" and ev[2] == timer then
            return true
        end
    end
end

local function playChunkOnSpeakers(samples, volume, playSeq)
    if not Peripherals.speakers or #Peripherals.speakers == 0 then return false end
    local controller = Peripherals.speakers[1]
    if controller and type(controller.playAudioAll) == "function" then
        while true do
            if shouldStop(playSeq) then return false end
            local ok = false
            pcall(function()
                ok = controller.playAudioAll(samples, volume)
            end)
            if ok then break end
            local ev = { os.pullEvent() }
            if ev[1] == "audio_interrupt" and tonumber(ev[2]) and tonumber(ev[2]) >= playSeq then
                return false
            end
        end
    else
    local pending = {}
    for _, sp in ipairs(Peripherals.speakers) do
        local name = peripheral.getName(sp)
        if name then pending[name] = sp end
    end

    while next(pending) do
        if shouldStop(playSeq) then return false end
        for name, sp in pairs(pending) do
            local ok = false
            pcall(function()
                ok = sp.playAudio(samples, volume)
            end)
            if ok then pending[name] = nil end
        end
        if next(pending) then
            local ev = { os.pullEvent() }
            if ev[1] == "audio_interrupt" and tonumber(ev[2]) and tonumber(ev[2]) >= playSeq then
                return false
            end
        end
    end
    end

    local waiting = {}
    for _, sp in ipairs(Peripherals.speakers) do
        local name = peripheral.getName(sp)
        if name then waiting[name] = true end
    end

    while next(waiting) do
        if shouldStop(playSeq) then return false end
        local ev = { os.pullEvent() }
        if ev[1] == "audio_interrupt" and tonumber(ev[2]) and tonumber(ev[2]) >= playSeq then
            return false
        end
        if ev[1] == "speaker_audio_empty" and ev[2] and waiting[ev[2]] then
            waiting[ev[2]] = nil
        end
    end

    return true
end

local function decodePcmS8Chunk(chunk)
    if type(chunk) ~= "string" or #chunk == 0 then return nil end
    local samples = {}
    for i = 1, #chunk do
        local b = string.byte(chunk, i)
        if b >= 128 then
            b = b - 256
        end
        samples[i] = b
    end
    return samples
end

local function readU16LE(data, offset)
    local a, b = string.byte(data, offset, offset + 1)
    if not a or not b then return nil end
    return a + b * 256
end

local function readS16LE(data, offset)
    local val = readU16LE(data, offset)
    if not val then return nil end
    if val >= 32768 then
        val = val - 65536
    end
    return val
end

local function readU32LE(data, offset)
    local a, b, c, d = string.byte(data, offset, offset + 3)
    if not a or not b or not c or not d then return nil end
    return a + b * 256 + c * 65536 + d * 16777216
end

local function clampSample8(val)
    if val > 127 then return 127 end
    if val < -128 then return -128 end
    return val
end

local function decodeWavChunkToSamples(chunk)
    if type(chunk) ~= "string" or #chunk < 44 then
        return nil, "wav chunk too short"
    end
    if chunk:sub(1, 4) ~= "RIFF" or chunk:sub(9, 12) ~= "WAVE" then
        return nil, "invalid wav header"
    end

    local offset = 13
    local audioFormat, channels, sampleRate, bitsPerSample
    local dataOffset, dataSize

    while offset + 7 <= #chunk do
        local chunkId = chunk:sub(offset, offset + 3)
        local chunkSize = readU32LE(chunk, offset + 4)
        if not chunkSize then break end
        local payloadOffset = offset + 8
        if chunkId == "fmt " and chunkSize >= 16 then
            audioFormat = readU16LE(chunk, payloadOffset)
            channels = readU16LE(chunk, payloadOffset + 2)
            sampleRate = readU32LE(chunk, payloadOffset + 4)
            bitsPerSample = readU16LE(chunk, payloadOffset + 14)
        elseif chunkId == "data" then
            dataOffset = payloadOffset
            dataSize = chunkSize
            break
        end
        offset = payloadOffset + chunkSize
        if chunkSize % 2 == 1 then
            offset = offset + 1
        end
    end

    if audioFormat ~= 1 then
        return nil, "unsupported wav format " .. tostring(audioFormat)
    end
    if channels ~= 1 and channels ~= 2 then
        return nil, "unsupported channels " .. tostring(channels)
    end
    if bitsPerSample ~= 8 and bitsPerSample ~= 16 then
        return nil, "unsupported bits " .. tostring(bitsPerSample)
    end
    if not dataOffset or not dataSize or dataOffset + dataSize - 1 > #chunk then
        return nil, "invalid wav data chunk"
    end

    local frameSize = channels * (bitsPerSample / 8)
    if frameSize <= 0 then
        return nil, "invalid frame size"
    end

    local samples = {}
    local sampleIndex = 1
    local endOffset = dataOffset + dataSize - frameSize

    for pos = dataOffset, endOffset, frameSize do
        local mixed = 0
        for ch = 0, channels - 1 do
            local sampleOffset = pos + ch * (bitsPerSample / 8)
            local sampleValue
            if bitsPerSample == 8 then
                local raw = string.byte(chunk, sampleOffset)
                sampleValue = (raw or 128) - 128
            else
                sampleValue = readS16LE(chunk, sampleOffset) or 0
                if sampleValue >= 0 then
                    sampleValue = math.floor(sampleValue / 256)
                else
                    sampleValue = math.ceil(sampleValue / 256)
                end
            end
            mixed = mixed + sampleValue
        end
        samples[sampleIndex] = clampSample8(math.floor(mixed / channels))
        sampleIndex = sampleIndex + 1
    end

    return samples, nil, {
        channels = channels,
        bitsPerSample = bitsPerSample,
        sampleRate = sampleRate or 0
    }
end

local function areHqSpeakersBusy(speakers)
    for _, sp in ipairs(speakers) do
        local playing = false
        local queued = 0
        pcall(function()
            if type(sp.speakIsPlaying) == "function" then
                playing = sp.speakIsPlaying() and true or false
            end
            if type(sp.speakQueueSize) == "function" then
                queued = tonumber(sp.speakQueueSize()) or 0
            end
        end)
        if playing or queued > 0 then return true end
    end
    return false
end

local function downloadAudioBytes(url)
    if type(url) ~= "string" or url == "" then return nil, nil, "empty url" end
    local ok, resp = pcall(function()
        return http.get(url, nil, true)
    end)
    if not ok or not resp then
        return nil, nil, "http.get failed"
    end

    local body = resp.readAll()
    resp.close()
    if type(body) ~= "string" or #body == 0 then
        return nil, nil, "empty response body"
    end

    local lower = url:lower()
    local ext = lower:match("%.([%a%d]+)$")
    return body, ext or "file", nil
end

local function playHqAudioItem(item)
    if not Peripherals.speakers or #Peripherals.speakers == 0 then
        Utils.log("WARN", "No speakers found; cannot play audio")
        return
    end

    local playSeq = State.interruptSeq
    local payload = item.audioData
    if type(payload) ~= "string" or #payload == 0 then return end

    local format = tostring(item.audioFormat or "file"):lower()
    if format == "stream" then
        local bytes, ext, err = downloadAudioBytes(payload)
        if not bytes then
            Utils.log("ERROR", "Failed to download stream audio: " .. tostring(err))
            return
        end
        Utils.log("INFO", "Downloaded stream audio: " .. tostring(#bytes) .. " bytes")
        payload = bytes
        if ext == "wav" then format = "wav"
        elseif ext == "mp3" then format = "mp3"
        elseif ext == "ogg" then format = "ogg"
        else format = "file" end
    end

    local controller = Peripherals.speakers[1]
    local called = false
    local loopEnabled = item.loop and true or false

    if controller then
        pcall(function()
            if type(controller.setLoopingAll) == "function" then
                controller.setLoopingAll(loopEnabled)
            end
        end)
        local ok, result = pcall(function()
            if format == "hls" and type(controller.speakHLSAll) == "function" then
                return controller.speakHLSAll(payload, CONFIG.AUDIO_VOLUME)
            elseif format == "wav" and type(controller.speakWavAll) == "function" then
                return controller.speakWavAll(payload, CONFIG.AUDIO_VOLUME)
            elseif format == "mp3" and type(controller.speakMp3All) == "function" then
                return controller.speakMp3All(payload, CONFIG.AUDIO_VOLUME)
            elseif format == "ogg" and type(controller.speakOggAll) == "function" then
                return controller.speakOggAll(payload, CONFIG.AUDIO_VOLUME)
            elseif type(controller.speakFileAll) == "function" then
                return controller.speakFileAll(payload, CONFIG.AUDIO_VOLUME)
            end
        end)
        if ok and result then
            called = true
        end
    end

    if not called then
        for _, sp in ipairs(Peripherals.speakers) do
            pcall(function()
                if type(sp.setLooping) == "function" then
                    sp.setLooping(loopEnabled)
                end
            end)
            local ok, result = pcall(function()
                if format == "hls" and type(sp.speakHLS) == "function" then
                    return sp.speakHLS(payload, CONFIG.AUDIO_VOLUME)
                elseif format == "wav" and type(sp.speakWav) == "function" then
                    return sp.speakWav(payload, CONFIG.AUDIO_VOLUME)
                elseif format == "mp3" and type(sp.speakMp3) == "function" then
                    return sp.speakMp3(payload, CONFIG.AUDIO_VOLUME)
                elseif format == "ogg" and type(sp.speakOgg) == "function" then
                    return sp.speakOgg(payload, CONFIG.AUDIO_VOLUME)
                elseif type(sp.speakFile) == "function" then
                    return sp.speakFile(payload, CONFIG.AUDIO_VOLUME)
                end
            end)
            if ok and result then
                called = true
            end
        end
    end

    if not called then
        Utils.log("ERROR", "HQ speaker did not accept audio for format " .. format)
        return
    end

    while areHqSpeakersBusy(Peripherals.speakers) do
        if shouldStop(playSeq) then
            Audio.stop("current")
            return
        end
        if not waitForInterruptibleDelay(playSeq, 0.1) then
            Audio.stop("current")
            return
        end
    end
end

local function pushWavChunkToSpeakers(payload, playSeq)
    local controller = Peripherals.speakers and Peripherals.speakers[1] or nil
    if controller and type(controller.speakWavAll) == "function" then
        local retryCount = 0
        while true do
            if shouldStop(playSeq) then return false end
            local ok = false
            local queueSize = -1
            local isPlaying = false
            pcall(function()
                ok = controller.speakWavAll(payload, CONFIG.AUDIO_VOLUME)
                if type(controller.speakQueueSize) == "function" then
                    queueSize = tonumber(controller.speakQueueSize()) or -1
                end
                if type(controller.speakIsPlaying) == "function" then
                    isPlaying = controller.speakIsPlaying() and true or false
                end
            end)
            if ok then
                Utils.log("INFO", string.format("WAV chunk accepted: bytes=%d queue=%d playing=%s", #payload, queueSize, tostring(isPlaying)))
                return true
            end
            retryCount = retryCount + 1
            if retryCount == 1 or retryCount % 20 == 0 then
                Utils.log("WARN", string.format("WAV chunk waiting: bytes=%d queue=%d playing=%s retries=%d", #payload, queueSize, tostring(isPlaying), retryCount))
            end
            if not waitForInterruptibleDelay(playSeq, 0.05) then
                return false
            end
        end
    end

    local pending = {}
    for _, sp in ipairs(Peripherals.speakers or {}) do
        local name = peripheral.getName(sp)
        if name then pending[name] = sp end
    end

    local retryCount = 0
    while next(pending) do
        if shouldStop(playSeq) then return false end
        for name, sp in pairs(pending) do
            local ok = false
            pcall(function()
                if type(sp.speakWav) == "function" then
                    ok = sp.speakWav(payload, CONFIG.AUDIO_VOLUME)
                end
            end)
            if ok then pending[name] = nil end
        end
        if next(pending) then
            retryCount = retryCount + 1
            if retryCount == 1 or retryCount % 20 == 0 then
                local pendingCount = 0
                for _ in pairs(pending) do
                    pendingCount = pendingCount + 1
                end
                Utils.log("WARN", string.format("WAV chunk waiting on %d speakers: bytes=%d retries=%d", pendingCount, #payload, retryCount))
            end
        else
            Utils.log("INFO", string.format("WAV chunk accepted by fallback speakers: bytes=%d", #payload))
        end
        if next(pending) and not waitForInterruptibleDelay(playSeq, 0.05) then
            return false
        end
    end

    return true
end

function Audio.playDfpwmItem(item)
    if not Peripherals.speakers or #Peripherals.speakers == 0 then
        Utils.log("WARN", "No speakers found; cannot play audio")
        return
    end
    
    local playSeq = State.interruptSeq
    local source = item.audioData
    
    -- Support both static string data and streaming functions
    if type(source) == "table" and source.read then
        source = source.read
    end

    if type(source) ~= "function" then
        local data = source
        source = function()
            local chunk = data
            data = nil
            return chunk
        end
    end

    local decoder = dfpwm.make_decoder()
    while true do
        if shouldStop(playSeq) then break end
        local chunk = source()
        if chunk == nil then break end
        if type(chunk) == "string" and #chunk > 0 then
            local samples = decoder(chunk)
            if samples and not playChunkOnSpeakers(samples, CONFIG.AUDIO_VOLUME, playSeq) then
                break
            end
        end
    end
end

function Audio.playPcmItem(item)
    if not Peripherals.speakers or #Peripherals.speakers == 0 then
        Utils.log("WARN", "No speakers found; cannot play audio")
        return
    end

    local playSeq = State.interruptSeq
    local source = item.audioData

    if type(source) == "table" and source.read then
        source = source.read
    end

    if type(source) ~= "function" then
        local data = source
        source = function()
            local chunk = data
            data = nil
            return chunk
        end
    end

    while true do
        if shouldStop(playSeq) then break end
        local chunk = source()
        if chunk == nil then break end
        if type(chunk) == "string" and #chunk > 0 then
            local samples = decodePcmS8Chunk(chunk)
            if samples and not playChunkOnSpeakers(samples, CONFIG.AUDIO_VOLUME, playSeq) then
                break
            end
        end
    end
end

function Audio.playWavStreamItem(item)
    if not Peripherals.speakers or #Peripherals.speakers == 0 then
        Utils.log("WARN", "No speakers found; cannot play audio")
        return
    end

    local playSeq = State.interruptSeq
    local source = item.audioData

    if type(source) == "table" and source.read then
        source = source.read
    end

    if type(source) ~= "function" then
        local data = source
        source = function()
            local chunk = data
            data = nil
            return chunk
        end
    end

    while true do
        if shouldStop(playSeq) then
            Audio.stop("current")
            return
        end

        local chunk = source()
        if chunk == nil then break end
        if type(chunk) == "string" and #chunk > 0 then
            local samples, err, meta = decodeWavChunkToSamples(chunk)
            if samples and #samples > 0 then
                Utils.log("INFO", string.format(
                    "Decoded WAV chunk: bytes=%d samples=%d rate=%d ch=%d bits=%d",
                    #chunk,
                    #samples,
                    tonumber(meta and meta.sampleRate) or 0,
                    tonumber(meta and meta.channels) or 0,
                    tonumber(meta and meta.bitsPerSample) or 0
                ))
                if not playChunkOnSpeakers(samples, CONFIG.AUDIO_VOLUME, playSeq) then
                    Audio.stop("current")
                    return
                end
            else
                Utils.log("WARN", "WAV chunk decode failed, falling back to HQ path: " .. tostring(err))
                if not pushWavChunkToSpeakers(chunk, playSeq) then
                    Audio.stop("current")
                    return
                end
            end
        end
    end

    while areHqSpeakersBusy(Peripherals.speakers) do
        if shouldStop(playSeq) then
            Audio.stop("current")
            return
        end
        if not waitForInterruptibleDelay(playSeq, 0.05) then
            Audio.stop("current")
            return
        end
    end
end

function Audio.playItem(item)
    local format = tostring(item.audioFormat or "dfpwm"):lower()
    if format == "wav" or format == "file" or format == "stream" or format == "hls" then
        return playHqAudioItem(item)
    elseif format == "pcm" then
        return Audio.playPcmItem(item)
    elseif format == "wav-stream" then
        return Audio.playWavStreamItem(item)
    end
    return Audio.playDfpwmItem(item)
end

function Audio.playerLoop()
    while true do
        if #State.audioQueue == 0 then
            os.pullEvent("audio_queue")
        else
            local item = table.remove(State.audioQueue, 1)
            State.currentPlaying = item
            State.currentPriority = tonumber(item.priority) or 0
            
            local ok, err = pcall(Audio.playItem, item)
            if not ok then
                Utils.log("ERROR", "Audio Playback Crash: " .. tostring(err))
            end
            
            State.currentPlaying = nil
            State.currentPriority = -1
        end
    end
end

function Utils.getChineseNumberAudio(val)
    local num = tonumber(val)
    if num then
        local seq = {}
        if num < 10 then
            table.insert(seq, "ch-" .. num)
        elseif num == 10 then
            table.insert(seq, "ch-10")
        elseif num > 10 and num < 20 then
            table.insert(seq, "ch-10")
            table.insert(seq, "ch-" .. (num % 10))
        elseif num >= 20 and num < 100 then
            local ten = math.floor(num / 10)
            local unit = num % 10
            table.insert(seq, "ch-" .. ten)
            table.insert(seq, "ch-10")
            if unit > 0 then
                table.insert(seq, "ch-" .. unit)
            end
        else
            table.insert(seq, "ch-" .. num)
        end
        return seq
    else
        -- Handle Alphanumeric (e.g., "1A", "2B")
        local digit, letter = tostring(val):match("^(%d+)([a-zA-Z])$")
        if digit and letter then
            local seq = Utils.getChineseNumberAudio(digit)
            table.insert(seq, letter:upper()) -- e.g. "A", "B"
            return seq
        end
        return {tostring(val)}
    end
end

function Utils.getStationAudio(code, langPrefix)
    if not code then return nil end
    local files = State.stationList[code]
    if files then
        local p = langPrefix:lower()
        for _, f in ipairs(files) do
            if f:lower():find("^" .. p) then
                return f
            end
        end
    end
    -- Fallback to hardcoded pattern
    return langPrefix .. code
end

-- ============================================================================
-- 6. Network System
-- ============================================================================
local Network = {}

function Network.connect()
    if State.ws then return end
    Utils.log("INFO", "Connecting to cloud...")
    State.ws = http.websocket(CONFIG.CLOUD_URL)
    if State.ws then
        Utils.log("SUCCESS", "Connected")
        Network.register()
    else
        Utils.log("ERROR", "Connection failed")
    end
end

function Network.send(data)
    if State.ws then
        local ok, err = pcall(function()
            State.ws.send(textutils.serializeJSON(data))
        end)
        if not ok then
            Utils.log("ERROR", "Failed to send WS message: " .. tostring(err))
        end
    end
end

function Network.register()
    State.stationName = (Peripherals.station.getStationName() or "Unknown"):match("^%s*(.-)%s*$") -- Trim
    -- Try to get a clean code from name, fallback to broadcast format
    State.stationCode = Utils.getStationCode(State.stationName) or Utils.getBroadcastStationCode(State.stationName)
    State.stationPlatform = Utils.getPlatformNumber(State.stationName, "1")
    
    Network.send({
        type = "station_register",
        stationName = State.stationName,
        stationCode = State.stationCode,
        stationPlatform = State.stationPlatform,
        stationVersion = APP_VERSION_TEXT
    })
end

function Network.syncFiles()
    -- Sync only config file (list.txt) periodically
    while true do
        local resp = http.get(CONFIG.API_URL .. "/list.txt")
        if not resp then
            resp = http.get(CONFIG.API_URL .. "/uploads/list.txt")
        end
        if resp then
            local content = resp.readAll()
            resp.close()
            if content and #content > 0 then
                local currentList = ""
                if fs.exists("list.txt") then
                    local f = fs.open("list.txt", "r")
                    currentList = f.readAll()
                    f.close()
                end
                
                if currentList ~= content then
                    local f = fs.open("list.txt", "w")
                    f.write(content)
                    f.close()
                    Audio.loadStationList()
                end
            end
        end
        os.sleep(CONFIG.SYNC_INTERVAL)
    end
end

function Network.messageLoop()
    local function finishAudioRx()
        if not State.audioRx then return end
        local rx = State.audioRx
        if rx.stream then
            rx.stream.finish()
        else
            Audio.enqueueItem({
                audioData = table.concat(rx.chunks or {}),
                audioFormat = rx.audioFormat or "wav",
                priority = rx.priority,
                loop = rx.loop and true or false,
                source = rx.source,
                audioId = rx.audioId
            })
        end
        State.audioRx = nil
    end

    while true do
        local event, url, msg = os.pullEvent()
        if event == "websocket_message" and url == CONFIG.CLOUD_URL then
            local ok, data = pcall(textutils.unserializeJSON, msg)
            if ok and type(data) == "table" then
                if data.type == "audio_start" then
                    if State.audioRx and State.audioRx.stream then
                        pcall(State.audioRx.stream.finish)
                    end
                    local priority = tonumber(data.priority) or 0
                    local audioFormat = tostring(data.audioFormat or "dfpwm"):lower()
                    local streamUrl = type(data.streamUrl) == "string" and data.streamUrl or nil
                    local interruptMode = tostring(data.interruptMode or "")
                    if interruptMode == "" then
                        if priority >= 2 then interruptMode = "all"
                        elseif priority >= 1 then interruptMode = "ifLower"
                        else interruptMode = "none" end
                    end

                    if interruptMode == "all" then
                        Audio.stop("all")
                    elseif interruptMode == "ifLower" and priority > (State.currentPriority or -1) then
                        Audio.stop("current", priority)
                    end

                    State.audioRx = {
                        audioId = data.audioId,
                        expectedBytes = tonumber(data.byteLength) or 0,
                        receivedBytes = 0,
                        priority = priority,
                        loop = data.loop and true or false,
                        source = data.source or data.category,
                        audioFormat = audioFormat
                    }
                    
                    if (audioFormat == "stream" or audioFormat == "hls") and streamUrl and streamUrl ~= "" then
                        Audio.enqueueItem({
                            audioData = streamUrl,
                            audioFormat = audioFormat,
                            priority = priority,
                            loop = State.audioRx.loop,
                            source = State.audioRx.source,
                            audioId = data.audioId
                        })
                        State.audioRx = nil
                    elseif audioFormat == "dfpwm" or audioFormat == "pcm" or audioFormat == "wav-stream" then
                        local stream = Audio.createStream()
                        State.audioRx.stream = stream
                        if audioFormat == "pcm" then
                            Utils.log("INFO", "Receiving live PCM audio stream")
                        elseif audioFormat == "wav-stream" then
                            Utils.log("INFO", "Receiving live WAV chunk stream")
                        end
                        Audio.enqueueItem({
                            audioData = stream,
                            audioFormat = audioFormat,
                            priority = priority,
                            source = State.audioRx.source,
                            audioId = data.audioId
                        })
                    else
                        State.audioRx.chunks = {}
                    end
                elseif data.type == "audio_end" then
                    if State.audioRx and (not data.audioId or data.audioId == State.audioRx.audioId) then
                        finishAudioRx()
                    end
                elseif data.type == "audio_stop" then
                    local scope = tostring(data.scope or "")
                    if scope == "music" then
                        local kept = {}
                        for _, it in ipairs(State.audioQueue) do
                            if tostring(it.source or "") ~= "music" then
                                table.insert(kept, it)
                            end
                        end
                        State.audioQueue = kept

                        if State.audioRx and tostring(State.audioRx.source or "") == "music" then
                            State.audioRx = nil
                        end

                        if State.currentPlaying and tostring(State.currentPlaying.source or "") == "music" then
                            Audio.stop("current")
                        end
                    else
                        local mode = tostring(data.mode or "current")
                        local flushBelow = data.flushBelow
                        Audio.stop(mode, flushBelow)
                    end
                end
            else
                    if State.audioRx then
                        -- Memory protection: limit to 10MB per audio item
                        local isLiveStream = State.audioRx.stream and (tonumber(State.audioRx.expectedBytes) or 0) <= 0
                        if (not isLiveStream) and State.audioRx.receivedBytes + #msg > 10 * 1024 * 1024 then
                            Utils.log("ERROR", "Audio item too large, discarding")
                            if State.audioRx.stream then
                                State.audioRx.stream.finish()
                            end
                            State.audioRx = nil
                        else
                            if State.audioRx.stream then
                                State.audioRx.stream.push(msg)
                            else
                                table.insert(State.audioRx.chunks, msg)
                            end
                            State.audioRx.receivedBytes = State.audioRx.receivedBytes + #msg
                            if State.audioRx.expectedBytes > 0 and State.audioRx.receivedBytes >= State.audioRx.expectedBytes then
                                finishAudioRx()
                            end
                        end
                    end
                end
        elseif event == "websocket_closed" then
            Utils.log("WARN", "WS Closed")
            State.ws = nil
            State.audioRx = nil -- Clear partial download
            os.sleep(5)
        end
    end
end

function Network.heartbeat()
    while true do
        if State.ws then
            Network.send({
                type = "heartbeat",
                stationName = State.stationName,
                stationCode = State.stationCode,
                stationPlatform = State.stationPlatform,
                stationVersion = APP_VERSION_TEXT
            })
        end
        os.sleep(10)
    end
end

-- ============================================================================
-- 7. Display System
-- ============================================================================
local Display = {}

function Display.render()
    local mon = Peripherals.primaryMonitor
    local w, h = mon.getSize()
    mon.clear()
    mon.setCursorPos(1,1)
    mon.setTextColor(COLORS.INFO)
    mon.write("STATION: " .. State.stationName .. " " .. APP_VERSION_TEXT)
    mon.setCursorPos(1,2)
    mon.write("TIME: " .. os.date("%H:%M:%S"))

    local function classifyAudioSource(source, priority)
        local s = tostring(source or ""):lower()
        if s == "train" or s == "station" or s == "broadcast" then return "Station Announcement" end
        if s ~= "" then return "Special Announcement(" .. tostring(source) .. ")" end
        if (tonumber(priority) or 0) >= 2 then return "Special Announcement" end
        return "Special Announcement"
    end

    local function trunc(str)
        str = tostring(str or "")
        if #str > w then return str:sub(1, w) end
        return str
    end

    mon.setCursorPos(1,3)
    if State.currentPlaying then
        local p = tonumber(State.currentPlaying.priority) or 0
        local kind = classifyAudioSource(State.currentPlaying.source, p)
        mon.setTextColor(COLORS.SUCCESS)
        mon.write(trunc("AUDIO: " .. kind .. " Playing (P=" .. tostring(p) .. ", Q=" .. tostring(#State.audioQueue) .. ")"))
    elseif State.audioRx then
        local p = tonumber(State.audioRx.priority) or 0
        local kind = classifyAudioSource(State.audioRx.source, p)
        local rx = tonumber(State.audioRx.receivedBytes) or 0
        local total = tonumber(State.audioRx.expectedBytes) or 0
        local pct = ""
        if total > 0 then pct = " " .. tostring(math.floor((rx / total) * 100)) .. "%" end
        mon.setTextColor(COLORS.DEBUG)
        mon.write(trunc("AUDIO: " .. kind .. " Receiving" .. pct .. " (Q=" .. tostring(#State.audioQueue) .. ")"))
    else
        mon.setTextColor(COLORS.INFO)
        mon.write(trunc("AUDIO: FREE (Q=" .. tostring(#State.audioQueue) .. ")"))
    end
    
    -- Current Train
    if State.currentTrain then
        mon.setCursorPos(1,4)
        mon.setTextColor(COLORS.SUCCESS)
        mon.write("CURRENT TRAIN:")
        mon.setTextColor(COLORS.INFO)
        mon.setCursorPos(1,5)
        mon.write(State.currentTrain.id)
        mon.setCursorPos(1,6)
        mon.write("Dest: " .. State.currentTrain.dest)
        
        -- Countdown
        if State.currentTrain.departureTime then
            local remaining = math.max(0, State.currentTrain.departureTime - os.epoch("utc") / 1000)
            mon.setCursorPos(1, 8)
            if remaining > 0 then
                mon.setTextColor(COLORS.WARNING)
                mon.write(string.format("Departing in: %02d:%02d", math.floor(remaining/60), math.floor(remaining%60)))
            else
                mon.setTextColor(COLORS.ERROR)
                mon.write("Departing...")
            end
        end
    else
        mon.setCursorPos(1,4)
        mon.setTextColor(COLORS.WARNING)
        mon.write("NO TRAIN AT PLATFORM")
    end
    
    -- Logs
    local y = h - 3
    for i = 1, 3 do
        local logIdx = i + State.logScrollOffset
        local entry = State.logs[logIdx]
        if entry then
            mon.setCursorPos(1, y + i - 1)
            mon.setTextColor(COLORS[entry.level] or colors.white)
            mon.write(entry.text:sub(1, w)) 
        end
    end
end

function Display.renderTerminal()
    local w, h = term.getSize()
    
    -- Header
    term.setCursorPos(1, 1)
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.white)
    term.clearLine()
    local title = " Station Broadcast Console (" .. State.stationName .. " / " .. APP_VERSION_TEXT .. ") "
    term.setCursorPos(math.floor((w - #title)/2) + 1, 1)
    term.write(title)
    term.setBackgroundColor(colors.black)
    term.setCursorPos(1, 2)
    term.setTextColor(colors.gray)
    term.write(string.rep("-", w))

    -- Logs
    local logStart = 3
    local maxLogs = h - logStart + 1
    for i = 1, maxLogs do
        local logIdx = i + State.logScrollOffset
        term.setCursorPos(1, logStart + i - 1)
        term.clearLine()
        local entry = State.logs[logIdx]
        if entry then
            term.setTextColor(COLORS[entry.level] or colors.white)
            term.write(entry.text:sub(1, w - 1))
        end
    end

    -- Scroll Indicator
    if State.logScrollOffset > 0 then
        term.setCursorPos(w, logStart)
        term.setTextColor(colors.yellow)
        term.write("^")
    end
    if #State.logs > State.logScrollOffset + maxLogs then
        term.setCursorPos(w, h)
        term.setTextColor(colors.yellow)
        term.write("v")
    end
end

-- ============================================================================
-- 7.5 Input Handling
-- ============================================================================
local Input = {}

function Input.listener()
    Utils.log("DEBUG", "Input listener started")
    local monitorName = peripheral.getName(Peripherals.primaryMonitor)
    
    while true do
        local event, param1, param2, param3 = os.pullEvent()
        local _, h = term.getSize()
        local maxLogs = h - 5 + 1
        
        if event == "mouse_scroll" then
            local direction = param1
            if direction == -1 then -- Scroll Up
                State.logScrollOffset = math.min(State.logScrollOffset + 1, math.max(0, #State.logs - maxLogs))
            elseif direction == 1 then -- Scroll Down
                State.logScrollOffset = math.max(0, State.logScrollOffset - 1)
            end
            Display.renderTerminal()
            Display.render()
        elseif event == "monitor_scroll" and param1 == monitorName then
            local direction = param2
            if direction == -1 then
                State.logScrollOffset = math.min(State.logScrollOffset + 1, math.max(0, #State.logs - 3))
            elseif direction == 1 then
                State.logScrollOffset = math.max(0, State.logScrollOffset - 1)
            end
            Display.renderTerminal()
            Display.render()
        elseif event == "monitor_touch" and param1 == monitorName then
            -- Simple touch to scroll: top half of log area scrolls up, bottom half scrolls down
            local _, monH = Peripherals.primaryMonitor.getSize()
            local y = param3
            if y >= monH - 3 then
                if y == monH - 3 then -- Top line of log area
                    State.logScrollOffset = math.min(State.logScrollOffset + 1, math.max(0, #State.logs - 3))
                elseif y == monH then -- Bottom line of log area
                    State.logScrollOffset = math.max(0, State.logScrollOffset - 1)
                end
                Display.renderTerminal()
                Display.render()
            end
        elseif event == "key" then
            if param1 == keys.up then
                State.logScrollOffset = math.min(State.logScrollOffset + 1, math.max(0, #State.logs - maxLogs))
            elseif param1 == keys.down then
                State.logScrollOffset = math.max(0, State.logScrollOffset - 1)
            elseif param1 == keys.pageUp then
                State.logScrollOffset = math.min(State.logScrollOffset + 10, math.max(0, #State.logs - maxLogs))
            elseif param1 == keys.pageDown then
                State.logScrollOffset = math.max(0, State.logScrollOffset - 10)
            elseif param1 == keys.home then
                State.logScrollOffset = 0
            elseif param1 == keys["end"] then
                State.logScrollOffset = math.max(0, #State.logs - maxLogs)
            end
            Display.renderTerminal()
            Display.render()
        end
    end
end

-- ============================================================================
-- 8. Main Logic
-- ============================================================================
local Main = {}

function Main.loop()
    while true do
        local hasTrain = Peripherals.station.isTrainPresent()
        
        if hasTrain then
            if not State.currentTrain then
                -- Train just arrived
                local id = Peripherals.station.getTrainName()
                local schedule = Peripherals.station.getSchedule()
                local dest = Utils.getDestination(schedule)
                local now = os.epoch("utc") / 1000
                local stationTime = Utils.getStopTime(schedule, State.stationName) or 60
                
                State.currentTrain = {
                    id = id,
                    trainType = Utils.parseTrainId(id),
                    schedule = schedule,
                    dest = dest,
                    arrivalTime = now,
                    departureTime = now + stationTime,
                    platform = Utils.getPlatformNumber(State.stationName, "1")
                }
            end
        else
            if State.currentTrain then
                State.currentTrain = nil
            end
        end
        
        Display.render()
        Display.renderTerminal()
        os.sleep(0.5)
    end
end

-- ============================================================================
-- 9. Bootstrap
-- ============================================================================
Peripherals.init()
Audio.loadStationList()
Utils.log("INFO", "StationBroadcast version " .. APP_VERSION_TEXT)

parallel.waitForAny(
    function() 
        while true do
            if not State.ws then Network.connect() end
            os.sleep(5)
        end
    end,
    Audio.playerLoop,
    Network.messageLoop,
    Network.heartbeat,
    Network.syncFiles,
    Input.listener,
    Main.loop
)