import { db } from '~/drizzle/db'
import { expectedPlayDates, songs } from '~/drizzle/schema'
import { desc, eq, and } from 'drizzle-orm'

export default defineEventHandler(async (event) => {
  const method = event.node.req.method
  const user = event.context.user

  if (!user || (user.role !== 'ADMIN' && user.role !== 'SUPER_ADMIN')) {
    throw createError({ statusCode: 403, message: '权限不足' })
  }

  if (method === 'GET') {
    const dates = await db.select().from(expectedPlayDates).orderBy(desc(expectedPlayDates.date))
    const result = []
    
    for (const d of dates) {
      const dateObj = new Date(d.date)
      const weekdays = ['周日', '周一', '周二', '周三', '周四', '周五', '周六']
      const weekday = weekdays[dateObj.getDay()]

      let availableSeqs: number[] = []
      if (d.availableSequences) {
        availableSeqs = d.availableSequences.split(',').map(s => parseInt(s.trim(), 10)).filter(n => !isNaN(n))
      }

      const takenSongs = await db.select({
        sequence: songs.expectedPlaySequence,
        title: songs.title,
        artist: songs.artist,
        requesterId: songs.requesterId
      })
      .from(songs)
      .where(
        and(
          eq(songs.expectedPlayDate, d.date),
          eq(songs.played, false)
        )
      )

      const takenSeqs = new Set(takenSongs.map(s => s.sequence).filter(seq => seq !== null))
      const takenDetails: Record<number, any> = {}
      takenSongs.forEach(s => {
        if (s.sequence !== null) {
          takenDetails[s.sequence] = { title: s.title, artist: s.artist }
        }
      })

      const freeSeqs = availableSeqs.filter(seq => !takenSeqs.has(seq))

      result.push({
        ...d,
        weekday,
        allSequences: availableSeqs.sort((a, b) => a - b),
        takenSequences: Array.from(takenSeqs).sort((a, b) => a - b),
        takenDetails,
        freeSequences: freeSeqs.sort((a, b) => a - b),
        isFull: freeSeqs.length === 0
      })
    }
    
    return result
  }

  if (method === 'POST') {
    const body = await readBody(event)
    const { date, availableSequences } = body

    if (!date || !availableSequences) {
      throw createError({ statusCode: 400, message: '日期和序号不能为空' })
    }

    try {
      // 检查是否存在
      const existing = await db.select().from(expectedPlayDates).where(eq(expectedPlayDates.date, date))
      
      if (existing.length > 0) {
        // 更新
        const result = await db.update(expectedPlayDates)
          .set({ availableSequences })
          .where(eq(expectedPlayDates.date, date))
          .returning()
        return result[0]
      } else {
        // 新增
        const result = await db.insert(expectedPlayDates)
          .values({ date, availableSequences })
          .returning()
        return result[0]
      }
    } catch (e: any) {
      throw createError({ statusCode: 500, message: e.message || '保存失败' })
    }
  }
})