import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'
import { auth } from '@/lib/auth'
import { compareSortKey } from '@/lib/sort-key'

export const dynamic = 'force-dynamic'

// GET /api/wx-users/[id] - Get a wx user and all levels with completion state
export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const session = await auth.api.getSession({
      headers: request.headers,
    })

    if (!session) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    const { id } = await params

    // levelProgress 这里不按 sortKey 排——MySQL collation 不可靠。
    // 下面用 progress 的 Map 按需组合，最终顺序由 levels 的 JS 排序决定。
    const user = await prisma.wxUser.findUnique({
      where: { id },
      select: {
        id: true,
        openid: true,
        sessionKey: true,
        nickname: true,
        avatarUrl: true,
        stamina: true,
        staminaUpdatedAt: true,
        createdAt: true,
        updatedAt: true,
        levelProgress: {
          select: {
            id: true,
            userId: true,
            levelId: true,
            completedAt: true,
            timeSpent: true,
          },
        },
      },
    })

    if (!user) {
      return NextResponse.json({ error: 'User not found' }, { status: 404 })
    }

    // sortKey 排序必须在 JS 侧做，避免大小写不敏感 collation 带来的顺序错乱
    const levels = await prisma.level.findMany({
      select: {
        id: true,
        answer: true,
        sortKey: true,
        sortOrder: true,
        createdAt: true,
      },
    })
    levels.sort((a, b) => {
      const c = compareSortKey(a.sortKey, b.sortKey)
      if (c !== 0) return c
      if (a.sortOrder !== b.sortOrder) return a.sortOrder - b.sortOrder
      return a.createdAt.getTime() - b.createdAt.getTime()
    })

    const progressByLevelId = new Map(
      user.levelProgress.map((progress) => [progress.levelId, progress])
    )

    return NextResponse.json({
      id: user.id,
      openid: user.openid,
      sessionKey: user.sessionKey,
      nickname: user.nickname,
      avatarUrl: user.avatarUrl,
      stamina: user.stamina,
      staminaUpdatedAt: user.staminaUpdatedAt,
      createdAt: user.createdAt,
      updatedAt: user.updatedAt,
      completedLevelCount: user.levelProgress.length,
      // 按 sortKey 排序后，数组下标即连续的 sortOrder，小程序端契约不变
      assignedLevels: levels.map((level, index) => {
        const progress = progressByLevelId.get(level.id)

        return {
          id: level.id,
          answer: level.answer,
          sortOrder: index,
          completed: Boolean(progress),
          progressId: progress?.id || null,
          completedAt: progress?.completedAt || null,
        }
      }),
    })
  } catch (error) {
    console.error('Error fetching wx user:', error)
    return NextResponse.json(
      { error: 'Failed to fetch wx user' },
      { status: 500 }
    )
  }
}