import { NextResponse } from 'next/server'
import { getUserFromToken } from '@/lib/auth'
import { prisma } from '@/lib/db'

export const runtime = 'nodejs'

/**
 * GET /api/user/reading-plans
 * Get all reading plans for the authenticated user
 */
export async function GET(request: Request) {
  try {
    // Get token from authorization header
    const authHeader = request.headers.get('authorization')
    const token = authHeader?.replace('Bearer ', '')

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

    // Verify token and get user
    const user = await getUserFromToken(token)

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

    const url = new URL(request.url)
    const status = url.searchParams.get('status') || 'ACTIVE'

    const userPlans = await prisma.userReadingPlan.findMany({
      where: {
        userId: user.id,
        ...(status !== 'ALL' && { status: status as any })
      },
      include: {
        plan: {
          select: {
            id: true,
            name: true,
            description: true,
            duration: true,
            difficulty: true,
            type: true
          }
        }
      },
      orderBy: {
        createdAt: 'desc'
      }
    })

    return NextResponse.json({
      success: true,
      plans: userPlans
    })

  } catch (error) {
    console.error('User reading plans fetch error:', error)
    return NextResponse.json(
      { error: 'Failed to fetch reading plans' },
      { status: 500 }
    )
  }
}

/**
 * POST /api/user/reading-plans
 * Enroll user in a reading plan
 */
export async function POST(request: Request) {
  try {
    // Get token from authorization header
    const authHeader = request.headers.get('authorization')
    const token = authHeader?.replace('Bearer ', '')

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

    // Verify token and get user
    const user = await getUserFromToken(token)

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

    const body = await request.json()
    const { planId, startDate, customSchedule, name } = body

    // Validate input
    if (!planId && !customSchedule) {
      return NextResponse.json(
        { error: 'Either planId or customSchedule is required' },
        { status: 400 }
      )
    }

    let planData: any = {}
    let duration = 365 // Default duration

    if (planId) {
      // Enrolling in a predefined plan
      const plan = await prisma.readingPlan.findUnique({
        where: { id: planId }
      })

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

      if (!plan.isActive) {
        return NextResponse.json(
          { error: 'This reading plan is no longer available' },
          { status: 400 }
        )
      }

      duration = plan.duration
      planData = {
        planId: plan.id,
        name: plan.name
      }
    } else {
      // Creating a custom plan
      if (!name) {
        return NextResponse.json(
          { error: 'Name is required for custom plans' },
          { status: 400 }
        )
      }

      if (!customSchedule || !Array.isArray(customSchedule)) {
        return NextResponse.json(
          { error: 'Valid customSchedule is required' },
          { status: 400 }
        )
      }

      duration = customSchedule.length
      planData = {
        name,
        customSchedule
      }
    }

    // Calculate target end date
    const start = startDate ? new Date(startDate) : new Date()
    const targetEnd = new Date(start)
    targetEnd.setDate(targetEnd.getDate() + duration)

    // Create user reading plan
    const userPlan = await prisma.userReadingPlan.create({
      data: {
        userId: user.id,
        startDate: start,
        targetEndDate: targetEnd,
        ...planData
      },
      include: {
        plan: true
      }
    })

    return NextResponse.json({
      success: true,
      message: 'Successfully enrolled in reading plan',
      plan: userPlan
    })

  } catch (error) {
    console.error('Reading plan enrollment error:', error)
    return NextResponse.json(
      { error: 'Failed to enroll in reading plan' },
      { status: 500 }
    )
  }
}