import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/db/prisma'
import { getCurrentUser } from '@/lib/auth'
import { canAccessWorkspace } from '@/lib/db/workspace-access'
import { addDays } from 'date-fns'

// GET /api/workspaces/[id]/treatment-plan
export async function GET(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  try {
    const user = await getCurrentUser()
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    const workspaceId = params.id
    const access = await canAccessWorkspace(user.id, workspaceId)
    if (!access) {
      return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
    }

    const plan = await prisma.treatmentPlan.findUnique({
      where: { workspaceId },
      include: {
        milestones: {
          orderBy: { cycleNumber: 'asc' }
        }
      }
    })

    if (!plan) {
      return NextResponse.json({ plan: null })
    }

    return NextResponse.json({ plan })
  } catch (error) {
    console.error('Failed to fetch treatment plan:', error)
    return NextResponse.json(
      { error: 'Failed to fetch treatment plan' },
      { status: 500 }
    )
  }
}

// POST /api/workspaces/[id]/treatment-plan
export async function POST(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  try {
    const user = await getCurrentUser()
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    const workspaceId = params.id
    const access = await canAccessWorkspace(user.id, workspaceId)
    if (!access || access.role === 'VIEWER') {
      return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
    }

    const body = await request.json()
    const { title, totalCycles, startDate, cycleType, cycleDays } = body

    // Validate required fields
    if (!title || !totalCycles || !startDate) {
      return NextResponse.json(
        { error: 'Missing required fields' },
        { status: 400 }
      )
    }

    // Calculate estimated end date
    const start = new Date(startDate)
    const estimatedEnd = addDays(start, cycleDays * totalCycles)

    // Create or update treatment plan
    const plan = await prisma.treatmentPlan.upsert({
      where: { workspaceId },
      create: {
        workspaceId,
        title,
        totalCycles,
        startDate: start,
        estimatedEnd,
        cycleType,
        cycleDays,
        createdById: user.id,
        milestones: {
          create: Array.from({ length: totalCycles }, (_, i) => ({
            cycleNumber: i + 1,
            date: addDays(start, cycleDays * i),
            status: i === 0 ? 'UPCOMING' : 'UPCOMING'
          }))
        }
      },
      update: {
        title,
        totalCycles,
        startDate: start,
        estimatedEnd,
        cycleType,
        cycleDays,
      },
      include: {
        milestones: {
          orderBy: { cycleNumber: 'asc' }
        }
      }
    })

    // Log audit
    await prisma.auditLog.create({
      data: {
        workspaceId,
        userId: user.id,
        action: 'CREATE',
        entityType: 'TREATMENT_PLAN',
        entityId: plan.id,
        details: { title, totalCycles }
      }
    })

    return NextResponse.json({ plan })
  } catch (error) {
    console.error('Failed to create treatment plan:', error)
    return NextResponse.json(
      { error: 'Failed to create treatment plan' },
      { status: 500 }
    )
  }
}