import { NextRequest, NextResponse } from 'next/server'
import { initDB, createContact, getContactById, getContactByPhone, getContactsByStage, getAllContacts, updateContact, deleteContact, searchContacts, getContactsByPaymentStatus, getTaskCountByContactId } from '@/lib/db'
import { STAGES } from '@/lib/types'

export async function GET(request: NextRequest) {
  const searchParams = request.nextUrl.searchParams
  const id = searchParams.get('id')
  const phone = searchParams.get('phone')
  const stage = searchParams.get('stage')
  const search = searchParams.get('search')
  const payment_status = searchParams.get('payment_status')
  
  try {
    await initDB()
    
    let contacts: any[] = []
    
    if (id) {
      const contact = getContactById(parseInt(id))
      if (!contact) {
        return NextResponse.json({ error: 'Contact not found' }, { status: 404 })
      }
      const taskCount = getTaskCountByContactId(contact.id)
      return NextResponse.json({ ...contact, taskCount })
    }
    
    if (phone) {
      const contact = getContactByPhone(phone)
      if (!contact) {
        return NextResponse.json({ error: 'Contact not found' }, { status: 404 })
      }
      return NextResponse.json(contact)
    }
    
    if (stage) {
      contacts = getContactsByStage(stage as any)
    } else if (search) {
      contacts = searchContacts(search)
    } else if (payment_status) {
      contacts = getContactsByPaymentStatus(payment_status as any)
    } else {
      contacts = getAllContacts()
    }
    
    if (!Array.isArray(contacts)) {
      contacts = []
    }
    
    return NextResponse.json(contacts)
  } catch (error: any) {
    console.error('API Error:', error)
    return NextResponse.json({ error: error.message }, { status: 500 })
  }
}

export async function POST(request: NextRequest) {
  try {
    await initDB()
    const body = await request.json()
    
    const { name, phone, notes, schedule_date, follow_up_date } = body
    
    if (!name || !phone) {
      return NextResponse.json(
        { error: 'Name and phone are required' },
        { status: 400 }
      )
    }
    
    const existingContact = getContactByPhone(phone)
    if (existingContact) {
      return NextResponse.json(
        { error: 'Contact with this phone already exists' },
        { status: 409 }
      )
    }
    
    const contact = createContact({ name, phone, notes, schedule_date, follow_up_date })
    return NextResponse.json(contact, { status: 201 })
  } catch (error: any) {
    return NextResponse.json({ error: error.message }, { status: 500 })
  }
}

export async function PUT(request: NextRequest) {
  try {
    await initDB()
    const body = await request.json()
    
    const { id, name, stage, notes, schedule_date, follow_up_date, payment_status } = body
    
    if (!id) {
      return NextResponse.json({ error: 'Contact ID is required' }, { status: 400 })
    }
    
    if (stage && !Object.values(STAGES).includes(stage)) {
      return NextResponse.json({ error: 'Invalid stage' }, { status: 400 })
    }
    
    const updated = updateContact(id, { name, stage, notes, schedule_date, follow_up_date, payment_status })
    if (!updated) {
      return NextResponse.json({ error: 'Contact not found' }, { status: 404 })
    }
    
    return NextResponse.json(updated)
  } catch (error: any) {
    return NextResponse.json({ error: error.message }, { status: 500 })
  }
}

export async function DELETE(request: NextRequest) {
  try {
    await initDB()
    const searchParams = request.nextUrl.searchParams
    const id = searchParams.get('id')
    
    if (!id) {
      return NextResponse.json({ error: 'Contact ID is required' }, { status: 400 })
    }
    
    deleteContact(parseInt(id))
    return NextResponse.json({ success: true })
  } catch (error: any) {
    return NextResponse.json({ error: error.message }, { status: 500 })
  }
}