'use client'

import { useState, useEffect, useCallback } from 'react'
import Link from 'next/link'
import { createClient } from '@/lib/supabase/client'
import { useToast } from '@/components/ui/use-toast'
import { DeadlineList } from '@/components/deadlines/DeadlineList'
import { Card, CardContent } from '@/components/ui/card'
import { Badge } from '@/components/ui/badge'
import { AlertTriangle, ArrowRight } from 'lucide-react'
import type { Deadline } from '@/types'

const supabase = createClient()

export default function DeadlinesPage() {
  const [deadlines, setDeadlines] = useState<Deadline[]>([])
  const [customers, setCustomers] = useState<{ id: string; name: string }[]>([])
  const [overdueInvoices, setOverdueInvoices] = useState<{ count: number; total: number }>({ count: 0, total: 0 })
  const [isLoading, setIsLoading] = useState(true)
  const { toast } = useToast()

  const fetchData = useCallback(async () => {
    setIsLoading(true)

    try {
      const today = new Date().toISOString().split('T')[0]

      // Fetch all data in parallel
      const [deadlinesRes, customersRes, overdueRes] = await Promise.all([
        supabase.from('deadlines').select('*, customer:customers(name)').order('due_date', { ascending: true }),
        supabase.from('customers').select('id, name').order('name', { ascending: true }),
        supabase.from('invoices').select('total_sek, total').in('status', ['sent', 'unpaid']).lt('due_date', today),
      ])

      if (deadlinesRes.error) throw deadlinesRes.error
      if (customersRes.error) throw customersRes.error
      if (overdueRes.error) throw overdueRes.error

      const overdueCount = overdueRes.data?.length || 0
      const overdueTotal = (overdueRes.data || []).reduce(
        (sum, inv) => sum + (inv.total_sek || inv.total || 0),
        0
      )

      setDeadlines(deadlinesRes.data || [])
      setCustomers(customersRes.data || [])
      setOverdueInvoices({ count: overdueCount, total: overdueTotal })
    } catch {
      toast({
        title: 'Kunde inte ladda deadlines',
        description: 'Kontrollera din anslutning och försök igen.',
        variant: 'destructive',
      })
    } finally {
      setIsLoading(false)
    }
  }, [toast])

  useEffect(() => {
    fetchData()
  }, [fetchData])

  const handleDeadlineCreate = async (
    data: Omit<Deadline, 'id' | 'user_id' | 'created_at' | 'updated_at'>
  ) => {
    try {
      const response = await fetch('/api/deadlines', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(data),
      })

      if (!response.ok) {
        const result = await response.json()
        throw new Error(result.error || 'Failed to create deadline')
      }

      toast({
        title: 'Deadline skapad',
        description: 'Din deadline har sparats',
      })

      fetchData()
    } catch (error) {
      toast({
        title: 'Kunde inte skapa deadline',
        description: error instanceof Error ? error.message : 'Försök igen.',
        variant: 'destructive',
      })
      throw error
    }
  }

  const handleDeadlineToggle = async (deadline: Deadline) => {
    try {
      const response = await fetch(`/api/deadlines/${deadline.id}/complete`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ is_completed: !deadline.is_completed }),
      })

      if (!response.ok) {
        const result = await response.json()
        throw new Error(result.error || 'Failed to toggle deadline')
      }

      toast({
        title: deadline.is_completed ? 'Markerad som ej klar' : 'Markerad som klar',
      })

      fetchData()
    } catch (error) {
      toast({
        title: 'Kunde inte uppdatera status',
        description: error instanceof Error ? error.message : 'Försök igen.',
        variant: 'destructive',
      })
    }
  }

  const handleDeadlineEdit = async (deadline: Deadline) => {
    try {
      const response = await fetch(`/api/deadlines/${deadline.id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(deadline),
      })

      if (!response.ok) {
        const result = await response.json()
        throw new Error(result.error || 'Failed to edit deadline')
      }

      toast({
        title: 'Deadline uppdaterad',
        description: 'Dina ändringar har sparats',
      })

      fetchData()
    } catch (error) {
      toast({
        title: 'Kunde inte spara ändringar',
        description: error instanceof Error ? error.message : 'Försök igen.',
        variant: 'destructive',
      })
    }
  }

  const handleDeadlineDelete = async (deadline: Deadline) => {
    try {
      const response = await fetch(`/api/deadlines/${deadline.id}`, {
        method: 'DELETE',
      })

      if (!response.ok) {
        const result = await response.json()
        throw new Error(result.error || 'Failed to delete deadline')
      }

      toast({
        title: 'Deadline borttagen',
      })

      fetchData()
    } catch (error) {
      toast({
        title: 'Kunde inte ta bort deadline',
        description: error instanceof Error ? error.message : 'Försök igen.',
        variant: 'destructive',
      })
    }
  }

  if (isLoading) {
    return (
      <div className="space-y-6">
        <div>
          <h1 className="font-display text-2xl md:text-3xl font-medium tracking-tight">Deadlines</h1>
        </div>
        {/* Overdue alert skeleton */}
        <div className="rounded-lg border p-4 animate-pulse">
          <div className="flex items-center justify-between">
            <div className="flex items-center gap-3">
              <div className="h-5 w-5 bg-muted rounded" />
              <div className="space-y-1">
                <div className="h-4 bg-muted rounded w-32" />
                <div className="h-3 bg-muted rounded w-24" />
              </div>
            </div>
            <div className="h-5 bg-muted rounded w-8" />
          </div>
        </div>
        {/* Deadline list skeleton */}
        <div className="space-y-3">
          {[1, 2, 3, 4].map((i) => (
            <div key={i} className="rounded-lg border p-4 animate-pulse">
              <div className="flex items-center justify-between">
                <div className="space-y-2">
                  <div className="h-4 bg-muted rounded w-48" />
                  <div className="h-3 bg-muted rounded w-32" />
                </div>
                <div className="flex items-center gap-2">
                  <div className="h-5 bg-muted rounded w-16" />
                  <div className="h-8 bg-muted rounded w-8" />
                </div>
              </div>
            </div>
          ))}
        </div>
      </div>
    )
  }

  return (
    <div className="space-y-6">
      <div>
        <h1 className="font-display text-2xl md:text-3xl font-medium tracking-tight">Deadlines</h1>
      </div>

      {overdueInvoices.count > 0 && (
        <Link href="/invoices?status=unpaid" className="block group">
          <Card className="border-destructive/50 bg-destructive/5 hover:bg-destructive/10 transition-colors">
            <CardContent className="p-4">
              <div className="flex items-center justify-between">
                <div className="flex items-center gap-3">
                  <AlertTriangle className="h-5 w-5 text-destructive flex-shrink-0" />
                  <div>
                    <p className="font-medium text-sm">Forfallna fakturor</p>
                    <p className="text-xs text-muted-foreground mt-0.5">
                      {overdueInvoices.count} st totalt{' '}
                      {overdueInvoices.total.toLocaleString('sv-SE')} kr
                    </p>
                  </div>
                </div>
                <div className="flex items-center gap-2">
                  <Badge variant="destructive">{overdueInvoices.count}</Badge>
                  <ArrowRight className="h-4 w-4 text-muted-foreground group-hover:translate-x-0.5 transition-transform" />
                </div>
              </div>
            </CardContent>
          </Card>
        </Link>
      )}

      <DeadlineList
        deadlines={deadlines}
        customers={customers}
        onDeadlineCreate={handleDeadlineCreate}
        onDeadlineToggle={handleDeadlineToggle}
        onDeadlineEdit={handleDeadlineEdit}
        onDeadlineDelete={handleDeadlineDelete}
      />
    </div>
  )
}