'use client';

import { useState, useEffect } from 'react';
import { Plus, Tag, RefreshCw, Trash, Edit, Check, X } from 'lucide-react';
import { useRouter } from 'next/navigation';
import { Button } from '@/components/ui/button';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from '@/components/ui/dialog';
import { toast } from '@/components/ui/use-toast';
import { Badge } from '@/components/ui/badge';
import { Promotion } from '@/lib/types/promotion';
import { fetchClient } from '@/lib/api';
import NewPromotionForm from './NewPromotionForm';
import EditPromotionForm from './EditPromotionForm';

export default function PromotionsList() {
  const router = useRouter();
  const [promotions, setPromotions] = useState<Promotion[]>([]);
  const [loading, setLoading] = useState(true);
  const [showNewDialog, setShowNewDialog] = useState(false);
  const [editingPromotion, setEditingPromotion] = useState<Promotion | null>(null);
  const [showDeleteDialog, setShowDeleteDialog] = useState(false);
  const [promotionToDelete, setPromotionToDelete] = useState<string | null>(null);

  // Load promotions on mount
  useEffect(() => {
    loadPromotions();
  }, []);

  const loadPromotions = async () => {
    setLoading(true);
    try {
      const response = await fetchClient<Promotion[]>('/promotions');
      setPromotions(response || []);
    } catch (error) {
      console.error('Failed to fetch promotions:', error);
      toast({
        title: 'Error',
        description: 'Failed to load promotions',
        variant: 'destructive',
      });
    } finally {
      setLoading(false);
    }
  };

  const deletePromotion = async (id: string) => {
    try {
      await fetchClient(`/promotions/${id}`, {
        method: 'DELETE',
      });
      
      toast({
        title: 'Success',
        description: 'Promotion deleted successfully',
      });
      
      // Refresh the list
      loadPromotions();
    } catch (error) {
      console.error('Error deleting promotion:', error);
      toast({
        title: 'Error',
        description: 'Failed to delete promotion',
        variant: 'destructive',
      });
    } finally {
      setShowDeleteDialog(false);
      setPromotionToDelete(null);
    }
  };

  function handleOpenEditDialog(promotion: Promotion) {
    setEditingPromotion(promotion);
  }

  function handleCloseEditDialog() {
    setEditingPromotion(null);
  }

  function handleCreateComplete() {
    setShowNewDialog(false);
    loadPromotions();
  }

  function handleEditComplete() {
    setEditingPromotion(null);
    loadPromotions();
  }

  function formatDate(dateString: string | null) {
    if (!dateString) return 'No end date';
    return new Date(dateString).toLocaleDateString();
  }

  return (
    <>
      <div className="flex justify-between items-center mb-4">
        <h2 className="text-xl font-semibold">Your Promotions</h2>
        <div className="flex gap-2">
          <Button onClick={loadPromotions} variant="outline" size="sm">
            <RefreshCw className="h-4 w-4 mr-2" />
            Refresh
          </Button>
          <Button onClick={() => setShowNewDialog(true)} size="sm">
            <Plus className="h-4 w-4 mr-2" />
            New Promotion
          </Button>
        </div>
      </div>

      <Card>
        <CardContent className="p-0">
          {loading ? (
            <div className="flex justify-center items-center h-64">
              <RefreshCw className="h-6 w-6 animate-spin" />
            </div>
          ) : promotions.length === 0 ? (
            <div className="flex flex-col justify-center items-center h-64 text-center p-6">
              <Tag className="h-12 w-12 mb-4 text-muted-foreground" />
              <h3 className="text-lg font-medium">No promotions yet</h3>
              <p className="text-muted-foreground mt-1 mb-4">
                Create your first promotion to offer discounts to your customers
              </p>
              <Button onClick={() => setShowNewDialog(true)}>
                <Plus className="h-4 w-4 mr-2" />
                Create Promotion
              </Button>
            </div>
          ) : (
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>Code</TableHead>
                  <TableHead>Type</TableHead>
                  <TableHead>Value</TableHead>
                  <TableHead>Min. Order</TableHead>
                  <TableHead>Usage</TableHead>
                  <TableHead>Valid Until</TableHead>
                  <TableHead>Status</TableHead>
                  <TableHead className="text-right">Actions</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {promotions.map((promotion) => (
                  <TableRow key={promotion._id}>
                    <TableCell className="font-medium">{promotion.code}</TableCell>
                    <TableCell>
                      {promotion.discountType === 'percentage' ? 'Percentage' : 'Fixed Amount'}
                    </TableCell>
                    <TableCell>
                      {promotion.discountType === 'percentage'
                        ? `${promotion.discountValue}%`
                        : `£${promotion.discountValue.toFixed(2)}`}
                    </TableCell>
                    <TableCell>
                      {promotion.minOrderAmount > 0
                        ? `£${promotion.minOrderAmount.toFixed(2)}`
                        : 'None'}
                    </TableCell>
                    <TableCell>
                      {promotion.usageCount} / {promotion.maxUsage || '∞'}
                    </TableCell>
                    <TableCell>{formatDate(promotion.endDate)}</TableCell>
                    <TableCell>
                      <Badge
                        variant={promotion.isActive ? 'default' : 'secondary'}
                        className={promotion.isActive ? 'bg-green-500' : ''}
                      >
                        {promotion.isActive ? 'Active' : 'Inactive'}
                      </Badge>
                    </TableCell>
                    <TableCell className="text-right">
                      <div className="flex justify-end gap-2">
                        <Button
                          onClick={() => handleOpenEditDialog(promotion)}
                          variant="ghost"
                          size="icon"
                        >
                          <Edit className="h-4 w-4" />
                        </Button>
                        <Button
                          onClick={() => {
                            setPromotionToDelete(promotion._id);
                            setShowDeleteDialog(true);
                          }}
                          variant="ghost"
                          size="icon"
                          className="text-red-500 hover:text-red-600"
                        >
                          <Trash className="h-4 w-4" />
                        </Button>
                      </div>
                    </TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          )}
        </CardContent>
      </Card>

      {/* New Promotion Dialog */}
      <Dialog open={showNewDialog} onOpenChange={setShowNewDialog}>
        <DialogContent className="max-w-4xl">
          <DialogHeader className="pb-4">
            <DialogTitle className="text-xl">Create New Promotion</DialogTitle>
            <DialogDescription>
              Add a promotional code to offer discounts to your customers.
            </DialogDescription>
          </DialogHeader>
          <div className="max-h-[70vh] overflow-y-auto pr-1">
            <NewPromotionForm onSuccess={handleCreateComplete} onCancel={() => setShowNewDialog(false)} />
          </div>
        </DialogContent>
      </Dialog>

      {/* Edit Promotion Dialog */}
      <Dialog open={!!editingPromotion} onOpenChange={() => editingPromotion && handleCloseEditDialog()}>
        <DialogContent className="max-w-4xl">
          <DialogHeader className="pb-4">
            <DialogTitle className="text-xl">Edit Promotion</DialogTitle>
            <DialogDescription>
              Modify this promotional code's details.
            </DialogDescription>
          </DialogHeader>
          <div className="max-h-[70vh] overflow-y-auto pr-1">
            {editingPromotion && (
              <EditPromotionForm 
                promotion={editingPromotion} 
                onSuccess={handleEditComplete} 
                onCancel={handleCloseEditDialog} 
              />
            )}
          </div>
        </DialogContent>
      </Dialog>

      {/* Delete Confirmation Dialog */}
      <Dialog open={showDeleteDialog} onOpenChange={setShowDeleteDialog}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>Confirm Deletion</DialogTitle>
            <DialogDescription>
              Are you sure you want to delete this promotion? This action cannot be undone.
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button
              variant="outline"
              onClick={() => setShowDeleteDialog(false)}
            >
              <X className="h-4 w-4 mr-2" />
              Cancel
            </Button>
            <Button
              variant="destructive"
              onClick={() => promotionToDelete && deletePromotion(promotionToDelete)}
            >
              <Trash className="h-4 w-4 mr-2" />
              Delete
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </>
  );
}