'use client';

import React, { useState, useTransition } from 'react';
import { Card, CardFooter, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Badge } from '@/components/ui/badge';
import { Checkbox } from '@/components/ui/checkbox';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { toast } from 'sonner';
import { approveDetection } from '../actions/approve-detection';
import { rejectDetection } from '../actions/reject-detection';
import { bulkApprove } from '../actions/bulk-approve';
import { bulkReject } from '../actions/bulk-reject';
import { triggerBulkMarketplaceMatchAction } from '@/features/marketplace/actions/trigger-bulk-marketplace-match';
import { resetDetection } from '../actions/edit-detection';
import { EditDetectionDialog } from './edit-detection-dialog';
import { AddProductDialog } from './add-product-dialog';
import { Check, X, ShieldCheck, ShoppingCart, Filter, CheckCircle2, Clock, CheckCircle, ShieldAlert, MousePointerClick, Heart, Sparkles } from 'lucide-react';
import Image from 'next/image';

interface Detection {
    detection: {
        id: string;
        objectName: string;
        category: string;
        confidenceScore: number;
        moderationStatus: 'PENDING' | 'APPROVED' | 'REJECTED';
        thumbnailUrl?: string | null;
        createdAt: Date;
    };
    video: {
        id: string;
        title: string;
        thumbnailUrl: string | null;
    };
    marketplaceMatches: any[];
    clickCount: number;
    interestPledgeCount: number;
}

interface ModerationQueueProps {
    initialDetections: Detection[];
    userId: string;
    videos: { id: string; title: string }[];
    stats: { pending: number; approved: number; rejected: number };
    initialStatus?: 'PENDING' | 'APPROVED' | 'REJECTED';
}

export function ModerationQueue({ initialDetections, userId, videos, stats, initialStatus = 'PENDING' }: ModerationQueueProps) {
    const [detections, setDetections] = useState(initialDetections);
    const [selectedIds, setSelectedIds] = useState<string[]>([]);
    const [filterStatus, setFilterStatus] = useState<'PENDING' | 'APPROVED' | 'REJECTED'>(initialStatus);
    const [minConfidence, setMinConfidence] = useState(0);
    const [filterVideo, setFilterVideo] = useState<string>('all');
    const [filterHasLink, setFilterHasLink] = useState<string>('all'); // 'all' | 'with-link' | 'without-link'
    const [sortBy, setSortBy] = useState<string>('date'); // 'date' | 'clicks' | 'interest' | 'confidence'
    const [isPending, startTransition] = useTransition();

    let filteredDetections = detections.filter(d => {
        // Status and confidence filter
        if (d.detection.moderationStatus !== filterStatus) return false;
        if (d.detection.confidenceScore < minConfidence) return false;

        // Video filter
        if (filterVideo !== 'all' && d.video.id !== filterVideo) return false;

        // Affiliate link filter
        if (filterHasLink === 'with-link' && d.marketplaceMatches.length === 0) return false;
        if (filterHasLink === 'without-link' && d.marketplaceMatches.length > 0) return false;

        return true;
    });

    // Sorting
    filteredDetections = [...filteredDetections].sort((a, b) => {
        switch (sortBy) {
            case 'clicks':
                return b.clickCount - a.clickCount;
            case 'interest':
                return b.interestPledgeCount - a.interestPledgeCount;
            case 'confidence':
                return b.detection.confidenceScore - a.detection.confidenceScore;
            case 'date':
            default:
                return b.detection.createdAt.getTime() - a.detection.createdAt.getTime();
        }
    });

    const toggleSelection = (id: string) => {
        setSelectedIds(prev =>
            prev.includes(id) ? prev.filter(i => i !== id) : [...prev, id]
        );
    };

    const toggleSelectAll = () => {
        if (selectedIds.length === filteredDetections.length) {
            setSelectedIds([]);
        } else {
            setSelectedIds(filteredDetections.map(d => d.detection.id));
        }
    };

    const handleApprove = async (id: string) => {
        startTransition(async () => {
            const result = await approveDetection(id);
            if (result.success) {
                setDetections(prev => prev.map(d =>
                    d.detection.id === id ? { ...d, detection: { ...d.detection, moderationStatus: 'APPROVED' } } : d
                ));
                toast.success('Detection approved');
            } else {
                toast.error(result.error);
            }
        });
    };

    const handleReject = async (id: string) => {
        startTransition(async () => {
            const result = await rejectDetection(id);
            if (result.success) {
                setDetections(prev => prev.map(d =>
                    d.detection.id === id ? { ...d, detection: { ...d.detection, moderationStatus: 'REJECTED' } } : d
                ));
                toast.success('Detection rejected');
            } else {
                toast.error(result.error);
            }
        });
    };

    const handleBulkApprove = async () => {
        startTransition(async () => {
            const result = await bulkApprove(selectedIds);
            if (result.success) {
                setDetections(prev => prev.map(d =>
                    selectedIds.includes(d.detection.id) ? { ...d, detection: { ...d.detection, moderationStatus: 'APPROVED' } } : d
                ));
                setSelectedIds([]);
                toast.success(`Approved ${result.count} items`);
            } else {
                toast.error(result.error);
            }
        });
    };

    const handleBulkReject = async () => {
        startTransition(async () => {
            const result = await bulkReject(selectedIds);
            if (result.success) {
                setDetections(prev => prev.map(d =>
                    selectedIds.includes(d.detection.id) ? { ...d, detection: { ...d.detection, moderationStatus: 'REJECTED' } } : d
                ));
                setSelectedIds([]);
                toast.success(`Rejected ${result.count} items`);
            } else {
                toast.error(result.error);
            }
        });
    };

    const handleBulkGenerateLinks = async () => {
        startTransition(async () => {
            const result = await triggerBulkMarketplaceMatchAction(selectedIds);
            if (result.success) {
                toast.success(`Generation triggered for ${result.count} items. Results will appear in a few moments.`);
                setSelectedIds([]);
            } else {
                toast.error(result.error || 'Failed to trigger link generation');
            }
        });
    };

    const handleReset = async (id: string) => {
        startTransition(async () => {
            const result = await resetDetection(id);
            if (result.success) {
                setDetections(prev => prev.map(d =>
                    d.detection.id === id ? { ...d, detection: { ...d.detection, moderationStatus: 'PENDING' } } : d
                ));
                toast.success('Detection reset to pending');
            } else {
                toast.error(result.error);
            }
        });
    };

    const statCards = [
        { status: 'PENDING' as const, title: 'Pending Review', count: stats.pending, icon: <Clock className="w-5 h-5 text-amber-500" />, description: 'Items awaiting your approval', activeClasses: 'ring-2 ring-amber-500 bg-amber-500/10 border-amber-500/50' },
        { status: 'APPROVED' as const, title: 'Approved', count: stats.approved, icon: <CheckCircle className="w-5 h-5 text-emerald-500" />, description: 'Successfully added to Vault', activeClasses: 'ring-2 ring-emerald-500 bg-emerald-500/10 border-emerald-500/50' },
        { status: 'REJECTED' as const, title: 'Rejected', count: stats.rejected, icon: <ShieldAlert className="w-5 h-5 text-rose-500" />, description: 'Hidden from your Vault', activeClasses: 'ring-2 ring-rose-500 bg-rose-500/10 border-rose-500/50' },
    ];

    return (
        <div className="space-y-6">
            <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
                {statCards.map(({ status, title, count, icon, description, activeClasses }) => (
                    <button
                        key={status}
                        type="button"
                        onClick={() => setFilterStatus(status)}
                        className={`text-left p-4 rounded-lg border transition-all group ${filterStatus === status ? activeClasses : 'bg-card/40 backdrop-blur-md border-border/40 hover:bg-card/60'
                            }`}
                    >
                        <div className="flex items-center justify-between pb-2">
                            <span className="text-sm font-medium">{title}</span>
                            <div className="p-2 bg-background/50 rounded-lg group-hover:scale-110 transition-transform">
                                {icon}
                            </div>
                        </div>
                        <div className="text-3xl font-bold">{count}</div>
                        <p className="text-xs text-muted-foreground mt-1">{description}</p>
                    </button>
                ))}
            </div>

            <div className="flex flex-col gap-4 bg-card/50 p-4 rounded-lg border border-border/50 backdrop-blur-sm">
                <div className="flex flex-wrap items-center gap-4">
                    <div className="space-y-1">
                        <Label>Status</Label>
                        <Select value={filterStatus} onValueChange={(v: any) => setFilterStatus(v)}>
                            <SelectTrigger className="w-[150px]">
                                <SelectValue placeholder="Status" />
                            </SelectTrigger>
                            <SelectContent>
                                <SelectItem value="PENDING">Pending</SelectItem>
                                <SelectItem value="APPROVED">Approved</SelectItem>
                                <SelectItem value="REJECTED">Rejected</SelectItem>
                            </SelectContent>
                        </Select>
                    </div>
                    <div className="space-y-1">
                        <Label htmlFor="min-confidence">Min Confidence ({Math.round(minConfidence * 100)}%)</Label>
                        <Input
                            id="min-confidence"
                            type="range"
                            min="0"
                            max="1"
                            step="0.05"
                            value={minConfidence}
                            onChange={(e) => setMinConfidence(parseFloat(e.target.value))}
                            className="w-[150px]"
                        />
                    </div>
                    <div className="space-y-1">
                        <Label>Video</Label>
                        <Select value={filterVideo} onValueChange={setFilterVideo}>
                            <SelectTrigger className="w-[200px]">
                                <SelectValue placeholder="All Videos" />
                            </SelectTrigger>
                            <SelectContent>
                                <SelectItem value="all">All Videos</SelectItem>
                                {videos.map(v => (
                                    <SelectItem key={v.id} value={v.id}>{v.title.slice(0, 40)}{v.title.length > 40 ? '...' : ''}</SelectItem>
                                ))}
                            </SelectContent>
                        </Select>
                    </div>
                    <div className="space-y-1">
                        <Label>Affiliate Link</Label>
                        <Select value={filterHasLink} onValueChange={setFilterHasLink}>
                            <SelectTrigger className="w-[150px]">
                                <SelectValue placeholder="All" />
                            </SelectTrigger>
                            <SelectContent>
                                <SelectItem value="all">All Items</SelectItem>
                                <SelectItem value="with-link">With Link</SelectItem>
                                <SelectItem value="without-link">No Link</SelectItem>
                            </SelectContent>
                        </Select>
                    </div>
                    <div className="space-y-1">
                        <Label>Sort By</Label>
                        <Select value={sortBy} onValueChange={setSortBy}>
                            <SelectTrigger className="w-[150px]">
                                <SelectValue placeholder="Sort By" />
                            </SelectTrigger>
                            <SelectContent>
                                <SelectItem value="date">Date (Newest)</SelectItem>
                                <SelectItem value="clicks">Most Clicks</SelectItem>
                                <SelectItem value="interest">Most Interest</SelectItem>
                                <SelectItem value="confidence">Confidence</SelectItem>
                            </SelectContent>
                        </Select>
                    </div>
                </div>

                <div className="flex items-center justify-between">
                    <div className="text-sm text-muted-foreground">
                        Showing {filteredDetections.length} of {detections.filter(d => d.detection.moderationStatus === filterStatus).length} items
                    </div>
                    <AddProductDialog
                        videos={videos}
                        onAdd={(newItem) => {
                            setDetections(prev => [{
                                detection: {
                                    id: newItem.id,
                                    objectName: newItem.objectName,
                                    category: newItem.category,
                                    confidenceScore: 1,
                                    moderationStatus: 'PENDING',
                                    thumbnailUrl: newItem.thumbnailUrl ?? null,
                                    createdAt: new Date(),
                                },
                                video: {
                                    id: newItem.videoId,
                                    title: newItem.videoTitle,
                                    thumbnailUrl: '',
                                },
                                marketplaceMatches: newItem.hasMarketplaceMatch ? [{ id: 'new', marketplace: 'amazon', productName: '', affiliateUrl: '' }] : [],
                                clickCount: 0,
                                interestPledgeCount: 0,
                            }, ...prev]);
                        }}
                    />
                </div>
            </div>

            {selectedIds.length > 0 && (
                <div className="flex items-center gap-2 bg-primary/10 px-4 py-2 rounded-full border border-primary/20 animate-in fade-in slide-in-from-top-2">
                    <span className="text-sm font-medium mr-2">{selectedIds.length} selected</span>
                    <Button size="sm" onClick={handleBulkApprove} disabled={isPending}>
                        <Check className="w-4 h-4 mr-1" /> Approve
                    </Button>
                    <Button size="sm" variant="outline" className="bg-emerald-500/10 hover:bg-emerald-500/20 text-emerald-500 border-none" onClick={handleBulkGenerateLinks} disabled={isPending}>
                        <Sparkles className="w-4 h-4 mr-1" /> Generate Links
                    </Button>
                    <Button size="sm" variant="destructive" onClick={handleBulkReject} disabled={isPending}>
                        <X className="w-4 h-4 mr-1" /> Reject
                    </Button>
                </div>
            )}

            <div className="flex items-center gap-2 mb-4">
                <Checkbox
                    id="select-all"
                    checked={selectedIds.length === filteredDetections.length && filteredDetections.length > 0}
                    onCheckedChange={toggleSelectAll}
                />
                <Label htmlFor="select-all" className="cursor-pointer">Select All Visible</Label>
            </div>

            <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-6">
                {filteredDetections.length > 0 ? (
                    filteredDetections.map((d) => {
                        const primaryMatch = d.marketplaceMatches[0];
                        const productImage = primaryMatch?.imageUrl;
                        const snapshotImage = d.detection.thumbnailUrl;

                        // Main image priority: Product Image -> Snapshot
                        const mainImage = productImage || snapshotImage;

                        // PiP Logic: Show Snapshot if we have BOTH images and they are different
                        // (i.e. snapshot is not just a fallback copy of product image)
                        const isSnapshotFallback = snapshotImage === productImage;
                        const showPip = snapshotImage && productImage && !isSnapshotFallback;

                        return (
                            <Card key={d.detection.id} className={`group overflow-hidden transition-all hover:ring-2 hover:ring-primary/50 ${selectedIds.includes(d.detection.id) ? 'ring-2 ring-primary' : 'bg-card/40 backdrop-blur-md border-border/40'}`}>
                                <div className="relative aspect-square overflow-hidden bg-muted">
                                    {mainImage ? (
                                        <Image
                                            src={mainImage}
                                            alt={d.detection.objectName}
                                            fill
                                            className="object-contain transition-transform group-hover:scale-105"
                                        />
                                    ) : (
                                        <div className="w-full h-full bg-muted flex items-center justify-center">
                                            <Filter className="w-8 h-8 text-muted-foreground" />
                                        </div>
                                    )}

                                    {/* Video Snapshot Inset (PiP) */}
                                    {showPip && (
                                        <div className="absolute bottom-2 left-2 w-16 h-16 rounded-lg overflow-hidden border-2 border-background shadow-xl z-20 transition-transform duration-300 group-hover:translate-x-1 group-hover:-translate-y-1">
                                            <Image
                                                src={snapshotImage!}
                                                alt="In video"
                                                fill
                                                className="object-cover"
                                                sizes="64px"
                                            />
                                            <div className="absolute inset-0 bg-black/20" />
                                            <div className="absolute bottom-0 left-0 right-0 bg-black/60 py-0.5 px-0.5">
                                                <span className="text-[6px] font-bold text-white uppercase tracking-tighter block text-center">
                                                    IN VIDEO
                                                </span>
                                            </div>
                                        </div>
                                    )}
                                    <div className="absolute top-2 left-2">
                                        <Checkbox
                                            checked={selectedIds.includes(d.detection.id)}
                                            onCheckedChange={() => toggleSelection(d.detection.id)}
                                            className="bg-background/80 backdrop-blur-sm"
                                        />
                                    </div>
                                    <div className="absolute top-2 right-2 flex flex-col gap-1 items-end">
                                        <Badge variant="secondary" className="bg-background/80 backdrop-blur-sm">
                                            {Math.round(d.detection.confidenceScore * 100)}%
                                        </Badge>
                                        {d.clickCount > 0 && (
                                            <Badge variant="secondary" className="bg-blue-500/90 text-white backdrop-blur-sm flex items-center gap-1 text-xs px-1.5 py-0.5">
                                                <MousePointerClick className="h-3 w-3" />
                                                {d.clickCount}
                                            </Badge>
                                        )}
                                        {d.interestPledgeCount > 0 && (
                                            <Badge variant="secondary" className="bg-rose-500/90 text-white backdrop-blur-sm flex items-center gap-1 text-xs px-1.5 py-0.5">
                                                <Heart className="h-3 w-3" />
                                                {d.interestPledgeCount}
                                            </Badge>
                                        )}
                                    </div>
                                    {d.marketplaceMatches.length > 0 && (
                                        <div className="absolute bottom-2 right-2">
                                            <Badge variant="default" className="bg-emerald-500/90 gap-1">
                                                <ShoppingCart className="w-3 h-3" /> {d.marketplaceMatches.length} matches
                                            </Badge>
                                        </div>
                                    )}
                                </div>

                                <CardHeader className="p-4 py-3 space-y-1">
                                    <div className="flex justify-between items-start">
                                        <CardTitle className="text-lg font-bold truncate pr-2">
                                            {d.detection.objectName}
                                        </CardTitle>
                                        <EditDetectionDialog
                                            detection={d.detection}
                                            marketplaceMatches={d.marketplaceMatches}
                                            onSave={(updated: { objectName: string; category: string; thumbnailUrl?: string }) => {
                                                setDetections(prev => prev.map(item =>
                                                    item.detection.id === d.detection.id ? { ...item, detection: { ...item.detection, ...updated } } : item
                                                ));
                                            }}
                                        />
                                    </div>
                                    <div className="flex items-center gap-2 text-sm text-muted-foreground">
                                        <Badge variant="outline" className="text-[10px] uppercase">
                                            {d.detection.category}
                                        </Badge>
                                        <span className="text-[10px] truncate">• {d.video.title}</span>
                                    </div>
                                </CardHeader>

                                <CardFooter className="p-4 pt-0 gap-2">
                                    {filterStatus === 'PENDING' ? (
                                        <>
                                            <Button
                                                variant="secondary"
                                                className="grow bg-emerald-500/10 hover:bg-emerald-500/20 text-emerald-500 border-none"
                                                onClick={() => handleApprove(d.detection.id)}
                                                disabled={isPending}
                                            >
                                                <Check className="w-4 h-4 mr-2" /> Approve
                                            </Button>
                                            <Button
                                                variant="secondary"
                                                className="grow bg-rose-500/10 hover:bg-rose-500/20 text-rose-500 border-none"
                                                onClick={() => handleReject(d.detection.id)}
                                                disabled={isPending}
                                            >
                                                <X className="w-4 h-4 mr-2" /> Reject
                                            </Button>
                                        </>
                                    ) : (
                                        <div className="flex items-center text-sm font-medium gap-2 py-2 text-muted-foreground">
                                            {filterStatus === 'APPROVED' ? (
                                                <><CheckCircle2 className="w-4 h-4 text-emerald-500" /> Approved</>
                                            ) : (
                                                <><X className="w-4 h-4 text-rose-500" /> Rejected</>
                                            )}
                                            <Button variant="link" size="sm" className="h-auto p-0 ml-auto" onClick={() => handleReset(d.detection.id)} disabled={isPending}>
                                                Reset
                                            </Button>
                                        </div>
                                    )}
                                </CardFooter>
                            </Card>
                        );
                    })
                ) : (
                    <div className="col-span-full py-20 text-center space-y-4 bg-muted/20 rounded-xl border-2 border-dashed border-border/50">
                        <div className="flex justify-center">
                            <ShieldCheck className="w-12 h-12 text-muted-foreground opacity-20" />
                        </div>
                        <div className="space-y-2">
                            <h3 className="text-xl font-semibold">Queue Clear!</h3>
                            <p className="text-muted-foreground">No {filterStatus.toLowerCase()} items found with current filters.</p>
                        </div>
                        <Button variant="outline" onClick={() => { setFilterStatus('PENDING'); setMinConfidence(0); }}>
                            View Pending Queue
                        </Button>
                    </div>
                )}
            </div>
        </div>
    );
}