import AuthenticatedLayout from '@/Layouts/AuthenticatedLayout';
import { Head, Link, useForm, router } from '@inertiajs/react';
import { useState, useCallback, useEffect } from 'react';
import { usePermission } from '@/hooks/usePermission';
import { debounce } from "lodash";
import { SearchableSelect } from "@/Components/ui/searchable-select";
import {
    Table,
    TableBody,
    TableCell,
    TableHead,
    TableHeader,
    TableRow,
} from '@/Components/ui/table';
import { Button } from '@/Components/ui/button';
import { Input } from '@/Components/ui/input';
import { Badge } from '@/Components/ui/badge';
import {
    Dialog,
    DialogContent,
    DialogDescription,
    DialogFooter,
    DialogHeader,
    DialogTitle,
    DialogTrigger,
} from "@/Components/ui/dialog";
import { Label } from '@/Components/ui/label';
import {
    Plus,
    Search,
    X,
    ClipboardCheck,
    Eye,
    Pencil,
    Trash2
} from 'lucide-react';
import {
    AlertDialog,
    AlertDialogAction,
    AlertDialogCancel,
    AlertDialogContent,
    AlertDialogDescription,
    AlertDialogFooter,
    AlertDialogHeader,
    AlertDialogTitle,
} from "@/Components/ui/alert-dialog";
import Pagination from '@/Components/shared/Pagination';
import { Can } from '@/Components/Permission/Can';

export default function Index({ docs, warehouses, filters }: any) {
    const [isCreateDialogOpen, setIsCreateDialogOpen] = useState(false);
    const [deleteId, setDeleteId] = useState<string | null>(null);
    const { data, setData, post, processing, reset, errors, delete: destroy } = useForm({
        warehouse_id: '',
        remarks: '',
    });

    const { can } = usePermission();

    const [searchTerm, setSearchTerm] = useState(filters.search || "");
    const [warehouseFilter, setWarehouseFilter] = useState(filters.warehouse_id || "all");
    const [perPage, setPerPage] = useState(filters.per_page || "10");

    // Sync state with props
    useEffect(() => {
        setSearchTerm(filters.search || "");
        setWarehouseFilter(filters.warehouse_id || "all");
        setPerPage(filters.per_page || "10");
    }, [filters]);

    // Debounced Search Handler
    const debouncedSearch = useCallback(
        debounce((term: string, warehouse: string) => {
            router.get(
                route('inventory.count.index'),
                { ...filters, search: term, warehouse_id: warehouse === "all" ? "" : warehouse },
                { preserveState: true, replace: true, preserveScroll: true }
            );
        }, 500),
        [filters]
    );

    const handleSearchChange = (term: string) => {
        setSearchTerm(term);
        debouncedSearch(term, warehouseFilter);
    };

    const handleFilterChange = (value: string) => {
        setWarehouseFilter(value);
        router.get(
            route('inventory.count.index'),
            { ...filters, warehouse_id: value === "all" ? "" : value },
            { preserveState: false, replace: true, preserveScroll: true }
        );
    };

    const handleClearSearch = () => {
        setSearchTerm("");
        router.get(
            route('inventory.count.index'),
            { ...filters, search: "", warehouse_id: warehouseFilter === "all" ? "" : warehouseFilter },
            { preserveState: true, replace: true, preserveScroll: true }
        );
    };

    const handlePerPageChange = (value: string) => {
        setPerPage(value);
        router.get(
            route('inventory.count.index'),
            { ...filters, per_page: value },
            { preserveState: false, replace: true, preserveScroll: true }
        );
    };

    const handleCreate = (e: React.FormEvent) => {
        e.preventDefault();
        post(route('inventory.count.store'), {
            onSuccess: () => {
                setIsCreateDialogOpen(false);
                reset();
            },
        });
    };

    const confirmDelete = (id: string) => {
        setDeleteId(id);
    };

    const handleDelete = () => {
        if (deleteId) {
            destroy(route('inventory.count.destroy', [deleteId]), {
                onSuccess: () => setDeleteId(null),
                onError: () => setDeleteId(null),
            });
        }
    };

    const getStatusBadge = (status: string) => {
        switch (status) {
            case 'draft':
                return <Badge variant="secondary">草稿</Badge>;
            case 'counting':
                return <Badge className="bg-blue-500 hover:bg-blue-600">盤點中</Badge>;
            case 'completed':
                return <Badge className="bg-green-500 hover:bg-green-600">盤點完成</Badge>;
            case 'no_adjust':
                return <Badge className="bg-green-600 hover:bg-green-700">盤點完成 (無需盤調)</Badge>;
            case 'adjusted':
                return <Badge className="bg-purple-500 hover:bg-purple-600">已盤調庫存</Badge>;
            case 'cancelled':
                return <Badge variant="destructive">已取消</Badge>;
            default:
                return <Badge variant="outline">{status}</Badge>;
        }
    };

    return (
        <AuthenticatedLayout
            breadcrumbs={[
                { label: '商品與庫存管理', href: '#' },
                { label: '庫存盤點', href: route('inventory.count.index'), isPage: true },
            ]}
        >
            <Head title="庫存盤點" />

            <div className="container mx-auto p-6 max-w-7xl">
                <div className="flex items-center justify-between mb-6">
                    <div>
                        <h1 className="text-2xl font-bold text-grey-0 flex items-center gap-2">
                            <ClipboardCheck className="h-6 w-6 text-primary-main" />
                            庫存盤點管理
                        </h1>
                        <p className="text-gray-500 mt-1">
                            建立與管理倉庫盤點單，執行定期庫存核對。
                        </p>
                    </div>
                </div>

                {/* Toolbar */}
                <div className="bg-white rounded-lg shadow-sm border p-4 mb-6">
                    <div className="flex flex-col md:flex-row gap-4">
                        {/* Search */}
                        <div className="flex-1 relative">
                            <Search className="absolute left-3 top-1/2 transform -translate-y-1/2 text-gray-400 h-4 w-4" />
                            <Input
                                placeholder="搜尋盤點單號、備註..."
                                value={searchTerm}
                                onChange={(e) => handleSearchChange(e.target.value)}
                                className="pl-10 pr-10 h-9"
                            />
                            {searchTerm && (
                                <button
                                    onClick={handleClearSearch}
                                    className="absolute right-3 top-1/2 transform -translate-y-1/2 text-gray-400 hover:text-gray-600"
                                >
                                    <X className="h-4 w-4" />
                                </button>
                            )}
                        </div>

                        {/* Warehouse Filter */}
                        <SearchableSelect
                            value={warehouseFilter}
                            onValueChange={handleFilterChange}
                            options={[
                                { label: "所有倉庫", value: "all" },
                                ...warehouses.map((w: any) => ({ label: w.name, value: w.id.toString() }))
                            ]}
                            placeholder="選擇倉庫"
                            className="w-full md:w-[200px] h-9"
                        />

                        {/* Action Buttons */}
                        <div className="flex gap-2 w-full md:w-auto">
                            <Can permission="inventory_count.create">
                                <Dialog open={isCreateDialogOpen} onOpenChange={setIsCreateDialogOpen}>
                                    <DialogTrigger asChild>
                                        <Button className="flex-1 md:flex-none button-filled-primary">
                                            <Plus className="w-4 h-4 mr-2" />
                                            新增盤點單
                                        </Button>
                                    </DialogTrigger>
                                    <DialogContent className="sm:max-w-[425px]">
                                        <form onSubmit={handleCreate}>
                                            <DialogHeader>
                                                <DialogTitle>建立新盤點單</DialogTitle>
                                                <DialogDescription>
                                                    建立後將自動對該倉庫庫存進行快照，請確認倉庫作業已暫停。
                                                </DialogDescription>
                                            </DialogHeader>
                                            <div className="grid gap-4 py-4">
                                                <div className="space-y-2">
                                                    <Label htmlFor="warehouse">選擇倉庫</Label>
                                                    <SearchableSelect
                                                        value={data.warehouse_id}
                                                        onValueChange={(val) => setData('warehouse_id', val)}
                                                        options={warehouses.map((w: any) => ({ label: w.name, value: w.id.toString() }))}
                                                        placeholder="請選擇倉庫"
                                                        className="h-9"
                                                    />
                                                    {errors.warehouse_id && <p className="text-red-500 text-sm">{errors.warehouse_id}</p>}
                                                </div>
                                                <div className="space-y-2">
                                                    <Label htmlFor="remarks">備註</Label>
                                                    <Input
                                                        id="remarks"
                                                        className="h-9"
                                                        value={data.remarks}
                                                        onChange={(e) => setData('remarks', e.target.value)}
                                                    />
                                                </div>
                                            </div>
                                            <DialogFooter>
                                                <Button type="button" variant="outline" className="button-outlined-primary" onClick={() => setIsCreateDialogOpen(false)}>
                                                    取消
                                                </Button>
                                                <Button type="submit" className="button-filled-primary" disabled={processing || !data.warehouse_id}>
                                                    新增
                                                </Button>
                                            </DialogFooter>
                                        </form>
                                    </DialogContent>
                                </Dialog>
                            </Can>
                        </div>
                    </div>
                </div>

                <div className="bg-white rounded-xl border border-gray-200 shadow-sm overflow-hidden">
                    <Table>
                        <TableHeader className="bg-gray-50">
                            <TableRow>
                                <TableHead className="w-[50px] text-center">#</TableHead>
                                <TableHead>單號</TableHead>
                                <TableHead>倉庫</TableHead>
                                <TableHead>狀態</TableHead>
                                <TableHead>快照時間</TableHead>
                                <TableHead>盤點進度</TableHead>
                                <TableHead>完成時間</TableHead>
                                <TableHead>建立人員</TableHead>
                                <TableHead className="text-center">操作</TableHead>
                            </TableRow>
                        </TableHeader>
                        <TableBody>
                            {docs.data.length === 0 ? (
                                <TableRow>
                                    <TableCell colSpan={9} className="text-center h-24 text-gray-500">
                                        尚無盤點紀錄
                                    </TableCell>
                                </TableRow>
                            ) : (
                                docs.data.map((doc: any, index: number) => (
                                    <TableRow key={doc.id}>
                                        <TableCell className="text-gray-500 font-medium text-center">
                                            {(docs.current_page - 1) * docs.per_page + index + 1}
                                        </TableCell>
                                        <TableCell className="font-medium text-primary-main">{doc.doc_no}</TableCell>
                                        <TableCell>{doc.warehouse_name}</TableCell>
                                        <TableCell>{getStatusBadge(doc.status)}</TableCell>
                                        <TableCell className="text-gray-500 text-sm">{doc.snapshot_date}</TableCell>
                                        <TableCell>
                                            <span className="font-medium text-gray-700">{doc.counted_items}</span>
                                            <span className="text-gray-400 mx-1">/</span>
                                            <span className="text-gray-500">{doc.total_items}</span>
                                        </TableCell>
                                        <TableCell className="text-gray-500 text-sm">{doc.completed_at || '-'}</TableCell>
                                        <TableCell className="text-sm">{doc.created_by}</TableCell>
                                        <TableCell className="text-center">
                                            <div className="flex items-center justify-center gap-2">
                                                {/* Action Button Logic: Prefer Edit if allowed and status is active, otherwise fallback to View if allowed */}
                                                {(() => {
                                                    const isEditable = !['completed', 'no_adjust', 'adjusted'].includes(doc.status);
                                                    const canEdit = can('inventory_count.edit');
                                                    const canView = can('inventory_count.view');

                                                    if (isEditable && canEdit) {
                                                        return (
                                                            <Link href={route('inventory.count.show', [doc.id])}>
                                                                <Button
                                                                    variant="outline"
                                                                    size="sm"
                                                                    className="button-outlined-primary"
                                                                    title="盤點"
                                                                >
                                                                    <Pencil className="w-4 h-4 ml-0.5" />
                                                                </Button>
                                                            </Link>
                                                        );
                                                    }

                                                    if (canView) {
                                                        return (
                                                            <Link href={route('inventory.count.show', [doc.id])}>
                                                                <Button
                                                                    variant="outline"
                                                                    size="sm"
                                                                    className="button-outlined-primary"
                                                                    title="查閱"
                                                                >
                                                                    <Eye className="w-4 h-4 ml-0.5" />
                                                                </Button>
                                                            </Link>
                                                        );
                                                    }

                                                    return null;
                                                })()}
                                                {!['completed', 'no_adjust', 'adjusted'].includes(doc.status) && (
                                                    <Can permission="inventory_count.delete">
                                                        <Button
                                                            variant="outline"
                                                            size="sm"
                                                            className="button-outlined-error"
                                                            title="作廢"
                                                            onClick={() => confirmDelete(doc.id)}
                                                        >
                                                            <Trash2 className="w-4 h-4 ml-0.5" />
                                                        </Button>
                                                    </Can>
                                                )}
                                            </div>
                                        </TableCell>
                                    </TableRow>
                                ))
                            )}
                        </TableBody>
                    </Table>
                </div>

                <div className="mt-4 flex flex-col sm:flex-row items-center justify-between gap-4">
                    <div className="flex items-center gap-4">
                        <div className="flex items-center gap-2 text-sm text-gray-500">
                            <span>每頁顯示</span>
                            <SearchableSelect
                                value={perPage}
                                onValueChange={handlePerPageChange}
                                options={[
                                    { label: "10", value: "10" },
                                    { label: "20", value: "20" },
                                    { label: "50", value: "50" },
                                    { label: "100", value: "100" }
                                ]}
                                className="w-[90px] h-8"
                                showSearch={false}
                            />
                            <span>筆</span>
                        </div>
                        <span className="text-sm text-gray-500">共 {docs.total} 筆紀錄</span>
                    </div>
                    <Pagination links={docs.links} />
                </div>

                <AlertDialog open={!!deleteId} onOpenChange={(open) => !open && setDeleteId(null)}>
                    <AlertDialogContent>
                        <AlertDialogHeader>
                            <AlertDialogTitle>確定要作廢此盤點單嗎？</AlertDialogTitle>
                            <AlertDialogDescription>
                                此動作無法復原。作廢後請重新建立盤點單。
                            </AlertDialogDescription>
                        </AlertDialogHeader>
                        <AlertDialogFooter>
                            <AlertDialogCancel>取消</AlertDialogCancel>
                            <AlertDialogAction onClick={handleDelete} className="bg-red-600 hover:bg-red-700">確認作廢</AlertDialogAction>
                        </AlertDialogFooter>
                    </AlertDialogContent>
                </AlertDialog>
            </div>
        </AuthenticatedLayout>
    );
}