import AuthenticatedLayout from '@/Layouts/AuthenticatedLayout';
import { Head, useForm, router, Link } from '@inertiajs/react';
import { usePermission } from '@/hooks/usePermission';
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,
    DialogHeader,
    DialogTitle,
} from "@/Components/ui/dialog";
import { Label } from "@/Components/ui/label";
import { Plus, Search, X, Eye, Pencil, ClipboardCheck, Trash2 } from "lucide-react";
import { useState, useCallback, useEffect } from 'react';
import {
    AlertDialog,
    AlertDialogAction,
    AlertDialogCancel,
    AlertDialogContent,
    AlertDialogDescription,
    AlertDialogFooter,
    AlertDialogHeader,
    AlertDialogTitle,
} from "@/Components/ui/alert-dialog";
import Pagination from '@/Components/shared/Pagination';
import { SearchableSelect } from '@/Components/ui/searchable-select';
import { Can } from '@/Components/Permission/Can';
import debounce from 'lodash/debounce';
import axios from 'axios';

interface Doc {
    id: string;
    doc_no: string;
    warehouse_name: string;
    reason: string;
    status: string;
    created_by: string;
    created_at: string;
    posted_at: string;
}

interface Warehouse {
    id: string;
    name: string;
}

interface Filters {
    search?: string;
    warehouse_id?: string;
    per_page?: string;
}

interface DocsPagination {
    data: Doc[];
    current_page: number;
    per_page: number;
    total: number;
    links: any[]; // Adjust type as needed for pagination links
}

export default function Index({ docs, warehouses, filters }: { docs: DocsPagination, warehouses: Warehouse[], filters: Filters }) {
    const [isDialogOpen, setIsDialogOpen] = useState(false);
    const [searchQuery, setSearchQuery] = useState(filters.search || '');
    const [warehouseId, setWarehouseId] = useState(filters.warehouse_id || '');
    const [perPage, setPerPage] = useState(filters.per_page || '10');
    const [deleteId, setDeleteId] = useState<string | null>(null);

    // For Count Doc Selection
    const [pendingCounts, setPendingCounts] = useState<any[]>([]);
    const [loadingPending, setLoadingPending] = useState(false);
    const [scanSearch, setScanSearch] = useState('');

    const fetchPendingCounts = useCallback(
        debounce((search = '') => {
            setLoadingPending(true);
            axios.get(route('inventory.adjust.pending-counts'), { params: { search } })
                .then(res => setPendingCounts(res.data))
                .finally(() => setLoadingPending(false));
        }, 300),
        []
    );

    useEffect(() => {
        if (isDialogOpen) {
            fetchPendingCounts();
        }
    }, [isDialogOpen, fetchPendingCounts]);

    const debouncedFilter = useCallback(
        debounce((params: Filters) => {
            router.get(route('inventory.adjust.index'), params as any, {
                preserveState: true,
                replace: true,
            });
        }, 300),
        []
    );

    const handleSearchChange = (val: string) => {
        setSearchQuery(val);
        debouncedFilter({ search: val, warehouse_id: warehouseId, per_page: perPage });
    };

    const handleWarehouseChange = (val: string) => {
        setWarehouseId(val);
        debouncedFilter({ search: searchQuery, warehouse_id: val, per_page: perPage });
    };

    const handlePerPageChange = (value: string) => {
        setPerPage(value);
        router.get(route('inventory.adjust.index'),
            { ...filters, search: searchQuery, warehouse_id: warehouseId, per_page: value, page: 1 },
            { preserveState: false, replace: true, preserveScroll: true }
        );
    };

    const confirmDelete = (id: string, e: React.MouseEvent) => {
        e.stopPropagation();
        setDeleteId(id);
    };

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

    const { can } = usePermission();

    const { data, setData, post, processing, reset } = useForm({
        count_doc_id: null as string | null,
        warehouse_id: '',
        reason: '手動調整庫存',
        remarks: '',
    });

    const handleCreate = (countDocId?: string) => {
        if (countDocId) {
            setData('count_doc_id', countDocId);
            router.post(route('inventory.adjust.store'), { count_doc_id: countDocId }, {
                onSuccess: () => setIsDialogOpen(false),
            });
            return;
        }

        post(route('inventory.adjust.store'), {
            onSuccess: () => {
                setIsDialogOpen(false);
                reset();
            },
        });
    };

    const getStatusBadge = (status: string) => {
        switch (status) {
            case 'draft':
                return <Badge variant="secondary" className="bg-gray-100 text-gray-600 border-none">草稿</Badge>;
            case 'posted':
                return <Badge className="bg-green-100 text-green-700 border-none">已過帳</Badge>;
            case 'voided':
                return <Badge variant="destructive" className="bg-red-100 text-red-700 border-none">已作廢</Badge>;
            default:
                return <Badge variant="outline">{status}</Badge>;
        }
    };

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

            <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" />
                            庫存盤調管理
                        </h1>
                        <p className="text-gray-500 mt-1">
                            針對盤點差異進行庫存調整與過帳 (盤盈、盤虧、報廢等)。
                        </p>
                    </div>
                </div>

                {/* Toolbar Context */}
                <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 -translate-y-1/2 h-4 w-4 text-gray-400" />
                            <Input
                                placeholder="搜尋單號、原因或備註..."
                                value={searchQuery}
                                onChange={(e) => handleSearchChange(e.target.value)}
                                className="pl-10 pr-10 h-9"
                            />
                            {searchQuery && (
                                <button
                                    onClick={() => handleSearchChange('')}
                                    className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
                                >
                                    <X className="h-4 w-4" />
                                </button>
                            )}
                        </div>

                        {/* Warehouse Filter */}
                        <SearchableSelect
                            options={[
                                { value: '', label: '所有倉庫' },
                                ...warehouses.map(w => ({ value: w.id, label: w.name }))
                            ]}
                            value={warehouseId}
                            onValueChange={handleWarehouseChange}
                            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_adjust.create">
                                <Button
                                    className="flex-1 md:flex-none button-filled-primary h-9"
                                    onClick={() => setIsDialogOpen(true)}
                                >
                                    <Plus className="mr-2 h-4 w-4" />
                                    新增盤調單
                                </Button>
                            </Can>
                        </div>
                    </div>
                </div>

                {/* Table Container */}
                <div className="bg-white rounded-xl border border-gray-200 shadow-sm overflow-hidden">
                    <Table>
                        <TableHeader className="bg-gray-50">
                            <TableRow>
                                <TableHead className="w-[60px] text-center font-medium text-grey-600">#</TableHead>
                                <TableHead className="w-[180px] font-medium text-grey-600">單號</TableHead>
                                <TableHead className="font-medium text-grey-600">倉庫</TableHead>
                                <TableHead className="font-medium text-grey-600">調整原因</TableHead>
                                <TableHead className="font-medium text-grey-600 text-center">狀態</TableHead>
                                <TableHead className="font-medium text-grey-600">建立者</TableHead>
                                <TableHead className="font-medium text-grey-600">建立時間</TableHead>
                                <TableHead className="font-medium text-grey-600">過帳時間</TableHead>
                                <TableHead className="text-center font-medium text-grey-600">操作</TableHead>
                            </TableRow>
                        </TableHeader>
                        <TableBody>
                            {docs.data.length === 0 ? (
                                <TableRow>
                                    <TableCell colSpan={9} className="h-32 text-center text-grey-400">
                                        尚無任何盤調單據
                                    </TableCell>
                                </TableRow>
                            ) : (
                                docs.data.map((doc: Doc, index: number) => (
                                    <TableRow
                                        key={doc.id}
                                        className="hover:bg-gray-50/50 transition-colors cursor-pointer group"
                                        onClick={() => router.visit(route('inventory.adjust.show', [doc.id]))}
                                    >
                                        <TableCell className="text-center text-gray-500 font-medium">
                                            {(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 className="text-gray-500 max-w-[200px] truncate">{doc.reason}</TableCell>
                                        <TableCell className="text-center">{getStatusBadge(doc.status)}</TableCell>
                                        <TableCell className="text-sm">{doc.created_by}</TableCell>
                                        <TableCell className="text-gray-500 text-sm">{doc.created_at}</TableCell>
                                        <TableCell className="text-gray-500 text-sm">{doc.posted_at || '-'}</TableCell>
                                        <TableCell className="text-center">
                                            <div className="flex items-center justify-center gap-2" onClick={(e) => e.stopPropagation()}>
                                                {(() => {
                                                    const isDraft = doc.status === 'draft';
                                                    const canEdit = can('inventory_adjust.edit');
                                                    const canView = can('inventory_adjust.view');

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

                                                    if (canView) {
                                                        return (
                                                            <Link href={route('inventory.adjust.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;
                                                })()}

                                                {doc.status === 'draft' && (
                                                    <Can permission="inventory_adjust.delete">
                                                        <Button
                                                            variant="outline"
                                                            size="sm"
                                                            className="button-outlined-error"
                                                            title="刪除"
                                                            onClick={(e) => confirmDelete(doc.id, e)}
                                                        >
                                                            <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 || 0} 筆紀錄</span>
                    </div>
                    <Pagination links={docs.links} />
                </div>

                <AlertDialog open={!!deleteId} onOpenChange={(open) => !open && setDeleteId(null)}>
                    <AlertDialogContent>
                        <AlertDialogHeader>
                            <AlertDialogTitle>確定要刪除此盤調單嗎？</AlertDialogTitle>
                            <AlertDialogDescription>
                                此動作無法復原。刪除後請重新建立盤調單。
                            </AlertDialogDescription>
                        </AlertDialogHeader>
                        <AlertDialogFooter>
                            <AlertDialogCancel>取消</AlertDialogCancel>
                            <AlertDialogAction onClick={handleDelete} className="bg-red-600 hover:bg-red-700">確認刪除</AlertDialogAction>
                        </AlertDialogFooter>
                    </AlertDialogContent>
                </AlertDialog>
            </div>

            {/* Create Dialog */}
            <Dialog open={isDialogOpen} onOpenChange={setIsDialogOpen}>
                <DialogContent className="max-w-2xl">
                    <DialogHeader>
                        <DialogTitle className="text-xl font-bold flex items-center gap-2">
                            <Plus className="h-5 w-5 text-primary-main" />
                            新增盤調單
                        </DialogTitle>
                        <DialogDescription>
                            請選擇一個已完成的盤點單來生成盤調項目，或手動建立。
                        </DialogDescription>
                    </DialogHeader>

                    <div className="py-4 space-y-6">
                        {/* Option 1: Scan/Select from Count Docs */}
                        <div className="space-y-4 p-4 rounded-xl bg-primary-lightest/50 border border-primary-light/20 shadow-sm">
                            <Label className="text-sm font-bold text-primary-main flex items-center gap-2">
                                <ClipboardCheck className="h-4 w-4" />
                                方法一：關聯盤點單 (推薦)
                            </Label>
                            <div className="relative">
                                <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-grey-3" />
                                <Input
                                    placeholder="掃描盤點單號或搜尋..."
                                    className="pl-9 h-9"
                                    value={scanSearch}
                                    onChange={(e) => {
                                        setScanSearch(e.target.value);
                                        fetchPendingCounts(e.target.value);
                                    }}
                                />
                            </div>

                            <div className="max-h-[200px] overflow-y-auto rounded-lg border-2 border-grey-3 bg-white">
                                {loadingPending ? (
                                    <div className="p-8 text-center text-sm text-grey-3">載入中...</div>
                                ) : pendingCounts.length === 0 ? (
                                    <div className="p-8 text-center text-sm text-grey-3">
                                        查無可供盤調的盤點單 (需為已核准狀態)
                                    </div>
                                ) : (
                                    <div className="divide-y divide-grey-4">
                                        {pendingCounts.map((c: any) => (
                                            <div
                                                key={c.id}
                                                className="p-3 hover:bg-primary-lightest flex items-center justify-between cursor-pointer group transition-colors"
                                                onClick={() => handleCreate(c.id)}
                                            >
                                                <div>
                                                    <p className="font-bold text-grey-0 group-hover:text-primary-main">{c.doc_no}</p>
                                                    <p className="text-xs text-grey-2">{c.warehouse_name} | 完成於: {c.completed_at}</p>
                                                </div>
                                                <Button size="sm" variant="outline" className="button-outlined-primary h-7 text-xs">
                                                    選擇並載入
                                                </Button>
                                            </div>
                                        ))}
                                    </div>
                                )}
                            </div>
                        </div>

                        <div className="relative flex items-center py-2">
                            <div className="flex-grow border-t border-grey-4"></div>
                            <span className="flex-shrink mx-4 text-xs font-semibold text-grey-3 uppercase tracking-wider">或</span>
                            <div className="flex-grow border-t border-grey-4"></div>
                        </div>

                        {/* Option 2: Manual (Optional, though less common in this flow) */}
                        <div className="space-y-4 px-1">
                            <Label className="text-sm font-bold text-grey-0">方法二：手動建立調整</Label>
                            <div className="grid grid-cols-2 gap-4">
                                <div className="space-y-2">
                                    <Label className="text-xs font-semibold text-grey-1">選擇倉庫</Label>
                                    <SearchableSelect
                                        options={warehouses.map(w => ({ value: w.id, label: w.name }))}
                                        value={data.warehouse_id}
                                        onValueChange={(val) => setData('warehouse_id', val)}
                                        placeholder="選擇倉庫"
                                        className="h-9"
                                    />
                                </div>
                                <div className="space-y-2">
                                    <Label className="text-xs font-semibold text-grey-1">調整原因</Label>
                                    <Input
                                        placeholder="例如: 報廢, 破損..."
                                        value={data.reason}
                                        onChange={(e) => setData('reason', e.target.value)}
                                        className="h-9"
                                    />
                                </div>
                            </div>
                            <div className="flex justify-end gap-2 pt-2">
                                <Button variant="outline" className="button-outlined-primary" onClick={() => setIsDialogOpen(false)}>取消</Button>
                                <Button
                                    className="button-filled-primary"
                                    disabled={processing || !data.warehouse_id || !data.reason}
                                    onClick={() => handleCreate()}
                                >
                                    新增
                                </Button>
                            </div>
                        </div>
                    </div>
                </DialogContent>
            </Dialog>
        </AuthenticatedLayout>
    );
}
