import { useState, useEffect } from "react";
import {
    Dialog,
    DialogContent,
    DialogHeader,
    DialogTitle,
    DialogFooter,
} from "@/Components/ui/dialog";
import { Button } from "@/Components/ui/button";
import { Input } from "@/Components/ui/input";
import { Label } from "@/Components/ui/label";
import {
    Select,
    SelectContent,
    SelectItem,
    SelectTrigger,
    SelectValue,
} from "@/Components/ui/select";
import { AlertCircle } from "lucide-react";

interface BatchAdjustmentModalProps {
    isOpen: boolean;
    onClose: () => void;
    onConfirm: (data: {
        operation: "add" | "subtract" | "set";
        quantity: number;
        reason: string;
    }) => void;
    batch?: {
        id: string;
        batchNumber: string;
        currentQuantity: number;
        productName: string;
    };
    processing?: boolean;
}

export default function BatchAdjustmentModal({
    isOpen,
    onClose,
    onConfirm,
    batch,
    processing = false,
}: BatchAdjustmentModalProps) {
    const [operation, setOperation] = useState<"add" | "subtract" | "set">("add");
    const [quantity, setQuantity] = useState<string>("");
    const [reason, setReason] = useState<string>("手動調整庫存");

    // 當開啟時重置
    useEffect(() => {
        if (isOpen) {
            setOperation("add");
            setQuantity("");
            setReason("手動調整庫存");
        }
    }, [isOpen]);

    const handleConfirm = () => {
        const numQty = parseFloat(quantity);
        if (isNaN(numQty) || numQty <= 0 && operation !== "set") {
            return;
        }

        onConfirm({
            operation,
            quantity: numQty,
            reason,
        });
    };

    const previewQuantity = () => {
        if (!batch) return 0;
        const numQty = parseFloat(quantity) || 0;
        if (operation === "add") return batch.currentQuantity + numQty;
        if (operation === "subtract") return Math.max(0, batch.currentQuantity - numQty);
        if (operation === "set") return numQty;
        return batch.currentQuantity;
    };

    if (!batch) return null;

    return (
        <Dialog open={isOpen} onOpenChange={(open) => !open && onClose()}>
            <DialogContent className="sm:max-w-[425px]">
                <DialogHeader>
                    <DialogTitle className="flex items-center gap-2">
                        庫存調整 - {batch.productName}
                    </DialogTitle>
                </DialogHeader>

                <div className="grid gap-4 py-4">
                    <div className="bg-gray-50 p-3 rounded-md border text-sm space-y-1">
                        <div className="flex justify-between">
                            <span className="text-gray-500">批號：</span>
                            <span className="font-mono font-medium">{batch.batchNumber || "-"}</span>
                        </div>
                        <div className="flex justify-between">
                            <span className="text-gray-500">當前數量：</span>
                            <span className="font-medium text-primary-main">{batch.currentQuantity}</span>
                        </div>
                    </div>

                    <div className="space-y-2">
                        <Label>調整方式</Label>
                        <Select
                            value={operation}
                            onValueChange={(value: any) => setOperation(value)}
                        >
                            <SelectTrigger>
                                <SelectValue placeholder="選擇調整方式" />
                            </SelectTrigger>
                            <SelectContent>
                                <SelectItem value="add">增加 (+)</SelectItem>
                                <SelectItem value="subtract">扣除 (-)</SelectItem>
                                <SelectItem value="set">設定為固定值 (=)</SelectItem>
                            </SelectContent>
                        </Select>
                    </div>

                    <div className="space-y-2">
                        <Label htmlFor="adj-qty">數量</Label>
                        <Input
                            id="adj-qty"
                            type="number"
                            step="0.01"
                            min="0"
                            value={quantity}
                            onChange={(e) => setQuantity(e.target.value)}
                            placeholder="請輸入數量"
                        />
                    </div>

                    <div className="space-y-2">
                        <Label htmlFor="adj-reason">調整原因</Label>
                        <Input
                            id="adj-reason"
                            value={reason}
                            onChange={(e) => setReason(e.target.value)}
                            placeholder="例：手動盤點修正"
                        />
                    </div>

                    <div className="flex items-center gap-2 mt-2 p-3 bg-primary/5 rounded-md border border-primary/20 text-sm">
                        <AlertCircle className="h-4 w-4 text-primary-main" />
                        <span>
                            調整後預計數量：
                            <span className="font-bold text-primary-main ml-1">
                                {previewQuantity()}
                            </span>
                        </span>
                    </div>
                </div>

                <DialogFooter>
                    <Button variant="outline" onClick={onClose} disabled={processing}>
                        取消
                    </Button>
                    <Button
                        onClick={handleConfirm}
                        disabled={processing || !quantity || parseFloat(quantity) < 0}
                        className="button-filled-primary"
                    >
                        確認調整
                    </Button>
                </DialogFooter>
            </DialogContent>
        </Dialog>
    );
}