"use client";

import React, { useState, useEffect } from "react";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from "@/components/ui/dialog";
import { Loader2, CheckCircle2, XCircle, Clock, FileCheck2 } from "lucide-react";
import {
  getApprovalRequest,
  processApprovalLine,
  cancelApprovalRequest,
  type ApprovalRequest,
} from "@/lib/api/approval";
import { useAuth } from "@/hooks/useAuth";

const statusConfig: Record<string, { label: string; variant: "default" | "secondary" | "destructive" | "outline" }> = {
  requested: { label: "요청됨", variant: "secondary" },
  in_progress: { label: "진행 중", variant: "default" },
  approved: { label: "승인됨", variant: "outline" },
  rejected: { label: "반려됨", variant: "destructive" },
  cancelled: { label: "취소됨", variant: "secondary" },
  post_pending: { label: "후결대기", variant: "secondary" },
};

const lineStatusConfig: Record<string, { label: string; icon: React.ReactNode }> = {
  waiting: { label: "대기", icon: <Clock className="h-3 w-3 text-muted-foreground" /> },
  pending: { label: "진행 중", icon: <Clock className="h-3 w-3 text-primary" /> },
  approved: { label: "승인", icon: <CheckCircle2 className="h-3 w-3 text-emerald-600" /> },
  rejected: { label: "반려", icon: <XCircle className="h-3 w-3 text-destructive" /> },
  skipped: { label: "건너뜀", icon: <Clock className="h-3 w-3 text-muted-foreground" /> },
};

export interface ApprovalDetailEventDetail {
  requestId: number;
}

export const ApprovalDetailModal: React.FC = () => {
  const { user } = useAuth();
  const [open, setOpen] = useState(false);
  const [request, setRequest] = useState<ApprovalRequest | null>(null);
  const [loading, setLoading] = useState(false);
  const [comment, setComment] = useState("");
  const [isProcessing, setIsProcessing] = useState(false);
  const [isCancelling, setIsCancelling] = useState(false);

  // 글로벌 이벤트 수신
  useEffect(() => {
    const handler = async (e: Event) => {
      const detail = (e as CustomEvent).detail as ApprovalDetailEventDetail;
      if (!detail?.requestId) return;
      setOpen(true);
      setLoading(true);
      const res = await getApprovalRequest(detail.requestId);
      setLoading(false);
      if (res.success && res.data) setRequest(res.data);
      else setRequest(null);
    };
    window.addEventListener("open-approval-detail-modal", handler);
    return () => window.removeEventListener("open-approval-detail-modal", handler);
  }, []);

  useEffect(() => {
    if (!open) {
      setComment("");
      setRequest(null);
    }
  }, [open]);

  // 내가 처리할 결재 라인 ID 찾기
  const pendingLineId = request?.lines?.find(
    (l) => l.approver_id === user?.userId && l.status === "pending"
  )?.line_id;

  const handleProcess = async (action: "approved" | "rejected") => {
    if (!pendingLineId) return;
    setIsProcessing(true);
    const res = await processApprovalLine(pendingLineId, { action, comment: comment.trim() || undefined });
    setIsProcessing(false);
    if (res.success) {
      setOpen(false);
      // 호출한 페이지에 새로고침 알림
      window.dispatchEvent(new CustomEvent("approval-processed", { detail: { requestId: request?.request_id, action } }));
    }
  };

  const handleCancel = async () => {
    if (!request) return;
    setIsCancelling(true);
    const res = await cancelApprovalRequest(request.request_id);
    setIsCancelling(false);
    if (res.success) {
      setOpen(false);
      window.dispatchEvent(new CustomEvent("approval-processed", { detail: { requestId: request.request_id, action: "cancelled" } }));
    }
  };

  if (!open) return null;

  const statusInfo = request ? (statusConfig[request.status] || { label: request.status, variant: "secondary" as const }) : null;
  const isRequester = request?.requester_id === user?.userId;

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogContent className="max-w-[95vw] sm:max-w-[600px]">
        {loading || !request ? (
          <div className="flex items-center justify-center py-12">
            <Loader2 className="h-6 w-6 animate-spin text-primary" />
          </div>
        ) : (
          <>
            <DialogHeader>
              <DialogTitle className="flex items-center gap-2 text-base sm:text-lg">
                <FileCheck2 className="h-5 w-5" />
                {request.title}
              </DialogTitle>
              <DialogDescription className="text-xs sm:text-sm">
                {statusInfo && (
                  <Badge variant={statusInfo.variant} className="mr-2">
                    {statusInfo.label}
                  </Badge>
                )}
                요청자: {request.requester_name || request.requester_id}
                {request.requester_dept ? ` (${request.requester_dept})` : ""}
              </DialogDescription>
            </DialogHeader>

            <div className="space-y-4">
              {request.description && (
                <div>
                  <p className="text-muted-foreground mb-1 text-xs font-medium">결재 사유</p>
                  <p className="rounded-md bg-muted p-3 text-xs sm:text-sm whitespace-pre-line">{request.description}</p>
                </div>
              )}

              <div>
                <p className="text-muted-foreground mb-2 text-xs font-medium">결재선</p>
                <div className="space-y-2">
                  {(request.lines || []).map((line) => {
                    const lineStatus = lineStatusConfig[line.status] || { label: line.status, icon: null };
                    return (
                      <div key={line.line_id} className="flex items-start justify-between rounded-md border p-3">
                        <div className="flex items-center gap-2">
                          {lineStatus.icon}
                          <div>
                            <p className="text-xs font-medium sm:text-sm">
                              {line.approver_label || `${line.step_order}차 결재`} — {line.approver_name || line.approver_id}
                            </p>
                            {line.approver_position && (
                              <p className="text-muted-foreground text-[10px] sm:text-xs">{line.approver_position}</p>
                            )}
                            {line.comment && (
                              <p className="text-muted-foreground mt-1 text-[10px] sm:text-xs">의견: {line.comment}</p>
                            )}
                          </div>
                        </div>
                        <span className="text-muted-foreground text-[10px] sm:text-xs">{lineStatus.label}</span>
                      </div>
                    );
                  })}
                </div>
              </div>

              {pendingLineId && (
                <div>
                  <p className="text-muted-foreground mb-1 text-xs font-medium">결재 의견 (선택사항)</p>
                  <Textarea
                    value={comment}
                    onChange={(e) => setComment(e.target.value)}
                    placeholder="결재 의견을 입력하세요"
                    className="min-h-[60px] text-xs sm:text-sm"
                  />
                </div>
              )}
            </div>

            <DialogFooter className="flex-wrap gap-2 sm:gap-1">
              {isRequester && (request.status === "requested" || request.status === "in_progress") && !pendingLineId && (
                <Button variant="outline" size="sm" onClick={handleCancel} disabled={isCancelling} className="h-8 text-xs">
                  {isCancelling ? <Loader2 className="mr-1 h-3 w-3 animate-spin" /> : null}
                  회수
                </Button>
              )}
              <Button variant="outline" onClick={() => setOpen(false)} className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm">
                닫기
              </Button>
              {pendingLineId && (
                <>
                  <Button variant="destructive" onClick={() => handleProcess("rejected")} disabled={isProcessing} className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm">
                    {isProcessing ? <Loader2 className="mr-1 h-3 w-3 animate-spin" /> : <XCircle className="mr-1 h-3 w-3" />}
                    반려
                  </Button>
                  <Button onClick={() => handleProcess("approved")} disabled={isProcessing} className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm">
                    {isProcessing ? <Loader2 className="mr-1 h-3 w-3 animate-spin" /> : <CheckCircle2 className="mr-1 h-3 w-3" />}
                    승인
                  </Button>
                </>
              )}
            </DialogFooter>
          </>
        )}
      </DialogContent>
    </Dialog>
  );
};

export default ApprovalDetailModal;