"use client";

import { useEffect, useState } from "react";
import { useRouter } from "next/navigation";
import { formatDistanceToNow } from "date-fns";
import { zhCN } from "date-fns/locale";
import { Trash2, FileImage, Loader2, Plus } from "lucide-react";
import { Button } from "@/components/ui/button";
import { ScrollArea } from "@/components/ui/scroll-area";
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogDescription,
} from "@/components/ui/dialog";
import { canvasService } from "@/services/canvas";
import { toast } from "sonner";
import { cn } from "@/lib/utils";
import type { CanvasProject } from "@/types/canvas";

interface CanvasFileListProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  currentId: string;
}

export function CanvasFileList({ open, onOpenChange, currentId }: CanvasFileListProps) {
  const router = useRouter();
  const [projects, setProjects] = useState<CanvasProject[]>([]);
  const [isLoading, setIsLoading] = useState(false);

  // 加载项目列表
  const loadProjects = async () => {
    setIsLoading(true);
    const result = await canvasService.getProjects();
    if (result.success && result.data) {
      // 按更新时间降序排序
      const sorted = result.data.sort((a, b) => 
        new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime()
      );
      setProjects(sorted);
    }
    setIsLoading(false);
  };

  useEffect(() => {
    if (open) {
      loadProjects();
    }
  }, [open]);

  // 创建新画布
  const handleCreateNew = async () => {
    // 生成一个新 ID 并跳转，具体的创建逻辑由页面组件处理
    const newId = crypto.randomUUID();
    router.push(`/canvas/${newId}`);
    onOpenChange(false);
  };

  // 切换画布
  const handleSwitch = (id: string) => {
    if (id === currentId) {
      onOpenChange(false);
      return;
    }
    // 先导航，再关闭弹窗（使用 setTimeout 确保导航生效）
    const targetUrl = `/canvas/${id}`;
    onOpenChange(false);
    // 使用 setTimeout 确保在 React 状态更新完成后再导航
    setTimeout(() => {
      window.location.assign(targetUrl);
    }, 100);
  };

  // 删除画布
  const handleDelete = async (e: React.MouseEvent, id: string) => {
    e.stopPropagation();
    if (!confirm("确定要删除这个画布吗？")) return;

    const result = await canvasService.deleteProject(id);
    if (result.success) {
      setProjects(prev => prev.filter(p => p.id !== id));
      toast.success("删除成功");
      
      // 如果删除的是当前画布，跳转到列表第一个或首页
      if (id === currentId) {
        const next = projects.find(p => p.id !== id);
        if (next) {
          router.push(`/canvas/${next.id}`);
        } else {
          router.push('/canvas'); // 或者 handleCreateNew()
        }
      }
    } else {
      toast.error("删除失败");
    }
  };

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="max-w-md max-h-[80vh] flex flex-col p-0 gap-0 overflow-hidden bg-background/95 backdrop-blur-md">
        <DialogHeader className="p-4 border-b">
          <div className="flex items-center justify-between">
            <DialogTitle>已生成文件列表</DialogTitle>
            <Button size="sm" onClick={handleCreateNew} className="h-8">
              <Plus className="h-4 w-4 mr-1" />
              新建画布
            </Button>
          </div>
          <DialogDescription className="hidden">画布列表</DialogDescription>
        </DialogHeader>

        <ScrollArea className="flex-1 p-4">
          {isLoading ? (
            <div className="flex justify-center py-8">
              <Loader2 className="h-6 w-6 animate-spin text-muted-foreground" />
            </div>
          ) : projects.length === 0 ? (
            <div className="text-center py-12 text-muted-foreground">
              <FileImage className="h-12 w-12 mx-auto mb-3 opacity-20" />
              <p>暂无画布历史</p>
            </div>
          ) : (
            <div className="space-y-2">
              {projects.map((project) => (
                <div
                  key={project.id}
                  onClick={() => handleSwitch(project.id)}
                  className={cn(
                    "flex items-center gap-3 p-2 rounded-xl cursor-pointer transition-all border",
                    "hover:bg-muted/50 hover:shadow-sm",
                    project.id === currentId 
                      ? "bg-primary/5 border-primary/20 ring-1 ring-primary/10" 
                      : "bg-card border-transparent"
                  )}
                >
                  {/* 缩略图 */}
                  <div className="h-12 w-12 rounded-lg bg-muted/50 overflow-hidden shrink-0 border">
                    {project.thumbnail ? (
                      <img 
                        src={project.thumbnail} 
                        alt={project.title}
                        className="h-full w-full object-cover"
                      />
                    ) : (
                      <div className="h-full w-full flex items-center justify-center">
                        <FileImage className="h-5 w-5 text-muted-foreground/40" />
                      </div>
                    )}
                  </div>

                  {/* 信息 */}
                  <div className="flex-1 min-w-0">
                    <h4 className={cn(
                      "font-medium text-sm truncate",
                      project.id === currentId && "text-primary"
                    )}>
                      {project.title || "未命名画布"}
                    </h4>
                    <p className="text-xs text-muted-foreground">
                      {formatDistanceToNow(new Date(project.updatedAt), { 
                        addSuffix: true, 
                        locale: zhCN 
                      })}
                    </p>
                  </div>

                  {/* 操作 */}
                  <Button
                    variant="ghost"
                    size="icon"
                    className="h-8 w-8 text-muted-foreground hover:text-destructive opacity-0 group-hover:opacity-100"
                    onClick={(e) => handleDelete(e, project.id)}
                  >
                    <Trash2 className="h-4 w-4" />
                  </Button>
                </div>
              ))}
              
              <div className="text-center py-4 text-xs text-muted-foreground/50">
                到底了
              </div>
            </div>
          )}
        </ScrollArea>
      </DialogContent>
    </Dialog>
  );
}