"use client";

import Link from "next/link";
import { useEffect, useMemo, useRef, useState } from "react";
import useSWR from "swr";
import { toast } from "sonner";
import {
  ArrowLeft,
  Image as ImageIcon,
  Loader2,
  Save,
  Sparkles,
  Upload,
} from "lucide-react";
import {
  defaultAgentWorkflowUiConfig,
  normalizeAgentWorkflowUiConfig,
} from "@/lib/agents/workflow-ui-config";
import { fetchUploadWithRetry } from "@/lib/client/upload-with-retry";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Textarea } from "@/components/ui/textarea";
import { Switch } from "@/components/ui/switch";
import type { AgentWorkflowUiConfig } from "@/types/agent";

const fetcher = (url: string) => fetch(url, { cache: "no-store" }).then((res) => res.json());

export function AgentWorkflowSettingsClient() {
  const { data, isLoading, mutate } = useSWR<{
    agentWorkflowUiConfig?: AgentWorkflowUiConfig;
  }>("/api/site-settings", fetcher);
  const [config, setConfig] = useState<AgentWorkflowUiConfig>(defaultAgentWorkflowUiConfig);
  const [isSaving, setIsSaving] = useState(false);
  const [uploadingKey, setUploadingKey] = useState<string | null>(null);
  const fileInputRefs = useRef<Record<string, HTMLInputElement | null>>({});

  useEffect(() => {
    if (!data) return;
    setConfig(normalizeAgentWorkflowUiConfig(data.agentWorkflowUiConfig));
  }, [data]);

  const sortedSteps = useMemo(
    () => [...config.steps].sort((left, right) => left.sortOrder - right.sortOrder),
    [config.steps]
  );

  const updateStep = (
    stepKey: string,
    updater: (step: AgentWorkflowUiConfig["steps"][number]) => AgentWorkflowUiConfig["steps"][number]
  ) => {
    setConfig((prev) => ({
      ...prev,
      steps: prev.steps.map((step) => (step.key === stepKey ? updater(step) : step)),
    }));
  };

  const updateOption = (
    stepKey: string,
    optionKey: string,
    updater: (
      option: AgentWorkflowUiConfig["steps"][number]["options"][number]
    ) => AgentWorkflowUiConfig["steps"][number]["options"][number]
  ) => {
    updateStep(stepKey, (step) => ({
      ...step,
      options: step.options.map((option) =>
        option.key === optionKey ? updater(option) : option
      ),
    }));
  };

  const handleUploadPreview = async (stepKey: string, optionKey: string, file: File) => {
    if (!file.type.startsWith("image/")) {
      toast.error("请上传图片文件");
      return;
    }

    const refKey = `${stepKey}:${optionKey}`;
    try {
      setUploadingKey(refKey);
      const formData = new FormData();
      formData.append("file", file);

      const response = await fetchUploadWithRetry(formData);
      const result = await response.json();

      if (!response.ok || !result?.url) {
        throw new Error(result?.error || "上传失败");
      }

      updateOption(stepKey, optionKey, (option) => ({
        ...option,
        previewImageUrl: result.url,
      }));
      toast.success("预览图上传成功");
    } catch (error) {
      toast.error(error instanceof Error ? error.message : "预览图上传失败");
    } finally {
      setUploadingKey(null);
    }
  };

  const handleSave = async () => {
    try {
      setIsSaving(true);
      const response = await fetch("/api/site-settings", {
        method: "PUT",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          agentWorkflowUiConfig: config,
        }),
      });

      if (!response.ok) {
        throw new Error("保存失败");
      }

      toast.success("智能体工作流配置已保存");
      await mutate();
    } catch (error) {
      toast.error(error instanceof Error ? error.message : "保存失败");
    } finally {
      setIsSaving(false);
    }
  };

  return (
    <div className="container mx-auto space-y-6 p-6">
      <div className="flex flex-wrap items-center justify-between gap-3">
        <div className="space-y-1">
          <div className="flex items-center gap-2 text-sm text-muted-foreground">
            <Sparkles className="h-4 w-4" />
            智能体配置中心
          </div>
          <h1 className="text-2xl font-semibold">智能体工作流配置</h1>
          <p className="text-sm text-muted-foreground">
            单独维护智能体页面左侧每个环节的功能按钮名称、说明、Prompt 片段和预览图。
          </p>
        </div>

        <div className="flex items-center gap-2">
          <Button asChild variant="outline">
            <Link href="/settings">
              <ArrowLeft className="mr-2 h-4 w-4" />
              返回设置
            </Link>
          </Button>
          <Button onClick={handleSave} disabled={isSaving}>
            {isSaving ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Save className="mr-2 h-4 w-4" />}
            保存配置
          </Button>
        </div>
      </div>

      <Card>
        <CardHeader>
          <CardTitle>功能说明</CardTitle>
          <CardDescription>
            这里配置的是智能体工作流页面的功能卡片。网站设置页只保留入口，不再承载这些详细配置。
          </CardDescription>
        </CardHeader>
      </Card>

      {isLoading ? (
        <Card>
          <CardContent className="flex items-center justify-center py-12">
            <Loader2 className="h-5 w-5 animate-spin text-muted-foreground" />
          </CardContent>
        </Card>
      ) : (
        <div className="space-y-5">
          <Card>
            <CardHeader>
              <CardTitle>基础下拉配置</CardTitle>
              <CardDescription>
                工作流左侧“品牌 / 店铺”采用后台配置的候选列表，前台支持输入关键字匹配下拉选择。
              </CardDescription>
            </CardHeader>
            <CardContent className="grid grid-cols-1 gap-4 md:grid-cols-2">
              <div className="space-y-2">
                <Label>品牌列表</Label>
                <Textarea
                  value={(config.inputOptions?.brands || []).join("\n")}
                  onChange={(event) =>
                    setConfig((prev) => ({
                      ...prev,
                      inputOptions: {
                        brands: event.target.value
                          .split("\n")
                          .map((item) => item.trim())
                          .filter(Boolean),
                        stores: prev.inputOptions?.stores || [],
                      },
                    }))
                  }
                  rows={10}
                  placeholder={"例如：\n宜家\n顾家家居\n林氏家居"}
                />
              </div>
              <div className="space-y-2">
                <Label>店铺列表</Label>
                <Textarea
                  value={(config.inputOptions?.stores || []).join("\n")}
                  onChange={(event) =>
                    setConfig((prev) => ({
                      ...prev,
                      inputOptions: {
                        brands: prev.inputOptions?.brands || [],
                        stores: event.target.value
                          .split("\n")
                          .map((item) => item.trim())
                          .filter(Boolean),
                      },
                    }))
                  }
                  rows={10}
                  placeholder={"例如：\n天猫旗舰店\n京东自营店\n抖音官方店"}
                />
              </div>
            </CardContent>
          </Card>

          {sortedSteps.map((step) => (
            <Card key={step.key}>
              <CardHeader>
                <div className="flex items-start justify-between gap-4">
                  <div className="flex-1 space-y-3">
                    <div className="space-y-2">
                      <Label>步骤标题</Label>
                      <Input
                        value={step.title}
                        onChange={(event) =>
                          updateStep(step.key, (current) => ({
                            ...current,
                            title: event.target.value,
                          }))
                        }
                        placeholder="步骤标题"
                      />
                    </div>
                    <div className="space-y-2">
                      <Label>步骤说明</Label>
                      <Textarea
                        value={step.description || ""}
                        onChange={(event) =>
                          updateStep(step.key, (current) => ({
                            ...current,
                            description: event.target.value,
                          }))
                        }
                        rows={2}
                        placeholder="步骤说明"
                      />
                    </div>
                  </div>

                  <div className="flex items-center gap-2 pt-8">
                    <Label htmlFor={`workflow-step-${step.key}`}>启用</Label>
                    <Switch
                      id={`workflow-step-${step.key}`}
                      checked={step.enabled}
                      onCheckedChange={(checked) =>
                        updateStep(step.key, (current) => ({
                          ...current,
                          enabled: checked,
                        }))
                      }
                    />
                  </div>
                </div>
              </CardHeader>

              <CardContent>
                <div className="grid grid-cols-1 gap-4 xl:grid-cols-2">
                  {step.options
                    .slice()
                    .sort((left, right) => left.sortOrder - right.sortOrder)
                    .map((option) => {
                      const refKey = `${step.key}:${option.key}`;
                      const isUploading = uploadingKey === refKey;

                      return (
                        <div key={option.key} className="rounded-xl border bg-muted/20 p-4 space-y-4">
                          <div className="flex items-start justify-between gap-4">
                            <div>
                              <div className="text-sm font-medium">{option.key}</div>
                              <div className="mt-1 text-xs text-muted-foreground">
                                配置按钮名称与预览图
                              </div>
                            </div>
                            <div className="flex items-center gap-2">
                              <Label
                                htmlFor={`workflow-option-${step.key}-${option.key}`}
                                className="text-xs text-muted-foreground"
                              >
                                启用
                              </Label>
                              <Switch
                                id={`workflow-option-${step.key}-${option.key}`}
                                checked={option.enabled}
                                onCheckedChange={(checked) =>
                                  updateOption(step.key, option.key, (current) => ({
                                    ...current,
                                    enabled: checked,
                                  }))
                                }
                              />
                            </div>
                          </div>

                          <div className="grid grid-cols-[148px_minmax(0,1fr)] gap-4">
                            <div className="space-y-3">
                              <div className="flex h-[120px] items-center justify-center overflow-hidden rounded-xl border bg-background">
                                {option.previewImageUrl ? (
                                  <img
                                    src={option.previewImageUrl}
                                    alt={option.buttonName}
                                    className="h-full w-full object-cover"
                                  />
                                ) : (
                                  <div className="px-3 text-center text-xs text-muted-foreground">
                                    <ImageIcon className="mx-auto mb-2 h-5 w-5 opacity-60" />
                                    暂无预览图
                                  </div>
                                )}
                              </div>

                              <input
                                ref={(element) => {
                                  fileInputRefs.current[refKey] = element;
                                }}
                                type="file"
                                accept="image/*"
                                className="hidden"
                                onChange={(event) => {
                                  const file = event.target.files?.[0];
                                  if (!file) return;
                                  void handleUploadPreview(step.key, option.key, file);
                                  event.target.value = "";
                                }}
                              />

                              <div className="grid grid-cols-1 gap-2">
                                <Button
                                  type="button"
                                  variant="outline"
                                  size="sm"
                                  disabled={isUploading}
                                  onClick={() => fileInputRefs.current[refKey]?.click()}
                                >
                                  {isUploading ? (
                                    <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                                  ) : (
                                    <Upload className="mr-2 h-4 w-4" />
                                  )}
                                  上传图片
                                </Button>
                                <Button
                                  type="button"
                                  variant="ghost"
                                  size="sm"
                                  onClick={() =>
                                    updateOption(step.key, option.key, (current) => ({
                                      ...current,
                                      previewImageUrl: "",
                                    }))
                                  }
                                >
                                  清空图片
                                </Button>
                              </div>
                            </div>

                            <div className="space-y-3">
                              <div className="space-y-2">
                                <Label>按钮名称</Label>
                                <Input
                                  value={option.buttonName}
                                  onChange={(event) =>
                                    updateOption(step.key, option.key, (current) => ({
                                      ...current,
                                      buttonName: event.target.value,
                                    }))
                                  }
                                  placeholder="按钮名称"
                                />
                              </div>
                              <div className="space-y-2">
                                <Label>说明文案</Label>
                                <Textarea
                                  value={option.description || ""}
                                  onChange={(event) =>
                                    updateOption(step.key, option.key, (current) => ({
                                      ...current,
                                      description: event.target.value,
                                    }))
                                  }
                                  rows={2}
                                  placeholder="说明文案"
                                />
                              </div>
                              <div className="space-y-2">
                                <Label>预览图链接</Label>
                                <Input
                                  value={option.previewImageUrl || ""}
                                  onChange={(event) =>
                                    updateOption(step.key, option.key, (current) => ({
                                      ...current,
                                      previewImageUrl: event.target.value,
                                    }))
                                  }
                                  placeholder="https://..."
                                />
                              </div>
                              <div className="space-y-2">
                                <Label>Prompt 片段</Label>
                                <Textarea
                                  value={option.promptFragment || ""}
                                  onChange={(event) =>
                                    updateOption(step.key, option.key, (current) => ({
                                      ...current,
                                      promptFragment: event.target.value,
                                    }))
                                  }
                                  rows={3}
                                  placeholder="用于执行时注入的提示片段"
                                />
                              </div>
                            </div>
                          </div>
                        </div>
                      );
                    })}
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
      )}
    </div>
  );
}