import { useEffect, useRef, useState } from "react";
import { api, AppInfo } from "../api";

export default function SettingsPage() {
  const [info, setInfo] = useState<AppInfo | null>(null);
  const [settings, setSettings] = useState<Record<string, string>>({});
  const [recommendDirDraft, setRecommendDirDraft] = useState("");
  const [uploadMsg, setUploadMsg] = useState<string | null>(null);
  const uploadInputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    api.appInfo().then(setInfo);
    api.settingsGet().then(setSettings);
  }, []);

  useEffect(() => {
    setRecommendDirDraft(settings.recommend_dir ?? "");
  }, [settings.recommend_dir]);

  async function handleSave(key: string, value: string) {
    await api.settingsSet(key, value);
    setSettings((prev) => ({ ...prev, [key]: value }));
  }

  async function handleUpload(file: File) {
    setUploadMsg(null);
    try {
      const text = await file.text();
      await api.importRecommendations(file.name, text);
      setUploadMsg(`已导入 ${file.name}`);
    } catch (e) {
      setUploadMsg(String(e));
    } finally {
      if (uploadInputRef.current) uploadInputRef.current.value = "";
    }
  }

  return (
    <div className="h-full overflow-auto p-6">
      <h1 className="text-xl font-semibold">设置</h1>
      <p className="mt-1 text-sm text-slate-400">运行路径与引擎配置</p>

      <div className="mt-6 max-w-xl space-y-4">
        <div className="rounded-xl border border-border bg-panel p-5">
          <div className="text-xs uppercase text-slate-400">关于</div>
          <div className="mt-2 space-y-1 text-sm">
            <div>
              版本：<span className="text-slate-300">{info?.version}</span>（{info?.platform}）
            </div>
            <div>
              数据目录：<span className="text-slate-300">{info?.db_path}</span>
            </div>
            <div className="flex items-center gap-2">
              <span>
                日志目录：<span className="text-slate-300">{info?.logs_dir}</span>
              </span>
              {info?.logs_dir ? (
                <button
                  className="text-xs text-slate-400 hover:text-slate-200"
                  onClick={() => api.openPath(info.logs_dir!)}
                >
                  打开
                </button>
              ) : null}
            </div>
            <div>
              引擎可用：
              {info?.engine_exists ? (
                <span className="text-emerald-400">是</span>
              ) : (
                <span className="text-red-400">否（请配置 llama-server 路径）</span>
              )}
            </div>
          </div>
        </div>

        <div className="rounded-xl border border-border bg-panel p-5">
          <div className="text-xs uppercase text-slate-400">引擎与路径</div>
          <div className="mt-3 space-y-3">
            <SettingInput
              label="模型目录"
              value={settings.model_dir ?? ""}
              onSave={(v) => handleSave("model_dir", v)}
            />
            <SettingInput
              label="llama-server 路径（llama-server-cpu/cuda/vulkan.exe）"
              value={settings.engine_bin ?? ""}
              onSave={(v) => handleSave("engine_bin", v)}
            />
            <SettingInput
              label="模型下载源（hf-mirror.com / huggingface.co / modelscope.cn）"
              value={settings.hf_endpoint ?? ""}
              onSave={(v) => handleSave("hf_endpoint", v)}
            />
            <SettingInput
              label="默认后端（auto / cpu / cuda / vulkan）"
              value={settings.backend ?? ""}
              onSave={(v) => handleSave("backend", v)}
            />
            <SettingInput
              label="上传图片/文件大小上限（MB）"
              value={settings.upload_max_mb ?? "10"}
              onSave={(v) => handleSave("upload_max_mb", v)}
            />
          </div>
        </div>

        <div className="rounded-xl border border-border bg-panel p-5">
          <div className="text-xs uppercase text-slate-400">对话</div>
          <div className="mt-3 flex items-center justify-between rounded-lg border border-border bg-panel-2 px-3 py-2.5">
            <div>
              <div className="text-sm">自动生成对话标题</div>
              <div className="mt-0.5 text-xs text-slate-400">
                首次对话生成回复后，自动为会话生成标题并覆盖
              </div>
            </div>
            <Toggle
              checked={settings.auto_title !== "false"}
              onChange={(checked) =>
                handleSave("auto_title", checked ? "true" : "false")
              }
            />
          </div>
          <div className="mt-3 flex items-center justify-between rounded-lg border border-border bg-panel-2 px-3 py-2.5">
            <div>
              <div className="text-sm">自动预测用户接下来说的话</div>
              <div className="mt-0.5 text-xs text-slate-400">
                大模型回答完成后自动预测几条用户可能要说的话，点击即可填入输入框
              </div>
            </div>
            <Toggle
              checked={settings.suggest_enabled !== "false"}
              onChange={(checked) =>
                handleSave("suggest_enabled", checked ? "true" : "false")
              }
            />
          </div>
          <div className="mt-3">
            <SettingInput
              label="预测条数（1-5）"
              value={settings.suggest_count ?? "3"}
              onSave={(v) => {
                const n = Math.max(1, Math.min(5, Number(v) || 3));
                handleSave("suggest_count", String(n));
              }}
            />
          </div>
        </div>

        <div className="rounded-xl border border-border bg-panel p-5">
          <div className="text-xs uppercase text-slate-400">推荐模型列表</div>
          <div className="mt-3 space-y-3">
            <div>
              <span className="text-xs text-slate-400">
                JSON 文件目录（软件自带默认列表，上传的 JSON 也会保存到这里）
              </span>
              <div className="mt-1 flex gap-2">
                <input
                  className="input flex-1"
                  value={recommendDirDraft}
                  onChange={(e) => setRecommendDirDraft(e.target.value)}
                />
                <button
                  className="btn-secondary"
                  onClick={() => handleSave("recommend_dir", recommendDirDraft)}
                  disabled={recommendDirDraft === settings.recommend_dir}
                >
                  保存
                </button>
                <button
                  className="btn-secondary"
                  onClick={() =>
                    recommendDirDraft && api.openPath(recommendDirDraft)
                  }
                >
                  打开
                </button>
              </div>
            </div>
            <div className="flex items-center gap-2">
              <input
                ref={uploadInputRef}
                type="file"
                accept=".json"
                className="hidden"
                onChange={(e) => {
                  if (e.target.files && e.target.files.length > 0) {
                    handleUpload(e.target.files[0]);
                  }
                }}
              />
              <button
                className="btn-secondary"
                onClick={() => uploadInputRef.current?.click()}
              >
                上传 JSON
              </button>
              <span className="text-xs text-slate-500">
                可上传多个推荐列表 JSON，同名文件将覆盖
              </span>
            </div>
            {uploadMsg ? (
              <div className="text-xs text-slate-400">{uploadMsg}</div>
            ) : null}
            <div className="text-xs text-slate-500">JSON 格式示例：</div>
            <pre className="mt-1 overflow-x-auto rounded-lg bg-panel-2 p-2 text-[11px] leading-relaxed text-slate-400">
              {`{
  "models": [
    {
      "id": "Qwen/Qwen2.5-7B-Instruct-GGUF",
      "source": "huggingface",
      "params": "7B",
      "architecture": "dense",
      "vision": false,
      "files": [
        {
          "path": "xx-q4_k_m.gguf",
          "quant": "Q4_K_M",
          "size_gb": 4.68,
          "links": [
            "https://hf-mirror.com/Qwen/Qwen2.5-7B-Instruct-GGUF/resolve/main/xx-q4_k_m.gguf",
            "https://modelscope.cn/models/Qwen/Qwen2.5-7B-Instruct-GGUF/resolve/master/xx-q4_k_m.gguf"
          ]
        }
      ]
    }
  ]
}`}
            </pre>
          </div>
        </div>

        <div className="text-xs text-slate-500">
          获取 llama-server：运行 <code className="text-slate-300">scripts/fetch-llama.ps1</code>{" "}
          自动下载预编译引擎，或手动指定已下载的 exe 路径。
        </div>
      </div>
    </div>
  );
}

function Toggle({
  checked,
  onChange,
}: {
  checked: boolean;
  onChange: (checked: boolean) => void;
}) {
  return (
    <button
      type="button"
      role="switch"
      aria-checked={checked}
      onClick={() => onChange(!checked)}
      className={`relative h-6 w-11 shrink-0 rounded-full transition-colors ${
        checked ? "bg-accent" : "bg-panel-2"
      }`}
    >
      <span
        className={`absolute top-0.5 h-5 w-5 rounded-full bg-white shadow transition-all ${
          checked ? "left-[22px]" : "left-0.5"
        }`}
      />
    </button>
  );
}

function SettingInput({
  label,
  value,
  onSave,
}: {
  label: string;
  value: string;
  onSave: (v: string) => void;
}) {
  const [draft, setDraft] = useState(value);
  useEffect(() => setDraft(value), [value]);
  return (
    <label className="block text-sm">
      <span className="text-xs text-slate-400">{label}</span>
      <div className="mt-1 flex gap-2">
        <input className="input flex-1" value={draft} onChange={(e) => setDraft(e.target.value)} />
        <button
          className="btn-secondary"
          onClick={() => onSave(draft)}
          disabled={draft === value}
        >
          保存
        </button>
      </div>
    </label>
  );
}