import React, { useEffect, useState } from "react";
import { ArrowUpCircle, Check, Loader2, RefreshCcw } from "lucide-react";
import AppLogo from "./AppLogo";
import AppWordmark from "./AppWordmark";
import { Button } from "./ui/button";
import { useApplicationBackend } from "../application/state/useApplicationBackend";
import type { UpdateState, UseUpdateCheckResult } from "../application/state/useUpdateCheck";
import { useI18n } from "../application/i18n/I18nProvider";
import { SettingsAnchor, SettingsTabContent } from "./settings/settings-ui";
import { toast } from "./ui/toast";
import { useStoredString } from "../application/state/useStoredString";
import { STORAGE_KEY_MONITORING_DASHBOARD_TITLE, STORAGE_KEY_REPORT_PRODUCT_NAME } from "../infrastructure/config/storageKeys";

type AppInfo = {
  name: string;
  version: string;
  platform?: string;
};

interface SettingsApplicationTabProps {
  updateState: UpdateState;
  checkNow: UseUpdateCheckResult['checkNow'];
  openReleasePage: UseUpdateCheckResult['openReleasePage'];
  installUpdate: UseUpdateCheckResult['installUpdate'];
  startDownload: UseUpdateCheckResult['startDownload'];
  isUpdateDemoMode: boolean;
  productName: string;
  setProductName: (value: string) => void;
}

export default function SettingsApplicationTab({ updateState, checkNow, openReleasePage, installUpdate, startDownload, isUpdateDemoMode, productName, setProductName }: SettingsApplicationTabProps) {
  const { t } = useI18n();
  const { openExternal, getApplicationInfo } = useApplicationBackend();
  const [appInfo, setAppInfo] = useState<AppInfo>({ name: "Netcatty", version: "" });
  const [lastCheckResult, setLastCheckResult] = useState<'none' | 'available' | 'upToDate'>('none');
  const [monitoringTitle, setMonitoringTitle] = useStoredString<string>(STORAGE_KEY_MONITORING_DASHBOARD_TITLE, '云启Net智能巡检监测系统');
  const [reportProductName, setReportProductName] = useStoredString<string>(STORAGE_KEY_REPORT_PRODUCT_NAME, '');

  useEffect(() => {
    let cancelled = false;
    const load = async () => {
      try {
        const info = await getApplicationInfo();
        if (!cancelled && info?.name && typeof info?.version === "string") {
          setAppInfo(info);
        }
      } catch {
        // Ignore: running in browser/dev without Electron bridge
      }
    };
    void load();
    return () => {
      cancelled = true;
    };
  }, [getApplicationInfo]);

  const handleOpenExternal = async (url: string) => {
    try {
      await openExternal(url);
    } catch (err) {
      console.warn("[SettingsApplicationTab] openExternal failed:", err);
      toast.error(
        t("settings.application.openExternal.failedBody"),
        t("settings.application.openExternal.failedTitle"),
      );
    }
  };

  const handleCheckForUpdates = async () => {
    // In demo mode, allow checking even for dev builds
    if (!isUpdateDemoMode && (!appInfo.version || appInfo.version === '0.0.0')) {
      // Dev build - just open releases page
      openReleasePage();
      return;
    }

    setLastCheckResult('none');

    const result = await checkNow();

    if (result?.hasUpdate && result.latestRelease) {
      setLastCheckResult('available');
      toast.info(
        t('update.available.message', { version: result.latestRelease.version }),
        t('update.available.title')
      );
      // Don't auto-open the release page here — checkNow() already triggers
      // electron-updater on supported platforms, and the Settings > System tab
      // shows a "Manual Download" link on unsupported platforms.
    } else if (result) {
      setLastCheckResult('upToDate');
      toast.success(
        t('update.upToDate.message', { version: appInfo.version }),
        t('update.upToDate.title')
      );
    }

    // Reset the result after 3 seconds
    setTimeout(() => setLastCheckResult('none'), 3000);
  };

  return (
    <SettingsTabContent value="application">
      <div className="flex flex-col lg:flex-row gap-10 lg:gap-14">
        <div className="lg:w-[320px] shrink-0">
          <div className="flex items-center gap-4">
            <AppLogo className="w-16 h-16" />
            <div>
              <AppWordmark accessibleLabel={productName} text={productName} className="h-8 w-auto text-foreground" />
              <div className="flex items-center gap-2 mt-1">
                <span className="text-sm text-muted-foreground">
                  {appInfo.version ? appInfo.version : " "}
                </span>
                {/* Update badge - reflects auto-download state */}
                {updateState.latestRelease && (updateState.hasUpdate || updateState.autoDownloadStatus === 'downloading' || updateState.autoDownloadStatus === 'ready') && (
                  <button
                    onClick={() => updateState.autoDownloadStatus === 'ready' ? installUpdate() : updateState.autoDownloadStatus === 'downloading' ? undefined : startDownload()}
                    className={cn(
                      "inline-flex items-center gap-1 px-2 py-0.5 rounded-full text-xs font-medium",
                      updateState.autoDownloadStatus === 'ready'
                        ? "bg-green-100 dark:bg-green-900 text-green-700 dark:text-green-300 hover:bg-green-200 dark:hover:bg-green-800"
                        : "bg-blue-100 dark:bg-blue-900 text-blue-700 dark:text-blue-300 hover:bg-blue-200 dark:hover:bg-blue-800",
                      "transition-colors cursor-pointer"
                    )}
                  >
                    <ArrowUpCircle size={12} />
                    v{updateState.latestRelease.version}{' '}
                    {updateState.autoDownloadStatus === 'ready'
                      ? t('update.restartNow')
                      : updateState.autoDownloadStatus === 'downloading'
                        ? `${updateState.downloadPercent}%`
                        : t('update.downloadNow')}
                  </button>
                )}
              </div>
            </div>
          </div>

          {/* 检查更新按钮已隐藏 */}

          {/* 产品名称配置 —— 本地 state 缓冲输入，blur/Enter 才提交，避免每次按键都触发全局持久化 + IPC 导致闪动 */}
          <SettingsAnchor anchorId="application-product-name" className="mt-6">
            <ProductNameInput value={productName} onChange={setProductName} />
          </SettingsAnchor>

          {/* 大屏名称配置 —— 同样用本地 state 缓冲，避免每次按键都触发 localStorage 写入和事件广播 */}
          <SettingsAnchor anchorId="application-monitoring-title" className="mt-6">
            <SettingsInputBuffered
              value={monitoringTitle}
              placeholder="云启Net智能巡检监测系统"
              label="大屏标题"
              hint="3D 拓扑监控大屏页面顶部显示的系统标题（回车或失焦后生效）"
              onCommit={(v) => {
                setMonitoringTitle(v);
                try { window.dispatchEvent(new CustomEvent('monitoringTitleChanged')); } catch {}
              }}
            />
          </SettingsAnchor>

          {/* 报告产品名配置 —— 专门用于 PDF 巡检报告标题 */}
          <SettingsAnchor anchorId="application-report-product-name" className="mt-6">
            <SettingsInputBuffered
              value={reportProductName}
              placeholder={productName}
              label="报告产品名"
              hint="巡检报告 PDF 首页显示的产品名称（回车或失焦后生效）。留空则使用上方「产品名称」。"
              trim
              onCommit={(v) => setReportProductName(v)}
            />
          </SettingsAnchor>
        </div>
      </div>

    </SettingsTabContent>
  );
}

/**
 * 带本地 state 缓冲的设置输入框。输入过程只更新本地 draft，
 * 回车或失焦才调用 onCommit，避免每次按键都触发全局持久化 + IPC 导致闪动。
 */
function SettingsInputBuffered({
  value,
  onCommit,
  placeholder,
  label,
  hint,
  trim = false,
}: {
  value: string;
  onCommit: (v: string) => void;
  placeholder?: string;
  label: string;
  hint?: string;
  trim?: boolean;
}) {
  const [draft, setDraft] = useState(value);

  useEffect(() => {
    setDraft(value);
  }, [value]);

  const commit = () => {
    const next = trim ? draft.trim() : draft;
    if (next !== value) onCommit(next);
  };

  return (
    <div className="space-y-1.5">
      <label className="text-sm font-medium text-foreground">{label}</label>
      <input
        type="text"
        value={draft}
        onChange={(e) => setDraft(e.target.value)}
        onBlur={commit}
        onKeyDown={(e) => {
          if (e.key === "Enter") {
            e.preventDefault();
            commit();
            (e.target as HTMLInputElement).blur();
          } else if (e.key === "Escape") {
            setDraft(value);
            (e.target as HTMLInputElement).blur();
          }
        }}
        placeholder={placeholder}
        className="w-full px-3 py-2 rounded-lg border border-input bg-background text-sm text-foreground focus:outline-none focus:ring-2 focus:ring-ring"
      />
      {hint && <p className="text-xs text-muted-foreground">{hint}</p>}
    </div>
  );
}

/**
 * 产品名称输入框 —— SettingsInputBuffered + trim 空白。
 */
function ProductNameInput({ value, onChange }: { value: string; onChange: (v: string) => void }) {
  return (
    <SettingsInputBuffered
      value={value}
      onCommit={onChange}
      placeholder="云启智能运维平台"
      label="产品名称"
      hint="用于窗口标题、侧边栏和设置页面（回车或失焦后生效）"
      trim
    />
  );
}