import { useEffect, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { Button, Col, Input, InputNumber, Row, Select, Space, Switch, Typography, message } from 'antd';
import { HttpUtil } from '@/utils';
import { useNodesQuery } from '@/api/queries/useNodesQuery';
import ProbeMetaSection from '../nodes/ProbeMetaSection';
import ProbeTasksPanel from './ProbeTasksPanel';

// V2.0.1 probe batch: the dedicated probe settings page. Everything
// probe-related that used to be scattered — the public-page block
// (public-page tab), the latency task manager (nodes-page modal)
// and the per-node probe metadata (node edit dialog) — is gathered
// here and lives nowhere else. Like the surfaces it replaces, each
// block loads and saves through its own endpoints and takes effect
// immediately (no panel save, no restart).
interface ProbeSettingsWire {
  publicPage: boolean;
  siteName: string;
  site: string;
  githubProxy: string;
  retentionDays: number;
  fastIntervalSec: number;
  favicon: string;
  touchIcon: string;
}

const JSON_HEADERS = { headers: { 'Content-Type': 'application/json' } };
const MAX_ICON_BYTES = 20 * 1024;

function readAsDataURL(blob: Blob): Promise<string> {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => resolve(String(reader.result));
    reader.onerror = () => reject(reader.error);
    reader.readAsDataURL(blob);
  });
}

// fileToIconDataURL fits a chosen image into the hub's 20 KiB site
// icon budget (moved unchanged from the public-page tab): small
// files pass through; a large raster is scaled down until it fits;
// a large SVG cannot be scaled and is refused here.
async function fileToIconDataURL(file: File): Promise<string> {
  if (file.size <= MAX_ICON_BYTES) return readAsDataURL(file);
  if (file.type === 'image/svg+xml' || file.type === 'image/x-icon' || file.type === 'image/gif') {
    throw new Error('tooLarge');
  }
  const bitmap = await createImageBitmap(file);
  try {
    for (const size of [256, 180, 128, 96, 64]) {
      const scale = Math.min(1, size / Math.max(bitmap.width, bitmap.height));
      const canvas = document.createElement('canvas');
      canvas.width = Math.max(1, Math.round(bitmap.width * scale));
      canvas.height = Math.max(1, Math.round(bitmap.height * scale));
      const ctx = canvas.getContext('2d');
      if (!ctx) break;
      ctx.drawImage(bitmap, 0, 0, canvas.width, canvas.height);
      const blob = await new Promise<Blob | null>((resolve) => canvas.toBlob(resolve, 'image/png'));
      if (blob && blob.size <= MAX_ICON_BYTES) return readAsDataURL(blob);
    }
  } finally {
    bitmap.close();
  }
  throw new Error('tooLarge');
}

export default function ProbeSettingsTab() {
  const { t } = useTranslation();
  const [messageApi, messageContextHolder] = message.useMessage();
  const [settings, setSettings] = useState<ProbeSettingsWire | null>(null);
  const [saving, setSaving] = useState(false);
  const [metaNodeId, setMetaNodeId] = useState<number | undefined>(undefined);
  const faviconRef = useRef<HTMLInputElement>(null);
  const touchRef = useRef<HTMLInputElement>(null);
  const { nodes } = useNodesQuery();
  const agentNodes = nodes.filter((n) => n.nodeType === 'agent');

  useEffect(() => {
    let cancelled = false;
    HttpUtil.get<ProbeSettingsWire>('/panel/api/probe/settings', { silent: true }).then((msg) => {
      if (!cancelled && msg?.success && msg.obj) setSettings(msg.obj);
    });
    return () => {
      cancelled = true;
    };
  }, []);

  async function saveSettings() {
    if (!settings) return;
    setSaving(true);
    try {
      const msg = await HttpUtil.put('/panel/api/probe/settings', settings, {
        silent: true,
        ...JSON_HEADERS,
      });
      if (msg?.success) messageApi.success(t('pages.settings.probeThemes.saved'));
      else messageApi.error(msg?.msg || t('pages.settings.probeThemes.saveFailed'));
    } finally {
      setSaving(false);
    }
  }

  async function pickIcon(which: 'favicon' | 'touchIcon', file: File | undefined) {
    if (!file || !settings) return;
    try {
      const url = await fileToIconDataURL(file);
      setSettings({ ...settings, [which]: url });
    } catch {
      messageApi.error(t('pages.settings.probeThemes.iconTooLarge'));
    }
  }

  const set = <K extends keyof ProbeSettingsWire>(key: K, value: ProbeSettingsWire[K]) =>
    setSettings((s) => (s ? { ...s, [key]: value } : s));

  return (
    <div>
      {messageContextHolder}
      <Typography.Title level={5}>{t('pages.settings.probeThemes.settingsTitle')}</Typography.Title>
      {settings ? (
        <>
          <Row gutter={[16, 12]}>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.publicPage')}</div>
              <Switch
                checked={settings.publicPage}
                onChange={(v) => set('publicPage', v)}
              />
              <Typography.Text type="secondary" style={{ marginLeft: 8 }}>
                {t('pages.settings.probeThemes.publicPageHint')}
              </Typography.Text>
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.siteName')}</div>
              <Input
                value={settings.siteName}
                onChange={(e) => set('siteName', e.target.value)}
              />
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.site')}</div>
              <Input
                value={settings.site}
                placeholder="https://"
                onChange={(e) => set('site', e.target.value)}
              />
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.githubProxy')}</div>
              <Input
                value={settings.githubProxy}
                placeholder="https://"
                onChange={(e) => set('githubProxy', e.target.value)}
              />
              <Typography.Text type="secondary">
                {t('pages.settings.probeThemes.githubProxyHint')}
              </Typography.Text>
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probe.retentionDays')}</div>
              <InputNumber
                min={1}
                max={365}
                value={settings.retentionDays}
                onChange={(v) => set('retentionDays', v ?? 7)}
                style={{ width: '100%' }}
              />
              <Typography.Text type="secondary">
                {t('pages.settings.probe.retentionHint')}
              </Typography.Text>
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probe.fastInterval')}</div>
              <InputNumber
                min={1}
                max={60}
                value={settings.fastIntervalSec}
                onChange={(v) => set('fastIntervalSec', v ?? 3)}
                addonAfter="s"
                style={{ width: '100%' }}
              />
              <Typography.Text type="secondary">
                {t('pages.settings.probe.fastIntervalHint')}
              </Typography.Text>
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.favicon')}</div>
              <Space>
                {settings.favicon ? (
                  <img src={settings.favicon} alt="" style={{ width: 24, height: 24 }} />
                ) : null}
                <Button size="small" onClick={() => faviconRef.current?.click()}>
                  {t('pages.settings.probeThemes.chooseImage')}
                </Button>
                {settings.favicon ? (
                  <Button size="small" onClick={() => set('favicon', '')}>
                    {t('clear')}
                  </Button>
                ) : null}
              </Space>
              <input
                ref={faviconRef}
                type="file"
                accept="image/*"
                hidden
                onChange={(e) => pickIcon('favicon', e.target.files?.[0])}
              />
            </Col>
            <Col xs={24} md={12}>
              <div style={{ marginBottom: 4 }}>{t('pages.settings.probeThemes.touchIcon')}</div>
              <Space>
                {settings.touchIcon ? (
                  <img src={settings.touchIcon} alt="" style={{ width: 24, height: 24 }} />
                ) : null}
                <Button size="small" onClick={() => touchRef.current?.click()}>
                  {t('pages.settings.probeThemes.chooseImage')}
                </Button>
                {settings.touchIcon ? (
                  <Button size="small" onClick={() => set('touchIcon', '')}>
                    {t('clear')}
                  </Button>
                ) : null}
              </Space>
              <input
                ref={touchRef}
                type="file"
                accept="image/*"
                hidden
                onChange={(e) => pickIcon('touchIcon', e.target.files?.[0])}
              />
              <div>
                <Typography.Text type="secondary">
                  {t('pages.settings.probeThemes.iconHint')}
                </Typography.Text>
              </div>
            </Col>
          </Row>
          <div style={{ marginTop: 12 }}>
            <Button type="primary" loading={saving} onClick={saveSettings}>
              {t('save')}
            </Button>
          </div>
        </>
      ) : null}

      <Typography.Title level={5} style={{ marginTop: 28 }}>
        {t('pages.nodes.probeTasks.title')}
      </Typography.Title>
      <ProbeTasksPanel nodes={nodes} />

      <Typography.Title level={5} style={{ marginTop: 28 }}>
        {t('pages.settings.probe.metaTitle')}
      </Typography.Title>
      <Select
        placeholder={t('pages.settings.probe.metaNodePlaceholder')}
        value={metaNodeId}
        onChange={setMetaNodeId}
        options={agentNodes.map((n) => ({ value: n.id, label: n.name }))}
        style={{ minWidth: 260, marginBottom: 16 }}
      />
      {metaNodeId ? <ProbeMetaSection key={metaNodeId} nodeId={metaNodeId} /> : null}
    </div>
  );
}