import { cli, Strategy } from '@jackwener/opencli/registry';
import { ArgumentError, AuthRequiredError, CommandExecutionError } from '@jackwener/opencli/errors';

const LINKEDIN_DOMAIN = 'www.linkedin.com';

function normalizeWhitespace(value) {
  return String(value ?? '').replace(/[\u00a0\u202f]/g, ' ').replace(/\s+/g, ' ').trim();
}

function unwrapEvaluateResult(payload) {
  if (payload && typeof payload === 'object' && 'data' in payload && 'session' in payload) return payload.data;
  return payload;
}

function isLinkedInHost(hostname) {
  const host = String(hostname || '').toLowerCase();
  return host === 'linkedin.com' || host.endsWith('.linkedin.com');
}

function canonicalizeLinkedInThreadUrl(value) {
  const raw = normalizeWhitespace(value);
  if (!raw) return '';
  try {
    const url = new URL(raw);
    if (url.protocol !== 'https:' || url.username || url.password || url.port || !isLinkedInHost(url.hostname)) return '';
    const match = url.pathname.match(/^\/messaging\/thread\/([^/]+)\/?$/i);
    if (!match || !match[1]) return '';
    url.hostname = 'www.linkedin.com';
    url.hash = '';
    url.search = '';
    if (!url.pathname.endsWith('/')) url.pathname += '/';
    return url.toString();
  } catch {
    return '';
  }
}

function requireStringArg(args, key, label = key) {
  const value = normalizeWhitespace(args[key]);
  if (!value) throw new ArgumentError(`${label} is required`);
  return value;
}

function requireLinkedInThreadUrl(value, label) {
  const url = canonicalizeLinkedInThreadUrl(value);
  if (!url) throw new ArgumentError(`${label} must be an exact https://www.linkedin.com/messaging/thread/<id>/ URL`);
  return url;
}

function parseMaxScrolls(value) {
  if (value === undefined || value === null || value === '') return 30;
  const scrolls = Number(value);
  if (!Number.isInteger(scrolls) || scrolls < 0 || scrolls > 80) {
    throw new ArgumentError('--max-scrolls must be an integer between 0 and 80');
  }
  return scrolls;
}

function buildThreadSnapshotScript(maxScrolls) {
  const scrolls = maxScrolls;
  return String.raw`(async () => {
    const marker = '__OPENCLI_LINKEDIN_THREAD_SNAPSHOT__';
    void marker;
    const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
    const clean = (s) => String(s || '').replace(/[\u00a0\u202f]/g, ' ').replace(/\s+/g, ' ').trim();
    const text = document.body ? (document.body.innerText || '') : '';
    const authRequired = /\b(sign in|log in|join linkedin)\b/i.test(text)
      || /linkedin\.com\/(login|checkpoint|authwall)/i.test(location.href)
      || /captcha|verification required/i.test(text);

    const selectors = [
      '.msg-s-message-list',
      '.msg-s-message-list-scrollable',
      '.msg-thread',
      'main [role="main"]',
      'main'
    ];
    let scroller = null;
    for (const selector of selectors) {
      const el = document.querySelector(selector);
      if (el && (el.scrollHeight > el.clientHeight || selector === 'main')) { scroller = el; break; }
    }
    scroller = scroller || document.scrollingElement || document.documentElement;
    let previousHeight = -1;
    let stable = 0;
    for (let i = 0; i < ${scrolls}; i += 1) {
      scroller.scrollTop = 0;
      window.scrollTo(0, 0);
      await sleep(750);
      const height = scroller.scrollHeight || document.body.scrollHeight || 0;
      if (height === previousHeight) stable += 1; else stable = 0;
      previousHeight = height;
      if (stable >= 3) break;
    }
    await sleep(1000);

    const headerCandidates = [];
    const headerSelectors = [
      '.msg-thread__link-to-profile',
      '.msg-thread__link-to-profile span[aria-hidden="true"]',
      '.msg-entity-lockup__entity-title',
      '.msg-conversation-card__participant-names',
      'main h1',
      'main h2',
      '[data-anonymize="person-name"]',
      'a[href*="/in/"] span[aria-hidden="true"]',
      'a[href*="/in/"]'
    ];
    for (const selector of headerSelectors) {
      for (const el of Array.from(document.querySelectorAll(selector)).slice(0, 8)) {
        const value = clean(el.innerText || el.textContent || el.getAttribute('aria-label'));
        if (value && value.length <= 120 && !/^(message|messaging|send|profile|view profile)$/i.test(value)) {
          headerCandidates.push(value);
        }
      }
    }

    const seen = new Set();
    const messages = [];
    const nodes = Array.from(document.querySelectorAll('.msg-s-message-list__event, .msg-s-event-listitem, [data-event-urn], .msg-s-message-list-content'));
    for (const [nodeIndex, el] of nodes.entries()) {
      const raw = clean(el.innerText || el.textContent);
      if (!raw || seen.has(raw)) continue;
      seen.add(raw);
      const lines = raw.split(/\n+/).map(clean).filter(Boolean);
      const speaker = lines.length > 1 && lines[0].length <= 120 ? lines[0] : '';
      messages.push({ index: messages.length, nodeIndex, speaker, text: raw });
    }

    const refreshedText = document.body ? (document.body.innerText || '') : '';
    const fallbackLines = refreshedText.split(/\n+/).map(clean).filter(Boolean);
    const latestMessageText = messages.length
      ? messages[messages.length - 1].text
      : ([...fallbackLines].reverse().find((line) => !/^(send|reply|write a message|press enter to send)$/i.test(line)) || '');

    return {
      url: location.href,
      title: document.title || '',
      headerNames: Array.from(new Set(headerCandidates)).slice(0, 10),
      bodyText: refreshedText,
      latestMessageText,
      messages,
      messageCount: messages.length,
      authRequired,
      extractedAt: new Date().toISOString(),
      maxScrolls: ${scrolls}
    };
  })()`;
}

cli({
  site: 'linkedin',
  name: 'thread-snapshot',
  access: 'read',
  description: 'Load a LinkedIn messaging thread, scroll for available history, and return a full context snapshot',
  domain: LINKEDIN_DOMAIN,
  strategy: Strategy.UI,
  browser: true,
  args: [
    { name: 'thread-url', required: true, help: 'Exact LinkedIn messaging thread URL to open and snapshot' },
    { name: 'max-scrolls', type: 'number', default: 30, help: 'Maximum upward scroll attempts to load older messages' },
    { name: 'json', type: 'bool', default: false, help: 'Return only JSON snapshot string in the snapshot_json field' },
  ],
  columns: ['thread_url', 'recipient', 'message_count', 'latest_text', 'snapshot_json'],
  func: async (page, args) => {
    if (!page) throw new CommandExecutionError('Browser session required for linkedin thread-snapshot');
    const threadUrl = requireLinkedInThreadUrl(requireStringArg(args, 'thread-url', '--thread-url'), '--thread-url');
    const maxScrolls = parseMaxScrolls(args['max-scrolls']);

    await page.goto('https://www.linkedin.com/messaging/');
    await page.wait(4);
    await page.goto(threadUrl);
    await page.wait(10);

    const snapshot = unwrapEvaluateResult(await page.evaluate(buildThreadSnapshotScript(maxScrolls)));
    if (snapshot?.authRequired) {
      throw new AuthRequiredError(LINKEDIN_DOMAIN, 'LinkedIn thread-snapshot requires an active signed-in LinkedIn browser session.');
    }
    if (!snapshot || typeof snapshot !== 'object' || Array.isArray(snapshot) || !Array.isArray(snapshot.headerNames) || !Array.isArray(snapshot.messages)) {
      throw new CommandExecutionError('LinkedIn thread-snapshot returned malformed snapshot payload');
    }

    const actualUrl = canonicalizeLinkedInThreadUrl(snapshot?.url || '');
    if (threadUrl && actualUrl && threadUrl !== actualUrl) {
      throw new CommandExecutionError('LinkedIn thread-snapshot blocked: thread_url_mismatch', `Expected ${threadUrl}; actual ${actualUrl}`);
    }

    const recipient = normalizeWhitespace(snapshot.headerNames[0] || '');
    const messageCount = snapshot.messages.length;
    const normalized = {
      ...snapshot,
      url: actualUrl || threadUrl,
      headerNames: snapshot.headerNames,
      latestMessageText: normalizeWhitespace(snapshot?.latestMessageText || ''),
      messages: snapshot.messages,
    };

    return [{
      thread_url: normalized.url,
      recipient,
      message_count: messageCount,
      latest_text: normalized.latestMessageText,
      snapshot_json: JSON.stringify(normalized),
    }];
  },
});

export const __test__ = {
  normalizeWhitespace,
  canonicalizeLinkedInThreadUrl,
  parseMaxScrolls,
  unwrapEvaluateResult,
  buildThreadSnapshotScript,
};