/**
 * Write commands — navigate and interact with pages (side effects)
 *
 * goto, back, forward, reload, click, fill, select, hover, type,
 * press, scroll, wait, viewport, cookie, header, useragent
 */

import type { BrowserManager } from './browser-manager';
import { findInstalledBrowsers, importCookies } from './cookie-import-browser';
import { validateNavigationUrl } from './url-validation';
import * as fs from 'fs';
import * as path from 'path';
import { TEMP_DIR, isPathWithin } from './platform';

export async function handleWriteCommand(
  command: string,
  args: string[],
  bm: BrowserManager
): Promise<string> {
  const page = bm.getPage();

  switch (command) {
    case 'goto': {
      const url = args[0];
      if (!url) throw new Error('Usage: browse goto <url>');
      await validateNavigationUrl(url);
      const response = await page.goto(url, { waitUntil: 'domcontentloaded', timeout: 15000 });
      const status = response?.status() || 'unknown';
      return `Navigated to ${url} (${status})`;
    }

    case 'back': {
      await page.goBack({ waitUntil: 'domcontentloaded', timeout: 15000 });
      return `Back → ${page.url()}`;
    }

    case 'forward': {
      await page.goForward({ waitUntil: 'domcontentloaded', timeout: 15000 });
      return `Forward → ${page.url()}`;
    }

    case 'reload': {
      await page.reload({ waitUntil: 'domcontentloaded', timeout: 15000 });
      return `Reloaded ${page.url()}`;
    }

    case 'click': {
      const selector = args[0];
      if (!selector) throw new Error('Usage: browse click <selector>');

      // Auto-route: if ref points to a real <option> inside a <select>, use selectOption
      const role = bm.getRefRole(selector);
      if (role === 'option') {
        const resolved = await bm.resolveRef(selector);
        if ('locator' in resolved) {
          const optionInfo = await resolved.locator.evaluate(el => {
            if (el.tagName !== 'OPTION') return null; // custom [role=option], not real <option>
            const option = el as HTMLOptionElement;
            const select = option.closest('select');
            if (!select) return null;
            return { value: option.value, text: option.text };
          });
          if (optionInfo) {
            await resolved.locator.locator('xpath=ancestor::select').selectOption(optionInfo.value, { timeout: 5000 });
            return `Selected "${optionInfo.text}" (auto-routed from click on <option>) → now at ${page.url()}`;
          }
          // Real <option> with no parent <select> or custom [role=option] — fall through to normal click
        }
      }

      const resolved = await bm.resolveRef(selector);
      try {
        if ('locator' in resolved) {
          await resolved.locator.click({ timeout: 5000 });
        } else {
          await page.click(resolved.selector, { timeout: 5000 });
        }
      } catch (err: any) {
        // Enhanced error guidance: clicking <option> elements always fails (not visible / timeout)
        const isOption = 'locator' in resolved
          ? await resolved.locator.evaluate(el => el.tagName === 'OPTION').catch(() => false)
          : await page.evaluate(
              (sel: string) => document.querySelector(sel)?.tagName === 'OPTION',
              (resolved as { selector: string }).selector
            ).catch(() => false);
        if (isOption) {
          throw new Error(
            `Cannot click <option> elements. Use 'browse select <parent-select> <value>' instead of 'click' for dropdown options.`
          );
        }
        throw err;
      }
      // Wait briefly for any navigation/DOM update
      await page.waitForLoadState('domcontentloaded').catch(() => {});
      return `Clicked ${selector} → now at ${page.url()}`;
    }

    case 'fill': {
      const [selector, ...valueParts] = args;
      const value = valueParts.join(' ');
      if (!selector || !value) throw new Error('Usage: browse fill <selector> <value>');
      const resolved = await bm.resolveRef(selector);
      if ('locator' in resolved) {
        await resolved.locator.fill(value, { timeout: 5000 });
      } else {
        await page.fill(resolved.selector, value, { timeout: 5000 });
      }
      return `Filled ${selector}`;
    }

    case 'select': {
      const [selector, ...valueParts] = args;
      const value = valueParts.join(' ');
      if (!selector || !value) throw new Error('Usage: browse select <selector> <value>');
      const resolved = await bm.resolveRef(selector);
      if ('locator' in resolved) {
        await resolved.locator.selectOption(value, { timeout: 5000 });
      } else {
        await page.selectOption(resolved.selector, value, { timeout: 5000 });
      }
      return `Selected "${value}" in ${selector}`;
    }

    case 'hover': {
      const selector = args[0];
      if (!selector) throw new Error('Usage: browse hover <selector>');
      const resolved = await bm.resolveRef(selector);
      if ('locator' in resolved) {
        await resolved.locator.hover({ timeout: 5000 });
      } else {
        await page.hover(resolved.selector, { timeout: 5000 });
      }
      return `Hovered ${selector}`;
    }

    case 'type': {
      const text = args.join(' ');
      if (!text) throw new Error('Usage: browse type <text>');
      await page.keyboard.type(text);
      return `Typed ${text.length} characters`;
    }

    case 'press': {
      const key = args[0];
      if (!key) throw new Error('Usage: browse press <key> (e.g., Enter, Tab, Escape)');
      await page.keyboard.press(key);
      return `Pressed ${key}`;
    }

    case 'scroll': {
      const selector = args[0];
      if (selector) {
        const resolved = await bm.resolveRef(selector);
        if ('locator' in resolved) {
          await resolved.locator.scrollIntoViewIfNeeded({ timeout: 5000 });
        } else {
          await page.locator(resolved.selector).scrollIntoViewIfNeeded({ timeout: 5000 });
        }
        return `Scrolled ${selector} into view`;
      }
      await page.evaluate(() => window.scrollTo(0, document.body.scrollHeight));
      return 'Scrolled to bottom';
    }

    case 'wait': {
      const selector = args[0];
      if (!selector) throw new Error('Usage: browse wait <selector|--networkidle|--load|--domcontentloaded>');
      if (selector === '--networkidle') {
        const timeout = args[1] ? parseInt(args[1], 10) : 15000;
        await page.waitForLoadState('networkidle', { timeout });
        return 'Network idle';
      }
      if (selector === '--load') {
        await page.waitForLoadState('load');
        return 'Page loaded';
      }
      if (selector === '--domcontentloaded') {
        await page.waitForLoadState('domcontentloaded');
        return 'DOM content loaded';
      }
      const timeout = args[1] ? parseInt(args[1], 10) : 15000;
      const resolved = await bm.resolveRef(selector);
      if ('locator' in resolved) {
        await resolved.locator.waitFor({ state: 'visible', timeout });
      } else {
        await page.waitForSelector(resolved.selector, { timeout });
      }
      return `Element ${selector} appeared`;
    }

    case 'viewport': {
      const size = args[0];
      if (!size || !size.includes('x')) throw new Error('Usage: browse viewport <WxH> (e.g., 375x812)');
      const [w, h] = size.split('x').map(Number);
      await bm.setViewport(w, h);
      return `Viewport set to ${w}x${h}`;
    }

    case 'cookie': {
      const cookieStr = args[0];
      if (!cookieStr || !cookieStr.includes('=')) throw new Error('Usage: browse cookie <name>=<value>');
      const eq = cookieStr.indexOf('=');
      const name = cookieStr.slice(0, eq);
      const value = cookieStr.slice(eq + 1);
      const url = new URL(page.url());
      await page.context().addCookies([{
        name,
        value,
        domain: url.hostname,
        path: '/',
      }]);
      return `Cookie set: ${name}=****`;
    }

    case 'header': {
      const headerStr = args[0];
      if (!headerStr || !headerStr.includes(':')) throw new Error('Usage: browse header <name>:<value>');
      const sep = headerStr.indexOf(':');
      const name = headerStr.slice(0, sep).trim();
      const value = headerStr.slice(sep + 1).trim();
      await bm.setExtraHeader(name, value);
      const sensitiveHeaders = ['authorization', 'cookie', 'set-cookie', 'x-api-key', 'x-auth-token'];
      const redactedValue = sensitiveHeaders.includes(name.toLowerCase()) ? '****' : value;
      return `Header set: ${name}: ${redactedValue}`;
    }

    case 'useragent': {
      const ua = args.join(' ');
      if (!ua) throw new Error('Usage: browse useragent <string>');
      bm.setUserAgent(ua);
      const error = await bm.recreateContext();
      if (error) {
        return `User agent set to "${ua}" but: ${error}`;
      }
      return `User agent set: ${ua}`;
    }

    case 'upload': {
      const [selector, ...filePaths] = args;
      if (!selector || filePaths.length === 0) throw new Error('Usage: browse upload <selector> <file1> [file2...]');

      // Validate all files exist before upload
      for (const fp of filePaths) {
        if (!fs.existsSync(fp)) throw new Error(`File not found: ${fp}`);
      }

      const resolved = await bm.resolveRef(selector);
      if ('locator' in resolved) {
        await resolved.locator.setInputFiles(filePaths);
      } else {
        await page.locator(resolved.selector).setInputFiles(filePaths);
      }

      const fileInfo = filePaths.map(fp => {
        const stat = fs.statSync(fp);
        return `${path.basename(fp)} (${stat.size}B)`;
      }).join(', ');
      return `Uploaded: ${fileInfo}`;
    }

    case 'dialog-accept': {
      const text = args.length > 0 ? args.join(' ') : null;
      bm.setDialogAutoAccept(true);
      bm.setDialogPromptText(text);
      return text
        ? `Dialogs will be accepted with text: "${text}"`
        : 'Dialogs will be accepted';
    }

    case 'dialog-dismiss': {
      bm.setDialogAutoAccept(false);
      bm.setDialogPromptText(null);
      return 'Dialogs will be dismissed';
    }

    case 'cookie-import': {
      const filePath = args[0];
      if (!filePath) throw new Error('Usage: browse cookie-import <json-file>');
      // Path validation — prevent reading arbitrary files
      if (path.isAbsolute(filePath)) {
        const safeDirs = [TEMP_DIR, process.cwd()];
        const resolved = path.resolve(filePath);
        if (!safeDirs.some(dir => isPathWithin(resolved, dir))) {
          throw new Error(`Path must be within: ${safeDirs.join(', ')}`);
        }
      }
      if (path.normalize(filePath).includes('..')) {
        throw new Error('Path traversal sequences (..) are not allowed');
      }
      if (!fs.existsSync(filePath)) throw new Error(`File not found: ${filePath}`);
      const raw = fs.readFileSync(filePath, 'utf-8');
      let cookies: any[];
      try { cookies = JSON.parse(raw); } catch { throw new Error(`Invalid JSON in ${filePath}`); }
      if (!Array.isArray(cookies)) throw new Error('Cookie file must contain a JSON array');

      // Auto-fill domain from current page URL when missing (consistent with cookie command)
      const pageUrl = new URL(page.url());
      const defaultDomain = pageUrl.hostname;

      for (const c of cookies) {
        if (!c.name || c.value === undefined) throw new Error('Each cookie must have "name" and "value" fields');
        if (!c.domain) c.domain = defaultDomain;
        if (!c.path) c.path = '/';
      }

      await page.context().addCookies(cookies);
      return `Loaded ${cookies.length} cookies from ${filePath}`;
    }

    case 'cookie-import-browser': {
      // Two modes:
      // 1. Direct CLI import: cookie-import-browser <browser> --domain <domain>
      // 2. Open picker UI: cookie-import-browser [browser]
      const browserArg = args[0];
      const domainIdx = args.indexOf('--domain');

      if (domainIdx !== -1 && domainIdx + 1 < args.length) {
        // Direct import mode — no UI
        const domain = args[domainIdx + 1];
        const browser = browserArg || 'comet';
        const result = await importCookies(browser, [domain]);
        if (result.cookies.length > 0) {
          await page.context().addCookies(result.cookies);
        }
        const msg = [`Imported ${result.count} cookies for ${domain} from ${browser}`];
        if (result.failed > 0) msg.push(`(${result.failed} failed to decrypt)`);
        return msg.join(' ');
      }

      // Picker UI mode — open in user's browser
      const port = bm.serverPort;
      if (!port) throw new Error('Server port not available');

      const browsers = findInstalledBrowsers();
      if (browsers.length === 0) {
        throw new Error('No Chromium browsers found. Supported: Comet, Chrome, Arc, Brave, Edge');
      }

      const pickerUrl = `http://127.0.0.1:${port}/cookie-picker`;
      try {
        Bun.spawn(['open', pickerUrl], { stdout: 'ignore', stderr: 'ignore' });
      } catch {
        // open may fail silently — URL is in the message below
      }

      return `Cookie picker opened at ${pickerUrl}\nDetected browsers: ${browsers.map(b => b.name).join(', ')}\nSelect domains to import, then close the picker when done.`;
    }

    default:
      throw new Error(`Unknown write command: ${command}`);
  }
}