/**
 * Feed/Web Tools
 * Provides RSS/Atom feed fetching, parsing, and monitoring capabilities.
 */

import Parser from 'rss-parser';
import { z } from 'zod';
import fetch from 'node-fetch';

// Zod schemas for validation
const rssFetchSchema = z.object({
  url: z.string().url(),
});

const atomParseSchema = z.object({
  xml_content: z.string().min(1),
});

const feedMonitorCheckSchema = z.object({
  feed_url: z.string().url(),
  last_etag: z.string().optional(),
});

/**
 * Fetch and parse an RSS/Atom feed.
 */
export async function rss_fetch(url: string): Promise<{ title: string; link: string; items: Array<{ title: string; link: string; description: string; pubDate: string }> }> {
  const validated = rssFetchSchema.parse({ url });

  try {
    const parser = new Parser();
    const feed = await parser.parseURL(validated.url);

    return {
      title: feed.title || '',
      link: feed.link || '',
      items: (feed.items || []).map(item => ({
        title: item.title || '',
        link: item.link || '',
        description: item.contentSnippet || item.content || '',
        pubDate: item.pubDate ? new Date(item.pubDate).toISOString() : ''
      }))
    };
  } catch (error) {
    throw new Error(`Failed to fetch RSS feed: ${error instanceof Error ? error.message : String(error)}`);
  }
}

/**
 * Parse Atom XML content directly.
 */
export async function atom_parse(xml_content: string): Promise<{ feed_info: any; entries: Array<{ title: string; link: string; summary: string; published: string }> }> {
  const validated = atomParseSchema.parse({ xml_content });

  try {
    // Parse XML manually (simple implementation)
    const parser = new Parser();
    const feed = await parser.parseString(validated.xml_content);

    return {
      feed_info: {
        title: feed.title || '',
        link: feed.link || '',
        updated: feed.updated ? new Date(feed.updated).toISOString() : ''
      },
      entries: (feed.items || []).map(item => ({
        title: item.title || '',
        link: item.link || '',
        summary: item.contentSnippet || item.content || '',
        published: item.pubDate ? new Date(item.pubDate).toISOString() : ''
      }))
    };
  } catch (error) {
    throw new Error(`Failed to parse Atom feed: ${error instanceof Error ? error.message : String(error)}`);
  }
}

/**
 * Check if a feed has been updated since last check.
 */
export async function feed_monitor_check(feed_url: string, last_etag?: string): Promise<{ updated: boolean; new_items?: Array<{ title: string; link: string }> }> {
  const validated = feedMonitorCheckSchema.parse({ feed_url, last_etag });

  try {
    const response = await fetch(validated.feed_url, {
      headers: {
        'User-Agent': 'BeledariansLMStudioTools/1.0',
        ...(validated.last_etag ? { 'If-None-Match': validated.last_etag } : {})
      },
      timeout: 30000 // 30 second timeout
    });

    if (response.status === 304) {
      return { updated: false };
    }

    const etag = response.headers.get('etag') || '';
    
    if (!etag && !validated.last_etag) {
      // First check - no ETag to compare against
      const feed = await rss_fetch(validated.feed_url);
      return { 
        updated: true, 
        new_items: feed.items.slice(0, 5).map(item => ({ title: item.title, link: item.link })) 
      };
    }

    // Parse and check for updates
    const parser = new Parser();
    const text = await response.text();
    const feed = await parser.parseString(text);

    return {
      updated: true,
      new_items: (feed.items || []).slice(0, 5).map(item => ({ title: item.title || '', link: item.link || '' }))
    };
  } catch (error) {
    throw new Error(`Feed monitoring check failed: ${error instanceof Error ? error.message : String(error)}`);
  }
}

/**
 * Feed/Web Tools
 * Provides RSS/Atom feed fetching, parsing, and monitoring capabilities.
 */

import Parser from 'rss-parser';
import { z } from 'zod';
import fetch from 'node-fetch';

// Zod schemas for validation
const rssFetchSchema = z.object({
  url: z.string().url(),
});

const atomParseSchema = z.object({
  xml_content: z.string().min(1),
});

const feedMonitorCheckSchema = z.object({
  feed_url: z.string().url(),
  last_etag: z.string().optional(),
});

/**
 * Fetch and parse an RSS/Atom feed.
 */
export async function rss_fetch(url: string): Promise<{ title: string; link: string; items: Array<{ title: string; link: string; description: string; pubDate: string }> }> {
  const validated = rssFetchSchema.parse({ url });

  try {
    const parser = new Parser();
    const feed = await parser.parseURL(validated.url);

    return {
      title: feed.title || '',
      link: feed.link || '',
      items: (feed.items || []).map(item => ({
        title: item.title || '',
        link: item.link || '',
        description: item.contentSnippet || item.content || '',
        pubDate: item.pubDate ? new Date(item.pubDate).toISOString() : ''
      }))
    };
  } catch (error) {
    throw new Error(`Failed to fetch RSS feed: ${error instanceof Error ? error.message : String(error)}`);
  }
}

/**
 * Parse Atom XML content directly.
 */
export async function atom_parse(xml_content: string): Promise<{ feed_info: any; entries: Array<{ title: string; link: string; summary: string; published: string }> }> {
  const validated = atomParseSchema.parse({ xml_content });

  try {
    // Parse XML manually (simple implementation)
    const parser = new Parser();
    const feed = await parser.parseString(validated.xml_content);

    return {
      feed_info: {
        title: feed.title || '',
        link: feed.link || '',
        updated: feed.updated ? new Date(feed.updated).toISOString() : ''
      },
      entries: (feed.items || []).map(item => ({
        title: item.title || '',
        link: item.link || '',
        summary: item.contentSnippet || item.content || '',
        published: item.pubDate ? new Date(item.pubDate).toISOString() : ''
      }))
    };
  } catch (error) {
    throw new Error(`Failed to parse Atom feed: ${error instanceof Error ? error.message : String(error)}`);
  }
}

/**
 * Check if a feed has been updated since last check.
 */
export async function feed_monitor_check(feed_url: string, last_etag?: string): Promise<{ updated: boolean; new_items?: Array<{ title: string; link: string }> }> {
  const validated = feedMonitorCheckSchema.parse({ feed_url, last_etag });

  try {
    const response = await fetch(validated.feed_url, {
      headers: {
        'User-Agent': 'BeledariansLMStudioTools/1.0',
        ...(validated.last_etag ? { 'If-None-Match': validated.last_etag } : {})
      },
      timeout: 30000 // 30 second timeout
    });

    if (response.status === 304) {
      return { updated: false };
    }

    const etag = response.headers.get('etag') || '';
    
    if (!etag && !validated.last_etag) {
      // First check - no ETag to compare against
      const feed = await rss_fetch(validated.feed_url);
      return { 
        updated: true, 
        new_items: feed.items.slice(0, 5).map(item => ({ title: item.title, link: item.link })) 
      };
    }

    // Parse and check for updates
    const parser = new Parser();
    const text = await response.text();
    const feed = await parser.parseString(text);

    return {
      updated: true,
      new_items: (feed.items || []).slice(0, 5).map(item => ({ title: item.title || '', link: item.link || '' }))
    };
  } catch (error) {
    throw new Error(`Feed monitoring check failed: ${error instanceof Error ? error.message : String(error)}`);
  }
}