const db = require('./db');
const { normalizeTitle } = require('./dedup');
const { fetchAndStoreContent } = require('./content');
const { markSourceRun } = require('./state');

const insertArticle = db.prepare(`
  INSERT INTO articles (
    title,
    description,
    content,
    image,
    url,
    normalized_title,
    source,
    pub_date,
    ingested_at
  ) VALUES (?, ?, NULL, NULL, ?, ?, ?, ?, ?)
`);
const findByUrl = db.prepare('SELECT id FROM articles WHERE url = ?');

function normalizePubDate(value) {
  if (!value) {
    return null;
  }

  if (typeof value === 'number') {
    const parsed = new Date(value);
    return Number.isNaN(parsed.getTime()) ? null : parsed.toISOString();
  }

  const input = String(value).trim();
  if (!input) {
    return null;
  }

  if (/^\d{8}T\d{6}$/.test(input)) {
    const normalized = `${input.slice(0, 4)}-${input.slice(4, 6)}-${input.slice(6, 8)}T${input.slice(9, 11)}:${input.slice(11, 13)}:${input.slice(13, 15)}Z`;
    const parsed = new Date(normalized);
    return Number.isNaN(parsed.getTime()) ? null : parsed.toISOString();
  }

  if (/^\d{8}T\d{6}Z$/.test(input)) {
    const normalized = `${input.slice(0, 4)}-${input.slice(4, 6)}-${input.slice(6, 8)}T${input.slice(9, 11)}:${input.slice(11, 13)}:${input.slice(13, 15)}Z`;
    const parsed = new Date(normalized);
    return Number.isNaN(parsed.getTime()) ? null : parsed.toISOString();
  }

  if (/^\d{4}-\d{2}-\d{2}$/.test(input)) {
    return `${input}T00:00:00.000Z`;
  }

  const parsed = new Date(input);
  return Number.isNaN(parsed.getTime()) ? null : parsed.toISOString();
}

function ingestArticle(article) {
  const title = String(article.title || '').trim();
  const url = String(article.url || '').trim();
  const source = String(article.source || '').trim();

  if (!title || !url || !source) {
    return { inserted: false, reason: 'missing_required_fields' };
  }

  const normalizedTitle = normalizeTitle(title);
  if (!normalizedTitle) {
    return { inserted: false, reason: 'empty_normalized_title' };
  }

  const description = article.description == null ? null : String(article.description).trim() || null;
  const pubDate = normalizePubDate(article.pubDate);
  const ingestedAt = new Date().toISOString();

  try {
    const result = insertArticle.run(
      title,
      description,
      url,
      normalizedTitle,
      source,
      pubDate,
      ingestedAt
    );

    fetchAndStoreContent(result.lastInsertRowid, url);

    return { inserted: true, id: result.lastInsertRowid };
  } catch (error) {
    if (error.code === 'SQLITE_CONSTRAINT_UNIQUE') {
      const duplicateByUrl = findByUrl.get(url);
      if (duplicateByUrl) {
        return { inserted: false, reason: 'duplicate_url', id: duplicateByUrl.id };
      }

      return { inserted: false, reason: 'duplicate' };
    }

    throw error;
  }
}

async function ingestBatch(source, articles) {
  let inserted = 0;

  for (const article of articles) {
    const result = ingestArticle({ ...article, source: article.source || source });
    if (result.inserted) {
      inserted += 1;
    }
  }

  markSourceRun(source);

  return { source, inserted, total: articles.length };
}

module.exports = {
  ingestArticle,
  ingestBatch,
};