/**
 * Meilisearch client configuration
 */

import { MeiliSearch } from 'meilisearch';
import { readFileSync } from 'fs';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';

const __dirname = dirname(fileURLToPath(import.meta.url));

const MEILISEARCH_HOST = process.env.MEILISEARCH_HOST || 'http://127.0.0.1:7700';
const MEILISEARCH_MASTER_KEY = process.env.MEILISEARCH_MASTER_KEY || 'changeme123';
const INDEX_NAME = process.env.MEILISEARCH_INDEX_NAME || 'navidocs-pages';

let client = null;
let index = null;
let tenantKeyUid = null;

export function getMeilisearchClient() {
  if (!client) {
    console.log(`[Meilisearch] Initializing client with host=${MEILISEARCH_HOST}, apiKey=${MEILISEARCH_MASTER_KEY}`);
    client = new MeiliSearch({
      host: MEILISEARCH_HOST,
      apiKey: MEILISEARCH_MASTER_KEY
    });
  }
  return client;
}

export async function getMeilisearchIndex() {
  if (!index) {
    const client = getMeilisearchClient();

    try {
      index = await client.getIndex(INDEX_NAME);
    } catch (error) {
      // Index doesn't exist, create it
      console.log('Creating Meilisearch index:', INDEX_NAME);
      await client.createIndex(INDEX_NAME, { primaryKey: 'id' });
      index = await client.getIndex(INDEX_NAME);

      // Configure index settings
      await configureIndex(index);
    }
  }
  return index;
}

async function configureIndex(index) {
  // Load config from docs
  const configPath = join(__dirname, '../../docs/architecture/meilisearch-config.json');
  const config = JSON.parse(readFileSync(configPath, 'utf8'));

  await index.updateSettings({
    searchableAttributes: config.settings.searchableAttributes,
    filterableAttributes: config.settings.filterableAttributes,
    sortableAttributes: config.settings.sortableAttributes,
    displayedAttributes: config.settings.displayedAttributes,
    synonyms: config.settings.synonyms,
    stopWords: config.settings.stopWords,
    rankingRules: config.settings.rankingRules,
    typoTolerance: config.settings.typoTolerance,
    faceting: config.settings.faceting,
    pagination: config.settings.pagination,
    separatorTokens: config.settings.separatorTokens,
    nonSeparatorTokens: config.settings.nonSeparatorTokens
  });

  console.log('Meilisearch index configured');
}

async function ensureTenantKeyUid() {
  if (tenantKeyUid) return tenantKeyUid;
  const client = getMeilisearchClient();
  try {
    const keys = await client.getKeys();
    const byName = keys.results?.find(k => k.name === 'navidocs-tenant-key' && k.actions?.includes('search'));
    if (byName) { tenantKeyUid = byName.uid; return tenantKeyUid; }
    // Fallback: use any search key that covers our index
    const anySearchKey = keys.results?.find(k => k.actions?.includes('search') && (k.indexes?.includes('*') || k.indexes?.includes(INDEX_NAME)));
    if (anySearchKey) { tenantKeyUid = anySearchKey.uid; return tenantKeyUid; }
  } catch (e) {
    // proceed to create
  }

  // Create a search-only key to act as parent for tenant tokens
  const created = await client.createKey({
    name: 'navidocs-tenant-key',
    description: 'Parent key for NaviDocs tenant tokens',
    actions: ['search'],
    indexes: [INDEX_NAME]
  });
  tenantKeyUid = created.uid;
  return tenantKeyUid;
}

export async function generateTenantToken(userId, organizationIds, expiresIn = 3600) {
  const client = getMeilisearchClient();

  // Quote string values for Meilisearch filter syntax
  const orgList = (organizationIds || []).map((id) => `"${id}"`).join(', ');
  const filter = `userId = "${userId}" OR organizationId IN [${orgList}]`;

  const searchRules = {
    [INDEX_NAME]: { filter }
  };

  const expiresAt = new Date(Date.now() + expiresIn * 1000);

  // Ensure a string is returned across client versions
  const parentUid = await ensureTenantKeyUid();
  const token = await client.generateTenantToken(parentUid, searchRules, { expiresAt });

  return typeof token === 'string' ? token : String(token);
}