#!/usr/bin/env tsx
/**
 * Enrich churches that have lat/lng=0 with real coordinates via Nominatim forward geocoding.
 * After this runs, enrich-with-reverse-geocode fills city/state from the new coordinates.
 *
 * Usage:
 *   npx tsx scripts/enrich-with-forward-geocode.ts --country HK --dry-run
 *   npx tsx scripts/enrich-with-forward-geocode.ts --country HK
 *   npx tsx scripts/enrich-with-forward-geocode.ts --limit 10
 *
 * Rate limit: 1 request/second (Nominatim usage policy — mandatory).
 */

import dotenv from 'dotenv';
import path from 'path';
dotenv.config({ path: path.resolve(process.cwd(), '.env.local') });
dotenv.config({ path: path.resolve(process.cwd(), '.env') });

import { Pool } from 'pg';
import { PrismaPg } from '@prisma/adapter-pg';
import { PrismaClient } from '@prisma/client';
import axios from 'axios';

const dbUrl = process.env.DATABASE_URL || 'postgresql://postgres:postgres@localhost:5432/nearestmass';
const pool = new Pool({
  connectionString: dbUrl,
  ssl: dbUrl.includes('neon') ? { rejectUnauthorized: false } : undefined,
});
const adapter = new PrismaPg(pool);
const prisma = new PrismaClient({ adapter });

const NOMINATIM_SEARCH_URL = 'https://nominatim.openstreetmap.org/search';
const RATE_LIMIT_MS = 1100;

// Some regions use a different ISO code in OSM than in our DB
const NOMINATIM_COUNTRY_MAP: Record<string, string> = {
  HK: 'cn', // Hong Kong is part of China in OSM
  MO: 'cn', // Macau likewise
};

interface ChurchRecord {
  id: string;
  name: string;
  address: string;
  country: string;
  city: string | null;
  state: string | null;
}

interface NominatimSearchResult {
  lat: string;
  lon: string;
  display_name: string;
  address?: {
    city?: string;
    town?: string;
    village?: string;
    municipality?: string;
    state?: string;
    province?: string;
  };
}

function log(msg: string) {
  console.log(`[${new Date().toISOString()}] ${msg}`);
}

function sleep(ms: number): Promise<void> {
  return new Promise(resolve => setTimeout(resolve, ms));
}

function cleanAddress(address: string): string {
  return address
    // Strip trailing city/region suffixes
    .replace(/,?\s*(H\.K\.|HK|Hong Kong|Kowloon|Kln\.|New Territories|N\.T\.|Lantau Island)\.?\s*$/i, '')
    // Strip "R.E." (Religious Education suffix used in HK addresses)
    .replace(/,?\s*R\.E\./i, '')
    .replace(/\.$/, '')
    .trim();
}

/**
 * Fallback: strip any leading non-numeric institution name prefix and floor/unit designators,
 * returning just the street number onwards. Handles patterns like:
 *   "Canossa School (H.K.) 8 Hoi Chak Street"  → "8 Hoi Chak Street"
 *   "G/F., Wai Ming Block, 111 Wing Hong Street" → "111 Wing Hong Street"
 *   "3/F., Chi Wo Commercial Building, 20 Saigon Street" → "20 Saigon Street"
 */
function extractStreetAddress(address: string): string | null {
  // Find the first occurrence of a standalone number (house number)
  const match = address.match(/(?:^|,\s*)(\d+[A-Za-z]?(?:\s|,).*)/);
  if (!match) return null;
  const candidate = match[1].trim();
  // Must be meaningfully shorter than the full address to be worth retrying
  return candidate.length < address.length * 0.9 ? cleanAddress(candidate) : null;
}

async function nominatimSearch(query: string, nominatimCountry: string): Promise<NominatimSearchResult | null> {
  const response = await axios.get(NOMINATIM_SEARCH_URL, {
    params: {
      q: query,
      format: 'json',
      limit: 1,
      countrycodes: nominatimCountry,
      addressdetails: 1,
    },
    headers: {
      'User-Agent': 'NearestMass/1.0 (privacy@nearestmass.com)',
      'Accept-Language': 'en',
    },
    timeout: 15000,
  });
  const results: NominatimSearchResult[] = response.data;
  return results.length > 0 ? results[0] : null;
}

async function forwardGeocode(
  address: string,
  countryCode: string
): Promise<{ result: NominatimSearchResult; usedFallback: boolean } | null> {
  const nominatimCountry = NOMINATIM_COUNTRY_MAP[countryCode] ?? countryCode.toLowerCase();
  const cleaned = cleanAddress(address);

  const primary = await nominatimSearch(cleaned, nominatimCountry);
  if (primary) return { result: primary, usedFallback: false };

  // Fallback: try just the street-number-onwards portion
  const streetOnly = extractStreetAddress(address);
  if (streetOnly && streetOnly !== cleaned) {
    await sleep(RATE_LIMIT_MS); // respect rate limit between retries
    const fallback = await nominatimSearch(streetOnly, nominatimCountry);
    if (fallback) return { result: fallback, usedFallback: true };
  }

  return null;
}

async function main() {
  const args = process.argv.slice(2);
  const dryRun = args.includes('--dry-run');
  const countryIdx = args.indexOf('--country');
  const limitIdx = args.indexOf('--limit');
  const countryCode = countryIdx !== -1 ? args[countryIdx + 1] : undefined;
  const limit = limitIdx !== -1 ? parseInt(args[limitIdx + 1], 10) : undefined;

  log('============================================================');
  log('Nominatim Forward Geocode Enrichment');
  log('============================================================');
  log(`Country: ${countryCode || 'All'}`);
  log(`Limit: ${limit || 'No limit'}`);
  log(`Dry run: ${dryRun ? 'Yes' : 'No'}`);
  log('============================================================');

  const churches = await prisma.church.findMany({
    where: {
      latitude: 0,
      longitude: 0,
      address: { not: null },
      ...(countryCode ? { country: countryCode } : {}),
    },
    select: { id: true, name: true, address: true, country: true, city: true, state: true },
    orderBy: { createdAt: 'asc' },
    take: limit,
  }) as ChurchRecord[];

  log(`Found ${churches.length} churches with lat/lng=0 and an address\n`);

  const stats = { found: 0, notFound: 0, errors: 0 };

  for (const church of churches) {
    try {
      const geocoded = await forwardGeocode(church.address, church.country);

      if (!geocoded) {
        log(`  - [NOT FOUND] ${church.name} | ${church.address}`);
        stats.notFound++;
      } else {
        const { result, usedFallback } = geocoded;
        const lat = parseFloat(result.lat);
        const lng = parseFloat(result.lon);
        const city = result.address?.city || result.address?.town ||
                     result.address?.village || result.address?.municipality || null;
        const state = result.address?.state || result.address?.province || null;

        log(`  + [FOUND${usedFallback ? ' (fallback)' : ''}] ${church.name}`);
        log(`           ${church.address}`);
        log(`           → ${lat}, ${lng}${city ? ` (${city})` : ''}`);

        if (!dryRun) {
          const updateData: Record<string, unknown> = { latitude: lat, longitude: lng };
          if (city && !church.city) updateData.city = city;
          if (state && !church.state) updateData.state = state;

          await prisma.church.update({
            where: { id: church.id },
            data: updateData,
          });
        }

        stats.found++;
      }
    } catch (err: any) {
      log(`  ! [ERROR] ${church.name}: ${err.message}`);
      stats.errors++;
    }

    await sleep(RATE_LIMIT_MS);
  }

  log('');
  log('============================================================');
  log('Forward Geocode Summary');
  log('============================================================');
  log(`Found coords:  ${stats.found}`);
  log(`Not found:     ${stats.notFound}`);
  log(`Errors:        ${stats.errors}`);
  log('============================================================');

  await prisma.$disconnect();
  await pool.end();
}

main().catch(err => {
  console.error('Fatal error:', err);
  process.exit(1);
});