/**
 * Fetch token IDs from Gamma events API (temperature markets).
 * Used as fallback when MarketSnapshot table is empty.
 */

import { CITY_ALIASES } from '@poly-weather/core';

const GAMMA_BASE = 'https://gamma-api.polymarket.com';

interface GammaEventMarket {
  id: string;
  groupItemTitle: string;
  clobTokenIds: string;
  closed: boolean;
}

interface GammaEvent {
  id: string;
  title: string;
  markets: GammaEventMarket[];
}

export interface TokenPair {
  yesTokenId: string;
  noTokenId: string;
}

// In-memory cache, refreshed every minute
let cache: Map<string, TokenPair> | null = null;
let cacheTime = 0;
const CACHE_TTL = 60_000;

/**
 * Fetch ALL temperature event markets from Gamma.
 * Returns a map of "city_slug|bucketLabel" -> { yesTokenId, noTokenId }
 */
export async function fetchAllGammaTokens(): Promise<Map<string, TokenPair>> {
  if (cache && Date.now() - cacheTime < CACHE_TTL) {
    return cache;
  }

  const tokenMap = new Map<string, TokenPair>();
  let offset = 0;

  try {
    while (offset <= 500) {
      const params = new URLSearchParams({
        tag_slug: 'temperature',
        active: 'true',
        closed: 'false',
        limit: '50',
        offset: offset.toString(),
      });

      const res = await fetch(`${GAMMA_BASE}/events?${params}`, {
        headers: { Accept: 'application/json' },
        signal: AbortSignal.timeout(15000),
      });

      if (!res.ok) break;
      const events = (await res.json()) as GammaEvent[];
      if (events.length === 0) break;

      for (const event of events) {
        // Parse city from event title: "Highest temperature in Atlanta on March 18?"
        const titleMatch = event.title.match(/temperature in (.+?) on /i);
        if (!titleMatch) continue;

        const rawCity = titleMatch[1].trim();
        // Use CITY_ALIASES to map Gamma titles (e.g. "NYC") to bot slugs (e.g. "new_york")
        const citySlug = CITY_ALIASES[rawCity] ?? rawCity.toLowerCase().replace(/\s+/g, '_');

        for (const m of event.markets || []) {
          if (m.closed) continue;
          const bucketLabel = m.groupItemTitle;
          if (!bucketLabel) continue;

          try {
            const tokenIds = JSON.parse(m.clobTokenIds || '[]');
            if (tokenIds.length >= 1) {
              tokenMap.set(`${citySlug}|${bucketLabel}`, {
                yesTokenId: tokenIds[0] || '',
                noTokenId: tokenIds[1] || '',
              });
            }
          } catch {
            // skip
          }
        }
      }

      offset += 50;
    }
  } catch (err) {
    console.error('Gamma events fetch failed:', err);
  }

  console.log(`[gamma-tokens] Cache loaded: ${tokenMap.size} buckets`);
  cache = tokenMap;
  cacheTime = Date.now();
  return tokenMap;
}

/**
 * Look up token pair for a specific city + bucket.
 * Tries MarketSnapshot DB first, then Gamma API fallback.
 */
export async function lookupTokenPair(
  city: string,
  bucket: string,
  prismaClient: { marketSnapshot: { findFirst: (...args: any[]) => Promise<any> } },
): Promise<TokenPair | null> {
  // Try DB first
  const snapshot = await prismaClient.marketSnapshot.findFirst({
    where: { city, bucketLabel: bucket },
    orderBy: { createdAt: 'desc' },
    select: { yesTokenId: true, noTokenId: true },
  });

  if (snapshot?.yesTokenId) {
    return {
      yesTokenId: snapshot.yesTokenId,
      noTokenId: snapshot.noTokenId || '',
    };
  }

  // Fallback to Gamma
  const gammaTokens = await fetchAllGammaTokens();
  return gammaTokens.get(`${city}|${bucket}`) || null;
}