/**
 * DataService — couche d'abstraction entre l'UI et les sources de données.
 *
 * Mode mock  (USE_LIVE_API = false) : données simulées, aucun appel réseau.
 * Mode live  (USE_LIVE_API = true)  : données réelles Ğ1v2.
 *   - Transactions   : Subsquid indexer  https://squidv2s.syoul.fr/v1/graphql
 *   - Géolocalisation : Cesium+           https://g1.data.e-is.pro
 *     → lookup par clé Duniter (_id) via conversion SS58 → base58 Ed25519
 *     → membres migrés v1→v2 : clé genesis (previousId) = _id Cesium+
 *     → carte d'identité (keyMap) mise en cache 10 min, 1 seule requête
 *
 * Pour activer : définir VITE_USE_LIVE_API=true dans .env.local
 */

import { fetchTransfers, buildIdentityKeyMap } from './adapters/SubsquidAdapter';
import { resolveGeoByKeys } from './adapters/CesiumAdapter';
import {
  getTransactionsForPeriod,
  computeStats,
  type Transaction,
} from '../data/mockData';

const USE_LIVE_API = import.meta.env.VITE_USE_LIVE_API === 'true';

// Cache de la carte identité SS58→DuniterKey, valide 10 minutes
let keyMapCache: { map: Map<string, string>; expiresAt: number } | null = null;

async function getIdentityKeyMap(): Promise<Map<string, string>> {
  if (keyMapCache && Date.now() < keyMapCache.expiresAt) return keyMapCache.map;
  const map = await buildIdentityKeyMap();
  keyMapCache = { map, expiresAt: Date.now() + 10 * 60 * 1000 };
  return map;
}

async function fetchLiveTransactions(periodDays: number): Promise<{
  geolocated: Transaction[];
  totalCount: number;
  totalVolume: number;
}> {
  const rawTransfers = await fetchTransfers(periodDays);
  if (rawTransfers.length === 0) return { geolocated: [], totalCount: 0, totalVolume: 0 };

  const totalCount  = rawTransfers.length;
  const totalVolume = rawTransfers.reduce((s, t) => s + t.amount, 0);

  // Carte SS58 courant → clé Duniter (= _id Cesium+)
  let keyMap = new Map<string, string>();
  try {
    keyMap = await getIdentityKeyMap();
  } catch (err) {
    console.warn('Identity key map indisponible :', err);
  }

  // Clés Duniter uniques des émetteurs
  const duniterKeys = [...new Set(
    rawTransfers.map((t) => keyMap.get(t.fromId)).filter(Boolean) as string[]
  )];

  // Résolution géo par clé Duniter (_id Cesium+)
  let geoMap = new Map<string, { lat: number; lng: number; city: string }>();
  try {
    const profiles = await resolveGeoByKeys(duniterKeys);
    for (const [key, p] of profiles) {
      geoMap.set(key, { lat: p.lat, lng: p.lng, city: p.city });
    }
  } catch (err) {
    console.warn('Cesium+ indisponible :', err);
  }

  // Seules les transactions avec un profil géo entrent dans le heatmap
  const geolocated: Transaction[] = [];
  for (const t of rawTransfers) {
    const duniterKey = keyMap.get(t.fromId);
    if (!duniterKey) continue;
    const geo = geoMap.get(duniterKey);
    if (!geo) continue;

    geolocated.push({
      id:        t.id,
      timestamp: t.timestamp,
      lat:       geo.lat,
      lng:       geo.lng,
      amount:    t.amount,
      city:      geo.city,
      fromKey:   t.fromId,
      toKey:     t.toId,
    });
  }

  return { geolocated, totalCount, totalVolume };
}

// ---------------------------------------------------------------------------
// Public API
// ---------------------------------------------------------------------------
export interface PeriodStats {
  totalVolume:      number;
  transactionCount: number;  // total blockchain (y compris non-géolocalisés)
  geoCount:         number;  // transactions visibles sur la carte
  topCities: { name: string; volume: number; count: number }[];
}

export interface DataResult {
  transactions: Transaction[];  // uniquement géolocalisées → heatmap
  stats:  PeriodStats;
  source: 'live' | 'mock';
}

export async function fetchData(periodDays: number): Promise<DataResult> {
  if (!USE_LIVE_API) {
    await new Promise((r) => setTimeout(r, 80));
    const transactions = getTransactionsForPeriod(periodDays);
    const base = computeStats(transactions);
    return {
      transactions,
      stats: { ...base, geoCount: transactions.length },
      source: 'mock',
    };
  }

  const { geolocated, totalCount, totalVolume } = await fetchLiveTransactions(periodDays);
  const base = computeStats(geolocated);

  return {
    transactions: geolocated,
    stats: {
      totalVolume,
      transactionCount: totalCount,
      geoCount: geolocated.length,
      topCities: base.topCities,
    },
    source: 'live',
  };
}