const axios = require('axios');
const {
  DEFAULT_VOICE_ASSISTANT_PROFILE,
  resolveAssistantProfile,
} = require('./assistantProfileConfig');

const assistantProfileCache = new Map();

function getAssistantProfileApiUrl() {
  const value = String(process.env.ASSISTANT_PROFILE_API_URL || '').trim();
  return value && !value.startsWith('your_') ? value : '';
}

function getAssistantProfileApiMethod() {
  const method = String(process.env.ASSISTANT_PROFILE_API_METHOD || 'GET').trim().toUpperCase();
  return method === 'POST' ? 'POST' : 'GET';
}

function getAssistantProfileTimeoutMs() {
  const value = Number(process.env.ASSISTANT_PROFILE_API_TIMEOUT_MS || 5000);
  return Number.isFinite(value) && value > 0 ? value : 5000;
}

function getAssistantProfileCacheTtlMs() {
  const value = Number(process.env.ASSISTANT_PROFILE_CACHE_TTL_MS || 60000);
  return Number.isFinite(value) && value >= 0 ? value : 60000;
}

function getAssistantProfileCacheKey(userId = null) {
  return String(userId || 'global').trim() || 'global';
}

function parseAssistantProfileHeaders() {
  const raw = String(process.env.ASSISTANT_PROFILE_API_HEADERS || '').trim();
  if (!raw) return {};
  try {
    const parsed = JSON.parse(raw);
    if (!parsed || typeof parsed !== 'object' || Array.isArray(parsed)) {
      return {};
    }
    return Object.fromEntries(
      Object.entries(parsed)
        .map(([key, value]) => [String(key || '').trim(), String(value || '').trim()])
        .filter(([key, value]) => key && value)
    );
  } catch (error) {
    console.warn('[AssistantProfile] parse headers failed:', error.message);
    return {};
  }
}

function pickAssistantProfilePayload(payload) {
  if (!payload || typeof payload !== 'object' || Array.isArray(payload)) {
    return {};
  }
  const candidates = [
    payload.assistantProfile,
    payload.profile,
    payload.data?.assistantProfile,
    payload.data?.profile,
    payload.data,
    payload,
  ];
  for (const candidate of candidates) {
    if (candidate && typeof candidate === 'object' && !Array.isArray(candidate)) {
      return candidate;
    }
  }
  return {};
}

function sanitizeAssistantProfilePayload(payload) {
  const source = pickAssistantProfilePayload(payload);
  return {
    documents: source.documents,
    email: source.email,
    nickname: source.nickname,
    wxl: source.wxl,
    mobile: source.mobile,
    wx_code: source.wx_code,
    intro: source.intro,
    sign: source.sign,
    story: source.story,
  };
}

async function fetchRemoteAssistantProfile(userId = null) {
  const url = getAssistantProfileApiUrl();
  if (!url) {
    return {
      profile: resolveAssistantProfile(),
      source: 'default',
      cached: false,
      fetchedAt: Date.now(),
      configured: false,
      error: null,
    };
  }
  const headers = {
    Accept: 'application/json',
    ...parseAssistantProfileHeaders(),
  };
  const token = String(process.env.ASSISTANT_PROFILE_API_TOKEN || '').trim();
  if (token) {
    headers.Authorization = `Bearer ${token}`;
  }
  const method = getAssistantProfileApiMethod();
  const timeout = getAssistantProfileTimeoutMs();
  const params = userId ? { userId } : undefined;
  const response = method === 'POST'
    ? await axios.post(url, userId ? { userId } : {}, { headers, timeout })
    : await axios.get(url, { headers, timeout, params });
  const profile = resolveAssistantProfile(sanitizeAssistantProfilePayload(response.data));
  return {
    profile,
    source: 'remote_api',
    cached: false,
    fetchedAt: Date.now(),
    configured: true,
    error: null,
  };
}

async function getAssistantProfile(options = {}) {
  const userId = String(options.userId || '').trim() || null;
  const forceRefresh = !!options.forceRefresh;
  const overrides = options.overrides && typeof options.overrides === 'object' ? options.overrides : null;
  const cacheKey = getAssistantProfileCacheKey(userId);
  const ttlMs = getAssistantProfileCacheTtlMs();
  const cached = assistantProfileCache.get(cacheKey);

  if (!forceRefresh && cached && (Date.now() - cached.fetchedAt) <= ttlMs) {
    return {
      profile: resolveAssistantProfile({ ...cached.profile, ...(overrides || {}) }),
      source: cached.source,
      cached: true,
      fetchedAt: cached.fetchedAt,
      configured: cached.configured,
      error: null,
    };
  }

  try {
    const fetched = await fetchRemoteAssistantProfile(userId);
    assistantProfileCache.set(cacheKey, fetched);
    return {
      profile: resolveAssistantProfile({ ...fetched.profile, ...(overrides || {}) }),
      source: fetched.source,
      cached: false,
      fetchedAt: fetched.fetchedAt,
      configured: fetched.configured,
      error: null,
    };
  } catch (error) {
    const fallback = cached?.profile || DEFAULT_VOICE_ASSISTANT_PROFILE;
    return {
      profile: resolveAssistantProfile({ ...fallback, ...(overrides || {}) }),
      source: cached ? 'cache_fallback' : 'default_fallback',
      cached: !!cached,
      fetchedAt: cached?.fetchedAt || null,
      configured: !!getAssistantProfileApiUrl(),
      error: error.message,
    };
  }
}

function clearAssistantProfileCache(userId = null) {
  if (userId == null || String(userId).trim() === '') {
    assistantProfileCache.clear();
    return;
  }
  assistantProfileCache.delete(getAssistantProfileCacheKey(userId));
}

module.exports = {
  getAssistantProfile,
  clearAssistantProfileCache,
};