function parseJsonReply(reply) {
  const text = String(reply ?? '').trim();
  if (!text) return null;
  const fenced = text.match(/```(?:json)?\s*([\s\S]*?)```/i);
  const candidate = fenced?.[1] ?? text;
  try {
    return JSON.parse(candidate);
  } catch {
    const start = candidate.indexOf('{');
    const end = candidate.lastIndexOf('}');
    if (start < 0 || end <= start) return null;
    try {
      return JSON.parse(candidate.slice(start, end + 1));
    } catch {
      return null;
    }
  }
}

function boundedConfidence(value, fallback = 0.7) {
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return fallback;
  return Math.min(1, Math.max(0, parsed));
}

function normalizeHourMinute(hour, minute, { defaultHour, defaultMinute }) {
  const safeHour = Number(hour);
  const safeMinute = Number(minute ?? 0);
  if (Number.isInteger(safeHour) && safeHour >= 0 && safeHour <= 23
    && Number.isInteger(safeMinute) && safeMinute >= 0 && safeMinute <= 59) {
    return { hour: safeHour, minute: safeMinute };
  }
  if (Number.isInteger(defaultHour) && Number.isInteger(defaultMinute)) {
    return { hour: defaultHour, minute: defaultMinute };
  }
  return null;
}

export function normalizeSubscribeMorningLlmIntent(raw, {
  phase = 'active',
  defaultHour = 8,
  defaultMinute = 0,
  minConfidence = 0.65,
} = {}) {
  const actionRaw = String(raw?.action ?? 'none').trim().toLowerCase();
  const allowed = new Set(['confirm', 'modify', 'cancel', 'clarify', 'none']);
  const action = allowed.has(actionRaw) ? actionRaw : 'none';
  const confidence = boundedConfidence(raw?.confidence);
  if (action === 'none' || confidence < minConfidence) {
    return { action: 'none', confidence, message: null, hour: null, minute: null };
  }

  const time = normalizeHourMinute(raw?.hour, raw?.minute, { defaultHour, defaultMinute });
  const message = String(raw?.message ?? '').trim() || null;

  if (action === 'clarify') {
    return {
      action,
      confidence,
      message: message || '请补充一下具体时间，例如「1 7点」或「早安改到 7 点」。',
      hour: null,
      minute: null,
    };
  }

  if (action === 'cancel') {
    return { action, confidence, message: null, hour: null, minute: null };
  }

  if (action === 'confirm') {
    if (phase !== 'pending') return { action: 'none', confidence, message: null, hour: null, minute: null };
    const resolved = time ?? normalizeHourMinute(defaultHour, defaultMinute, { defaultHour, defaultMinute });
    if (!resolved) return { action: 'none', confidence, message: null, hour: null, minute: null };
    return { action, confidence, message: null, ...resolved };
  }

  if (action === 'modify') {
    if (phase !== 'active' || !time) {
      return {
        action: 'clarify',
        confidence,
        message: message || '请告诉我想改到几点，例如「早安改到 7 点」。',
        hour: null,
        minute: null,
      };
    }
    return { action, confidence, message: null, ...time };
  }

  return { action: 'none', confidence, message: null, hour: null, minute: null };
}

function buildSystemPrompt() {
  return [
    '你是微信服务号「每日早安提醒」助手，只做意图识别，不生成页面。',
    '只输出 JSON，不要 markdown。',
    '{"action":"confirm|modify|cancel|clarify|none","hour":7,"minute":30,"confidence":0.0,"message":"可选中文追问"}',
    'confirm：用户在关注欢迎语后想开通每日早安推送；可带具体时间。例：「1」「1 7点」「不要8点改7点半」。',
    'modify：用户已开通，想改时间。例：「早安改到7点」「改成7点半」。必须给出 hour/minute。',
    'cancel：用户明确不要早安提醒。例：「取消早安」「不要早安了」。',
    'clarify：想改/想开但时间不清楚，message 用一句中文追问。',
    'none：普通聊天、做页面、其它提醒，与早安订阅无关；或无法判断。',
    'hour 取 0-23，minute 取 0-59；没提到分钟则 minute=0。',
  ].join('\n');
}

async function withTimeout(promise, timeoutMs, label) {
  if (!timeoutMs || timeoutMs <= 0) return promise;
  let timer = null;
  try {
    return await Promise.race([
      promise,
      new Promise((_, reject) => {
        timer = setTimeout(() => {
          reject(new Error(`${label} timed out after ${timeoutMs}ms`));
        }, timeoutMs);
        timer.unref?.();
      }),
    ]);
  } finally {
    if (timer) clearTimeout(timer);
  }
}

export async function parseSubscribeMorningIntentWithLlm({
  text,
  phase = 'active',
  defaultHour = 8,
  defaultMinute = 0,
  currentHour = null,
  currentMinute = null,
  llmProviderService,
  modelProviderKeyId = null,
  model = null,
  minConfidence = 0.65,
  timeoutMs = 4000,
  logger = console,
}) {
  if (!llmProviderService || typeof llmProviderService.createChatCompletion !== 'function') {
    return null;
  }
  try {
    const result = await withTimeout(
      llmProviderService.createChatCompletion({
        ...(modelProviderKeyId ? { providerKeyId: modelProviderKeyId } : {}),
        ...(model ? { model } : {}),
        temperature: 0,
        messages: [
          { role: 'system', content: buildSystemPrompt() },
          {
            role: 'user',
            content: JSON.stringify({
              phase,
              userMessage: String(text ?? '').trim(),
              defaultHour,
              defaultMinute,
              currentHour,
              currentMinute,
            }),
          },
        ],
      }),
      timeoutMs,
      'subscribe-morning-llm',
    );
    if (!result?.ok) {
      logger?.warn?.('[wechat-subscribe-morning-llm] skipped:', result?.message ?? 'unknown');
      return null;
    }
    const parsed = parseJsonReply(result.reply);
    if (!parsed) return null;
    return normalizeSubscribeMorningLlmIntent(parsed, {
      phase,
      defaultHour,
      defaultMinute,
      minConfidence,
    });
  } catch (err) {
    logger?.warn?.(
      '[wechat-subscribe-morning-llm] skipped:',
      err instanceof Error ? err.message : err,
    );
    return null;
  }
}

export async function resolveSubscribeMorningLlmIntent({
  text,
  phase = 'active',
  defaultHour = 8,
  defaultMinute = 0,
  currentHour = null,
  currentMinute = null,
  wechatSubscribeMorningLlmConfigService = null,
  llmProviderService = null,
  logger = console,
}) {
  if (!wechatSubscribeMorningLlmConfigService || !llmProviderService) return null;

  let enabled = false;
  let config = null;
  try {
    enabled = await wechatSubscribeMorningLlmConfigService.isSubscribeMorningLlmEnabled();
    config = await wechatSubscribeMorningLlmConfigService.getConfig();
  } catch (err) {
    logger?.warn?.(
      '[wechat-subscribe-morning-llm] config load failed:',
      err instanceof Error ? err.message : err,
    );
    return null;
  }
  if (!enabled) return null;

  return parseSubscribeMorningIntentWithLlm({
    text,
    phase,
    defaultHour,
    defaultMinute,
    currentHour,
    currentMinute,
    llmProviderService,
    modelProviderKeyId: config?.modelProviderKeyId ?? null,
    model: config?.model ?? null,
    minConfidence: config?.minConfidence ?? 0.65,
    timeoutMs: config?.timeoutMs ?? 4000,
    logger,
  });
}