import type { ChatMessage } from '../types/workbench';

/** 收集消息的所有可对账身份键 */
export function getMessageKeys(m: ChatMessage): string[] {
  const keys: string[] = [];
  if (m.clientTurnId) {
    keys.push(`turn:${m.clientTurnId}:${m.role}`);
  }
  if (m.clientMessageId) {
    keys.push(`client:${m.clientMessageId}`);
  }
  keys.push(`id:${m.id}`);
  if (m.serverId) {
    keys.push(`server:${m.serverId}`);
  }
  return keys;
}

/** 判断两条消息是否代表同一条物理消息 */
export function isSameMessage(a: ChatMessage, b: ChatMessage): boolean {
  if (a.sessionId !== b.sessionId || a.role !== b.role) {
    return false;
  }
  if (a.id && b.id && a.id === b.id) {
    return true;
  }
  if (a.clientTurnId && b.clientTurnId && a.clientTurnId === b.clientTurnId) {
    return true;
  }
  if (a.serverId && b.serverId && a.serverId === b.serverId) {
    return true;
  }
  if (a.clientMessageId && b.clientMessageId && a.clientMessageId === b.clientMessageId) {
    return true;
  }
  if (a.content === b.content && a.timestamp === b.timestamp) {
    return true;
  }
  return false;
}

/** 构建历史 bucket 中已有消息的身份键集合 */
export function buildExistingMessageKeySet(messages: ChatMessage[]): Set<string> {
  const keys = new Set<string>();
  for (const m of messages) {
    for (const k of getMessageKeys(m)) {
      keys.add(k);
    }
  }
  return keys;
}

/** live 消息是否已在历史中（按身份对账，而非仅 m.id） */
export function isLiveMessageInHistory(
  live: ChatMessage,
  historyMessages: ChatMessage[],
): boolean {
  return historyMessages.some((h) => isSameMessage(live, h));
}

/** 过滤出尚未出现在历史中的 live 消息 */
export function filterPendingLiveMessages(
  liveMessages: ChatMessage[],
  historyMessages: ChatMessage[],
): ChatMessage[] {
  return liveMessages.filter((m) => !isLiveMessageInHistory(m, historyMessages));
}

/** 用 live 流状态覆盖历史快照中的同一条消息 */
export function mergeLiveOverHistory(
  history: ChatMessage,
  live: ChatMessage,
): ChatMessage {
  if (!isSameMessage(history, live)) {
    return history;
  }
  return {
    ...history,
    ...live,
    id: history.id,
    serverId: live.serverId ?? history.serverId,
    clientTurnId: live.clientTurnId ?? history.clientTurnId,
    clientMessageId: live.clientMessageId ?? history.clientMessageId,
    phaseEvents: live.phaseEvents?.length ? live.phaseEvents : history.phaseEvents,
    livePhaseLabel: live.livePhaseLabel ?? history.livePhaseLabel,
    taskDurationMs: live.taskDurationMs ?? history.taskDurationMs,
    phaseSnapshot: live.phaseSnapshot ?? history.phaseSnapshot,
  };
}