export const DEFAULT_AGENT_ID = 'main';
export const DEFAULT_MAIN_SESSION_SUFFIX = 'main';

export interface AgentSummary {
  id: string;
  name: string;
  isDefault: boolean;
  providerAccountId: string | null;
  modelRef: string | null;
  modelDisplay: string;
  mainSessionKey: string;
  vendorId?: string | null;
  source?: 'synthetic-main' | 'provider-account';
}

export interface AgentsSnapshot {
  agents: AgentSummary[];
  defaultAgentId: string;
  defaultProviderAccountId: string | null;
  defaultModelRef: string | null;
  mainSessionSuffix: string;
  configuredChannelTypes: string[];
  channelOwners: Record<string, string>;
  channelAccountOwners: Record<string, string>;
}

export interface ParsedSessionKey {
  sessionKey: string;
  agentId: string;
  sessionId: string;
  isAgentSession: boolean;
}

export function normalizeAgentId(value: string | null | undefined): string {
  const normalized = String(value ?? '').trim().toLowerCase();
  return normalized || DEFAULT_AGENT_ID;
}

export function normalizeSessionSuffix(value: string | null | undefined): string {
  const normalized = String(value ?? '').trim().toLowerCase();
  return normalized || DEFAULT_MAIN_SESSION_SUFFIX;
}

export function buildAgentSessionKey(agentId: string, sessionId: string): string {
  return `agent:${normalizeAgentId(agentId)}:${normalizeSessionSuffix(sessionId)}`;
}

export function buildMainSessionKey(
  agentId: string,
  sessionId = DEFAULT_MAIN_SESSION_SUFFIX,
): string {
  return buildAgentSessionKey(agentId, sessionId);
}

export function parseSessionKey(sessionKey: string): ParsedSessionKey {
  const trimmed = String(sessionKey ?? '').trim();

  if (trimmed.startsWith('agent:')) {
    const parts = trimmed.split(':');
    const agentId = normalizeAgentId(parts[1]);
    const sessionId = normalizeSessionSuffix(parts.slice(2).join(':'));
    return {
      sessionKey: buildAgentSessionKey(agentId, sessionId),
      agentId,
      sessionId,
      isAgentSession: true,
    };
  }

  if (trimmed.startsWith('local:')) {
    const parts = trimmed.split(':');
    const agentId = normalizeAgentId(parts[1]);
    const sessionId = normalizeSessionSuffix(parts.slice(2).join(':'));
    return {
      sessionKey: buildAgentSessionKey(agentId, sessionId),
      agentId,
      sessionId,
      isAgentSession: true,
    };
  }

  return {
    sessionKey: trimmed,
    agentId: DEFAULT_AGENT_ID,
    sessionId: normalizeSessionSuffix(trimmed),
    isAgentSession: false,
  };
}

export function normalizeAgentSessionKey(sessionKey: string): string {
  return parseSessionKey(sessionKey).sessionKey;
}