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

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' | 'agent-config';
  overrideModelRef?: string | null;
  inheritedModel?: boolean;
  workspace?: string;
  agentDir?: string;
  channelTypes?: string[];
}

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

export interface AgentChannelBinding {
  channelType: string;
  accountId: string;
  agentId: string;
}

export interface AgentChannelBindingInput {
  channelType: string;
  accountId: string;
  agentId: string;
}

export interface AgentChannelUnbindingInput {
  channelType: string;
  accountId: string;
}

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 normalizeChannelType(value: string | null | undefined): string {
  return String(value ?? '').trim().toLowerCase();
}

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

export function buildChannelAccountOwnerKey(
  channelType: string,
  accountId: string | null | undefined = DEFAULT_CHANNEL_ACCOUNT_ID,
): string {
  return `${normalizeChannelType(channelType)}:${normalizeChannelAccountId(accountId)}`;
}

export function parseChannelAccountOwnerKey(key: string): {
  channelType: string;
  accountId: string;
} {
  const trimmed = String(key ?? '').trim();
  const separatorIndex = trimmed.indexOf(':');
  if (separatorIndex === -1) {
    return {
      channelType: normalizeChannelType(trimmed),
      accountId: DEFAULT_CHANNEL_ACCOUNT_ID,
    };
  }

  return {
    channelType: normalizeChannelType(trimmed.slice(0, separatorIndex)),
    accountId: normalizeChannelAccountId(trimmed.slice(separatorIndex + 1)),
  };
}

export function resolveChannelAccountOwner(
  channelAccountOwners: Record<string, string> | null | undefined,
  channelType: string,
  accountId?: string | null,
): string | null {
  if (!channelAccountOwners) return null;
  const key = buildChannelAccountOwnerKey(channelType, accountId);
  const owner = channelAccountOwners[key];
  return typeof owner === 'string' && owner.trim() ? owner : null;
}

export type AgentSummaryLike = AgentSummary;
export type AgentsSnapshotLike = AgentsSnapshot;