/** DTOs for agent registration + scoped/revocable bridge tokens (US-007). */

export interface RegisterAgentDto {
  /** Agent alias slug, e.g. "pi0". Combined with host into the agent slug. */
  alias: string;
  /** Host slug, e.g. "web1". Combined with alias into the agent slug. */
  host: string;
  display_name?: string;
}

export interface RevokeAgentDto {
  agent_user_id: string;
}

export interface RegisterAgentResponse {
  agent_user_id: string;
  bridge_token: string;
}

export interface AgentSummary {
  agent_user_id: string;
  alias: string;
  host: string;
  display_name?: string;
  created_at: string;
  active_token_count: number;
}

const SLUG_RE = /^[a-z0-9][a-z0-9_.-]*$/;

/** Combined agent slug, e.g. alias="pi0", host="web1" -> "pi0-web1". */
export function agentSlug(alias: string, host: string): string {
  return `${alias}-${host}`;
}

const assertSlug = (value: unknown, field: string): void => {
  if (typeof value !== 'string' || value.length === 0 || !SLUG_RE.test(value)) {
    throw new Error(`${field} must match [a-z0-9][a-z0-9_.-]* (lowercase, non-empty)`);
  }
};

export function validateRegisterAgent(input: unknown): asserts input is RegisterAgentDto {
  const o = input as Partial<RegisterAgentDto> | null | undefined;
  if (!o || typeof o !== 'object') throw new Error('payload must be an object');
  assertSlug(o.alias, 'alias');
  assertSlug(o.host, 'host');
  if (o.display_name !== undefined) {
    if (typeof o.display_name !== 'string' || o.display_name.length === 0) {
      throw new Error('display_name must be a non-empty string');
    }
    if (o.display_name.length > 100) {
      throw new Error('display_name must be at most 100 chars');
    }
  }
}

export function validateRevokeAgent(input: unknown): asserts input is RevokeAgentDto {
  const o = input as Partial<RevokeAgentDto> | null | undefined;
  if (!o || typeof o !== 'object') throw new Error('payload must be an object');
  if (typeof o.agent_user_id !== 'string' || !o.agent_user_id.startsWith('@')) {
    throw new Error('agent_user_id must be a Matrix user id');
  }
}