import { loadConfig } from '../config.js';

export interface AgentIdentity {
  canonical: string;
  names: Set<string>;
}

/**
 * Resolve an agent, configured alias, or role name to the canonical roster
 * agent. Projects without an explicit roster keep accepting free-form agent
 * names for backward compatibility.
 */
export function resolveAgentName(cwd: string, recipient: string): string {
  const raw = recipient?.trim();
  if (!raw) throw new Error('Agent recipient is required');
  const key = raw.toLowerCase();
  let config;
  try {
    config = loadConfig(cwd);
  } catch {
    return raw;
  }

  const role = Object.entries(config.roles).find(([name]) => name.toLowerCase() === key);
  if (role) return role[1].preferredAgent;

  const agents = config.agents;
  if (!agents || Object.keys(agents).length === 0) return raw;

  for (const [canonical, entry] of Object.entries(agents)) {
    if (canonical.toLowerCase() === key || entry.aliases.some((alias) => alias.toLowerCase() === key)) {
      return canonical;
    }
  }
  throw new Error(`Unknown agent, alias, or role: "${raw}"`);
}

/** All names that should compare equal for task/handoff/inbox matching. */
export function agentIdentity(cwd: string, recipient: string): AgentIdentity {
  const canonical = resolveAgentName(cwd, recipient);
  const config = loadConfig(cwd);
  const names = new Set<string>([canonical.toLowerCase()]);
  const entry = config.agents?.[canonical];
  for (const alias of entry?.aliases ?? []) names.add(alias.toLowerCase());
  for (const [role, roleConfig] of Object.entries(config.roles)) {
    if (roleConfig.preferredAgent.toLowerCase() === canonical.toLowerCase()) names.add(role.toLowerCase());
  }
  return { canonical, names };
}