import type { TaskSession, TaskSessionState } from "@/lib/types/http";
import type { AgentProfileOption } from "@/lib/state/slices";

const STATUS_ORDER: Record<TaskSessionState, number> = {
  RUNNING: 1,
  STARTING: 1,
  WAITING_FOR_INPUT: 2,
  // Office sessions sit IDLE between turns — order them with WAITING_FOR_INPUT
  // (parked, conversation alive, just not currently running).
  IDLE: 2,
  CREATED: 3,
  COMPLETED: 4,
  FAILED: 5,
  CANCELLED: 6,
};

export function sortSessions(sessions: readonly TaskSession[]): TaskSession[] {
  return [...sessions].sort((a, b) => {
    const d = (STATUS_ORDER[a.state] ?? 99) - (STATUS_ORDER[b.state] ?? 99);
    return d !== 0 ? d : new Date(b.started_at).getTime() - new Date(a.started_at).getTime();
  });
}

export function buildAgentLabelsById(
  agentProfiles: readonly AgentProfileOption[],
): Record<string, string> {
  return Object.fromEntries(agentProfiles.map((p) => [p.id, p.label]));
}

/**
 * Resolves the display label for a session's agent.
 *
 * Store first so that renaming an agent profile is reflected everywhere that
 * calls this (matches the long-standing dropdown behavior). Falls back to the
 * snapshot label only when the profile is no longer in the store — that keeps
 * tabs/rows for sessions whose profile was deleted from rendering as
 * "Unknown agent".
 */
export function resolveAgentLabelFor(
  session: TaskSession,
  agentLabelsById: Record<string, string>,
): string {
  const storeLabel = session.agent_profile_id
    ? (agentLabelsById[session.agent_profile_id] ?? null)
    : null;
  if (storeLabel) return storeLabel;
  const snapshotLabel = (session.agent_profile_snapshot?.label as string | undefined) ?? null;
  if (snapshotLabel) return snapshotLabel;
  return "Unknown agent";
}

export function pickActiveSessionId(
  sessions: readonly TaskSession[],
  preferredSessionId: string | null | undefined,
): string | null {
  if (sessions.length === 0) return null;
  if (preferredSessionId && sessions.some((s) => s.id === preferredSessionId)) {
    return preferredSessionId;
  }
  const primary = sessions.find((s) => s.is_primary);
  return (primary ?? sessions[0]).id;
}

export function isSessionActive(state: TaskSessionState | null | undefined): boolean {
  return state === "RUNNING" || state === "STARTING";
}