export const SUBAGENT_MODES = ["single", "parallel", "chain"] as const;

export type SubagentMode = (typeof SUBAGENT_MODES)[number];

export interface SubagentRunResult {
  task: string;
  exitCode: number;
  agent: string;
  output: string;
  error?: string;
  elapsedMs: number;
  model?: string;
  tools?: string;
}

export interface IndexedSubagentRunResult extends SubagentRunResult {
  taskIndex: number;
}

export interface SubagentResultDetails {
  mode: SubagentMode;
  tasks: IndexedSubagentRunResult[];
}

export function normalizeSubagentRunResult(
  value: Partial<SubagentRunResult> & Pick<SubagentRunResult, "task" | "exitCode" | "output">,
): SubagentRunResult {
  return {
    task: String(value.task),
    exitCode: Number.isFinite(value.exitCode) ? Number(value.exitCode) : 1,
    agent: typeof value.agent === "string" && value.agent.trim() ? value.agent : "subagent",
    output: String(value.output || ""),
    error: typeof value.error === "string" && value.error ? value.error : undefined,
    elapsedMs: Number.isFinite(value.elapsedMs) ? Math.max(0, Number(value.elapsedMs)) : 0,
    model: typeof value.model === "string" && value.model ? value.model : undefined,
    tools: typeof value.tools === "string" && value.tools ? value.tools : undefined,
  };
}

export function makeSubagentResultDetails(mode: SubagentMode, tasks: SubagentRunResult[]): SubagentResultDetails {
  return {
    mode,
    tasks: tasks.map((task, index) => ({ ...task, taskIndex: index + 1 })),
  };
}

export function isSubagentRunResult(value: unknown): value is SubagentRunResult {
  if (!value || typeof value !== "object") return false;
  const candidate = value as Partial<SubagentRunResult>;

  if (typeof candidate.task !== "string") return false;
  if (typeof candidate.agent !== "string") return false;
  if (typeof candidate.output !== "string") return false;
  if (typeof candidate.exitCode !== "number" || !Number.isFinite(candidate.exitCode)) return false;
  if (typeof candidate.elapsedMs !== "number" || !Number.isFinite(candidate.elapsedMs)) return false;

  if (candidate.error !== undefined && typeof candidate.error !== "string") return false;
  if (candidate.model !== undefined && typeof candidate.model !== "string") return false;
  if (candidate.tools !== undefined && typeof candidate.tools !== "string") return false;

  return true;
}

export function isSubagentResultDetails(value: unknown): value is SubagentResultDetails {
  if (!value || typeof value !== "object") return false;
  const candidate = value as Partial<SubagentResultDetails>;

  if (typeof candidate.mode !== "string" || !(SUBAGENT_MODES as readonly string[]).includes(candidate.mode)) {
    return false;
  }

  if (!Array.isArray(candidate.tasks)) return false;

  return candidate.tasks.every((task) => {
    if (!task || typeof task !== "object") return false;
    const item = task as Partial<IndexedSubagentRunResult>;
    return isSubagentRunResult(item) && typeof item.taskIndex === "number" && Number.isFinite(item.taskIndex);
  });
}