import { normalizeAgentId } from "../routing/session-key.js";
import { parseAbsoluteTimeMs } from "./parse.js";
import { migrateLegacyCronPayload } from "./payload-migration.js";
import type { CronJobCreate, CronJobPatch } from "./types.js";

type UnknownRecord = Record<string, unknown>;

type NormalizeOptions = {
  applyDefaults?: boolean;
};

const DEFAULT_OPTIONS: NormalizeOptions = {
  applyDefaults: false,
};

function isRecord(value: unknown): value is UnknownRecord {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function coerceSchedule(schedule: UnknownRecord) {
  const next: UnknownRecord = { ...schedule };
  const kind = typeof schedule.kind === "string" ? schedule.kind : undefined;
  const atMsRaw = schedule.atMs;
  const atRaw = schedule.at;
  const parsedAtMs =
    typeof atMsRaw === "string"
      ? parseAbsoluteTimeMs(atMsRaw)
      : typeof atRaw === "string"
        ? parseAbsoluteTimeMs(atRaw)
        : null;

  if (!kind) {
    if (
      typeof schedule.atMs === "number" ||
      typeof schedule.at === "string" ||
      typeof schedule.atMs === "string"
    )
      next.kind = "at";
    else if (typeof schedule.everyMs === "number") next.kind = "every";
    else if (typeof schedule.expr === "string") next.kind = "cron";
  }

  if (typeof schedule.atMs !== "number" && parsedAtMs !== null) {
    next.atMs = parsedAtMs;
  }

  if ("at" in next) delete next.at;

  return next;
}

function coercePayload(payload: UnknownRecord) {
  const next: UnknownRecord = { ...payload };
  // Back-compat: older configs used `provider` for delivery channel.
  migrateLegacyCronPayload(next);
  return next;
}

function unwrapJob(raw: UnknownRecord) {
  if (isRecord(raw.data)) return raw.data;
  if (isRecord(raw.job)) return raw.job;
  return raw;
}

export function normalizeCronJobInput(
  raw: unknown,
  options: NormalizeOptions = DEFAULT_OPTIONS,
): UnknownRecord | null {
  if (!isRecord(raw)) return null;
  const base = unwrapJob(raw);
  const next: UnknownRecord = { ...base };

  if ("agentId" in base) {
    const agentId = (base as UnknownRecord).agentId;
    if (agentId === null) {
      next.agentId = null;
    } else if (typeof agentId === "string") {
      const trimmed = agentId.trim();
      if (trimmed) next.agentId = normalizeAgentId(trimmed);
      else delete next.agentId;
    }
  }

  if ("enabled" in base) {
    const enabled = (base as UnknownRecord).enabled;
    if (typeof enabled === "boolean") {
      next.enabled = enabled;
    } else if (typeof enabled === "string") {
      const trimmed = enabled.trim().toLowerCase();
      if (trimmed === "true") next.enabled = true;
      if (trimmed === "false") next.enabled = false;
    }
  }

  if (isRecord(base.schedule)) {
    next.schedule = coerceSchedule(base.schedule);
  }

  if (isRecord(base.payload)) {
    next.payload = coercePayload(base.payload);
  }

  if (options.applyDefaults) {
    if (!next.wakeMode) next.wakeMode = "next-heartbeat";
    if (!next.sessionTarget && isRecord(next.payload)) {
      const kind = typeof next.payload.kind === "string" ? next.payload.kind : "";
      if (kind === "systemEvent") next.sessionTarget = "main";
      if (kind === "agentTurn") next.sessionTarget = "isolated";
    }
  }

  return next;
}

export function normalizeCronJobCreate(
  raw: unknown,
  options?: NormalizeOptions,
): CronJobCreate | null {
  return normalizeCronJobInput(raw, {
    applyDefaults: true,
    ...options,
  }) as CronJobCreate | null;
}

export function normalizeCronJobPatch(
  raw: unknown,
  options?: NormalizeOptions,
): CronJobPatch | null {
  return normalizeCronJobInput(raw, {
    applyDefaults: false,
    ...options,
  }) as CronJobPatch | null;
}