import type { ScheduleGroup, ScheduleKind, ScheduleSpec, ScheduleTrigger } from "@umt/contracts";
import type { ServerContext } from "../types.ts";

// 定时任务注册表(进程内):模块在 start() 里登记 {key, defaults, run},schedules 模块的调度器
// 把定义同步进 scheduled_job 表(不覆盖用户改过的开关/调度),按 next_run_at 调用 run。
// 各模块只 import 本文件(不依赖调度器实现);没装 schedules 模块时登记只是一张内存表,不会执行。

export interface ScheduledJobDefaults {
  name: string;
  description?: string;
  group: ScheduleGroup;
  schedule: ScheduleSpec;
  /** 缺省 true */
  enabled?: boolean;
  /** 任务参数(看板可改;task 浅合并,agent_check 整体替换) */
  config?: Record<string, unknown>;
  /** false = 占位(如备份未配置),不执行、不可开启 */
  available?: boolean;
  /** 首次登记时何时第一次运行:now(缺省,尽快)/ after_interval(一个周期后) */
  firstRun?: "now" | "after_interval";
}

export interface JobRunContext {
  jobId: string;
  /** scheduled_job_run.id */
  runId: string;
  trigger: Exclude<ScheduleTrigger, "skip">;
  now: Date;
  /** 当前任务参数(表里的 config) */
  config: Record<string, unknown>;
  /**
   * 时间槽:按调度周期取整的稳定串(interval:floor(now/everyMs);cron:本次计划时间)。
   * 入队幂等键用它拼,多实例 / 重复触发同槽只入队一次;立即执行用 manual:<runId>。
   */
  slot: string;
}

export interface JobRunResult {
  /** 缺省 ok;业务侧主动放弃(如只读对账模式)返回 skipped */
  status?: "ok" | "skipped";
  summary?: string | null;
  agentRunId?: string | null;
}

export type JobRunFn = (c: JobRunContext) => Promise<JobRunResult | undefined>;

export interface ScheduledJobDef {
  /** 稳定 key(表主键),如 feeds.poll */
  key: string;
  kind?: ScheduleKind;
  defaults: ScheduledJobDefaults;
  run: JobRunFn;
}

export interface ScheduleRegistry {
  /** 每次登记 +1,调度器据此判断是否需要重新同步到表 */
  readonly version: number;
  get(key: string): ScheduledJobDef | undefined;
  list(): ScheduledJobDef[];
  register(def: ScheduledJobDef): void;
  unregister(key: string): void;
}

class MemoryRegistry implements ScheduleRegistry {
  version = 0;
  private defs = new Map<string, ScheduledJobDef>();
  get(key: string) {
    return this.defs.get(key);
  }
  list() {
    return [...this.defs.values()];
  }
  register(def: ScheduledJobDef) {
    if (!/^[a-z][a-z0-9_.:-]{1,120}$/.test(def.key)) throw new Error(`定时任务 key 不合法:${def.key}`);
    this.defs.set(def.key, def);
    this.version += 1;
  }
  unregister(key: string) {
    if (this.defs.delete(key)) this.version += 1;
  }
}

const registries = new WeakMap<object, ScheduleRegistry>();

/** 取 ctx 对应的注册表(同一 ServerContext 共用一张) */
export function scheduleRegistry(ctx: Pick<ServerContext, "db">): ScheduleRegistry {
  const k = ctx as object;
  let r = registries.get(k);
  if (!r) {
    r = new MemoryRegistry();
    registries.set(k, r);
  }
  return r;
}

/** 模块 start() 里调用:登记一个周期任务(同 key 重复登记以最后一次为准) */
export function registerScheduledJob(ctx: Pick<ServerContext, "db">, def: ScheduledJobDef): void {
  scheduleRegistry(ctx).register(def);
}