import { readFileSync, realpathSync } from "node:fs";
import { join } from "node:path";

export interface ContainerSnapshot {
  Id: string;
  State: { StartedAt: string; Running: boolean };
}
export interface ContainerEvent {
  Type: string;
  Action: string;
  Actor: { ID: string; Attributes: { name: string } };
}
export interface LifecycleWindow {
  since: string;
  until: string;
  run: string;
  resultSeq: number;
}

/** 原始历史事件覆盖杀前到目标结果落账；spawn 后的快照本身不证明恢复没有重启。 */
export function sameContainerThroughResult(
  snapshots: ContainerSnapshot[],
  events: ContainerEvent[],
  container: string,
) {
  const original = snapshots[0]!;
  const target = events.filter(
    (e) =>
      e.Type === "container" &&
      (e.Actor.ID === original.Id || e.Actor.Attributes.name === container),
  );
  return {
    snapshotsAgree:
      original.State.Running &&
      snapshots.every(
        (s) =>
          s.Id === original.Id &&
          s.State.StartedAt === original.State.StartedAt,
      ),
    // Docker 只保留最近 256 条事件；碰到上限不能据此声称整个区间没有重启。
    historyWithinLimit: events.length < 256,
    completionObserved: target.some(
      (e) => e.Actor.ID === original.Id && e.Action === "die",
    ),
    noRestartOrReplacement: target.every(
      (e) =>
        e.Actor.ID === original.Id &&
        !["start", "restart", "create"].includes(e.Action),
    ),
  };
}

export interface StudySummary {
  dir: string;
  study: string;
  pass: boolean;
  accounts: { checks: { adoptedAndStopped: boolean } };
  kill: { checks: Record<string, boolean> } | null;
}
interface LaunchEvent {
  event: "start" | "end";
  pid: number;
  at: string;
}

/** 任务书16的总体程序验收；逐研究 stats 通过不等于三份研究的总体验收通过。 */
export function forwardAcceptance(summaries: StudySummary[]) {
  const intervals = summaries.map((s) => {
    const launches = readFileSync(join(s.dir, "launches.jsonl"), "utf8")
      .trim()
      .split("\n")
      .filter(Boolean)
      .map((line) => JSON.parse(line) as LaunchEvent);
    const paired =
      launches.length > 0 &&
      launches.length % 2 === 0 &&
      launches.every((e, i) => {
        if (i % 2 === 1) return e.event === "end";
        const end = launches[i + 1];
        return (
          e.event === "start" &&
          end?.event === "end" &&
          end.pid === e.pid &&
          Date.parse(e.at) <= Date.parse(end.at) &&
          (i === 0 || Date.parse(launches[i - 1]!.at) <= Date.parse(e.at))
        );
      });
    return {
      study: s.study,
      dir: realpathSync(s.dir),
      paired,
      start: launches[0]?.at ?? null,
      end: launches.at(-1)?.at ?? null,
    };
  });
  const ordered = [...intervals].sort(
    (a, b) => Date.parse(a.start!) - Date.parse(b.start!),
  );
  const checks = {
    threeDifferentStudies:
      summaries.length === 3 &&
      new Set(summaries.map((s) => s.study)).size === 3 &&
      new Set(intervals.map((s) => s.dir)).size === 3,
    allCompletedAndPassed: summaries.every(
      (s) => s.pass && s.accounts.checks.adoptedAndStopped,
    ),
    successfulKill: summaries.some(
      (s) => s.kill !== null && Object.values(s.kill.checks).every(Boolean),
    ),
    launchIntervalsComplete: intervals.every((s) => s.paired),
    studiesDoNotOverlap: ordered.every(
      (s, i) =>
        s.paired &&
        (i === 0 || Date.parse(ordered[i - 1]!.end!) <= Date.parse(s.start!)),
    ),
  };
  return {
    scope: "任务书16总体程序验收（不替代独立研究质量审阅）",
    intervals,
    checks,
    pass: Object.values(checks).every(Boolean),
    limit:
      "启动区间含同份研究杀后恢复的间隔；只核对所给三份研究，不据此排除任意外部进程抢占CPU。",
  };
}