import { describe, expect, it, vi } from "vitest";
import {
  cleanupOwnedProcessGroup,
  parseProcessEnvironment,
  selectCapturedProcessGroupIds,
  type ProcessOwnershipHost,
} from "../src/application/ProcessOwnership.js";

const ownership = {
  runId: "run-token",
  leaderPid: 100,
  processGroupId: 100,
};

const host = (
  environments: Readonly<Record<number, Readonly<Record<string, string>>>>,
): {
  readonly adapter: ProcessOwnershipHost;
  readonly signalGroup: ReturnType<typeof vi.fn>;
} => {
  const signalGroup = vi.fn();
  return {
    adapter: {
      listMembers: () =>
        Promise.resolve(
          Object.keys(environments).map((pid) => ({
            pid: Number(pid),
            parentPid: Number(pid) === 100 ? 1 : 100,
            processGroupId: 100,
            command: "fixture",
          })),
        ),
      environment: (pid) => Promise.resolve(environments[pid] ?? {}),
      signalGroup,
    },
    signalGroup,
  };
};

describe("owned process-group cleanup", () => {
  it("excludes sampled groups whose leader was outside the captured tree", () => {
    expect(
      selectCapturedProcessGroupIds(100, [
        { pid: 100, process_group_id: 42 },
        { pid: 100, process_group_id: 100 },
        { pid: 101, process_group_id: 42 },
        { pid: 102, process_group_id: 102 },
        { pid: 103, process_group_id: 102 },
      ]),
    ).toEqual([100, 102]);
  });

  it("drops nameless Linux environment entries", () => {
    expect(
      parseProcessEnvironment("=ignored\0REA_PROCESS_RUN_ID=owned\0EMPTY=\0"),
    ).toEqual({ REA_PROCESS_RUN_ID: "owned", EMPTY: "" });
  });

  it("signals only a group whose every member carries the run token", async () => {
    const { adapter, signalGroup } = host({
      100: { REA_PROCESS_RUN_ID: "run-token" },
      101: { REA_PROCESS_RUN_ID: "run-token" },
    });
    expect(await cleanupOwnedProcessGroup(ownership, adapter)).toEqual({
      cleaned: true,
      signaled: true,
    });
    expect(signalGroup).toHaveBeenCalledWith(100, "SIGKILL");
  });

  it("fails closed for stale metadata or an unrelated concurrent process", async () => {
    const { adapter, signalGroup } = host({
      100: { REA_PROCESS_RUN_ID: "run-token" },
      101: { REA_PROCESS_RUN_ID: "different-run" },
    });
    expect(await cleanupOwnedProcessGroup(ownership, adapter)).toEqual({
      cleaned: false,
      reason: "process group contains an unowned or PID-reused process",
    });
    expect(signalGroup).not.toHaveBeenCalled();
  });

  it("is idempotent when the owned group has already exited", async () => {
    const { adapter } = host({});
    expect(await cleanupOwnedProcessGroup(ownership, adapter)).toEqual({
      cleaned: true,
      signaled: false,
    });
  });

  it("fails closed when the launcher command identity changes", async () => {
    const { adapter, signalGroup } = host({
      100: { REA_PROCESS_RUN_ID: "run-token" },
    });
    expect(
      await cleanupOwnedProcessGroup(
        {
          ...ownership,
          expectedCommand: "/owned/hopper",
          expectedParentPid: 1,
        },
        adapter,
      ),
    ).toEqual({
      cleaned: false,
      reason: "owned launcher command identity did not match",
    });
    expect(signalGroup).not.toHaveBeenCalled();
  });

  it("fails closed when the launcher parent identity changes", async () => {
    const { adapter, signalGroup } = host({
      100: { REA_PROCESS_RUN_ID: "run-token" },
    });
    expect(
      await cleanupOwnedProcessGroup(
        { ...ownership, expectedCommand: "fixture", expectedParentPid: 999 },
        adapter,
      ),
    ).toEqual({
      cleaned: false,
      reason: "owned launcher parent identity did not match",
    });
    expect(signalGroup).not.toHaveBeenCalled();
  });
});