import { INestApplication } from "@nestjs/common";
import { getRepositoryToken } from "@nestjs/typeorm";
import { Repository } from "typeorm";
import { buildTestApp } from "./app.harness";
import { ScenarioSchedulerService } from "../src/scenario/scenario-scheduler.service";
import { ScenarioRunEntity } from "../src/scenario/scenario-run.entity";
import { ScenarioRunStepEntity } from "../src/scenario/scenario-run-step.entity";
import { ScenarioRunLogEntity } from "../src/scenario/scenario-run-log.entity";
import { ScenarioEntity } from "../src/scenario/scenario.entity";
import { ScenarioStepEntity } from "../src/scenario/scenario-step.entity";

describe("ScenarioSchedulerService.onModuleInit", () => {
  let app: INestApplication;
  let scheduler: ScenarioSchedulerService;
  let scenarioRepo: Repository<ScenarioEntity>;
  let stepRepo: Repository<ScenarioStepEntity>;
  let runRepo: Repository<ScenarioRunEntity>;
  let runStepRepo: Repository<ScenarioRunStepEntity>;
  let runLogRepo: Repository<ScenarioRunLogEntity>;

  beforeAll(async () => {
    app = await buildTestApp();
    scheduler = app.get(ScenarioSchedulerService);
    scenarioRepo = app.get<Repository<ScenarioEntity>>(
      getRepositoryToken(ScenarioEntity),
    );
    stepRepo = app.get<Repository<ScenarioStepEntity>>(
      getRepositoryToken(ScenarioStepEntity),
    );
    runRepo = app.get<Repository<ScenarioRunEntity>>(
      getRepositoryToken(ScenarioRunEntity),
    );
    runStepRepo = app.get<Repository<ScenarioRunStepEntity>>(
      getRepositoryToken(ScenarioRunStepEntity),
    );
    runLogRepo = app.get<Repository<ScenarioRunLogEntity>>(
      getRepositoryToken(ScenarioRunLogEntity),
    );
  });

  afterAll(async () => {
    await app.close();
  });

  // ── helpers ────────────────────────────────────────────────────────────────

  async function seedScenarioWithStep() {
    const scenario = await scenarioRepo.save(
      scenarioRepo.create({ name: "test-scenario" }),
    );
    const step = await stepRepo.save(
      stepRepo.create({ scenarioId: scenario.id, order: 1 }),
    );
    return { scenario, step };
  }

  async function seedRun(
    scenarioId: string,
    runStatus: ScenarioRunEntity["status"],
  ) {
    return runRepo.save(
      runRepo.create({ scenarioId, status: runStatus }),
    );
  }

  async function seedStepRun(
    runId: string,
    scenarioStepId: string,
    status: ScenarioRunStepEntity["status"],
  ) {
    return runStepRepo.save(
      runStepRepo.create({ runId, scenarioStepId, order: 1, status }),
    );
  }

  // ── tests ──────────────────────────────────────────────────────────────────

  it("does nothing when no in_progress runs exist", async () => {
    // All existing runs (if any) should already be clean after app init.
    // This call should be a no-op and not throw.
    await expect(scheduler.onModuleInit()).resolves.toBeUndefined();
  });

  it("fails an in_progress run left from a previous server instance", async () => {
    const { scenario } = await seedScenarioWithStep();
    const run = await seedRun(scenario.id, "in_progress");

    await scheduler.onModuleInit();

    const updated = await runRepo.findOneByOrFail({ id: run.id });
    expect(updated.status).toBe("fail");
  });

  it("leaves pending and completed runs untouched", async () => {
    const { scenario } = await seedScenarioWithStep();
    const pending = await seedRun(scenario.id, "pending");
    const passed = await seedRun(scenario.id, "pass");
    const failed = await seedRun(scenario.id, "fail");

    await scheduler.onModuleInit();

    expect((await runRepo.findOneByOrFail({ id: pending.id })).status).toBe(
      "pending",
    );
    expect((await runRepo.findOneByOrFail({ id: passed.id })).status).toBe(
      "pass",
    );
    expect((await runRepo.findOneByOrFail({ id: failed.id })).status).toBe(
      "fail",
    );
  });

  it("fails in_progress step runs belonging to the stale run", async () => {
    const { scenario, step } = await seedScenarioWithStep();
    const run = await seedRun(scenario.id, "in_progress");
    const stepRun = await seedStepRun(run.id, step.id, "in_progress");

    await scheduler.onModuleInit();

    const updated = await runStepRepo.findOneByOrFail({ id: stepRun.id });
    expect(updated.status).toBe("fail");
  });

  it("cancels pending and waiting step runs of a stale run", async () => {
    const { scenario, step } = await seedScenarioWithStep();
    const run = await seedRun(scenario.id, "in_progress");
    const pendingStep = await seedStepRun(run.id, step.id, "pending");
    const waitingStep = await seedStepRun(run.id, step.id, "waiting");

    await scheduler.onModuleInit();

    expect(
      (await runStepRepo.findOneByOrFail({ id: pendingStep.id })).status,
    ).toBe("cancelled");
    expect(
      (await runStepRepo.findOneByOrFail({ id: waitingStep.id })).status,
    ).toBe("cancelled");
  });

  it("does not affect step runs of non-stale runs", async () => {
    const { scenario, step } = await seedScenarioWithStep();
    const staleRun = await seedRun(scenario.id, "in_progress");
    const passedRun = await seedRun(scenario.id, "pass");
    const staleStep = await seedStepRun(staleRun.id, step.id, "in_progress");
    const passedStep = await seedStepRun(passedRun.id, step.id, "pass");

    await scheduler.onModuleInit();

    // in_progress step of the stale run → fail
    expect(
      (await runStepRepo.findOneByOrFail({ id: staleStep.id })).status,
    ).toBe("fail");
    // step of a completed run → untouched
    expect(
      (await runStepRepo.findOneByOrFail({ id: passedStep.id })).status,
    ).toBe("pass");
  });

  it("persists an error log entry for each failed run", async () => {
    const { scenario } = await seedScenarioWithStep();
    const run = await seedRun(scenario.id, "in_progress");

    await scheduler.onModuleInit();

    // Allow the void log persist to flush (persistLog uses void save)
    await new Promise((r) => setTimeout(r, 50));

    const logs = await runLogRepo.findBy({ runId: run.id });
    expect(logs.length).toBeGreaterThanOrEqual(1);
    const errorLog = logs.find((l) => l.level === "error");
    expect(errorLog).toBeDefined();
    expect(errorLog!.message).toMatch(/server restarted/i);
  });

  it("handles multiple stale runs in one pass", async () => {
    const { scenario } = await seedScenarioWithStep();
    const run1 = await seedRun(scenario.id, "in_progress");
    const run2 = await seedRun(scenario.id, "in_progress");

    await scheduler.onModuleInit();

    expect((await runRepo.findOneByOrFail({ id: run1.id })).status).toBe(
      "fail",
    );
    expect((await runRepo.findOneByOrFail({ id: run2.id })).status).toBe(
      "fail",
    );
  });
});