import { describe, it, expect } from "vitest";
import { createActor } from "xstate";
import { pipelineMachine } from "../src/orchestrator/machine.js";

function runMachine(events: Array<Record<string, unknown>>) {
  const actor = createActor(pipelineMachine);
  actor.start();
  for (const event of events) {
    actor.send(event as any);
  }
  const snapshot = actor.getSnapshot();
  actor.stop();
  return snapshot;
}

describe("pipelineMachine", () => {
  it("starts in idle", () => {
    const actor = createActor(pipelineMachine);
    actor.start();
    expect(actor.getSnapshot().value).toBe("idle");
    actor.stop();
  });

  it("happy path: idle → planning → implementing → reviewing → deploying → done", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "build something" },
      { type: "PLAN_READY", planDir: "/tmp/plans", sprintId: "SPRINT-001" },
      { type: "IMPL_DONE", branch: "feature/sprint-001", commits: ["abc1234"] },
      { type: "APPROVE", reviewArtifact: "/tmp/review.json" },
      { type: "DEPLOY_DONE", deployArtifact: "/tmp/deploy.json" },
    ]);
    expect(snapshot.value).toBe("done");
    expect(snapshot.status).toBe("done");
  });

  it("REQUEST_CHANGES loops back to implementing (up to maxReviewRounds)", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "PLAN_READY", planDir: "/tmp", sprintId: "S1" },
      { type: "IMPL_DONE", branch: "b", commits: ["c1"] },
      { type: "REQUEST_CHANGES", issues: [{ severity: "major", message: "fix it" }] },
    ]);
    expect(snapshot.value).toBe("implementing");
    expect(snapshot.context.reviewRound).toBe(1);
  });

  it("escalates after max review rounds exceeded", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "PLAN_READY", planDir: "/tmp", sprintId: "S1" },
      // Round 1 (reviewRound: 0 → 1)
      { type: "IMPL_DONE", branch: "b", commits: ["c1"] },
      { type: "REQUEST_CHANGES", issues: [{ severity: "major", message: "fix" }] },
      // Round 2 (reviewRound: 1 → 2)
      { type: "IMPL_DONE", branch: "b", commits: ["c2"] },
      { type: "REQUEST_CHANGES", issues: [{ severity: "major", message: "fix" }] },
      // Round 3 (reviewRound: 2 → 3)
      { type: "IMPL_DONE", branch: "b", commits: ["c3"] },
      { type: "REQUEST_CHANGES", issues: [{ severity: "major", message: "fix" }] },
      // Round 4 — reviewRound=3, guard 3 < 3 = false → escalated
      { type: "IMPL_DONE", branch: "b", commits: ["c4"] },
      { type: "REQUEST_CHANGES", issues: [{ severity: "major", message: "fix" }] },
    ]);
    expect(snapshot.value).toBe("escalated");
    expect(snapshot.context.lastError).toContain("review rounds");
  });

  it("retryable error goes to retrying, then back (if under limit)", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "ERROR", actor: "planner", reason: "timeout", retryable: true },
    ]);
    // retrying has an always transition — if canRetry, goes to idle
    expect(snapshot.value).toBe("idle");
    expect(snapshot.context.retryCount).toBe(1);
  });

  it("non-retryable error goes to escalated", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "ERROR", actor: "planner", reason: "permission denied", retryable: false },
    ]);
    expect(snapshot.value).toBe("escalated");
    expect(snapshot.context.lastError).toBe("permission denied");
  });

  it("escalated → RESUME goes back to idle", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "ERROR", actor: "planner", reason: "fail", retryable: false },
      { type: "RESUME" },
    ]);
    expect(snapshot.value).toBe("idle");
    expect(snapshot.context.lastError).toBeNull();
  });

  it("ABORT from any active state goes to aborted", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "test", requirements: "" },
      { type: "ABORT", reason: "user cancelled" },
    ]);
    expect(snapshot.value).toBe("aborted");
    expect(snapshot.context.lastError).toBe("user cancelled");
  });

  it("context tracks projectName and requirements from REQUEST", () => {
    const snapshot = runMachine([
      { type: "REQUEST", projectName: "arang", requirements: "Live2D avatar" },
    ]);
    expect(snapshot.context.projectName).toBe("arang");
    expect(snapshot.context.requirements).toBe("Live2D avatar");
  });
});