import { execSync } from "node:child_process";
import * as os from "node:os";
import * as path from "node:path";
import * as fs from "node:fs";
import { GitBranch } from "../core/git-branch.js";

function createTempRepo(): string {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "ciagent-branch-test-"));
  execSync("git init", { cwd: dir, stdio: "pipe" });
  execSync('git config user.email "test@test.com"', { cwd: dir, stdio: "pipe" });
  execSync('git config user.name "Test"', { cwd: dir, stdio: "pipe" });
  fs.writeFileSync(path.join(dir, "file.txt"), "initial", "utf-8");
  execSync("git add . && git commit -m 'initial'", { cwd: dir, stdio: "pipe" });
  return dir;
}

function cleanup(dir: string): void {
  fs.rmSync(dir, { recursive: true, force: true });
}

describe("GitBranch", () => {
  let repoDir: string;

  beforeEach(() => {
    repoDir = createTempRepo();
  });

  afterEach(() => {
    cleanup(repoDir);
  });

  describe("createPhaseBranch", () => {
    it("creates a phase branch with correct naming", () => {
      const gitBranch = new GitBranch(repoDir);
      const result = gitBranch.createPhaseBranch(1, "authentication");

      expect(result.created).toBe(true);
      expect(result.name).toBe("phase/01-authentication");
    });

    it("detects already existing phase branch", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createPhaseBranch(1, "authentication");

      const result = gitBranch.createPhaseBranch(1, "authentication");
      expect(result.alreadyExisted).toBe(true);
      expect(result.created).toBe(false);
    });

    it("zero-pads phase numbers", () => {
      const gitBranch = new GitBranch(repoDir);
      const result = gitBranch.createPhaseBranch(3, "real-time-notifications");

      expect(result.name).toBe("phase/03-real-time-notifications");
    });

    it("creates project-prefixed phase branch when projectSlug is set", () => {
      const gitBranch = new GitBranch(repoDir, "task-api");
      const result = gitBranch.createPhaseBranch(1, "authentication");

      expect(result.created).toBe(true);
      expect(result.name).toBe("task-api/phase/01-authentication");
    });

    it("updates project prefix after setProjectSlug", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.setProjectSlug("auth-svc");
      const result = gitBranch.createPhaseBranch(2, "token-rotation");

      expect(result.name).toBe("auth-svc/phase/02-token-rotation");
    });
  });

  describe("createMilestoneBranch", () => {
    it("creates a milestone branch with correct naming", () => {
      const gitBranch = new GitBranch(repoDir);
      const result = gitBranch.createMilestoneBranch("v1.0", "mvp");

      expect(result.created).toBe(true);
      expect(result.name).toBe("milestone/v1.0-mvp");
    });

    it("detects already existing milestone branch", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createMilestoneBranch("v1.0", "mvp");

      const result = gitBranch.createMilestoneBranch("v1.0", "mvp");
      expect(result.alreadyExisted).toBe(true);
    });

    it("creates project-prefixed milestone branch when projectSlug is set", () => {
      const gitBranch = new GitBranch(repoDir, "task-api");
      const result = gitBranch.createMilestoneBranch("v1.0", "mvp");

      expect(result.created).toBe(true);
      expect(result.name).toBe("task-api/milestone/v1.0-mvp");
    });
  });

  describe("listPhases", () => {
    it("lists phase branches with status", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createPhaseBranch(1, "auth");
      gitBranch.createPhaseBranch(2, "tasks");

      const phases = gitBranch.listPhases();
      expect(phases.length).toBeGreaterThanOrEqual(2);

      const phase1 = phases.find((p) => p.phaseNumber === 1);
      expect(phase1).toBeDefined();
      expect(phase1!.status).toBe("active");
    });
  });

  describe("getPhaseStatus", () => {
    it("returns status for existing phase branch", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createPhaseBranch(1, "auth");

      const status = gitBranch.getPhaseStatus(1);
      expect(status).not.toBeNull();
      expect(status!.phaseNumber).toBe(1);
      expect(status!.status).toBe("active");
    });

    it("returns null for non-existent phase", () => {
      const gitBranch = new GitBranch(repoDir);
      const status = gitBranch.getPhaseStatus(99);
      expect(status).toBeNull();
    });
  });

  describe("slugify", () => {
    it("creates correct branch slugs", () => {
      const gitBranch = new GitBranch(repoDir);
      const result = gitBranch.createPhaseBranch(1, "Real-Time Notifications & Stuff!");
      expect(result.name).toMatch(/^phase\/01-/);
    });
  });

  describe("validateMergeOrder", () => {
    it("rejects phase → main when milestone branch exists", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createMilestoneBranch("v0.5", "baseline");
      gitBranch.createPhaseBranch(1, "auth");
      execSync(`git checkout main`, { cwd: repoDir, stdio: "pipe" });

      const result = gitBranch.validateMergeOrder("phase/01-auth", "main");
      expect(result.valid).toBe(false);
      expect(result.reason).toContain("milestone");
    });

    it("allows phase → milestone branch", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createMilestoneBranch("v0.5", "baseline");
      gitBranch.createPhaseBranch(1, "auth");
      execSync(`git checkout milestone/v0.5-baseline`, { cwd: repoDir, stdio: "pipe" });

      const result = gitBranch.validateMergeOrder("phase/01-auth", "milestone/v0.5-baseline");
      expect(result.valid).toBe(true);
    });

    it("allows phase → main when no milestone branch exists", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createPhaseBranch(1, "auth");
      execSync(`git checkout main`, { cwd: repoDir, stdio: "pipe" });

      const result = gitBranch.validateMergeOrder("phase/01-auth", "main");
      expect(result.valid).toBe(true);
    });

    it("allows hotfix → main", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createMilestoneBranch("v0.5", "baseline");
      execSync(`git checkout -b hotfix/critical-fix main`, { cwd: repoDir, stdio: "pipe" });
      fs.writeFileSync(path.join(repoDir, "fix.txt"), "fix");
      execSync(`git add . && git commit -m "hotfix: critical fix"`, { cwd: repoDir, stdio: "pipe" });
      execSync(`git checkout main`, { cwd: repoDir, stdio: "pipe" });

      const result = gitBranch.validateMergeOrder("hotfix/critical-fix", "main");
      expect(result.valid).toBe(true);
    });
  });

  describe("computeMilestoneTag", () => {
    it("computes next minor for feature milestone", () => {
      execSync(`git tag -a v0.5.1 -m "v0.5.1"`, { cwd: repoDir, stdio: "pipe" });
      execSync(`git tag -a v0.5.2 -m "v0.5.2"`, { cwd: repoDir, stdio: "pipe" });

      const gitBranch = new GitBranch(repoDir);
      const tag = gitBranch.computeMilestoneTag("feature");
      expect(tag).toBe("v0.6.0");
    });

    it("computes next major for major milestone", () => {
      execSync(`git tag -a v0.5.1 -m "v0.5.1"`, { cwd: repoDir, stdio: "pipe" });

      const gitBranch = new GitBranch(repoDir);
      const tag = gitBranch.computeMilestoneTag("major");
      expect(tag).toBe("v1.0.0");
    });

    it("starts from v0.1.0 when no tags exist", () => {
      const gitBranch = new GitBranch(repoDir);
      const tag = gitBranch.computeMilestoneTag("feature");
      expect(tag).toBe("v0.1.0");
    });
  });

  describe("mergeMilestoneBranch", () => {
    it("rejects merge when unmerged phase branches remain", () => {
      const gitBranch = new GitBranch(repoDir);
      gitBranch.createMilestoneBranch("v0.5", "baseline");
      gitBranch.createPhaseBranch(1, "auth");
      execSync(`git checkout main`, { cwd: repoDir, stdio: "pipe" });

      const result = gitBranch.mergeMilestoneBranch("milestone/v0.5-baseline", "main", true);
      expect(result.success).toBe(false);
      expect(result.message).toContain("unmerged");
    });
  });
});