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 { GitContext } from "../core/git-context.js";

function createTempRepo(): string {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "ciagent-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" });
  return dir;
}

function commit(repoDir: string, message: string): void {
  const filePath = path.join(repoDir, `file-${Date.now()}.txt`);
  fs.writeFileSync(filePath, "test", "utf-8");
  execSync(`git add "${filePath}"`, { cwd: repoDir, stdio: "pipe" });
  execSync(`git commit -m "${message.replace(/"/g, '\\"')}"`, { cwd: repoDir, stdio: "pipe" });
}

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

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

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

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

  describe("isGitRepo", () => {
    it("returns true for a git repo", () => {
      const ctx = new GitContext(repoDir);
      expect(ctx.isGitRepo()).toBe(true);
    });

    it("returns false for non-git directory", () => {
      const nonGit = fs.mkdtempSync(path.join(os.tmpdir(), "ciagent-nongit-"));
      const ctx = new GitContext(nonGit);
      expect(ctx.isGitRepo()).toBe(false);
      cleanup(nonGit);
    });
  });

  describe("getCurrentBranch", () => {
    it("returns current branch name", () => {
      const ctx = new GitContext(repoDir);
      commit(repoDir, "initial");
      expect(ctx.getCurrentBranch()).toBeTruthy();
    });
  });

  describe("projectSlug", () => {
    it("defaults to undefined", () => {
      const ctx = new GitContext(repoDir);
      expect(ctx.getProjectSlug()).toBeUndefined();
    });

    it("accepts project slug in constructor", () => {
      const ctx = new GitContext(repoDir, "task-api");
      expect(ctx.getProjectSlug()).toBe("task-api");
    });

    it("setProjectSlug updates slug", () => {
      const ctx = new GitContext(repoDir);
      ctx.setProjectSlug("auth-svc");
      expect(ctx.getProjectSlug()).toBe("auth-svc");
    });
  });

  describe("getRecentCommits", () => {
    it("returns parsed commits with ci blocks", () => {
      commit(repoDir, `docs(init): initialize project

---ci---
phase: 0
milestone: v1.0
status: specify
---/ci---

Initial commit`);

      const ctx = new GitContext(repoDir);
      const commits = ctx.getRecentCommits(5);

      expect(commits.length).toBeGreaterThanOrEqual(1);
      const ciCommit = commits.find((c) => c.ci !== null);
      expect(ciCommit).toBeDefined();
      expect(ciCommit!.ci!.phase).toBe(0);
      expect(ciCommit!.ci!.milestone).toBe("v1.0");
    });

    it("returns commits without ci blocks as null ci", () => {
      commit(repoDir, "feat: some feature");

      const ctx = new GitContext(repoDir);
      const commits = ctx.getRecentCommits(5);

      expect(commits.length).toBeGreaterThanOrEqual(1);
      expect(commits[0].ci).toBeNull();
    });
  });

  describe("reconstructState", () => {
    it("reconstructs state from latest ci commit", () => {
      commit(repoDir, `docs(init): initialize project

---ci---
phase: 1
milestone: v1.0
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      const state = ctx.reconstructState();

      expect(state.currentPhase).toBe(1);
      expect(state.currentMilestone).toBe("v1.0");
      expect(state.currentStage).toBe("execute");
    });

    it("returns default state without ci commits", () => {
      commit(repoDir, "feat: some regular feature");

      const ctx = new GitContext(repoDir);
      const state = ctx.reconstructState();

      expect(state.currentPhase).toBe(0);
      expect(state.currentStage).toBe("specify");
    });
  });

  describe("getDecisionsFromCommits", () => {
    it("extracts decisions from parsed commits", () => {
      commit(repoDir, `feat(P01): add auth

---ci---
phase: 1
milestone: v1.0
status: execute
decisions:
  - id: D-001
    decision: Use bcrypt
    rationale: Industry standard
    confidence: 0.90
    alternatives: [argon2]
---/ci---`);

      const ctx = new GitContext(repoDir);
      const commits = ctx.getRecentCommits(5);
      const decisions = ctx.getDecisionsFromCommits(commits);

      expect(decisions).toHaveLength(1);
      expect(decisions[0].id).toBe("D-001");
      expect(decisions[0].decision).toBe("Use bcrypt");
    });
  });

  describe("getLessons", () => {
    it("extracts lessons from commits", () => {
      commit(repoDir, `docs(P01): complete phase

---ci---
phase: 1
milestone: v1.0
status: complete
lessons:
  - Never use sync bcrypt
  - Always check JWT expiry first
---/ci---`);

      const ctx = new GitContext(repoDir);
      const commits = ctx.getRecentCommits(10);
      const lessons: string[] = [];
      for (const commit of commits) {
        if (commit.ci?.lessons) lessons.push(...commit.ci.lessons);
      }

      expect(lessons).toContain("Never use sync bcrypt");
      expect(lessons).toContain("Always check JWT expiry first");
    });
  });

  describe("getBranches", () => {
    it("lists branches with type info", () => {
      commit(repoDir, "initial");
      execSync("git checkout -b phase/01-auth", { cwd: repoDir, stdio: "pipe" });
      commit(repoDir, "feat: auth work");
      execSync("git checkout -b milestone/v1.0-mvp", { cwd: repoDir, stdio: "pipe" });
      commit(repoDir, "feat: milestone work");

      const ctx = new GitContext(repoDir);
      const branches = ctx.getBranches();

      const phaseBranches = branches.filter((b) => b.type === "phase");
      const milestoneBranches = branches.filter((b) => b.type === "milestone");

      expect(phaseBranches.length).toBeGreaterThanOrEqual(1);
      expect(milestoneBranches.length).toBeGreaterThanOrEqual(1);
      expect(phaseBranches[0].phaseNumber).toBe(1);
    });

    it("strips project prefix when projectSlug is set", () => {
      commit(repoDir, "initial");
      execSync("git checkout -b task-api/phase/01-auth", { cwd: repoDir, stdio: "pipe" });
      commit(repoDir, "feat: auth work");

      const ctx = new GitContext(repoDir, "task-api");
      const branches = ctx.getBranches();

      const phaseBranches = branches.filter((b) => b.type === "phase");
      expect(phaseBranches.length).toBeGreaterThanOrEqual(1);
      expect(phaseBranches[0].phaseNumber).toBe(1);
      expect(phaseBranches[0].name).toBe("task-api/phase/01-auth");
    });
  });

  describe("detectProjectFromCommit", () => {
    it("detects project from ci block project field", () => {
      commit(repoDir, `feat(P01): task work

---ci---
phase: 1
milestone: v1.0
project: task-api
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.detectProjectFromCommit()).toBe("task-api");
    });

    it("detects project from branch prefix", () => {
      commit(repoDir, "initial");
      execSync("git checkout -b auth-svc/phase/01-auth", { cwd: repoDir, stdio: "pipe" });
      commit(repoDir, "feat: auth work");

      const ctx = new GitContext(repoDir);
      expect(ctx.detectProjectFromCommit()).toBe("auth-svc");
    });

    it("returns null when no project detected", () => {
      commit(repoDir, "feat: some work");
      const ctx = new GitContext(repoDir);
      expect(ctx.detectProjectFromCommit()).toBeNull();
    });
  });

  describe("isNfrMilestone", () => {
    it("returns true when no feat commits exist", () => {
      commit(repoDir, `chore(P01): cleanup

---ci---
phase: 1
milestone: v0.1.1
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.isNfrMilestone()).toBe(true);
    });

    it("returns false when feat commits exist", () => {
      commit(repoDir, `feat(P01): add feature

---ci---
phase: 1
milestone: v1.0
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.isNfrMilestone()).toBe(false);
    });
  });

  describe("getMilestoneType", () => {
    it("returns nfr when only NFR commits exist", () => {
      commit(repoDir, `chore(P01): cleanup

---ci---
phase: 1
milestone: v0.1.1
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.getMilestoneType()).toBe("nfr");
    });

    it("returns feature when feat commits exist", () => {
      commit(repoDir, `feat(P01): add feature

---ci---
phase: 1
milestone: v1.0
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.getMilestoneType()).toBe("feature");
    });

    it("returns schema-breaking when refactor commits exist", () => {
      commit(repoDir, `refactor(P01): rewrite core

---ci---
phase: 1
milestone: v0.5
status: execute
---/ci---`);

      const ctx = new GitContext(repoDir);
      expect(ctx.getMilestoneType()).toBe("schema-breaking");
    });
  });
});