/**
 * KHAELOR
 * File: tests/workspace/file-times.test.ts
 * Description: Unit tests for the FileTimeRegistry — read-before-write and external-modification detection.
 *
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 */

import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import * as path from "node:path";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { InMemoryFileTimeRegistry } from "../../src/workspace/index.js";

let dir: string;
let registry: InMemoryFileTimeRegistry;

beforeEach(() => {
  dir = mkdtempSync(path.join(tmpdir(), "khaelor-ft-"));
  registry = new InMemoryFileTimeRegistry();
});

afterEach(() => {
  rmSync(dir, { recursive: true, force: true });
});

describe("FileTimeRegistry", () => {
  it("reports unread for files never stamped", () => {
    expect(registry.check(path.join(dir, "unknown.ts"), "anything")).toBe("unread");
    expect(registry.get(path.join(dir, "unknown.ts"))).toBeUndefined();
  });

  it("reports clean when disk content matches the stamped content", () => {
    const file = path.join(dir, "a.ts");
    writeFileSync(file, "const a = 1;\n");
    registry.stamp(file, "const a = 1;\n");
    expect(registry.check(file, "const a = 1;\n")).toBe("clean");
  });

  it("detects external modification when content changed since the stamp", () => {
    const file = path.join(dir, "b.ts");
    writeFileSync(file, "original\n");
    registry.stamp(file, "original\n");
    writeFileSync(file, "changed by the user\n");
    expect(registry.check(file, "changed by the user\n")).toBe("externally-modified");
  });

  it("records path, size, sha256, mtime and timestamp", () => {
    const file = path.join(dir, "c.ts");
    writeFileSync(file, "abc");
    const before = Date.now();
    registry.stamp(file, "abc");
    const stamp = registry.get(file);
    expect(stamp).toBeDefined();
    expect(stamp?.path).toBe(file);
    expect(stamp?.size).toBe(3);
    expect(stamp?.sha256).toMatch(/^[0-9a-f]{64}$/);
    expect(stamp?.mtimeMs).toBeGreaterThan(0);
    expect(stamp?.at).toBeGreaterThanOrEqual(before);
  });

  it("re-stamping after an agent write returns the file to clean", () => {
    const file = path.join(dir, "d.ts");
    writeFileSync(file, "v1");
    registry.stamp(file, "v1");
    writeFileSync(file, "v2");
    expect(registry.check(file, "v2")).toBe("externally-modified");
    registry.stamp(file, "v2");
    expect(registry.check(file, "v2")).toBe("clean");
  });

  it("normalizes paths so relative and absolute forms agree", () => {
    const file = path.join(dir, "e.ts");
    writeFileSync(file, "x");
    registry.stamp(file, "x");
    expect(registry.get(path.join(dir, ".", "e.ts"))?.path).toBe(file);
  });
});