import { describe, it, expect, beforeEach, afterEach } from "vitest";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import { BaselineStore, type Baseline } from "../src/baselineStore";

let dir: string;

beforeEach(() => {
  dir = fs.mkdtempSync(path.join(os.tmpdir(), "baseline-store-"));
});
afterEach(() => {
  fs.rmSync(dir, { recursive: true, force: true });
});

function sample(docPath = "notes/chapter-1.md"): Baseline {
  return { docPath, text: "hello\nworld\n", capturedAt: "2026-06-11T00:00:00.000Z", reason: "opened" };
}

describe("BaselineStore", () => {
  it("returns null for a document with no baseline", () => {
    expect(new BaselineStore(dir).load("notes/chapter-1.md")).toBeNull();
  });

  it("computes the baseline path as baselines/<docPath>.json", () => {
    const store = new BaselineStore(dir);
    expect(store.baselinePath("notes/chapter-1.md")).toBe(
      path.join(dir, "baselines", "notes", "chapter-1.md.json"),
    );
  });

  it("save then load round-trips the baseline (including nested docPaths)", () => {
    const store = new BaselineStore(dir);
    const b = sample();
    store.save(b.docPath, b);
    expect(store.load(b.docPath)).toEqual(b);
  });

  it("overwrites in place: the newest epoch wins, no history kept", () => {
    const store = new BaselineStore(dir);
    store.save("d.md", { docPath: "d.md", text: "v1", capturedAt: "2026-06-11T00:00:00.000Z", reason: "opened" });
    store.save("d.md", { docPath: "d.md", text: "v2", capturedAt: "2026-06-11T00:01:00.000Z", reason: "pinned" });
    expect(store.load("d.md")).toEqual({ docPath: "d.md", text: "v2", capturedAt: "2026-06-11T00:01:00.000Z", reason: "pinned" });
  });

  it("writes pretty JSON with a trailing newline", () => {
    const store = new BaselineStore(dir);
    const b = sample("d.md");
    store.save("d.md", b);
    const raw = fs.readFileSync(store.baselinePath("d.md"), "utf8");
    expect(raw).toBe(JSON.stringify(b, null, 2) + "\n");
  });
});