import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { describe, expect, test } from "vitest";
import { buildEventsFromChanges, listSpecChanges } from "../src/changes.js";
import { JsonCharterDatabase } from "../src/db/json.js";
import { buildImportPlan } from "../src/spec-files.js";

async function makeProject(): Promise<string> {
  const root = await fs.mkdtemp(path.join(os.tmpdir(), "charter-changes-"));
  await fs.mkdir(path.join(root, "spec"));
  return root;
}

describe("spec changes", () => {
  test("detects added, modified, and deleted spec documents against materialized state", async () => {
    const root = await makeProject();
    await fs.writeFile(path.join(root, "spec", "a.md"), "---\nid: a\ntitle: A\nkind: note\n---\n\n# A\n", "utf8");

    const initialPlan = await buildImportPlan({ projectRoot: root });
    const db = new JsonCharterDatabase({ projectRoot: root, projectId: "charter" });
    let snapshot = await db.loadSnapshot();
    let changes = listSpecChanges(initialPlan, snapshot);
    expect(changes.map((change) => change.type)).toEqual(["added"]);

    for (const row of initialPlan.rows) await db.upsertDocument(row);
    for (const event of buildEventsFromChanges(initialPlan, changes)) await db.appendEvent(event);
    await db.saveSnapshot();

    await fs.writeFile(path.join(root, "spec", "a.md"), "---\nid: a\ntitle: A\nkind: note\n---\n\n# A\n\nChanged.\n", "utf8");
    await fs.writeFile(path.join(root, "spec", "b.md"), "---\nid: b\ntitle: B\nkind: note\n---\n\n# B\n", "utf8");
    snapshot = await new JsonCharterDatabase({ projectRoot: root, projectId: "charter" }).loadSnapshot();
    const changedPlan = await buildImportPlan({ projectRoot: root });
    changes = listSpecChanges(changedPlan, snapshot);
    expect(changes.map((change) => [change.documentId, change.type])).toEqual([
      ["b", "added"],
      ["a", "modified"],
    ]);

    await fs.rm(path.join(root, "spec", "a.md"));
    const deletedPlan = await buildImportPlan({ projectRoot: root });
    const deletedChanges = listSpecChanges(deletedPlan, snapshot);
    expect(deletedChanges.map((change) => [change.documentId, change.type])).toEqual([
      ["b", "added"],
      ["a", "deleted"],
    ]);
  });
});