import * as assert from "node:assert";
import { execFileSync } from "node:child_process";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import * as vscode from "vscode";
import { activateApi, settle, settleUntil } from "./helpers";

const WS = process.env.E2E_WORKSPACE!;

suite("baseline router (PUC-1, INV-7/D13/D14)", () => {
  test("snapshot mode: enter captures; markReviewed re-pins clean", async () => {
    const api = await activateApi();
    const doc = await vscode.workspace.openTextDocument({ language: "markdown", content: "one\n" });
    const ed = await vscode.window.showTextDocument(doc);
    await vscode.commands.executeCommand("cowriting.coeditDocument");
    await settle();
    assert.strictEqual(api.diffViewController.modeOf(doc.uri.toString()), "snapshot");
    assert.strictEqual(api.diffViewController.getBaseline(doc.uri.toString())?.text, "one\n");
    await ed.edit((b) => b.insert(new vscode.Position(1, 0), "two\n"));
    // Task 3 (INV-13): the status-bar/SCM change count tracks the live edit.
    await settleUntil(() => api.scmSurfaceController.changeCount(doc.uri.toString()) === 1);
    await vscode.commands.executeCommand("cowriting.markReviewed");
    const b = api.diffViewController.getBaseline(doc.uri.toString());
    assert.strictEqual(b?.text, "one\ntwo\n");
    assert.strictEqual(b?.reason, "pinned");
    // A pin re-baselines to the clean current text, so the change count resets.
    await settleUntil(() => api.scmSurfaceController.changeCount(doc.uri.toString()) === 0);
  });

  test("head mode: baseline = HEAD; commit advances it", async function () {
    this.timeout(30000);
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "cw-git-"));
    const git = (...a: string[]) => execFileSync("git", ["-C", dir, ...a], { encoding: "utf8" });
    git("init", "-q");
    fs.writeFileSync(path.join(dir, "doc.md"), "committed\n");
    git("add", "doc.md");
    git("-c", "user.name=t", "-c", "user.email=t@t", "commit", "-qm", "c1");
    const api = await activateApi();
    const doc = await vscode.workspace.openTextDocument(vscode.Uri.file(path.join(dir, "doc.md")));
    const ed = await vscode.window.showTextDocument(doc);
    await vscode.commands.executeCommand("cowriting.coeditDocument");
    await settleUntil(() => api.diffViewController.modeOf(doc.uri.toString()) === "head", 10000);
    assert.strictEqual(api.diffViewController.getBaseline(doc.uri.toString())?.text, "committed\n");
    await ed.edit((b) => b.insert(new vscode.Position(1, 0), "uncommitted\n"));
    await doc.save();
    git("-c", "user.name=t", "-c", "user.email=t@t", "commit", "-aqm", "c2");
    await settleUntil(
      () => api.diffViewController.getBaseline(doc.uri.toString())?.text === "committed\nuncommitted\n",
      15000,
    );
    assert.strictEqual(api.diffViewController.getBaseline(doc.uri.toString())?.reason, "head");
  });

  // Finding 3 (final whole-branch review, session native-surfaces-exec):
  // DiffViewController only establishes a baseline on the registry's ENTER
  // transition (a doc it can find already open) and, at startup, for docs
  // already open at that moment. A registry member entered while its document
  // was NOT yet open (the real-world case: a persisted coediting set restored
  // after a window reload, whose member is only lazily opened later) used to
  // never get a baseline at all — reproduced here directly via
  // `coeditingRegistry.enter(uri)` on a URI with no open document yet (the
  // registry API doesn't require one), then a genuine later open.
  test("a registry member entered before its doc was open gets its baseline established once the doc IS opened", async () => {
    const api = await activateApi();
    const rel = "docs/finding3-establish-on-open.md";
    const abs = path.join(WS, rel);
    const content = "# late open\n\nestablish-on-open should catch this.\n";
    fs.writeFileSync(abs, content, "utf8");
    const uri = vscode.Uri.file(abs);

    // Membership without an open document — DiffViewController's enter-
    // transition handler no-ops (`textDocuments.find` misses), reproducing
    // the gap: a coediting member with no mode/baseline yet.
    api.coeditingRegistry.enter(uri);
    assert.strictEqual(api.coeditingRegistry.isCoediting(uri), true, "sanity: registry membership recorded");
    assert.strictEqual(api.diffViewController.modeOf(uri.toString()), undefined, "sanity: the gap is reproduced");

    // A genuine later open — the fix's `renderIfOpen`/`onDidOpenTextDocument`
    // path must establish the baseline it missed.
    const doc = await vscode.workspace.openTextDocument(uri);
    await vscode.window.showTextDocument(doc);
    await settleUntil(() => api.diffViewController.modeOf(uri.toString()) !== undefined, 10000);
    assert.strictEqual(api.diffViewController.modeOf(uri.toString()), "snapshot");
    assert.strictEqual(api.diffViewController.getBaseline(uri.toString())?.text, content);
  });
});