import * as assert from "assert";
import * as fs from "fs";
import * as path from "path";
import { execFileSync } from "child_process";
import * as vscode from "vscode";
import type { CowritingApi } from "../../../src/extension";
import type { Artifact } from "../../../src/model";

const WS = process.env.E2E_WORKSPACE!;
const PROJECT_ROOT = path.resolve(__dirname, "../../../..");
const STANDIN = path.join(PROJECT_ROOT, "scripts", "crossrung-reply.mjs");

function sidecarPath(docRel: string): string {
  return path.join(WS, ".threads", `${docRel}.json`);
}
async function open(docRel: string): Promise<vscode.TextDocument> {
  const uri = vscode.Uri.file(path.join(WS, docRel));
  const doc = await vscode.workspace.openTextDocument(uri);
  await vscode.window.showTextDocument(doc);
  // INV-10: thread creation/rendering is gated on coediting (Task 4).
  await vscode.commands.executeCommand("cowriting.coeditDocument");
  return doc;
}
async function getApi(): Promise<CowritingApi> {
  const ext = vscode.extensions.getExtension("benstull.vscode-cowriting-plugin")!;
  const api = (await ext.activate()) as CowritingApi;
  assert.ok(api?.versionGuard, "extension exports versionGuard (F5)");
  return api;
}
// The extension host is Electron: run the stand-in with the same binary in
// plain-node mode — a forge's write is just a local process to git (fork e).
function runStandin(...args: string[]): void {
  execFileSync(process.execPath, [STANDIN, ...args], {
    encoding: "utf8",
    env: { ...process.env, ELECTRON_RUN_AS_NODE: "1" },
  });
}
function commentsOf(api: CowritingApi, docRel: string, threadId: string): number {
  const docs = (
    api.threadController as unknown as {
      docs: Map<string, { vsThreads: Map<string, vscode.CommentThread> }>;
    }
  ).docs;
  const vsThread = docs.get(docRel)?.vsThreads.get(threadId);
  return vsThread ? vsThread.comments.length : -1;
}
async function until(cond: () => boolean, ms = 5000): Promise<void> {
  const t0 = Date.now();
  while (!cond()) {
    if (Date.now() - t0 > ms) throw new Error("timed out waiting for condition");
    await new Promise((r) => setTimeout(r, 100));
  }
}

suite("F5 cross-rung round-trip (host E2E)", () => {
  test("stand-in reply lands in the editor's thread via external change (PUC-2)", async () => {
    const DOC = "docs/crossrung.md";
    const doc = await open(DOC);
    const api = await getApi();
    // Task 6 (D10): createThreadOnSelection also fires the respond-in-thread
    // turn now — stub it off so it can't race the forge stand-in's reply
    // below (this test asserts an EXACT 2-message sequence: editor note +
    // forge reply).
    api.threadController.setTurnRunnerForTest(async () => {
      throw new Error("crossrung suite: reply-loop turn stubbed off");
    });
    const target = "portable record";
    const start = doc.getText().indexOf(target);
    const editor = vscode.window.activeTextEditor!;
    editor.selection = new vscode.Selection(doc.positionAt(start), doc.positionAt(start + target.length));
    const threadId = await api.threadController.createThreadOnSelection("Editor note");
    assert.ok(threadId, "thread created in the editor");

    // the Gitea-rung stand-in appends a reply OUT OF EDITOR (spec fork e)
    runStandin(sidecarPath(DOC), threadId!, "Reply from the forge", "--author-id", "gitea", "--author-email", "forge@example.org");

    // watcher → external change → re-render with the new message (the F2 path)
    await until(() => commentsOf(api, DOC, threadId!) === 2);
    const rendered = api.threadController.getRendered(DOC);
    const mine = rendered.find((r) => r.id === threadId)!;
    assert.strictEqual(mine.orphaned, false, "anchor still resolves after the foreign write");
    const anchorLine = doc.positionAt(doc.getText().indexOf(target)).line;
    assert.strictEqual(mine.range.startLine, anchorLine, "rendered at the re-resolved anchor");

    const art = JSON.parse(fs.readFileSync(sidecarPath(DOC), "utf8")) as Artifact;
    const msgs = art.threads.find((t) => t.id === threadId)!.messages;
    assert.strictEqual(msgs.length, 2);
    assert.deepStrictEqual(msgs[1].author, { kind: "human", id: "gitea", email: "forge@example.org" });
  });

  test("newer-major sidecar: warning + read-only, file bytes never change (PUC-4)", async () => {
    const DOC = "docs/v2.md";
    const scPath = sidecarPath(DOC);
    fs.mkdirSync(path.dirname(scPath), { recursive: true });
    // a v2 sidecar: valid v1 sections plus future content this build can't know
    const v2 = {
      schemaVersion: 2,
      document: { path: DOC },
      anchors: {
        a_1: { fingerprint: { text: "Anchored text", before: "", after: " from the future.", lineHint: 2 } },
      },
      threads: [
        {
          id: "t_1",
          anchorId: "a_1",
          status: "open",
          messages: [{ id: "m_1", author: { kind: "human", id: "future" }, body: "from v2", createdAt: "2026-06-10T00:00:00.000Z" }],
        },
      ],
      attributions: [],
      proposals: [],
      v2OnlySection: { shiny: true },
    };
    fs.writeFileSync(scPath, JSON.stringify(v2, null, 2) + "\n", "utf8");
    const before = fs.readFileSync(scPath, "utf8");

    const doc = await open(DOC);
    const api = await getApi();
    api.threadController.renderAll(doc); // render best-effort: the v1 subset shows
    const rendered = api.threadController.getRendered(DOC);
    assert.strictEqual(rendered.length, 1, "renders what it understands");

    // write gestures are refused + warned (PUC-4)
    const target = "Anchored text";
    const start = doc.getText().indexOf(target);
    const editor = vscode.window.activeTextEditor!;
    editor.selection = new vscode.Selection(doc.positionAt(start), doc.positionAt(start + target.length));
    const created = await api.threadController.createThreadOnSelection("should not land");
    assert.strictEqual(created, undefined, "createThread refused on newer major");
    assert.strictEqual(api.versionGuard.wasWarned(DOC), true, "user warned once (PUC-4)");

    // an edit + save must NOT rewrite the sidecar (INV-16)
    await editor.edit((b) => b.insert(doc.positionAt(0), "edited "));
    await doc.save();
    await new Promise((r) => setTimeout(r, 500));
    assert.strictEqual(fs.readFileSync(scPath, "utf8"), before, "sidecar bytes untouched (INV-16)");
  });
});