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

const WS = process.env.E2E_WORKSPACE!;
const settle = () => new Promise((r) => setTimeout(r, 300));

async function getApi(): Promise<CowritingApi> {
  const ext = vscode.extensions.getExtension("benstull.vscode-cowriting-plugin")!;
  const api = (await ext.activate()) as CowritingApi;
  assert.ok(api?.trackChangesPreviewController && api?.proposalController, "exports preview + proposal");
  return api;
}

// F9 host E2E (no LLM): authorship mode reflects Claude's landed span. Owns its
// own markdown doc, disjoint from the other suites' fixtures.
suite("F9 authorship preview (host E2E — seam ingress, no LLM)", () => {
  const DOC_REL = "docs/f9authorship.md";
  const TARGET = "The sentence Claude will compose over.";

  test("authorship mode marks Claude's accepted edit; track-changes mode still works", async () => {
    const abs = path.join(WS, DOC_REL);
    fs.mkdirSync(path.dirname(abs), { recursive: true });
    fs.writeFileSync(abs, `# F9\n\n${TARGET}\n`, "utf8");
    const uri = vscode.Uri.file(abs);
    const doc = await vscode.workspace.openTextDocument(uri);
    await vscode.window.showTextDocument(doc);
    await settle();
    const api = await getApi();
    const key = uri.toString();

    // open the preview (track-changes mode by default)
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    assert.ok(api.trackChangesPreviewController.isOpen(key), "preview open");
    assert.strictEqual(api.trackChangesPreviewController.getMode(key), "changes", "defaults to track-changes");

    // Claude composes via the seam (propose → accept)
    const start = doc.getText().indexOf(TARGET);
    const id = await vscode.commands.executeCommand<string>("cowriting.proposeAgentEdit", {
      uri: key,
      start,
      end: start + TARGET.length,
      newText: "The sentence CLAUDE COMPOSED.",
      model: "sonnet",
      sessionId: "e2e-f9",
      turnId: "turn-f9",
    });
    assert.ok(await api.proposalController.acceptById(DOC_REL, id!), "accept applies");
    await settle();

    // attribution has a Claude span now
    const claudeSpan = api.attributionController.getSpans(DOC_REL).find((s) => s.authorKind === "agent");
    assert.ok(claudeSpan, "Claude span recorded by F3");

    // flip to authorship mode → the preview reads a Claude span
    api.trackChangesPreviewController.setMode(key, "authorship");
    await settle();
    assert.strictEqual(api.trackChangesPreviewController.getMode(key), "authorship");
    const spans = api.attributionController.spansFor(doc);
    assert.ok(spans.some((s) => s.author === "claude"), "spansFor reports a Claude span for the preview");

    // back to track-changes — still functional (regression)
    api.trackChangesPreviewController.setMode(key, "changes");
    await settle();
    assert.strictEqual(api.trackChangesPreviewController.getMode(key), "changes");
    assert.ok(
      (api.trackChangesPreviewController.getLastModel(key) ?? []).length >= 1,
      "track-changes model still computed",
    );
  });
});