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";
import type { Artifact } from "../../../src/model";

const WS = process.env.E2E_WORKSPACE!;
const DOC_REL = "docs/attrib.md";

function sidecarPath(): string {
  return path.join(WS, ".threads", "docs", "attrib.md.json");
}
function readSidecar(): Artifact {
  return JSON.parse(fs.readFileSync(sidecarPath(), "utf8")) as Artifact;
}
async function openDoc(): Promise<vscode.TextDocument> {
  const uri = vscode.Uri.file(path.join(WS, DOC_REL));
  const doc = await vscode.workspace.openTextDocument(uri);
  await vscode.window.showTextDocument(doc);
  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?.attributionController, "extension exports attributionController");
  return api;
}
async function externalWriteAndReload(uri: vscode.Uri, content: string): Promise<vscode.TextDocument> {
  fs.writeFileSync(uri.fsPath, content, "utf8");
  const doc = await vscode.workspace.openTextDocument(uri);
  await vscode.window.showTextDocument(doc);
  await vscode.commands.executeCommand("workbench.action.files.revert");
  return doc;
}
const settle = () => new Promise((r) => setTimeout(r, 300));

suite("F3 live attribution (host E2E — seam-driven, no LLM)", () => {
  const TYPED = "A human-typed sentence. ";

  test("typing produces a live human span", async () => {
    const doc = await openDoc();
    const api = await getApi();
    const editor = vscode.window.activeTextEditor!;
    const insertAt = doc.getText().length;
    await editor.edit((eb) => eb.insert(doc.positionAt(insertAt), TYPED));
    await settle();
    const spans = api.attributionController.getSpans(DOC_REL);
    assert.strictEqual(spans.length, 1);
    assert.strictEqual(spans[0].authorKind, "human");
    assert.strictEqual(doc.getText().slice(spans[0].range.start, spans[0].range.end), TYPED);
  });

  test("a seam edit produces an agent span; mixed edits stay char-honest (INV-7/INV-9)", async () => {
    const doc = await openDoc();
    const api = await getApi();
    const target = "target sentence";
    const start = doc.getText().indexOf(target);
    const ok = await api.attributionController.applyAgentEdit(
      doc,
      new vscode.Range(doc.positionAt(start), doc.positionAt(start + target.length)),
      "REWRITTEN-BY-CLAUDE sentence",
      { kind: "agent", id: "claude", agent: { sdk: "@cline/sdk", model: "sonnet", sessionId: "e2e-run" } },
      { turnId: "turn-e2e-1" },
    );
    assert.strictEqual(ok, true, "seam edit applies");
    await settle();
    const spans = api.attributionController.getSpans(DOC_REL);
    const agent = spans.find((s) => s.authorKind === "agent");
    assert.ok(agent, "agent span exists");
    assert.strictEqual(agent!.turnId, "turn-e2e-1");
    assert.strictEqual(
      doc.getText().slice(agent!.range.start, agent!.range.end),
      "REWRITTEN-BY-CLAUDE sentence",
    );
    assert.ok(spans.some((s) => s.authorKind === "human"), "human span still tracked");
  });

  test("stale expectedVersion refuses to apply (spec §6.9)", async () => {
    const doc = await openDoc();
    const api = await getApi();
    const ok = await api.attributionController.applyAgentEdit(
      doc,
      new vscode.Range(doc.positionAt(0), doc.positionAt(1)),
      "X",
      { kind: "agent", id: "claude", agent: { sdk: "@cline/sdk", model: "sonnet", sessionId: "e2e" } },
      { expectedVersion: doc.version - 1 },
    );
    assert.strictEqual(ok, false);
  });

  test("save persists attributions[]; reload restores spans at re-resolved anchors (PUC-4)", async () => {
    const doc = await openDoc();
    const api = await getApi();
    await doc.save();
    await settle();
    const art = readSidecar();
    assert.ok(art.attributions.length >= 2, "human + agent records persisted");
    const agentRec = art.attributions.find((a) => a.author.kind === "agent")!;
    assert.strictEqual(art.anchors[agentRec.anchorId].fingerprint.text, "REWRITTEN-BY-CLAUDE sentence");
    assert.strictEqual(agentRec.turnId, "turn-e2e-1");

    api.attributionController.loadAll(doc);
    const spans = api.attributionController.getSpans(DOC_REL);
    assert.ok(spans.some((s) => s.authorKind === "agent"), "agent span restored from sidecar");
    assert.strictEqual(api.attributionController.getOrphanCount(DOC_REL), 0);
  });

  test("external move re-anchors; mangling the text orphans (INV-1/INV-6)", async () => {
    const uri = vscode.Uri.file(path.join(WS, DOC_REL));
    const original = fs.readFileSync(uri.fsPath, "utf8");
    const api = await getApi();

    let doc = await externalWriteAndReload(uri, "PREPENDED LINE\n\n" + original);
    await settle();
    api.attributionController.loadAll(doc);
    let spans = api.attributionController.getSpans(DOC_REL);
    const agent = spans.find((s) => s.authorKind === "agent")!;
    const moved = doc.getText().indexOf("REWRITTEN-BY-CLAUDE sentence");
    assert.strictEqual(agent.range.start, moved, "agent span re-anchored after move");
    assert.strictEqual(api.attributionController.getOrphanCount(DOC_REL), 0);

    const mangled = doc.getText().replace("REWRITTEN-BY-CLAUDE sentence", "now something else entirely");
    doc = await externalWriteAndReload(uri, mangled);
    await settle();
    api.attributionController.loadAll(doc);
    spans = api.attributionController.getSpans(DOC_REL);
    assert.ok(!spans.some((s) => s.authorKind === "agent"), "mangled agent span not rendered");
    assert.ok(api.attributionController.getOrphanCount(DOC_REL) >= 1, "…it is orphaned instead (INV-1)");
  });
});