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, 400));

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?.diffViewController, "exports preview + diffView");
  return api;
}

/** Create + open a fresh markdown doc under WS, returning the doc + its uri key. */
async function freshDoc(rel: string, body: string): Promise<{ doc: vscode.TextDocument; key: string }> {
  const abs = path.join(WS, rel);
  fs.mkdirSync(path.dirname(abs), { recursive: true });
  fs.writeFileSync(abs, body, "utf8");
  const uri = vscode.Uri.file(abs);
  const doc = await vscode.workspace.openTextDocument(uri);
  await vscode.window.showTextDocument(doc);
  await settle();
  return { doc, key: uri.toString() };
}

// F11 host E2E (no LLM): the preview toolbar is the primary interaction surface.
// The webview posts intent messages; the host routes them through the existing
// F4/F6/F3 seams (INV-35). The webview DOM (real button clicks) is sealed and
// manual-smoke only; here we simulate the inbound messages via `receiveMessage`.
suite("F11 preview toolbar (host E2E — message → seam wiring, no LLM)", () => {
  // SLICE-1: the Pin baseline button.
  test("pinBaseline message pins the PREVIEWED doc → marks clear, baseline reason is pinned (PUC-5, INV-35)", async () => {
    const { doc, key } = await freshDoc("docs/f11pin.md", "# F11 pin\n\nA baseline paragraph that will diverge.\n");
    const api = await getApi();
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    assert.strictEqual(api.trackChangesPreviewController.isOpen(key), true, "panel open");

    // Diverge from the opened baseline so the preview carries a real change-mark.
    const edit = new vscode.WorkspaceEdit();
    edit.insert(doc.uri, doc.positionAt(doc.getText().length), "\n\nA freshly typed paragraph that diverges.\n");
    assert.ok(await vscode.workspace.applyEdit(edit), "operator edit applied");
    await settle();
    const marked = (api.trackChangesPreviewController.getLastModel(key) ?? []).some((o) => o.kind !== "unchanged");
    assert.ok(marked, "the typed paragraph shows as a change before pinning");

    // Simulate the webview's Pin baseline button posting its intent.
    api.trackChangesPreviewController.receiveMessage(key, { type: "pinBaseline" });
    await settle();

    const model = api.trackChangesPreviewController.getLastModel(key) ?? [];
    assert.ok(model.length > 0 && model.every((o) => o.kind === "unchanged"), "after pin, every block is unchanged");
    assert.strictEqual(api.diffViewController.getBaseline(key)?.reason, "pinned", "baseline reason advanced to pinned");
  });

  // SLICE-1 reachability: the orphaned pin command gets a real palette `when`.
  test("pinDiffBaseline is reachable from the command palette (when: editorLangId == markdown)", async () => {
    const pkg = JSON.parse(fs.readFileSync(path.join(__dirname, "../../../../package.json"), "utf8"));
    const entry = (pkg.contributes.menus.commandPalette as Array<{ command: string; when?: string }>).find(
      (m) => m.command === "cowriting.pinDiffBaseline",
    );
    assert.ok(entry, "pinDiffBaseline has a commandPalette entry");
    assert.notStrictEqual(entry!.when, "false", "it is no longer hidden (when:false)");
    assert.match(entry!.when ?? "", /editorLangId == markdown/, "guarded on markdown");
  });

  // #47 (was INV-37): Edit Document now cuts at BLOCK granularity — two word
  // changes in ONE paragraph are ONE block proposal (INV-39 supersedes INV-37's
  // per-word cut). Full block coverage lives in f12Review.test.ts.
  test("runEditAndPropose(document) — two word edits in one paragraph → ONE block proposal (PUC-4, INV-39)", async () => {
    const { doc, key } = await freshDoc(
      "docs/f11doc.md",
      "# F11 doc\n\nThe quick brown fox jumps over the lazy dog.\n",
    );
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();

    // Stub the host edit turn (no LLM in CI): rewrite two distinct words.
    ctl.setEditTurnForTest(async () => ({
      replacement: "# F11 doc\n\nThe quick RED fox jumps over the lazy CAT.\n",
      model: "sonnet",
      sessionId: "e2e-f11-doc",
    }));

    const ids = await ctl.runEditAndPropose(doc, { kind: "document" }, "swap brown→RED and dog→CAT");
    await settle();
    assert.strictEqual(ids.length, 1, "two changed words in one block → ONE block proposal (INV-39)");

    const views = api.proposalController.listProposals(doc);
    const view = views.find((v) => v.id === ids[0]);
    assert.ok(view, "the returned proposal id is a live pending proposal");
    assert.strictEqual(
      view!.replacement,
      "The quick RED fox jumps over the lazy CAT.",
      "the block proposal carries the whole rewritten paragraph",
    );
    // INV-10: proposing never mutates the document.
    assert.ok(doc.getText().includes("brown fox") && doc.getText().includes("lazy dog"), "document unchanged by propose");
    void key;
  });

  // SLICE-4: Edit Selection → one single-range proposal over the resolved block-union.
  test("runEditAndPropose(range) with a stubbed turn → exactly one proposal over the resolved range (PUC-3, INV-37)", async () => {
    const body = "# F11 sel\n\nThe target paragraph Claude will rewrite.\n\nAnother untouched paragraph.\n";
    const { doc, key } = await freshDoc("docs/f11sel.md", body);
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();

    const target = "The target paragraph Claude will rewrite.";
    const start = doc.getText().indexOf(target);
    const end = start + target.length;
    ctl.setEditTurnForTest(async (_instruction, text) => {
      assert.strictEqual(text, target, "the turn receives exactly the selected source range");
      return { replacement: "The REWRITTEN paragraph from Claude.", model: "sonnet", sessionId: "e2e-f11-sel" };
    });

    const ids = await ctl.runEditAndPropose(doc, { kind: "range", start, end }, "rewrite this paragraph");
    await settle();
    assert.strictEqual(ids.length, 1, "a selection yields exactly one proposal");
    const views = api.proposalController.listProposals(doc);
    const view = views.find((v) => v.id === ids[0]);
    assert.ok(view, "the proposal is live");
    assert.strictEqual(view!.replacement, "The REWRITTEN paragraph from Claude.", "carries the turn replacement");
    assert.strictEqual(view!.replaced, target, "replaces exactly the selected range");
    assert.ok(doc.getText().includes(target), "document unchanged by propose (INV-10)");
    void key;
  });

  // SLICE-4: a no-op turn (Claude returns the input unchanged) produces no proposal.
  test("runEditAndPropose(range) where Claude returns the selection unchanged → no proposal", async () => {
    const { doc } = await freshDoc("docs/f11noop.md", "# noop\n\nLeave me exactly as I am.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    const target = "Leave me exactly as I am.";
    const start = doc.getText().indexOf(target);
    ctl.setEditTurnForTest(async (_i, text) => ({ replacement: text, model: "sonnet", sessionId: "e2e-noop" }));
    const ids = await ctl.runEditAndPropose(doc, { kind: "range", start, end: start + target.length }, "no change");
    assert.strictEqual(ids.length, 0, "an unchanged replacement proposes nothing");
  });

  // SLICE-3 (review follow-up): a document rewrite that INSERTS text → an
  // acceptable proposal (not a born-orphaned zero-width hunk), and accepting all
  // hunks of a multi-hunk rewrite lands the intended document.
  test("document rewrite with an insertion → acceptable proposals; accept-all reaches the rewrite", async () => {
    const original = "# F11 accept\n\nThe brown fox sleeps.\n";
    const rewrite = "# F11 accept\n\nThe brown fox QUIETLY sleeps today.\n";
    const { doc } = await freshDoc("docs/f11accept.md", original);
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();

    ctl.setEditTurnForTest(async () => ({ replacement: rewrite, model: "sonnet", sessionId: "e2e-accept" }));
    const ids = await ctl.runEditAndPropose(doc, { kind: "document" }, "expand the sentence");
    await settle();
    assert.ok(ids.length >= 1, "the rewrite produced at least one proposal");

    // Every proposal must be acceptable (the insertion-anchoring fix): accept each.
    for (const id of ids) {
      const ok = await api.proposalController.acceptById("docs/f11accept.md", id);
      assert.ok(ok, `proposal ${id} is acceptable (not born-orphaned)`);
      await settle();
    }
    assert.strictEqual(doc.getText(), rewrite, "accepting all hunks reconstructs the intended rewrite");
    assert.strictEqual(api.proposalController.listProposals(doc).length, 0, "no proposals left pending");
  });

  // SLICE-3: the document-scoped command exists for #42 reuse, guarded on markdown.
  test("cowriting.editDocument is a registered command, palette-guarded on markdown", async () => {
    const all = await vscode.commands.getCommands(true);
    assert.ok(all.includes("cowriting.editDocument"), "editDocument command registered");
    const pkg = JSON.parse(fs.readFileSync(path.join(__dirname, "../../../../package.json"), "utf8"));
    const entry = (pkg.contributes.menus.commandPalette as Array<{ command: string; when?: string }>).find(
      (m) => m.command === "cowriting.editDocument",
    );
    assert.ok(entry, "editDocument has a commandPalette entry");
    assert.match(entry!.when ?? "", /editorLangId == markdown/, "guarded on markdown");
  });

  // SLICE-5: the minimal right-click gateway lives in editor/title (markdown only).
  test("the editor/title gateway opens the preview, and the menu entry is markdown-guarded (PUC-6)", async () => {
    const pkg = JSON.parse(fs.readFileSync(path.join(__dirname, "../../../../package.json"), "utf8"));
    const entry = (pkg.contributes.menus["editor/title"] as Array<{ command: string; when?: string }>).find(
      (m) => m.command === "cowriting.showTrackChangesPreview",
    );
    assert.ok(entry, "showTrackChangesPreview is in editor/title");
    assert.match(entry!.when ?? "", /editorLangId == markdown/, "gateway guarded on markdown");
    // the command it invokes opens the panel.
    const { key } = await freshDoc("docs/f11gw.md", "# F11 gateway\n\nReachable end to end.\n");
    const api = await getApi();
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    assert.strictEqual(api.trackChangesPreviewController.isOpen(key), true, "gateway command opens the preview");
  });

  // SLICE-5: edit controls are inert on a non-authorable (read-only scheme) doc.
  test("toolbar edit controls are disabled for a non-authorable document (PUC-1/7)", async () => {
    const SCHEME = "cwf11ro";
    const provider = new (class implements vscode.TextDocumentContentProvider {
      onDidChange = undefined;
      provideTextDocumentContent(): string {
        return "# Read only\n\nThis markdown doc is not authorable.\n";
      }
    })();
    const reg = vscode.workspace.registerTextDocumentContentProvider(SCHEME, provider);
    try {
      const uri = vscode.Uri.parse(`${SCHEME}:/readonly.md`);
      const doc = await vscode.workspace.openTextDocument(uri);
      await vscode.languages.setTextDocumentLanguage(doc, "markdown");
      await vscode.window.showTextDocument(doc);
      await settle();
      const api = await getApi();
      const key = uri.toString();
      assert.strictEqual(doc.languageId, "markdown", "fixture is markdown");
      await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
      await settle();
      assert.strictEqual(api.trackChangesPreviewController.isOpen(key), true, "preview opens (reading is always allowed)");
      assert.strictEqual(
        api.trackChangesPreviewController.editControlsEnabled(key),
        false,
        "Pin + Ask-Claude controls are disabled on a non-authorable doc",
      );
    } finally {
      reg.dispose();
    }
  });
});