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 { addProposal, setProposalApplied } from "../../../src/proposalModel";
import { buildFingerprint } from "../../../src/anchorer";

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?.proposalController, "exports controllers");
  return api;
}

/** Also enters coediting (INV-10/Task 2): the baseline is established only on
 *  entry, not merely on open. */
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 vscode.commands.executeCommand("cowriting.coeditDocument");
  await settle();
  return { doc, key: uri.toString() };
}

suite("F12 inline diff — seam landBaseline (#64, INV-48)", () => {
  test("applyAgentEdit with landBaseline:false applies text but does NOT advance the baseline", async () => {
    const { doc, key } = await freshDoc("docs/f12-land.md", "# T\n\nalpha here.\n");
    const api = await getApi();
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    const before = api.diffViewController.getBaseline(key)?.text ?? doc.getText();
    const start = doc.getText().indexOf("alpha");
    const ok = await api.attributionController.applyAgentEdit(
      doc,
      new vscode.Range(doc.positionAt(start), doc.positionAt(start + "alpha".length)),
      "ALPHA",
      { kind: "agent", id: "claude", agent: { sdk: "x", model: "m", sessionId: "s" } },
      { landBaseline: false },
    );
    await settle();
    assert.ok(ok, "edit applied");
    assert.ok(doc.getText().includes("ALPHA"), "text in buffer");
    assert.strictEqual(api.diffViewController.getBaseline(key)?.text ?? doc.getText(), before, "baseline unchanged");
  });
});

suite("F12 inline diff — finalize / revert in place (#64, INV-51)", () => {
  // Optimistic apply lands the text + re-anchors; the buffer becomes the accepted result.
  test("optimisticApply puts the proposed text in the buffer and re-anchors", async () => {
    const { doc } = await freshDoc("docs/f12-opt.md", "# T\n\nReplace alpha please.\n");
    const api = await getApi();
    const p = api.proposalController;
    const fp = { text: "Replace alpha please.", before: "", after: "", lineHint: 2 };
    const id = await p.propose(doc, fp, "Replace ALPHA please.",
      { kind: "agent", id: "claude", agent: { sdk: "x", model: "m", sessionId: "s" } }, { granularity: "block" });
    await api.proposalController.optimisticApply(doc, id!);
    await settle();
    assert.ok(doc.getText().includes("Replace ALPHA please."), "applied to buffer");
    // re-anchored: the proposal still resolves against the mutated buffer
    assert.strictEqual(p.listProposals(doc)[0].anchorStart !== null, true, "re-anchored, resolves");
    assert.strictEqual(p.listProposals(doc)[0].original, "Replace alpha please.", "original stored");
  });

  test("finalizeInPlace clears the proposal and keeps the applied text (no double-apply)", async () => {
    const { doc } = await freshDoc("docs/f12-fin.md", "# T\n\nKeep alpha now.\n");
    const api = await getApi();
    const p = api.proposalController;
    const docPath = p.keyFor(doc);
    const fp = { text: "Keep alpha now.", before: "", after: "", lineHint: 2 };
    const id = await p.propose(doc, fp, "Keep ALPHA now.",
      { kind: "agent", id: "claude", agent: { sdk: "x", model: "m", sessionId: "s" } }, { granularity: "block" });
    await p.optimisticApply(doc, id!);
    await settle();
    const ok = await p.finalizeInPlace(docPath, id!);
    await settle();
    assert.ok(ok, "finalized");
    assert.strictEqual(doc.getText(), "# T\n\nKeep ALPHA now.\n", "applied text retained, no double-apply");
    assert.strictEqual(p.listProposals(doc).length, 0, "proposal cleared");
  });

  test("revertInPlace restores the original and clears the proposal", async () => {
    const { doc } = await freshDoc("docs/f12-rev.md", "# T\n\nUndo alpha here.\n");
    const api = await getApi();
    const p = api.proposalController;
    const docPath = p.keyFor(doc);
    const fp = { text: "Undo alpha here.", before: "", after: "", lineHint: 2 };
    const id = await p.propose(doc, fp, "Undo ALPHA here.",
      { kind: "agent", id: "claude", agent: { sdk: "x", model: "m", sessionId: "s" } }, { granularity: "block" });
    await p.optimisticApply(doc, id!);
    await settle();
    const ok = await p.revertInPlace(docPath, id!);
    await settle();
    assert.ok(ok, "reverted");
    assert.strictEqual(doc.getText(), "# T\n\nUndo alpha here.\n", "original restored");
    assert.strictEqual(p.listProposals(doc).length, 0, "proposal cleared");
  });

  test("rejectAll reverts every pending proposal", async () => {
    const { doc } = await freshDoc("docs/f12-rejall.md", "# T\n\nOne aaa.\n\nTwo bbb.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    const p = api.proposalController;
    ctl.setEditTurnForTest(async () => ({ replacement: "# T\n\nOne AAA.\n\nTwo BBB.\n", model: "m", sessionId: "s" }));
    const ids = await ctl.runEditAndPropose(doc, { kind: "document" }, "up");
    await settle();
    for (const id of ids) await p.optimisticApply(doc, id);
    await settle();
    assert.ok(doc.getText().includes("AAA") && doc.getText().includes("BBB"), "both applied");
    const { reverted } = await p.rejectAll(doc);
    await settle();
    assert.strictEqual(reverted, ids.length, "all reverted");
    assert.strictEqual(doc.getText(), "# T\n\nOne aaa.\n\nTwo bbb.\n", "document restored");
    assert.strictEqual(p.listProposals(doc).length, 0, "all cleared");
  });
});

suite("F12 inline diff — INV-50 listProposals.replaced", () => {
  test("listProposals reports the original as `replaced` after optimistic apply", async () => {
    const { doc } = await freshDoc("docs/f12-replaced.md", "# R\n\nbrown here.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    ctl.setEditTurnForTest(async () => ({ replacement: "# R\n\nred here.\n", model: "m", sessionId: "s" }));
    await ctl.runEditAndPropose(doc, { kind: "document" }, "x");
    await settle(); await settle();
    assert.strictEqual(api.proposalController.listProposals(doc)[0].replaced, "brown here.");
  });
});

suite("F12 inline diff — editor surface (#64, INV-48/52)", () => {
  test("proposing optimistically applies into the editor and the buffer is the accepted result", async () => {
    const { doc } = await freshDoc("docs/f12-editor.md", "# E\n\nThe brown fox runs.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    ctl.setEditTurnForTest(async () => ({ replacement: "# E\n\nThe red fox runs.\n", model: "m", sessionId: "s" }));
    await ctl.runEditAndPropose(doc, { kind: "document" }, "recolor the fox");
    await settle(); await settle();
    assert.ok(doc.getText().includes("The red fox runs."), "optimistically applied into the buffer");
    const v = api.proposalController.listProposals(doc)[0];
    assert.strictEqual(v.original, "The brown fox runs.", "original captured for the deletion hint/revert");
  });

  test("editing the inserted text then finalizing keeps the human edit", async () => {
    const { doc } = await freshDoc("docs/f12-edit-keep.md", "# E\n\nalpha word here.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    ctl.setEditTurnForTest(async () => ({ replacement: "# E\n\nALPHA word here.\n", model: "m", sessionId: "s" }));
    const ids = await ctl.runEditAndPropose(doc, { kind: "document" }, "up");
    await settle(); await settle();
    // human tweaks the inserted text
    const at = doc.getText().indexOf("ALPHA");
    const we = new vscode.WorkspaceEdit();
    we.replace(doc.uri, new vscode.Range(doc.positionAt(at), doc.positionAt(at + 5)), "ALPHA!");
    await vscode.workspace.applyEdit(we);
    await settle();
    // keyFor(doc) gives the repo-relative path that finalizeInPlace uses as its key;
    // the `key` from freshDoc is the URI string, which would not match for in-workspace docs.
    const docKey = api.proposalController.keyFor(doc);
    await api.proposalController.finalizeInPlace(docKey, ids[0]);
    await settle();
    assert.ok(doc.getText().includes("ALPHA! word here."), "human edit preserved on accept");
    assert.strictEqual(api.proposalController.listProposals(doc).length, 0, "cleared");
  });
});

suite("F12 inline diff — control parity (#64, INV-53)", () => {
  test("reject from the webview reverts in place; rejectAll clears every proposal", async () => {
    const { doc, key } = await freshDoc("docs/f12-parity.md", "# P\n\nuno aaa.\n\ndos bbb.\n");
    const api = await getApi();
    const ctl = api.trackChangesPreviewController;
    await vscode.commands.executeCommand("cowriting.showTrackChangesPreview");
    await settle();
    ctl.setEditTurnForTest(async () => ({ replacement: "# P\n\nuno AAA.\n\ndos BBB.\n", model: "m", sessionId: "s" }));
    const ids = await ctl.runEditAndPropose(doc, { kind: "document" }, "up");
    await settle(); await settle();
    assert.ok(doc.getText().includes("AAA") && doc.getText().includes("BBB"));
    // reject ONE via the webview intent → that block reverts, the other stays applied
    ctl.receiveMessage(key, { type: "reject", proposalId: ids[0] });
    await settle(); await settle();
    assert.ok(doc.getText().includes("uno aaa.") && doc.getText().includes("BBB"), "one reverted, one applied");
    // rejectAll via the command → all gone, document restored
    ctl.receiveMessage(key, { type: "rejectAll" });
    await settle(); await settle();
    assert.strictEqual(doc.getText(), "# P\n\nuno aaa.\n\ndos bbb.\n", "document restored");
    assert.strictEqual(api.proposalController.listProposals(doc).length, 0);
  });

  test("cowriting.rejectAllProposals is registered + markdown-guarded", async () => {
    const all = await vscode.commands.getCommands(true);
    assert.ok(all.includes("cowriting.rejectAllProposals"));
    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.rejectAllProposals",
    );
    assert.ok(entry && /editorLangId == markdown/.test(entry.when ?? ""), "palette-guarded on markdown");
  });
});

// Reload-safety: a proposal that was optimistically applied in a PRIOR session
// persists with `original` set and its fp re-anchored to the applied text. A fresh
// controller (empty in-memory `applied` set) must NOT re-capture `original` from the
// already-applied buffer — doing so would clobber the true revert target and break
// Reject. (Regression for the final-review CRITICAL; INV-51/54.)
suite("F12 inline diff — reload-safety (#64, INV-51/54)", () => {
  test("optimisticApply does not clobber a previously-persisted original", async () => {
    const TRUE_ORIGINAL = "The original sentence here.";
    const APPLIED = "The APPLIED sentence here.";
    const { doc } = await freshDoc("docs/f12-reload.md", `# R\n\n${TRUE_ORIGINAL}\n`);
    const api = await getApi();
    const p = api.proposalController;
    const key = p.keyFor(doc);

    // 1) The buffer holds the APPLIED text (as the saved-while-pending file would).
    const at = doc.getText().indexOf(TRUE_ORIGINAL);
    const we = new vscode.WorkspaceEdit();
    we.replace(doc.uri, new vscode.Range(doc.positionAt(at), doc.positionAt(at + TRUE_ORIGINAL.length)), APPLIED);
    assert.ok(await vscode.workspace.applyEdit(we), "apply the prior-session applied text");
    await settle();

    // 2) Record the proposal directly in the sidecar exactly as a prior session left
    //    it: fp anchored to the APPLIED text + `original` = the TRUE original. We do
    //    NOT call optimisticApply, so this controller's in-memory `applied` stays empty.
    const appliedAt = doc.getText().indexOf(APPLIED);
    const appliedFp = buildFingerprint(doc.getText(), { start: appliedAt, end: appliedAt + APPLIED.length });
    let id = "";
    api.sidecarRouter.update(key, (a) => {
      id = addProposal(a, appliedFp, APPLIED, { kind: "agent", id: "claude", agent: { sdk: "x", model: "m", sessionId: "s" } }, { granularity: "block" }).proposalId;
      setProposalApplied(a, id, appliedFp, TRUE_ORIGINAL);
    });
    p.renderAll(doc);
    await settle();

    // 3) Re-entry as a reload would trigger (EditorProposalController re-applies on
    //    onDidChangeProposals because `applied` is empty). The guard must preserve original.
    await p.optimisticApply(doc, id);
    await settle();
    const view = p.listProposals(doc).find((v) => v.id === id);
    assert.ok(view, "proposal still present");
    assert.strictEqual(view!.original, TRUE_ORIGINAL, "true original preserved, NOT clobbered with the applied text");

    // 4) Reject restores the TRUE original (not the applied text).
    assert.ok(await p.revertInPlace(key, id), "revert");
    await settle();
    assert.ok(doc.getText().includes(TRUE_ORIGINAL), "reject restored the true original");
    assert.ok(!doc.getText().includes(APPLIED), "applied text removed on reject");
  });
});