import { test, expect } from "@playwright/test";
import { CanvasRevisionConflict, VideoCanvasSaveQueue } from "@/lib/video-canvas/save-queue";

test("coalesces edits made during a save and uses the returned revision", async () => {
  let release!: (value: string) => void;
  const calls: string[][] = [];
  const queue = new VideoCanvasSaveQueue(
    "initial",
    "r0",
    async (value, revision) => {
      calls.push([value, revision]);
      return calls.length === 1
        ? new Promise<string>((resolve) => {
            release = resolve;
          })
        : "r2";
    },
    () => {},
  );
  queue.update("first");
  const pending = queue.flush();
  queue.update("second");
  queue.update("latest");
  expect(queue.flush()).toBe(pending);
  release("r1");
  await pending;
  expect(calls).toEqual([
    ["first", "r0"],
    ["latest", "r1"],
  ]);
  expect(queue.dirty).toBe(false);
});

test("failed save retains edits and retries only the latest snapshot", async () => {
  const calls: string[][] = [];
  const queue = new VideoCanvasSaveQueue(
    "initial",
    "r0",
    async (value, revision) => {
      calls.push([value, revision]);
      if (calls.length === 1) throw new Error("offline");
      return "r1";
    },
    () => {},
  );
  queue.update("first");
  await queue.flush();
  expect(queue.dirty).toBe(true);
  expect(queue.failed).toBe(true);
  queue.update("latest");
  await queue.flush();
  expect(calls).toEqual([
    ["first", "r0"],
    ["latest", "r0"],
  ]);
  expect(queue.dirty).toBe(false);
});

test("revision conflict cannot be retried as an overwrite", async () => {
  let calls = 0;
  const queue = new VideoCanvasSaveQueue(
    "initial",
    "r0",
    async () => {
      calls++;
      throw new CanvasRevisionConflict("changed elsewhere");
    },
    () => {},
  );
  queue.update("first");
  await queue.flush();
  queue.update("latest");
  await queue.flush();
  expect(calls).toBe(1);
  expect(queue.dirty).toBe(true);
});

test("unchanged canvas does not write", async () => {
  let calls = 0;
  const queue = new VideoCanvasSaveQueue(
    "initial",
    "r0",
    async () => {
      calls++;
      return "r1";
    },
    () => {},
  );
  queue.update("initial");
  await queue.flush();
  expect(calls).toBe(0);
});

import { mergeCanvasSnapshots } from "@/lib/video-canvas/merge-snapshot";
const snapshot = (nodes: any[], edges: any[] = []) =>
  JSON.stringify({
    title: "QA",
    canvasData: {
      nodes,
      edges,
      viewport: { x: 0, y: 0, zoom: 1 },
      selectedNodeIds: [],
      tool: "select",
    },
  });
const base = snapshot([
  { id: "a", title: "A", x: 0, draftValues: { text: "original" } },
  { id: "b", title: "B", x: 0 },
]);
test("merges independent node edits, additions and deletion without reviving removed edges", () => {
  const local = snapshot([
    { id: "a", title: "A", x: 20, draftValues: { text: "original" } },
    { id: "b", title: "B", x: 0 },
    { id: "c", title: "C" },
  ]);
  const remote = snapshot(
    [
      { id: "a", title: "new A", x: 0, draftValues: { text: "original" } },
      { id: "d", title: "D" },
    ],
    [{ id: "e", source: "a", target: "b" }],
  );
  const merged = mergeCanvasSnapshots(base, local, remote);
  expect(merged.conflicts).toEqual([]);
  expect(JSON.parse(merged.snapshot).canvasData.nodes).toEqual([
    { id: "a", title: "new A", x: 20, draftValues: { text: "original" } },
    { id: "d", title: "D" },
    { id: "c", title: "C" },
  ]);
  expect(JSON.parse(merged.snapshot).canvasData.edges).toEqual([]);
});
test("same field and deletion versus modification require a decision, preserving other edits", () => {
  const local = snapshot([{ id: "a", title: "local", x: 10, draftValues: { text: "original" } }]);
  const remote = snapshot([
    { id: "a", title: "remote", x: 0, draftValues: { text: "new" } },
    { id: "b", title: "changed B", x: 0 },
  ]);
  const merged = mergeCanvasSnapshots(base, local, remote);
  expect(merged.conflicts).toEqual(["canvasData.nodes[a].title", "canvasData.nodes[b]"]);
  const localChoice = JSON.parse(mergeCanvasSnapshots(base, local, remote, "local").snapshot)
    .canvasData.nodes;
  expect(localChoice).toEqual([{ id: "a", title: "local", x: 10, draftValues: { text: "new" } }]);
  const remoteChoice = JSON.parse(mergeCanvasSnapshots(base, local, remote, "remote").snapshot)
    .canvasData.nodes;
  expect(remoteChoice[0]).toMatchObject({ title: "remote", x: 10, draftValues: { text: "new" } });
  expect(remoteChoice).toHaveLength(2);
});
test("view state stays local, metadata timestamps do not create false content conflicts", () => {
  const local = JSON.parse(base),
    remote = JSON.parse(base);
  local.canvasData.nodes[0].updatedAt = "local";
  remote.canvasData.nodes[0].updatedAt = "remote";
  remote.canvasData.nodes[0].title = "remote";
  remote.canvasData.viewport.x = 50;
  const merged = mergeCanvasSnapshots(base, JSON.stringify(local), JSON.stringify(remote));
  expect(merged.conflicts).toEqual([]);
  expect(JSON.parse(merged.snapshot).canvasData.viewport.x).toBe(0);
});
test("queued edits made while reading a conflict survive the automatic merge and CAS retry", async () => {
  let release!: (e: Error) => void;
  let calls = 0;
  let applied = "";
  const local = snapshot([
    { id: "a", title: "A", x: 10, draftValues: { text: "original" } },
    { id: "b", title: "B", x: 0 },
  ]);
  const newer = snapshot([
    { id: "a", title: "A", x: 20, draftValues: { text: "original" } },
    { id: "b", title: "B", x: 0 },
  ]);
  const remote = snapshot([
    { id: "a", title: "remote", x: 0, draftValues: { text: "original" } },
    { id: "b", title: "B", x: 0 },
  ]);
  const queue = new VideoCanvasSaveQueue(
    base,
    "r0",
    async (value, revision) => {
      calls++;
      if (calls === 1) return new Promise((_, reject) => (release = reject));
      expect(revision).toBe("r1");
      expect(JSON.parse(value).canvasData.nodes[0]).toMatchObject({ title: "remote", x: 20 });
      return "r2";
    },
    () => {},
    { merge: mergeCanvasSnapshots, apply: (value) => (applied = value), conflict: () => {} },
  );
  queue.update(local);
  const saving = queue.flush();
  queue.update(newer);
  release(new CanvasRevisionConflict("conflict", remote, "r1"));
  await saving;
  expect(calls).toBe(2);
  expect(queue.dirty).toBe(false);
  expect(applied).toContain("remote");
});
test("conflict resolution and restored browser drafts never blindly overwrite the remote document", async () => {
  const local = snapshot([
    { id: "a", title: "local", x: 0, draftValues: { text: "original" } },
    { id: "b", title: "B", x: 0 },
  ]);
  const remote = snapshot([
    { id: "a", title: "remote", x: 0, draftValues: { text: "new" } },
    { id: "b", title: "B", x: 0 },
  ]);
  let conflict: string[] = [];
  let written = "";
  const queue = new VideoCanvasSaveQueue(
    remote,
    "r2",
    async (value, revision) => {
      expect(revision).toBe("r2");
      written = value;
      return "r3";
    },
    () => {},
    { merge: mergeCanvasSnapshots, apply: () => {}, conflict: (fields) => (conflict = fields) },
  );
  queue.restoreBackup(base, local);
  await queue.flush();
  expect(written).toBe("");
  expect(conflict).toHaveLength(1);
  await queue.resolveConflict("local");
  expect(JSON.parse(written).canvasData.nodes[0]).toMatchObject({
    title: "local",
    draftValues: { text: "new" },
  });
  expect(conflict).toEqual([]);
  expect(queue.dirty).toBe(false);
});

test("rapid remote saves pause automatic merging without permanently blocking manual retry", async () => {
  let calls = 0;
  let conflictFields: string[] = [];
  const local = JSON.parse(base);
  local.canvasData.nodes[0].title = "local";
  const queue = new VideoCanvasSaveQueue(
    base,
    "r0",
    async (value) => {
      calls++;
      if (calls <= 4) {
        const remote = JSON.parse(base);
        remote.canvasData.nodes[1].title = `remote-${calls}`;
        throw new CanvasRevisionConflict("conflict", JSON.stringify(remote), `r${calls}`);
      }
      const nodes = JSON.parse(value).canvasData.nodes;
      expect(nodes[0].title).toBe("local");
      expect(nodes[1].title).toBe("remote-4");
      return "r5";
    },
    () => {},
    {
      merge: mergeCanvasSnapshots,
      apply: () => {},
      conflict: (fields) => {
        conflictFields = fields;
      },
    },
  );
  queue.update(JSON.stringify(local));
  await queue.flush();
  expect(calls).toBe(4);
  expect(queue.failed).toBe(true);
  expect(queue.dirty).toBe(true);
  expect(conflictFields).toEqual([]);
  await queue.flush();
  expect(calls).toBe(5);
  expect(queue.dirty).toBe(false);
});