import { describe, expect, it, vi } from "vitest";
import { CommandHistory, createTransaction } from "../../src/commands/history";

describe("source transaction history", () => {
  it("undoes and redoes exact source without normalization", () => {
    const history = new CommandHistory();
    const transaction = createTransaction({
      label: "Set fill",
      baseRevision: 1,
      sourceBefore: "<svg><path/></svg>\r\n",
      sourceAfter: '<svg><path fill="red"/></svg>\r\n',
    });
    history.commit(transaction);
    expect(history.undo(transaction.sourceAfter)?.sourceBefore).toBe(
      transaction.sourceBefore,
    );
    expect(history.redo(transaction.sourceBefore)?.sourceAfter).toBe(
      transaction.sourceAfter,
    );
  });

  it("coalesces rapid source-editor transactions with a shared merge key", () => {
    vi.spyOn(Date, "now").mockReturnValueOnce(100).mockReturnValueOnce(200);
    const history = new CommandHistory();
    history.commit(
      createTransaction({
        label: "Type",
        baseRevision: 0,
        sourceBefore: "a",
        sourceAfter: "ab",
        mergeKey: "typing",
      }),
    );
    history.commit(
      createTransaction({
        label: "Type",
        baseRevision: 1,
        sourceBefore: "ab",
        sourceAfter: "abc",
        mergeKey: "typing",
      }),
    );
    expect(history.snapshot.past).toHaveLength(1);
    expect(history.snapshot.past[0]).toMatchObject({
      sourceBefore: "a",
      sourceAfter: "abc",
    });
  });

  it("rejects stale undo and bounds history", () => {
    const history = new CommandHistory(2, 10_000);
    history.commit(
      createTransaction({
        label: "one",
        baseRevision: 0,
        sourceBefore: "a",
        sourceAfter: "b",
      }),
    );
    expect(() => history.undo("not-b")).toThrow(/stale/u);
    history.commit(
      createTransaction({
        label: "two",
        baseRevision: 1,
        sourceBefore: "b",
        sourceAfter: "c",
      }),
    );
    history.commit(
      createTransaction({
        label: "three",
        baseRevision: 2,
        sourceBefore: "c",
        sourceAfter: "d",
      }),
    );
    expect(history.snapshot.past).toHaveLength(2);
  });
});