import { Actions, Task, UndoRedoStore } from 'mailspring-exports';

class Undoable extends Task {
  constructor() {
    super();
    this.canBeUndone = true;
  }
}

class PermanentTask extends Task {
  constructor() {
    super();
    this.canBeUndone = false;
  }
}

describe('UndoRedoStore', function undoRedoStoreSpec() {
  beforeEach(() => {
    UndoRedoStore._undo = [];
    UndoRedoStore._redo = [];
    spyOn(UndoRedoStore, 'trigger');
    spyOn(Actions, 'queueTask').andCallFake((...args) => {
      UndoRedoStore._onQueue(...args);
    });
    spyOn(Actions, 'queueTasks').andCallFake((...args) => {
      UndoRedoStore._onQueue(...args);
    });

    this.ids = arrarr => arrarr.map(arr => arr.map(itm => itm.id));
    this.t1 = new Undoable();
    this.t2 = new Undoable();
    this.t3 = new Undoable();
    this.t4 = new Undoable();
    this.p1 = new PermanentTask();
    this.t1.id = 't1';
    this.t2.id = 't2';
    this.t3.id = 't3';
    this.t4.id = 't4';
    this.p1.id = 'p1';
  });

  it('pushes single tasks onto undo/redo', () => {
    Actions.queueTask(this.t1);
    expect(UndoRedoStore._redo).toEqual([]);
    expect(UndoRedoStore._undo).toEqual([[this.t1]]);
    expect(UndoRedoStore.trigger).toHaveBeenCalled();
  });

  it('pushes multiple tasks onto redo', () => {
    Actions.queueTasks([this.t1, this.t2]);
    expect(UndoRedoStore._redo).toEqual([]);
    expect(UndoRedoStore._undo).toEqual([[this.t1, this.t2]]);
    expect(UndoRedoStore.trigger).toHaveBeenCalled();
  });

  it("only undoes task if they're all 'undoable'", () => {
    Actions.queueTask([this.t1, this.p1]);
    expect(UndoRedoStore._redo).toEqual([]);
    expect(UndoRedoStore._undo).toEqual([]);
    expect(UndoRedoStore.trigger).not.toHaveBeenCalled();
  });

  it('refreshes redo if we get a new task', () => {
    UndoRedoStore._redo = [[this.t1, this.t2], [this.t3]];
    Actions.queueTask(this.t3);
    expect(UndoRedoStore._redo).toEqual([]);
  });

  it("doesn't refresh redo if our task is itself a redo task", () => {
    UndoRedoStore._redo = [[this.t1, this.t2], [this.t3]];
    const tr = new Undoable();
    tr.source = 'redo';
    Actions.queueTask(tr);
    expect(UndoRedoStore._redo).toEqual([[this.t1, this.t2], [this.t3]]);
    expect(UndoRedoStore._undo).toEqual([[tr]]);
  });

  it('runs undoTask on each group of undo tasks', () => {
    UndoRedoStore._undo = [[this.t3], [this.t1, this.t2]];
    UndoRedoStore.undo();
    expect(Actions.queueTask.calls.length).toBe(2);
    expect(Actions.queueTask.calls[0].args[0]).toBe('t1');
    expect(Actions.queueTask.calls[1].args[0]).toBe('t2');
    expect(UndoRedoStore._undo).toEqual([[this.t3]]);
  });

  it('creates identical redo tasks and pushes on the stack', () => {
    UndoRedoStore._undo = [[this.t3], [this.t1, this.t2]];
    UndoRedoStore.undo();
    expect(UndoRedoStore._undo).toEqual([[this.t3]]);
    expect(UndoRedoStore._redo[0][0].id).toBe('t1');
    expect(UndoRedoStore._redo[0][1].id).toBe('t2');
    expect(UndoRedoStore._redo.length).toBe(1);
  });

  it('redoes the latest task', () => {
    UndoRedoStore._undo = [[this.t3], [this.t1, this.t2]];
    UndoRedoStore.undo();
    UndoRedoStore.redo();
    expect(Actions.queueTasks.calls[0].args[0][0].id).toBe('t1');
    expect(Actions.queueTasks.calls[0].args[0][1].id).toBe('t2');
    expect(UndoRedoStore._undo[0]).toEqual([this.t3]);
    expect(UndoRedoStore._undo[1][0].id).toBe('t1');
    expect(UndoRedoStore._undo[1][1].id).toBe('t2');
  });

  it('marks the incoming task as a redo task', () => {
    UndoRedoStore._undo = [[this.t3], [this.t1, this.t2]];
    UndoRedoStore.undo();
    UndoRedoStore.redo();
    expect(Actions.queueTasks.calls[0].args[0][0].source).toEqual('redo');
    expect(Actions.queueTasks.calls[0].args[0][1].source).toEqual('redo');
  });

  it('correctly follows the undo redo sequence of events', () => {
    Actions.queueTask(this.t1);
    Actions.queueTask(this.t2);
    Actions.queueTasks([this.t3, this.t4]);
    expect(UndoRedoStore._undo).toEqual([[this.t1], [this.t2], [this.t3, this.t4]]);
    UndoRedoStore.undo();
    UndoRedoStore.undo();
    UndoRedoStore.undo();
    UndoRedoStore.undo();
    UndoRedoStore.undo();
    expect(UndoRedoStore._undo).toEqual([]);
    expect(this.ids(UndoRedoStore._redo)).toEqual([['t3', 't4'], ['t2'], ['t1']]);
    UndoRedoStore.redo();
    UndoRedoStore.redo();
    UndoRedoStore.redo();
    UndoRedoStore.redo();
    UndoRedoStore.redo();
    UndoRedoStore.redo();
    expect(this.ids(UndoRedoStore._undo)).toEqual([['t1'], ['t2'], ['t3', 't4']]);
    expect(this.ids(UndoRedoStore._redo)).toEqual([]);
  });
});