/*
 * Copyright (C)  2021-2022 Kristóf Marussy <kristof@marussy.com>
 *
 * This file is part of Sophie.
 *
 * Sophie is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * SPDX-License-Identifier: AGPL-3.0-only
 */

import { jest } from '@jest/globals';
import {
  Action,
  MainToRendererIpcMessage,
  RendererToMainIpcMessage,
  SharedStoreSnapshotIn,
  SophieRenderer,
} from '@sophie/shared';
import { mocked } from 'jest-mock';
import log from 'loglevel';
import type { IJsonPatch } from 'mobx-state-tree';

jest.unstable_mockModule('electron', () => ({
  ipcRenderer: {
    invoke: jest.fn(),
    on: jest.fn(),
    send: jest.fn(),
  },
}));

const { ipcRenderer } = await import('electron');

const { default: createSophieRenderer } = await import('../createSophieRenderer');

const event: Electron.IpcRendererEvent = null as unknown as Electron.IpcRendererEvent;

const snapshot: SharedStoreSnapshotIn = {
  shouldUseDarkColors: true,
};

const invalidSnapshot = {
  shouldUseDarkColors: -1,
} as unknown as SharedStoreSnapshotIn;

const patch: IJsonPatch = {
  op: 'replace',
  path: 'foo',
  value: 'bar',
};

const action: Action = {
  action: 'set-theme-source',
  themeSource: 'dark',
};

const invalidAction = {
  action: 'not-a-valid-action',
} as unknown as Action;

beforeAll(() => {
  log.disableAll();
});

describe('createSophieRenderer', () => {
  it('registers a shared store patch listener', () => {
    createSophieRenderer(false);
    expect(ipcRenderer.on).toHaveBeenCalledWith(
      MainToRendererIpcMessage.SharedStorePatch,
      expect.anything(),
    );
  });
});

describe('SharedStoreConnector', () => {
  let sut: SophieRenderer;
  let onSharedStorePatch: (eventArg: Electron.IpcRendererEvent, patchArg: unknown) => void;
  const listener = {
    // eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
    onSnapshot: jest.fn((_snapshot: SharedStoreSnapshotIn) => {}),
    // eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
    onPatch: jest.fn((_patch: IJsonPatch) => {}),
  };

  beforeEach(() => {
    sut = createSophieRenderer(false);
    [, onSharedStorePatch] = mocked(ipcRenderer.on).mock.calls.find(
      ([channel]) => channel === MainToRendererIpcMessage.SharedStorePatch,
    )!;
  });

  describe('onSharedStoreChange', () => {
    it('should request a snapshot from the main process', async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(snapshot);
      await sut.onSharedStoreChange(listener);
      expect(ipcRenderer.invoke).toBeCalledWith(RendererToMainIpcMessage.GetSharedStoreSnapshot);
      expect(listener.onSnapshot).toBeCalledWith(snapshot);
    });

    it('should catch IPC errors without exposing them', async () => {
      mocked(ipcRenderer.invoke).mockRejectedValue(new Error('s3cr3t'));
      await expect(sut.onSharedStoreChange(listener)).rejects.not.toHaveProperty(
        'message',
        expect.stringMatching(/s3cr3t/),
      );
      expect(listener.onSnapshot).not.toBeCalled();
    });

    it('should not pass on invalid snapshots', async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(invalidSnapshot);
      await expect(sut.onSharedStoreChange(listener)).rejects.toBeInstanceOf(Error);
      expect(listener.onSnapshot).not.toBeCalled();
    });
  });

  describe('dispatchAction', () => {
    it('should dispatch valid actions', () => {
      sut.dispatchAction(action);
      expect(ipcRenderer.send).toBeCalledWith(RendererToMainIpcMessage.DispatchAction, action);
    });

    it('should not dispatch invalid actions', () => {
      expect(() => sut.dispatchAction(invalidAction)).toThrowError();
      expect(ipcRenderer.send).not.toBeCalled();
    });
  });

  describe('when no listener is registered', () => {
    it('should discard the received patch without any error', () => {
      onSharedStorePatch(event, patch);
    });
  });

  function itRefusesToRegisterAnotherListener(): void {
    it('should refuse to register another listener', async () => {
      await expect(sut.onSharedStoreChange(listener)).rejects.toBeInstanceOf(Error);
    });
  }

  function itDoesNotPassPatchesToTheListener(
    name = 'should not pass patches to the listener',
  ): void {
    it(name, () => {
      onSharedStorePatch(event, patch);
      expect(listener.onPatch).not.toBeCalled();
    });
  }

  describe('when a listener registered successfully', () => {
    beforeEach(async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(snapshot);
      await sut.onSharedStoreChange(listener);
    });

    it('should pass patches to the listener', () => {
      onSharedStorePatch(event, patch);
      expect(listener.onPatch).toBeCalledWith(patch);
    });

    it('should catch listener errors', () => {
      mocked(listener.onPatch).mockImplementation(() => { throw new Error(); });
      onSharedStorePatch(event, patch);
    });

    itRefusesToRegisterAnotherListener();

    describe('after the listener threw in onPatch', () => {
      beforeEach(() => {
        mocked(listener.onPatch).mockImplementation(() => { throw new Error(); });
        onSharedStorePatch(event, patch);
        listener.onPatch.mockRestore();
      });

      itDoesNotPassPatchesToTheListener('should not pass on patches any more');
    });
  });

  describe('when a listener failed to register due to IPC error', () => {
    beforeEach(async () => {
      mocked(ipcRenderer.invoke).mockRejectedValue(new Error());
      try {
        await sut.onSharedStoreChange(listener);
      } catch {
        // Ignore error.
      }
    });

    itRefusesToRegisterAnotherListener();

    itDoesNotPassPatchesToTheListener();
  });

  describe('when a listener failed to register due to an invalid snapshot', () => {
    beforeEach(async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(invalidSnapshot);
      try {
        await sut.onSharedStoreChange(listener);
      } catch {
        // Ignore error.
      }
    });

    itRefusesToRegisterAnotherListener();

    itDoesNotPassPatchesToTheListener();
  });

  describe('when a listener failed to register due to listener error', () => {
    beforeEach(async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(snapshot);
      mocked(listener.onSnapshot).mockImplementation(() => { throw new Error(); });
      try {
        await sut.onSharedStoreChange(listener);
      } catch {
        // Ignore error.
      }
    });

    itRefusesToRegisterAnotherListener();

    itDoesNotPassPatchesToTheListener();
  });

  describe('when it is allowed to replace listeners', () => {
    const snapshot2 = {
      shouldUseDarkColors: false,
    };
    const listener2 = {
      // eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
      onSnapshot: jest.fn((_snapshot: SharedStoreSnapshotIn) => { }),
      // eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
      onPatch: jest.fn((_patch: IJsonPatch) => { }),
    };

    it('should fetch a second snapshot', async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(snapshot2);
      await sut.onSharedStoreChange(listener2);
      expect(ipcRenderer.invoke).toBeCalledWith(RendererToMainIpcMessage.GetSharedStoreSnapshot);
      expect(listener2.onSnapshot).toBeCalledWith(snapshot2);
    });

    it('should pass the second snapshot to the new listener', async () => {
      mocked(ipcRenderer.invoke).mockResolvedValueOnce(snapshot2);
      await sut.onSharedStoreChange(listener2);
      onSharedStorePatch(event, patch);
      expect(listener2.onPatch).toBeCalledWith(patch);
    });
  });
});