import PouchDB from 'pouchdb'

import { put, take, takeLatest, all } from 'redux-saga/effects'

import * as types from '../constants/actionTypes';

import PouchDBFind from 'pouchdb-find';

import Immutable from 'immutable';

import APIClient from '../APIClient';

PouchDB.debug.disable();

PouchDB.plugin(PouchDBFind);

const sessionsDB = new PouchDB('sessions');

const notesDB = new PouchDB('notes');

notesDB.createIndex({

  index: { fields: ['session'] }

});

const client = new APIClient('http://localhost:8000')

// ---

export function* loadSessions() {

  const response = yield sessionsDB.allDocs({ include_docs: true })

  const sessions = response.rows.map(row => row.doc)

  yield put({ type: types.LOAD_SESSIONS, sessions: Immutable.List(sessions) })

}

export function* watchLoadSessions() {

  yield takeLatest(types.LOAD_SESSIONS_ASYNC, loadSessions)

}

// ---

export function* createSession(action) {

  const response = yield sessionsDB.put(action.session);

  // TODO Error control

  const session = Object.assign({}, action.session, { rev: response.rev });

  yield put({ type: types.CREATE_SESSION, session: session })

}

export function* watchCreateSession() {

  yield takeLatest(types.CREATE_SESSION_ASYNC, createSession)

}

// ---

export function* updateSession(action) {

  const { _id } = action.session;

  let session;

  const doc = yield sessionsDB.get(_id);

  session = Object.assign({}, doc, action.values);

  const response = yield sessionsDB.put(session);

  yield put({

    type: types.UPDATE_SESSION,

    session: Object.assign({}, session, { rev: response.rev })

  })

}

export function* watchUpdateSession() {

  yield takeLatest(types.UPDATE_SESSION_ASYNC, updateSession)

}

// ---

export function* addNote(action) {

  const response = yield notesDB.put(action.note);

  // TODO Error control

  const note = Object.assign({}, action.note, { rev: response.rev });

  yield put({ type: types.ADD_NOTE, note: note })

}

export function* watchAddNote() {

  yield takeLatest(types.ADD_NOTE_ASYNC, addNote)

}

// ---

export function* loadNotesBySession(action) {

  const result = yield notesDB.find({

    selector: { session: action.session._id },

    // sort: ['name']

  });

  yield put({ type: types.LOAD_NOTES_BY_SESSION, notes: Immutable.List(result.docs) })

}

export function* watchLoadNotesBySession() {

  yield takeLatest(types.LOAD_NOTES_BY_SESSION_ASYNC, loadNotesBySession)

}

// ---

export function* watchLoginSubmit() {

  while (true) {

    const { username, password } = yield take(types.AUTH_LOGIN_SUBMIT);

    yield put({ type: types.AUTH_LOGIN_REQUEST, username, password });

  }

}

function* watchLoginRequest() {

  while (true) {

    try {

        const { username, password } = yield take(types.AUTH_LOGIN_REQUEST);

        const response = yield client.post('/api/auth/login/', { username, password });

        localStorage.setItem('currentUser', JSON.stringify(response.user));

        localStorage.setItem('token', response.token);

        const actions = [{

          type: types.AUTH_LOGIN_SUCCESS,

          user: response.user,

          token: response.token,

          meta: {

            transition: (prevState, nextState, action) => ({

              pathname: '/sessions',

            }),

          },

        }, {

          type: types.AUTH_STORE_TOKEN_ASYNC,

          token: response.token,

        }];

        yield actions.map(action => put(action))

    } catch(e) {

        yield put({ type: types.AUTH_LOGIN_ERROR, error: e });

    }

  }

}

function* watchStoreToken() {

  while (true) {

    const { token } = yield take(types.AUTH_STORE_TOKEN_ASYNC);

    yield put({ type: types.AUTH_STORE_TOKEN, token });

  }

}

// ---

export default function* rootSaga() {

  yield all([

    watchLoadSessions(),

    watchLoadNotesBySession(),

    watchAddNote(),

    watchCreateSession(),

    watchUpdateSession(),

    watchLoginSubmit(),

    watchLoginRequest(),

    watchStoreToken(),

  ])

}