import PouchDB from 'pouchdb'
import { put, takeLatest, all } from 'redux-saga/effects'
import * as types from '../constants/actionTypes';
import PouchDBFind from 'pouchdb-find';
import Immutable from 'immutable';

PouchDB.debug.disable();
PouchDB.plugin(PouchDBFind);

const sessionsDB = new PouchDB('sessions');
const notesDB = new PouchDB('notes');
notesDB.createIndex({
  index: { fields: ['session'] }
});

// ---

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 default function* rootSaga() {
  yield all([
    watchLoadSessions(),
    watchLoadNotesBySession(),
    watchAddNote(),
    watchCreateSession(),
    watchUpdateSession(),
  ])
}