# QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
# Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from AlgorithmImports import *
from QuantConnect.Logging import *
from enum import Enum

class RsiAlphaModel(AlphaModel):
    '''Uses Wilder's RSI to create insights.
    Using default settings, a cross over below 30 or above 70 will trigger a new insight.'''

    def __init__(self,
                 period = 14,
                 resolution = Resolution.Daily):
        '''Initializes a new instance of the RsiAlphaModel class
        Args:
            period: The RSI indicator period'''
        self.period = period
        self.resolution = resolution
        self.insightPeriod = Time.Multiply(Extensions.ToTimeSpan(resolution), period)
        self.symbolDataBySymbol ={}

        resolutionString = Extensions.GetEnumString(resolution, Resolution)
        self.Name = '{}({},{})'.format(self.__class__.__name__, period, resolutionString)

    def Update(self, algorithm, data):
        '''Updates this alpha model with the latest data from the algorithm.
        This is called each time the algorithm receives data for subscribed securities
        Args:
            algorithm: The algorithm instance
            data: The new data available
        Returns:
            The new insights generated'''
        insights = []
        for symbol, symbolData in self.symbolDataBySymbol.items():
            rsi = symbolData.RSI
            previous_state = symbolData.State
            state = self.GetState(rsi, previous_state)

            if state != previous_state and rsi.IsReady:
                if state == State.TrippedLow:
                    insights.append(Insight.Price(symbol, self.insightPeriod, InsightDirection.Up))
                if state == State.TrippedHigh:
                    insights.append(Insight.Price(symbol, self.insightPeriod, InsightDirection.Down))

            symbolData.State = state

        return insights


    def OnSecuritiesChanged(self, algorithm, changes):
        '''Cleans out old security data and initializes the RSI for any newly added securities.
        Event fired each time the we add/remove securities from the data feed
        Args:
            algorithm: The algorithm instance that experienced the change in securities
            changes: The security additions and removals from the algorithm'''
        # clean up data for removed securities
        for security in changes.RemovedSecurities:
            symbol_data = self.symbolDataBySymbol.pop(security.Symbol, None)
            if symbol_data:
                symbol_data.dispose()

        # initialize data for added securities
        added_symbols = []
        for security in changes.AddedSecurities:
            symbol = security.Symbol 
            if symbol not in self.symbolDataBySymbol:
                symbol_data = SymbolData(algorithm, symbol, self.period, self.resolution)
                self.symbolDataBySymbol[symbol] = symbol_data
                added_symbols.append(symbol)
                
        if added_symbols:
            history = algorithm.History[TradeBar](added_symbols, self.period, self.resolution)
            for trade_bars in history:
                for bar in trade_bars.Values:
                    self.symbolDataBySymbol[bar.Symbol].update(bar)


    def GetState(self, rsi, previous):
        ''' Determines the new state. This is basically cross-over detection logic that
        includes considerations for bouncing using the configured bounce tolerance.'''
        if rsi.Current.Value > 70:
            return State.TrippedHigh
        if rsi.Current.Value < 30:
            return State.TrippedLow
        if previous == State.TrippedLow:
            if rsi.Current.Value > 35:
                return State.Middle
        if previous == State.TrippedHigh:
            if rsi.Current.Value < 65:
                return State.Middle

        return previous


class SymbolData:
    '''Contains data specific to a symbol required by this model'''
    def __init__(self, algorithm, symbol, period, resolution):
        self.algorithm = algorithm
        self.Symbol = symbol
        self.State = State.Middle

        self.RSI = RelativeStrengthIndex(period, MovingAverageType.Wilders)
        self.consolidator = algorithm.ResolveConsolidator(symbol, resolution)
        algorithm.RegisterIndicator(symbol, self.RSI, self.consolidator)

    def update(self, bar):
        self.consolidator.Update(bar)

    def dispose(self):
        self.algorithm.SubscriptionManager.RemoveConsolidator(self.Symbol, self.consolidator)


class State(Enum):
    '''Defines the state. This is used to prevent signal spamming and aid in bounce detection.'''
    TrippedLow = 0
    Middle = 1
    TrippedHigh = 2