import logging
import time
from pathlib import Path
from typing import Any, Dict, List

import pandas as pd

from freqtrade.constants import Config
from freqtrade.exceptions import OperationalException
from freqtrade.optimize.lookahead_analysis import LookaheadAnalysis
from freqtrade.resolvers import StrategyResolver


logger = logging.getLogger(__name__)


class LookaheadAnalysisSubFunctions:
    @staticmethod
    def text_table_lookahead_analysis_instances(lookahead_instances: List[LookaheadAnalysis]):
        headers = ['filename', 'strategy', 'has_bias', 'total_signals',
                   'biased_entry_signals', 'biased_exit_signals', 'biased_indicators']
        data = []
        for inst in lookahead_instances:
            if inst.failed_bias_check:
                data.append(
                    [
                        inst.strategy_obj['location'].parts[-1],
                        inst.strategy_obj['name'],
                        'error while checking'
                    ]
                )
            else:
                data.append(
                    [
                        inst.strategy_obj['location'].parts[-1],
                        inst.strategy_obj['name'],
                        inst.current_analysis.has_bias,
                        inst.current_analysis.total_signals,
                        inst.current_analysis.false_entry_signals,
                        inst.current_analysis.false_exit_signals,
                        ", ".join(inst.current_analysis.false_indicators)
                    ]
                )
        from tabulate import tabulate
        table = tabulate(data, headers=headers, tablefmt="orgtbl")
        print(table)

    @staticmethod
    def export_to_csv(config: Dict[str, Any], lookahead_analysis: List[LookaheadAnalysis]):
        def add_or_update_row(df, row_data):
            if (
                    (df['filename'] == row_data['filename']) &
                    (df['strategy'] == row_data['strategy'])
            ).any():
                # Update existing row
                pd_series = pd.DataFrame([row_data])
                df.loc[
                    (df['filename'] == row_data['filename']) &
                    (df['strategy'] == row_data['strategy'])
                    ] = pd_series
            else:
                # Add new row
                df = pd.concat([df, pd.DataFrame([row_data], columns=df.columns)])

            return df

        if Path(config['lookahead_analysis_exportfilename']).exists():
            # Read CSV file into a pandas dataframe
            csv_df = pd.read_csv(config['lookahead_analysis_exportfilename'])
        else:
            # Create a new empty DataFrame with the desired column names and set the index
            csv_df = pd.DataFrame(columns=[
                'filename', 'strategy', 'has_bias', 'total_signals',
                'biased_entry_signals', 'biased_exit_signals', 'biased_indicators'
            ],
                index=None)

        for inst in lookahead_analysis:
            new_row_data = {'filename': inst.strategy_obj['location'].parts[-1],
                            'strategy': inst.strategy_obj['name'],
                            'has_bias': inst.current_analysis.has_bias,
                            'total_signals': inst.current_analysis.total_signals,
                            'biased_entry_signals': inst.current_analysis.false_entry_signals,
                            'biased_exit_signals': inst.current_analysis.false_exit_signals,
                            'biased_indicators': ",".join(inst.current_analysis.false_indicators)}
            csv_df = add_or_update_row(csv_df, new_row_data)

        logger.info(f"saving {config['lookahead_analysis_exportfilename']}")
        csv_df.to_csv(config['lookahead_analysis_exportfilename'], index=False)

    @staticmethod
    def initialize_single_lookahead_analysis(strategy_obj: Dict[str, Any], config: Dict[str, Any]):

        logger.info(f"Bias test of {Path(strategy_obj['location']).name} started.")
        start = time.perf_counter()
        current_instance = LookaheadAnalysis(config, strategy_obj)
        current_instance.start()
        elapsed = time.perf_counter() - start
        logger.info(f"checking look ahead bias via backtests "
                    f"of {Path(strategy_obj['location']).name} "
                    f"took {elapsed:.0f} seconds.")
        return current_instance

    @staticmethod
    def start(config: Config):
        if config['targeted_trade_amount'] < config['minimum_trade_amount']:
            # this combo doesn't make any sense.
            raise OperationalException(
                "targeted trade amount can't be smaller than minimum trade amount."
            )

        strategy_objs = StrategyResolver.search_all_objects(
                config, enum_failed=False, recursive=config.get('recursive_strategy_search', False))

        lookaheadAnalysis_instances = []

        # unify --strategy and --strategy_list to one list
        if not (strategy_list := config.get('strategy_list', [])):
            if config.get('strategy') is None:
                raise OperationalException(
                    "No Strategy specified. Please specify a strategy via --strategy or "
                    "--strategy_list"
                )
            strategy_list = [config['strategy']]

        # check if strategies can be properly loaded, only check them if they can be.
        for strat in strategy_list:
            for strategy_obj in strategy_objs:
                if strategy_obj['name'] == strat and strategy_obj not in strategy_list:
                    lookaheadAnalysis_instances.append(
                        LookaheadAnalysisSubFunctions.initialize_single_lookahead_analysis(
                            strategy_obj, config))
                    break

        # report the results
        if lookaheadAnalysis_instances:
            LookaheadAnalysisSubFunctions.text_table_lookahead_analysis_instances(
                lookaheadAnalysis_instances)
            if config.get('lookahead_analysis_exportfilename') is not None:
                LookaheadAnalysisSubFunctions.export_to_csv(config, lookaheadAnalysis_instances)
        else:
            logger.error("There were no strategies specified neither through "
                         "--strategy nor through "
                         "--strategy_list "
                         "or timeframe was not specified.")