# Copyright (c) Microsoft Corporation.
# Licensed under the MIT license.

"""A module for data diagnosis rule ops."""

from typing import Dict, Callable
import re

import pandas as pd

from superbench.benchmarks.context import Enum
from superbench.common.utils import logger


class DiagnosisRuleType(Enum):
    """The Enum class representing different rule ops."""

    VARIANCE = 'variance'
    VALUE = 'value'
    MULTI_RULES = 'multi_rules'
    FAILURE_CHECK = 'failure_check'


class RuleOp:
    """RuleOp class to maintain all rule functions."""

    functions: Dict[DiagnosisRuleType, Callable] = dict()

    @classmethod
    def add_rule_func(cls, rule_type):
        """Add rule fuction.

        Args:
            rule_type (DiagnosisRuleType): The type of rule function.

        Return:
            decorator (Callable): return the decorator to add the rule function.
        """
        def decorator(func):
            cls.functions[rule_type] = func
            return func

        return decorator

    @classmethod
    def get_rule_func(cls, rule_type):
        """Get rule fuction by rule_type.

        Args:
            rule_type (DiagnosisRuleType): The type of rule function.

        Return:
            func (Callable): rule function, None means invalid rule type.
        """
        if rule_type in cls.functions:
            return cls.functions[rule_type]

        return None

    @staticmethod
    def check_criterion_with_a_value(rule):
        """Check if the criterion is valid with a numeric variable and return bool type.

        Args:
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
        """
        # parse criteria and check if valid
        if not isinstance(eval(rule['criteria'])(0), bool):
            logger.log_and_raise(exception=ValueError, msg='invalid criteria format')

    @staticmethod
    def miss_test(metric, rule, data_row, details, categories):
        """Check if the metric in the rule missed test and if so add details and categories.

        Args:
            metric (str): the name of the metric
            data_row (pd.Series): raw data of the metrics
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
            details (list): details about violated rules and related data
            categories (set): categories of violated rules

        Returns:
            bool: if the metric in the rule missed test, return True, otherwise return False
        """
        # metric not in raw_data or the value is none, miss test
        if metric not in data_row or pd.isna(data_row[metric]):
            RuleOp.add_categories_and_details(metric + '_miss', 'FailedTest', details, categories)
            return True
        return False

    @staticmethod
    def add_categories_and_details(detail, category, details, categories):
        """Add details and categories.

        Args:
            detail (str): violated rule and related data
            category (str): category of violated rule
            details (list): list of details about violated rules and related data
            categories (set): set of categories of violated rules
        """
        details.append(detail)
        if category:
            categories.add(category)

    @staticmethod
    def variance(data_row, rule, summary_data_row, details, categories):
        """Rule op function of variance.

        Each metric in the rule will calculate the variance (val - baseline / baseline),
        and use criteria in the rule to determine whether metric's variance meet the criteria,
        if any metric meet the criteria, the rule is not passed.

        Args:
            data_row (pd.Series): raw data of the metrics
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
            summary_data_row (pd.Series): results of the metrics processed after the function
            details (list): details about violated rules and related data
            categories (set): categories of violated rules

        Returns:
            number: the number of the metrics that violate the rule if the rule is not passed, otherwise 0
        """
        violated_metric_num = 0
        RuleOp.check_criterion_with_a_value(rule)
        # every metric should pass the rule
        for metric in rule['metrics']:
            # metric not in raw_data or the value is none, miss test
            if not RuleOp.miss_test(metric, rule, data_row, details, categories):
                violate_metric = False
                # check if metric pass the rule
                val = data_row[metric]
                baseline = rule['metrics'][metric]
                if baseline is None or baseline == 0:
                    logger.log_and_raise(
                        exception=ValueError, msg='invalid baseline 0 or baseline not found in variance rule'
                    )
                var = (val - baseline) / baseline
                summary_data_row[metric] = var
                violate_metric = eval(rule['criteria'])(var)
                # add issued details and categories
                if violate_metric:
                    violated_metric_num += 1
                    info = '(B/L: {:.4f} VAL: {:.4f} VAR: {:.2f}% Rule:{})'.format(
                        baseline, val, var * 100, rule['criteria']
                    )
                    if 'store' not in rule or not rule['store']:
                        RuleOp.add_categories_and_details(metric + info, rule['categories'], details, categories)
                    else:
                        RuleOp.add_categories_and_details(metric + info, None, details, categories)
        return violated_metric_num

    @staticmethod
    def value(data_row, rule, summary_data_row, details, categories):
        """Rule op function of value.

        Each metric in the rule will use criteria in the rule
        to determine whether metric's value meet the criteria,
        if any metric meet the criteria, the rule is not passed.

        Args:
            data_row (pd.Series): raw data of the metrics
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
            summary_data_row (pd.Series): results of the metrics processed after the function
            details (list): details about violated rules and related data
            categories (set): categories of violated rules

        Returns:
            number: the number of the metrics that violate the rule if the rule is not passed, otherwise 0
        """
        violated_metric_num = 0
        # parse criteria and check if valid
        RuleOp.check_criterion_with_a_value(rule)
        # every metric should pass the rule
        for metric in rule['metrics']:
            # metric not in raw_data or the value is none, miss test
            if not RuleOp.miss_test(metric, rule, data_row, details, categories):
                violate_metric = False
                # check if metric pass the rule
                val = data_row[metric]
                summary_data_row[metric] = val
                violate_metric = eval(rule['criteria'])(val)
                # add issued details and categories
                if violate_metric:
                    violated_metric_num += 1
                    info = '(VAL: {:.4f} Rule:{})'.format(val, rule['criteria'])
                    if 'store' not in rule or not rule['store']:
                        RuleOp.add_categories_and_details(metric + info, rule['categories'], details, categories)
                    else:
                        RuleOp.add_categories_and_details(metric + info, None, details, categories)
        return violated_metric_num

    @staticmethod
    def multi_rules(rule, details, categories, store_values):
        """Rule op function of multi_rules.

        The criteria in this rule will use the combined results of multiple previous rules and their metrics
        which has been stored in advance to determine whether this rule is passed.

        Args:
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
            details (list): details about violated rules and related data
            categories (set): categories of violated rules
            store_values (dict): including the number of the metrics that violate the rule, and the values of
            the metrics for the rules with 'store' True
        Returns:
            number: 0 if the rule is passed, otherwise 1
        """
        try:
            violated = eval(rule['criteria'])(store_values)
            if not isinstance(violated, bool):
                logger.log_and_raise(exception=ValueError, msg='invalid criteria format')
            if violated:
                info = '{}:{}'.format(rule['name'], rule['criteria'])
                RuleOp.add_categories_and_details(info, rule['categories'], details, categories)
            return 1 if violated else 0
        # the key defined in criteria is not found
        except KeyError as e:
            logger.log_and_raise(exception=KeyError, msg='invalid criteria format - {}'.format(str(e)))
        # miss/failed test
        except Exception:
            return 0

    @staticmethod
    def failure_check(data_row, rule, summary_data_row, details, categories, raw_rule):
        """Rule op function of failure_check.

        Args:
            data_row (pd.Series): raw data of the metrics
            rule (dict): rule including function, criteria, metrics with their baseline values and categories
            summary_data_row (pd.Series): results of the metrics processed after the function
            details (list): details about violated rules and related data
            categories (set): categories of violated rules
            raw_rule (dict): raw rule read from rule file

        Returns:
            number: the number of the metrics that violate the rule if the rule is not passed, otherwise 0
        """
        violated_metric_num = 0
        for metric_regex in raw_rule['metrics']:
            match = False
            for metric in rule['metrics']:
                if re.search(metric_regex, metric):
                    match = True
                    # metric not in raw_data or the value is none, miss test
                    if metric not in data_row or pd.isna(data_row[metric]):
                        violated_metric_num += 1
                    break
            # metric_regex written in rules is not matched by any metric, miss test
            if not match:
                violated_metric_num += 1
                RuleOp.add_categories_and_details(metric_regex + '_miss', rule['categories'], details, categories)
        # return code != 0, failed test
        violated_metric_num += RuleOp.value(data_row, rule, summary_data_row, details, categories)
        return violated_metric_num


RuleOp.add_rule_func(DiagnosisRuleType.VARIANCE)(RuleOp.variance)
RuleOp.add_rule_func(DiagnosisRuleType.VALUE)(RuleOp.value)
RuleOp.add_rule_func(DiagnosisRuleType.MULTI_RULES)(RuleOp.multi_rules)
RuleOp.add_rule_func(DiagnosisRuleType.FAILURE_CHECK)(RuleOp.failure_check)
