"""
Metrics calculation for sentiment analysis dashboard
Provides key performance indicators and statistical metrics
"""
import pandas as pd
import numpy as np
from typing import Dict, List, Tuple


class SentimentMetrics:
    """
    Calculates various metrics for sentiment analysis
    """

    @staticmethod
    def calculate_overall_metrics(df):
        """
        Calculate overall summary metrics

        Args:
            df: Sentiment dataframe

        Returns:
            dict: Overall metrics
        """
        total_comments = len(df)
        total_reply_required = df['requires_reply'].sum() if 'requires_reply' in df.columns else 0

        # Sentiment distribution
        sentiment_dist = df['sentiment_polarity'].value_counts(normalize=True) * 100

        # Calculate sentiment score (vectorized — no copy needed)
        sentiment_weights = {
            'very_negative': -2,
            'negative': -1,
            'neutral': 0,
            'positive': 1,
            'very_positive': 2
        }
        avg_sentiment_score = df['sentiment_polarity'].map(sentiment_weights).mean()

        # Negative sentiment percentage
        negative_sentiments = ['negative', 'very_negative']
        negative_pct = (df['sentiment_polarity'].isin(negative_sentiments).sum() / total_comments * 100) if total_comments > 0 else 0

        # Positive sentiment percentage
        positive_sentiments = ['positive', 'very_positive']
        positive_pct = (df['sentiment_polarity'].isin(positive_sentiments).sum() / total_comments * 100) if total_comments > 0 else 0

        return {
            'total_comments': total_comments,
            'total_reply_required': int(total_reply_required),
            'reply_required_pct': (total_reply_required / total_comments * 100) if total_comments > 0 else 0,
            'avg_sentiment_score': avg_sentiment_score,
            'negative_pct': negative_pct,
            'positive_pct': positive_pct,
            'sentiment_distribution': sentiment_dist.to_dict()
        }

    @staticmethod
    def calculate_brand_metrics(df):
        """
        Calculate metrics by brand

        Args:
            df: Sentiment dataframe

        Returns:
            dict: Metrics by brand
        """
        brand_metrics = {}

        for brand in df['brand'].unique():
            brand_df = df[df['brand'] == brand]
            brand_metrics[brand] = SentimentMetrics.calculate_overall_metrics(brand_df)

        return brand_metrics

    @staticmethod
    def calculate_platform_metrics(df):
        """
        Calculate metrics by platform

        Args:
            df: Sentiment dataframe

        Returns:
            dict: Metrics by platform
        """
        platform_metrics = {}

        for platform in df['platform'].unique():
            platform_df = df[df['platform'] == platform]
            platform_metrics[platform] = SentimentMetrics.calculate_overall_metrics(platform_df)

        return platform_metrics

    @staticmethod
    def calculate_content_engagement_score(content_df):
        """
        Calculate engagement score for a content piece

        Args:
            content_df: DataFrame for a single content

        Returns:
            float: Engagement score (0-100)
        """
        if len(content_df) == 0:
            return 0

        # Factors:
        # 1. Number of comments (normalized)
        # 2. Sentiment positivity
        # 3. Intent diversity
        # 4. Reply requirement rate

        comment_count = len(content_df)
        comment_score = min(comment_count / 100 * 30, 30)  # Max 30 points for 100+ comments

        # Sentiment score (max 40 points) — vectorized, no copy needed
        sentiment_weights = {
            'very_negative': -2,
            'negative': -1,
            'neutral': 0,
            'positive': 1,
            'very_positive': 2
        }
        avg_sentiment = content_df['sentiment_polarity'].map(sentiment_weights).mean()
        sentiment_score = ((avg_sentiment + 2) / 4) * 40  # Normalize to 0-40

        # Intent diversity score (max 20 points)
        unique_intents = content_df['intent'].str.split(',').explode().str.strip().nunique()
        intent_score = min(unique_intents / 8 * 20, 20)  # Max 20 points for 8 unique intents

        # Interaction requirement (max 10 points)
        reply_rate = content_df['requires_reply'].sum() / len(content_df) if len(content_df) > 0 else 0
        interaction_score = reply_rate * 10

        total_score = comment_score + sentiment_score + intent_score + interaction_score
        return round(total_score, 2)

    @staticmethod
    def get_sentiment_health_status(negative_pct):
        """
        Determine health status based on negative sentiment percentage

        Args:
            negative_pct: Percentage of negative sentiments

        Returns:
            tuple: (status, color)
        """
        if negative_pct < 10:
            return ("Excellent", "green")
        elif negative_pct < 20:
            return ("Good", "lightgreen")
        elif negative_pct < 30:
            return ("Fair", "orange")
        elif negative_pct < 50:
            return ("Poor", "darkorange")
        else:
            return ("Critical", "red")

    @staticmethod
    def calculate_intent_priority_score(intent_counts):
        """
        Calculate priority score for different intents

        Args:
            intent_counts: Dictionary of intent counts

        Returns:
            dict: Priority scores for each intent
        """
        # Priority weights (higher = more urgent)
        priority_weights = {
            'feedback_negative': 5,
            'request': 4,
            'question': 4,
            'suggestion': 3,
            'praise': 2,
            'humor_sarcasm': 1,
            'off_topic': 1,
            'spam_selfpromo': 0
        }

        priority_scores = {}
        for intent, count in intent_counts.items():
            weight = priority_weights.get(intent, 1)
            priority_scores[intent] = count * weight

        return priority_scores

    @staticmethod
    def calculate_response_urgency(df):
        """
        Calculate response urgency metrics

        Args:
            df: Sentiment dataframe

        Returns:
            dict: Urgency metrics
        """
        reply_required_df = df[df['requires_reply'] == True]

        if len(reply_required_df) == 0:
            return {
                'urgent_count': 0,
                'high_priority_count': 0,
                'medium_priority_count': 0,
                'low_priority_count': 0
            }

        # Classify urgency based on sentiment and intent
        urgent = reply_required_df[
            reply_required_df['sentiment_polarity'].isin(['very_negative', 'negative'])
        ]
        high_priority = reply_required_df[
            (reply_required_df['sentiment_polarity'] == 'neutral') &
            (reply_required_df['intent'].str.contains('feedback_negative|request', na=False))
        ]
        medium_priority = reply_required_df[
            reply_required_df['sentiment_polarity'] == 'positive'
        ]
        low_priority = reply_required_df[
            reply_required_df['sentiment_polarity'] == 'very_positive'
        ]

        return {
            'urgent_count': len(urgent),
            'high_priority_count': len(high_priority),
            'medium_priority_count': len(medium_priority),
            'low_priority_count': len(low_priority)
        }

    @staticmethod
    def calculate_trend_indicator(df, current_period, previous_period, metric='sentiment_score'):
        """
        Calculate trend indicator comparing two periods

        Args:
            df: Sentiment dataframe
            current_period: Tuple of (start_date, end_date) for current period
            previous_period: Tuple of (start_date, end_date) for previous period
            metric: Metric to compare

        Returns:
            dict: Trend information
        """
        if 'comment_timestamp' not in df.columns:
            return {'trend': 'stable', 'change': 0}

        # Filter data for each period
        current_df = df[
            (df['comment_timestamp'] >= pd.Timestamp(current_period[0])) &
            (df['comment_timestamp'] <= pd.Timestamp(current_period[1]))
        ]
        previous_df = df[
            (df['comment_timestamp'] >= pd.Timestamp(previous_period[0])) &
            (df['comment_timestamp'] <= pd.Timestamp(previous_period[1]))
        ]

        if len(current_df) == 0 or len(previous_df) == 0:
            return {'trend': 'stable', 'change': 0}

        # Calculate metric for each period
        if metric == 'sentiment_score':
            # Vectorized — no copy needed
            sentiment_weights = {
                'very_negative': -2, 'negative': -1, 'neutral': 0,
                'positive': 1, 'very_positive': 2
            }
            current_value = current_df['sentiment_polarity'].map(sentiment_weights).mean()
            previous_value = previous_df['sentiment_polarity'].map(sentiment_weights).mean()
        else:
            current_value = len(current_df)
            previous_value = len(previous_df)

        # Calculate change
        change = ((current_value - previous_value) / previous_value * 100) if previous_value != 0 else 0

        # Determine trend
        if abs(change) < 5:
            trend = 'stable'
        elif change > 0:
            trend = 'improving' if metric == 'sentiment_score' else 'increasing'
        else:
            trend = 'declining' if metric == 'sentiment_score' else 'decreasing'

        return {
            'trend': trend,
            'change': round(change, 2),
            'current_value': round(current_value, 2),
            'previous_value': round(previous_value, 2)
        }