"""
Activity Metrics Calculation Engine

Implements A1-A8 from visualization concept:
- A1: Training volume per week
- A2: Intensity distribution
- A3: Training quality matrix
- A4: Ability balance radar
- A5: Load monitoring (proxy-based)
- A6: Activity goal alignment score
- A7: Rest day compliance
- A8: VO2max development

All calculations work with training_types abilities system.
"""
from datetime import datetime, timedelta
from typing import Optional, Dict, List
import statistics

from db import get_db, get_cursor


# ============================================================================
# A1: Training Volume Calculations
# ============================================================================

def calculate_training_minutes_week(profile_id: str) -> Optional[int]:
    """Calculate total training minutes last 7 days"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT SUM(duration_min) as total_minutes
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
        """, (profile_id,))

        row = cur.fetchone()
        return int(row['total_minutes']) if row and row['total_minutes'] else None


def calculate_training_frequency_7d(profile_id: str) -> Optional[int]:
    """Calculate number of training sessions last 7 days"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT COUNT(*) as session_count
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
        """, (profile_id,))

        row = cur.fetchone()
        return int(row['session_count']) if row else None


def calculate_quality_sessions_pct(profile_id: str) -> Optional[int]:
    """Calculate percentage of quality sessions (good or better) last 28 days"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT
                COUNT(*) as total,
                COUNT(*) FILTER (WHERE quality_label IN ('excellent', 'very_good', 'good')) as quality_count
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '28 days'
        """, (profile_id,))

        row = cur.fetchone()
        if not row or row['total'] == 0:
            return None

        pct = (row['quality_count'] / row['total']) * 100
        return int(pct)


# ============================================================================
# A2: Intensity Distribution (Proxy-based)
# ============================================================================

def calculate_intensity_proxy_distribution(profile_id: str) -> Optional[Dict]:
    """
    Calculate intensity distribution (proxy until HR zones available)
    Returns dict: {'low': X, 'moderate': Y, 'high': Z} in minutes
    """
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT duration_min, hr_avg, hr_max
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '28 days'
        """, (profile_id,))

        activities = cur.fetchall()

        if not activities:
            return None

        low_min = 0
        moderate_min = 0
        high_min = 0

        for activity in activities:
            duration = activity['duration_min']
            avg_hr = activity['hr_avg']
            max_hr = activity['hr_max']

            # Simple proxy classification
            if avg_hr:
                # Rough HR-based classification (assumes max HR ~190)
                if avg_hr < 120:
                    low_min += duration
                elif avg_hr < 150:
                    moderate_min += duration
                else:
                    high_min += duration
            else:
                # Fallback: assume moderate
                moderate_min += duration

        return {
            'low': low_min,
            'moderate': moderate_min,
            'high': high_min
        }


# ============================================================================
# A4: Ability Balance Calculations
# ============================================================================

def calculate_ability_balance(profile_id: str) -> Optional[Dict]:
    """
    Calculate ability balance from training_types.abilities
    Returns dict with scores per ability dimension (0-100)
    """
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT a.duration_min, tt.abilities
            FROM activity_log a
            JOIN training_types tt ON a.training_category = tt.category
            WHERE a.profile_id = %s
              AND a.date >= CURRENT_DATE - INTERVAL '28 days'
              AND tt.abilities IS NOT NULL
        """, (profile_id,))

        activities = cur.fetchall()

        if not activities:
            return None

        # Accumulate ability load (duration × ability weight)
        ability_loads = {
            'strength': 0,
            'endurance': 0,
            'mental': 0,
            'coordination': 0,
            'mobility': 0
        }

        for activity in activities:
            duration = activity['duration_min']
            abilities = activity['abilities']  # JSONB

            if not abilities:
                continue

            for ability, weight in abilities.items():
                if ability in ability_loads:
                    ability_loads[ability] += duration * weight

        # Normalize to 0-100 scale
        max_load = max(ability_loads.values()) if ability_loads else 1
        if max_load == 0:
            return None

        normalized = {
            ability: int((load / max_load) * 100)
            for ability, load in ability_loads.items()
        }

        return normalized


def calculate_ability_balance_strength(profile_id: str) -> Optional[int]:
    """Get strength ability score"""
    balance = calculate_ability_balance(profile_id)
    return balance['strength'] if balance else None


def calculate_ability_balance_endurance(profile_id: str) -> Optional[int]:
    """Get endurance ability score"""
    balance = calculate_ability_balance(profile_id)
    return balance['endurance'] if balance else None


def calculate_ability_balance_mental(profile_id: str) -> Optional[int]:
    """Get mental ability score"""
    balance = calculate_ability_balance(profile_id)
    return balance['mental'] if balance else None


def calculate_ability_balance_coordination(profile_id: str) -> Optional[int]:
    """Get coordination ability score"""
    balance = calculate_ability_balance(profile_id)
    return balance['coordination'] if balance else None


def calculate_ability_balance_mobility(profile_id: str) -> Optional[int]:
    """Get mobility ability score"""
    balance = calculate_ability_balance(profile_id)
    return balance['mobility'] if balance else None


# ============================================================================
# A5: Load Monitoring (Proxy-based)
# ============================================================================

def calculate_proxy_internal_load_7d(profile_id: str) -> Optional[int]:
    """
    Calculate proxy internal load (last 7 days)
    Formula: duration × intensity_factor × quality_factor
    """
    intensity_factors = {'low': 1.0, 'moderate': 1.5, 'high': 2.0}
    quality_factors = {
        'excellent': 1.15,
        'very_good': 1.05,
        'good': 1.0,
        'acceptable': 0.9,
        'poor': 0.75,
        'excluded': 0.0
    }

    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT duration_min, hr_avg, rpe
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
        """, (profile_id,))

        activities = cur.fetchall()

        if not activities:
            return None

        total_load = 0

        for activity in activities:
            duration = activity['duration_min']
            avg_hr = activity['hr_avg']
            # Map RPE to quality (rpe 8-10 = excellent, 6-7 = good, 4-5 = moderate, <4 = poor)
            rpe = activity.get('rpe')
            if rpe and rpe >= 8:
                quality = 'excellent'
            elif rpe and rpe >= 6:
                quality = 'good'
            elif rpe and rpe >= 4:
                quality = 'moderate'
            else:
                quality = 'good'  # default

            # Determine intensity
            if avg_hr:
                if avg_hr < 120:
                    intensity = 'low'
                elif avg_hr < 150:
                    intensity = 'moderate'
                else:
                    intensity = 'high'
            else:
                intensity = 'moderate'

            load = float(duration) * intensity_factors[intensity] * quality_factors.get(quality, 1.0)
            total_load += load

        return int(total_load)


def calculate_monotony_score(profile_id: str) -> Optional[float]:
    """
    Calculate training monotony (last 7 days)
    Monotony = mean daily load / std dev daily load
    Higher = more monotonous
    """
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT date, SUM(duration_min) as daily_duration
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
            GROUP BY date
            ORDER BY date
        """, (profile_id,))

        daily_loads = [float(row['daily_duration']) for row in cur.fetchall() if row['daily_duration']]

        if len(daily_loads) < 4:
            return None

        mean_load = sum(daily_loads) / len(daily_loads)
        std_dev = statistics.stdev(daily_loads)

        if std_dev == 0:
            return None

        monotony = mean_load / std_dev
        return round(monotony, 2)


def calculate_strain_score(profile_id: str) -> Optional[int]:
    """
    Calculate training strain (last 7 days)
    Strain = weekly load × monotony
    """
    weekly_load = calculate_proxy_internal_load_7d(profile_id)
    monotony = calculate_monotony_score(profile_id)

    if weekly_load is None or monotony is None:
        return None

    strain = weekly_load * monotony
    return int(strain)


# ============================================================================
# A6: Activity Goal Alignment Score (Dynamic Focus Areas)
# ============================================================================

def calculate_activity_score(profile_id: str, focus_weights: Optional[Dict] = None) -> Optional[int]:
    """
    Activity goal alignment score 0-100
    Weighted by user's activity-related focus areas
    """
    if focus_weights is None:
        from calculations.scores import get_user_focus_weights
        focus_weights = get_user_focus_weights(profile_id)

    # Activity-related focus areas
    activity_focus = {
        'kraftaufbau': focus_weights.get('kraftaufbau', 0),
        'cardio': focus_weights.get('cardio', 0),
        'bewegungsumfang': focus_weights.get('bewegungsumfang', 0),
        'trainingsqualität': focus_weights.get('trainingsqualität', 0),
        'ability_balance': focus_weights.get('ability_balance', 0),
    }

    total_activity_weight = sum(activity_focus.values())

    if total_activity_weight == 0:
        return None  # No activity goals

    components = []

    # 1. Weekly minutes (if bewegungsumfang goal)
    if activity_focus['bewegungsumfang'] > 0:
        minutes = calculate_training_minutes_week(profile_id)
        if minutes is not None:
            # WHO: 150-300 min/week
            if 150 <= minutes <= 300:
                minutes_score = 100
            elif minutes < 150:
                minutes_score = max(40, (minutes / 150) * 100)
            else:
                minutes_score = max(80, 100 - ((minutes - 300) / 10))

            components.append(('minutes', minutes_score, activity_focus['bewegungsumfang']))

    # 2. Quality sessions (if trainingsqualität goal)
    if activity_focus['trainingsqualität'] > 0:
        quality_pct = calculate_quality_sessions_pct(profile_id)
        if quality_pct is not None:
            components.append(('quality', quality_pct, activity_focus['trainingsqualität']))

    # 3. Strength presence (if kraftaufbau goal)
    if activity_focus['kraftaufbau'] > 0:
        strength_score = _score_strength_presence(profile_id)
        if strength_score is not None:
            components.append(('strength', strength_score, activity_focus['kraftaufbau']))

    # 4. Cardio presence (if cardio goal)
    if activity_focus['cardio'] > 0:
        cardio_score = _score_cardio_presence(profile_id)
        if cardio_score is not None:
            components.append(('cardio', cardio_score, activity_focus['cardio']))

    # 5. Ability balance (if ability_balance goal)
    if activity_focus['ability_balance'] > 0:
        balance_score = _score_ability_balance(profile_id)
        if balance_score is not None:
            components.append(('balance', balance_score, activity_focus['ability_balance']))

    if not components:
        return None

    # Weighted average
    total_score = sum(score * weight for _, score, weight in components)
    total_weight = sum(weight for _, _, weight in components)

    return int(total_score / total_weight)


def _score_strength_presence(profile_id: str) -> Optional[int]:
    """Score strength training presence (0-100)"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT COUNT(DISTINCT date) as strength_days
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
              AND training_category = 'strength'
        """, (profile_id,))

        row = cur.fetchone()
        if not row:
            return None

        strength_days = row['strength_days']

        # Target: 2-4 days/week
        if 2 <= strength_days <= 4:
            return 100
        elif strength_days == 1:
            return 60
        elif strength_days == 5:
            return 85
        elif strength_days == 0:
            return 0
        else:
            return 70


def _score_cardio_presence(profile_id: str) -> Optional[int]:
    """Score cardio training presence (0-100)"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT COUNT(DISTINCT date) as cardio_days, SUM(duration_min) as cardio_minutes
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '7 days'
              AND training_category = 'cardio'
        """, (profile_id,))

        row = cur.fetchone()
        if not row:
            return None

        cardio_days = row['cardio_days']
        cardio_minutes = row['cardio_minutes'] or 0

        # Target: 3-5 days/week, 150+ minutes
        day_score = min(100, (cardio_days / 4) * 100)
        minute_score = min(100, (cardio_minutes / 150) * 100)

        return int((day_score + minute_score) / 2)


def _score_ability_balance(profile_id: str) -> Optional[int]:
    """Score ability balance (0-100)"""
    balance = calculate_ability_balance(profile_id)

    if not balance:
        return None

    # Good balance = all abilities > 40, std_dev < 30
    values = list(balance.values())
    min_value = min(values)
    std_dev = statistics.stdev(values) if len(values) > 1 else 0

    # Score based on minimum coverage and balance
    min_score = min(100, min_value * 2)  # Want all > 50
    balance_score = max(0, 100 - (std_dev * 2))  # Want low std_dev

    return int((min_score + balance_score) / 2)


# ============================================================================
# A7: Rest Day Compliance
# ============================================================================

def calculate_rest_day_compliance(profile_id: str) -> Optional[int]:
    """
    Calculate rest day compliance percentage (last 28 days)
    Returns percentage of planned rest days that were respected
    """
    with get_db() as conn:
        cur = get_cursor(conn)

        # Get planned rest days
        cur.execute("""
            SELECT date, rest_config->>'focus' as rest_type
            FROM rest_days
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '28 days'
        """, (profile_id,))

        rest_days = {row['date']: row['rest_type'] for row in cur.fetchall()}

        if not rest_days:
            return None

        # Check if training occurred on rest days
        cur.execute("""
            SELECT date, training_category
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '28 days'
        """, (profile_id,))

        training_days = {}
        for row in cur.fetchall():
            if row['date'] not in training_days:
                training_days[row['date']] = []
            training_days[row['date']].append(row['training_category'])

        # Count compliance
        compliant = 0
        total = len(rest_days)

        for rest_date, rest_type in rest_days.items():
            if rest_date not in training_days:
                # Full rest = compliant
                compliant += 1
            else:
                # Check if training violates rest type
                categories = training_days[rest_date]
                if rest_type == 'strength_rest' and 'strength' not in categories:
                    compliant += 1
                elif rest_type == 'cardio_rest' and 'cardio' not in categories:
                    compliant += 1
                # If rest_type == 'recovery', any training = non-compliant

        compliance_pct = (compliant / total) * 100
        return int(compliance_pct)


# ============================================================================
# A8: VO2max Development
# ============================================================================

def calculate_vo2max_trend_28d(profile_id: str) -> Optional[float]:
    """Calculate VO2max trend (change over 28 days)"""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("""
            SELECT vo2_max, date
            FROM vitals_baseline
            WHERE profile_id = %s
              AND vo2_max IS NOT NULL
              AND date >= CURRENT_DATE - INTERVAL '28 days'
            ORDER BY date DESC
        """, (profile_id,))

        measurements = cur.fetchall()

        if len(measurements) < 2:
            return None

        recent = measurements[0]['vo2_max']
        oldest = measurements[-1]['vo2_max']

        change = recent - oldest
        return round(change, 1)


# ============================================================================
# Data Quality Assessment
# ============================================================================

def calculate_activity_data_quality(profile_id: str) -> Dict[str, any]:
    """
    Assess data quality for activity metrics
    Returns dict with quality score and details
    """
    with get_db() as conn:
        cur = get_cursor(conn)

        # Activity entries last 28 days
        cur.execute("""
            SELECT COUNT(*) as total,
                   COUNT(hr_avg) as with_hr,
                   COUNT(rpe) as with_quality
            FROM activity_log
            WHERE profile_id = %s
              AND date >= CURRENT_DATE - INTERVAL '28 days'
        """, (profile_id,))

        counts = cur.fetchone()

    total_entries = counts['total']
    hr_coverage = counts['with_hr'] / total_entries if total_entries > 0 else 0
    quality_coverage = counts['with_quality'] / total_entries if total_entries > 0 else 0

    # Score components
    frequency_score = min(100, (total_entries / 15) * 100)  # 15 = ~4 sessions/week
    hr_score = hr_coverage * 100
    quality_score = quality_coverage * 100

    # Overall score
    overall_score = int(
        frequency_score * 0.5 +
        hr_score * 0.25 +
        quality_score * 0.25
    )

    if overall_score >= 80:
        confidence = "high"
    elif overall_score >= 60:
        confidence = "medium"
    else:
        confidence = "low"

    return {
        "overall_score": overall_score,
        "confidence": confidence,
        "measurements": {
            "activities_28d": total_entries,
            "hr_coverage_pct": int(hr_coverage * 100),
            "quality_coverage_pct": int(quality_coverage * 100)
        },
        "component_scores": {
            "frequency": int(frequency_score),
            "hr": int(hr_score),
            "quality": int(quality_score)
        }
    }