#!/usr/bin/env python3
"""
Usage tracking module for monitoring profile usage, user activity, and cost estimation
"""

import os
import json
from datetime import datetime
from threading import Lock

# Usage log directory
USAGE_LOG_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'usage_logs')
os.makedirs(USAGE_LOG_DIR, exist_ok=True)

# Thread-safe log writing
log_lock = Lock()

# Cost per 1K tokens (USD)
# Last updated: 2026-04-22
# Source: Official API pricing pages
#
# OpenAI GPT-4o: https://openai.com/api/pricing/
# Google Gemini 2.5 Pro: https://ai.google.dev/gemini-api/docs/pricing
#
# Notes:
# - Gemini 2.5 Pro uses tiered pricing: standard rate for prompts ≤200K tokens,
#   2x rate for prompts >200K. Our typical QC calls (image + prompt) are well
#   under 200K so we use the standard tier. If brand guideline PDFs push
#   usage into the >200K tier we'd need to detect this per-call.
# - Output pricing for Gemini 2.5 Pro doubled from $5/1M to $10/1M between
#   2026-02 and 2026-04 — prior reports understated Gemini cost.
#
# IMPORTANT: Update these values when pricing changes
# To verify current pricing, run: python validate_pricing.py
COST_PER_1K_TOKENS = {
    'OpenAI': {
        'input': 0.0025,   # GPT-4o: $2.50 per 1M input tokens
        'output': 0.010,   # GPT-4o: $10.00 per 1M output tokens
        'model': 'gpt-4o',
        'last_verified': '2026-04-22'
    },
    'Gemini': {
        'input': 0.00125,  # Gemini 2.5 Pro (≤200K prompt): $1.25 per 1M input tokens
        'output': 0.010,   # Gemini 2.5 Pro (≤200K prompt): $10.00 per 1M output tokens
        'model': 'gemini-2.5-pro',
        'last_verified': '2026-04-22'
    }
}

def get_pricing_info():
    """Get current pricing information for all providers"""
    return COST_PER_1K_TOKENS.copy()

def update_pricing(provider, input_cost_per_1k, output_cost_per_1k):
    """
    Update pricing for a specific provider

    Args:
        provider: 'OpenAI' or 'Gemini'
        input_cost_per_1k: Cost per 1K input tokens (USD)
        output_cost_per_1k: Cost per 1K output tokens (USD)
    """
    if provider in COST_PER_1K_TOKENS:
        COST_PER_1K_TOKENS[provider]['input'] = input_cost_per_1k
        COST_PER_1K_TOKENS[provider]['output'] = output_cost_per_1k
        COST_PER_1K_TOKENS[provider]['last_verified'] = datetime.now().strftime('%Y-%m-%d')
        print(f"Updated {provider} pricing: Input=${input_cost_per_1k}/1K, Output=${output_cost_per_1k}/1K")
        return True
    else:
        print(f"Unknown provider: {provider}")
        return False

def log_analysis_start(session_id, client, profile, user_info, file_info):
    """
    Log the start of an analysis

    Args:
        session_id: Unique session identifier
        client: Client name (diageo, unilever, loreal, general)
        profile: Profile name used
        user_info: User information from g.user (user_id, email, name)
        file_info: File information (filename, size)
    """
    log_entry = {
        'event': 'analysis_start',
        'timestamp': datetime.now().isoformat(),
        'session_id': session_id,
        'client': client,
        'profile': profile,
        'user_id': user_info.get('user_id'),
        'user_email': user_info.get('email'),
        'user_name': user_info.get('name'),
        'filename': file_info.get('filename'),
        'filesize': file_info.get('size')
    }

    _write_log_entry(log_entry)
    return log_entry

def log_analysis_complete(session_id, client, profile, user_info, results):
    """
    Log the completion of an analysis

    Args:
        session_id: Unique session identifier
        client: Client name
        profile: Profile name used
        user_info: User information from g.user
        results: Analysis results with check count, scores, token usage, etc.
    """
    # Calculate cost based on actual token usage
    total_cost, token_stats = _calculate_analysis_cost(results)

    log_entry = {
        'event': 'analysis_complete',
        'timestamp': datetime.now().isoformat(),
        'session_id': session_id,
        'client': client,
        'profile': profile,
        'user_id': user_info.get('user_id'),
        'user_email': user_info.get('email'),
        'user_name': user_info.get('name'),
        'checks_completed': results.get('checks_completed', 0),
        'overall_score': results.get('overall_score', 0),
        'status': results.get('status', 'unknown'),
        'total_cost_usd': round(total_cost, 4),
        'token_usage': token_stats
    }

    _write_log_entry(log_entry)
    return log_entry

def log_check_execution(session_id, check_name, llm_used, execution_time_ms, token_usage=None):
    """Log individual check execution for detailed tracking"""
    log_entry = {
        'event': 'check_execution',
        'timestamp': datetime.now().isoformat(),
        'session_id': session_id,
        'check_name': check_name,
        'llm_used': llm_used,
        'execution_time_ms': execution_time_ms
    }

    # Add token usage if provided
    if token_usage:
        log_entry['token_usage'] = token_usage

    _write_log_entry(log_entry)

def log_user_login(user_info):
    """
    Log a user login/visit event for tracking all platform users.

    Args:
        user_info: User information from auth (user_id, email, name)
    """
    log_entry = {
        'event': 'user_login',
        'timestamp': datetime.now().isoformat(),
        'user_id': user_info.get('user_id'),
        'user_email': user_info.get('email'),
        'user_name': user_info.get('name'),
    }

    _write_log_entry(log_entry)
    return log_entry


def log_access_change(audit_entry):
    """
    Log an access grant/revoke/promote/demote event.

    Args:
        audit_entry: dict from user_access.set_user_clients / promote_admin / demote_admin
    """
    log_entry = {
        'event': 'access_change',
        'timestamp': datetime.now().isoformat(),
        **audit_entry
    }
    _write_log_entry(log_entry)
    return log_entry


def log_access_request(entry):
    """
    Log a self-service client access request from a signed-in user.

    Args:
        entry: dict with at least user_email, user_name, requested_clients, recipients, email_sent
    """
    log_entry = {
        'event': 'access_request',
        'timestamp': datetime.now().isoformat(),
        **entry
    }
    _write_log_entry(log_entry)
    return log_entry


def _calculate_analysis_cost(results):
    """
    Calculate cost based on actual token usage from LLM responses

    Returns:
        tuple: (total_cost, token_statistics)
    """
    total_cost = 0
    token_stats = {
        'total_prompt_tokens': 0,
        'total_completion_tokens': 0,
        'total_tokens': 0,
        'by_provider': {}
    }

    check_results = results.get('check_results', {})

    # Handle both dict (keyed by check name) and list formats
    if isinstance(check_results, dict):
        check_results = check_results.values()

    for check_result in check_results:
        # Skip if check_result is not a dict (e.g., string error message)
        if not isinstance(check_result, dict):
            continue

        # Get model info
        model_used = check_result.get('model_used', {})
        if isinstance(model_used, dict):
            provider = model_used.get('provider', 'Gemini')
        else:
            provider = 'Gemini'  # Default

        # Get actual token usage from check result
        token_usage = check_result.get('token_usage', {})
        prompt_tokens = token_usage.get('prompt_tokens', 0)
        completion_tokens = token_usage.get('completion_tokens', 0)
        total_tokens = token_usage.get('total_tokens', 0)

        # If no token data available, use estimates as fallback
        if total_tokens == 0:
            prompt_tokens = 1000  # Estimate
            completion_tokens = 200  # Estimate
            total_tokens = prompt_tokens + completion_tokens

        # Update statistics
        token_stats['total_prompt_tokens'] += prompt_tokens
        token_stats['total_completion_tokens'] += completion_tokens
        token_stats['total_tokens'] += total_tokens

        # Track by provider
        if provider not in token_stats['by_provider']:
            token_stats['by_provider'][provider] = {
                'prompt_tokens': 0,
                'completion_tokens': 0,
                'total_tokens': 0,
                'cost': 0
            }

        token_stats['by_provider'][provider]['prompt_tokens'] += prompt_tokens
        token_stats['by_provider'][provider]['completion_tokens'] += completion_tokens
        token_stats['by_provider'][provider]['total_tokens'] += total_tokens

        # Calculate cost using actual tokens
        if provider in COST_PER_1K_TOKENS:
            cost_input = (prompt_tokens / 1000) * COST_PER_1K_TOKENS[provider]['input']
            cost_output = (completion_tokens / 1000) * COST_PER_1K_TOKENS[provider]['output']
            check_cost = cost_input + cost_output
            total_cost += check_cost
            token_stats['by_provider'][provider]['cost'] += check_cost

    return total_cost, token_stats

def _write_log_entry(log_entry):
    """Write a log entry to the daily log file"""
    # Create daily log file (YYYY-MM-DD.jsonl)
    log_date = datetime.now().strftime('%Y-%m-%d')
    log_file = os.path.join(USAGE_LOG_DIR, f'{log_date}.jsonl')

    with log_lock:
        with open(log_file, 'a') as f:
            f.write(json.dumps(log_entry) + '\n')

def get_usage_stats(start_date=None, end_date=None, client=None, user_id=None):
    """
    Get usage statistics for a date range

    Args:
        start_date: Start date (YYYY-MM-DD) or None for all time
        end_date: End date (YYYY-MM-DD) or None for today
        client: Filter by client or None for all clients
        user_id: Filter by user or None for all users

    Returns:
        Dictionary with usage statistics
    """
    import glob
    from collections import defaultdict

    # Find relevant log files
    if start_date and end_date:
        # TODO: Implement date range filtering
        pass

    log_files = glob.glob(os.path.join(USAGE_LOG_DIR, '*.jsonl'))

    stats = {
        'total_analyses': 0,
        'total_tokens': 0,
        'total_prompt_tokens': 0,
        'total_completion_tokens': 0,
        'by_client': defaultdict(lambda: {
            'count': 0,
            'profiles': defaultdict(int),
            'users': set(),
            'total_checks': 0,
            'estimated_cost': 0,
            'total_tokens': 0,
            'prompt_tokens': 0,
            'completion_tokens': 0
        }),
        'by_user': defaultdict(lambda: {
            'count': 0,
            'clients': defaultdict(int),
            'total_checks': 0,
            'total_tokens': 0,
            'prompt_tokens': 0,
            'completion_tokens': 0
        }),
        'by_profile': defaultdict(int),
        'by_provider': defaultdict(lambda: {
            'total_tokens': 0,
            'prompt_tokens': 0,
            'completion_tokens': 0,
            'cost': 0
        })
    }

    # Read and aggregate logs
    for log_file in log_files:
        with open(log_file, 'r') as f:
            for line in f:
                try:
                    entry = json.loads(line.strip())

                    # Filter by client if specified
                    if client and entry.get('client') != client:
                        continue

                    # Filter by user if specified
                    if user_id and entry.get('user_id') != user_id:
                        continue

                    # Process complete analyses only
                    if entry.get('event') == 'analysis_complete':
                        stats['total_analyses'] += 1

                        # By client
                        client_name = entry.get('client', 'unknown')
                        profile_name = entry.get('profile', 'unknown')
                        user_email = entry.get('user_email', 'unknown')

                        # Get token usage data
                        token_usage = entry.get('token_usage', {})
                        total_tokens = token_usage.get('total_tokens', 0)
                        prompt_tokens = token_usage.get('total_prompt_tokens', 0)
                        completion_tokens = token_usage.get('total_completion_tokens', 0)
                        cost = entry.get('total_cost_usd', entry.get('estimated_cost_usd', 0))

                        # Update global stats
                        stats['total_tokens'] += total_tokens
                        stats['total_prompt_tokens'] += prompt_tokens
                        stats['total_completion_tokens'] += completion_tokens

                        stats['by_client'][client_name]['count'] += 1
                        stats['by_client'][client_name]['profiles'][profile_name] += 1
                        stats['by_client'][client_name]['users'].add(user_email)
                        stats['by_client'][client_name]['total_checks'] += entry.get('checks_completed', 0)
                        stats['by_client'][client_name]['estimated_cost'] += cost
                        stats['by_client'][client_name]['total_tokens'] += total_tokens
                        stats['by_client'][client_name]['prompt_tokens'] += prompt_tokens
                        stats['by_client'][client_name]['completion_tokens'] += completion_tokens

                        # By user
                        user_uid = entry.get('user_id', 'unknown')
                        stats['by_user'][user_uid]['count'] += 1
                        stats['by_user'][user_uid]['clients'][client_name] += 1
                        stats['by_user'][user_uid]['total_checks'] += entry.get('checks_completed', 0)
                        stats['by_user'][user_uid]['total_tokens'] += total_tokens
                        stats['by_user'][user_uid]['prompt_tokens'] += prompt_tokens
                        stats['by_user'][user_uid]['completion_tokens'] += completion_tokens

                        # By profile
                        stats['by_profile'][profile_name] += 1

                        # By provider
                        by_provider = token_usage.get('by_provider', {})
                        for provider, provider_stats in by_provider.items():
                            stats['by_provider'][provider]['total_tokens'] += provider_stats.get('total_tokens', 0)
                            stats['by_provider'][provider]['prompt_tokens'] += provider_stats.get('prompt_tokens', 0)
                            stats['by_provider'][provider]['completion_tokens'] += provider_stats.get('completion_tokens', 0)
                            stats['by_provider'][provider]['cost'] += provider_stats.get('cost', 0)

                except json.JSONDecodeError:
                    continue

    # Convert sets to lists for JSON serialization
    for client_data in stats['by_client'].values():
        client_data['users'] = list(client_data['users'])

    return dict(stats)