"""
Year-in-Review API Endpoints

This module provides REST API endpoints for the year-in-review experience,
including recap generation, summary retrieval, and video generation.
"""

import logging
from datetime import datetime
from typing import Dict, List, Optional, Any
from flask import Blueprint, request, jsonify
from flask_login import login_required, current_user

from swingmusic.db import db
from swingmusic.services.recap_service import recap_service, RecapTheme
from swingmusic.utils.request import APIError, success_response, error_response

logger = logging.getLogger(__name__)

recap_bp = Blueprint('recap', __name__, url_prefix='/api/recap')


def get_current_user_id() -> int:
    """Get current user ID from Flask-Login"""
    return current_user.id if current_user.is_authenticated else None


@recap_bp.route('/generate/<int:year>', methods=['POST'])
@login_required
async def generate_recap(year: int):
    """
    Generate year-in-review for a specific year
    
    Path Parameters:
    - year: Year to generate recap for
    
    Query Parameters:
    - force: Force regeneration even if recap exists (default: false)
    """
    try:
        user_id = get_current_user_id()
        force_regeneration = request.args.get('force', 'false').lower() == 'true'
        
        # Check if recap already exists
        if not force_regeneration:
            existing_recap = await recap_service.get_recap_summary(user_id, year)
            if existing_recap:
                return success_response({
                    'message': f'Recap for {year} already exists',
                    'recap': existing_recap
                })
        
        # Generate new recap
        recap_data = await recap_service.generate_year_recap(user_id, year)
        
        return success_response({
            'message': f'Successfully generated recap for {year}',
            'recap_id': f"{user_id}_{year}",
            'year': recap_data.year,
            'stats': {
                'total_minutes': recap_data.stats.total_minutes,
                'total_tracks': recap_data.stats.total_tracks,
                'total_artists': recap_data.stats.total_artists,
                'unique_tracks': recap_data.stats.unique_tracks,
                'listening_streak': recap_data.stats.listening_streak,
                'personality_type': recap_data.personality.personality_type
            }
        })
        
    except Exception as e:
        logger.error(f"Error generating recap: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/summary/<int:year>', methods=['GET'])
@login_required
async def get_recap_summary(year: int):
    """
    Get recap summary for a specific year
    
    Path Parameters:
    - year: Year to get recap summary for
    """
    try:
        user_id = get_current_user_id()
        
        recap_summary = await recap_service.get_recap_summary(user_id, year)
        
        if not recap_summary:
            return error_response(f"No recap found for year {year}", 404)
        
        return success_response({
            'recap': recap_summary
        })
        
    except Exception as e:
        logger.error(f"Error getting recap summary: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/details/<int:year>', methods=['GET'])
@login_required
async def get_recap_details(year: int):
    """
    Get detailed recap data for a specific year
    
    Path Parameters:
    - year: Year to get recap details for
    
    Query Parameters:
    - include_top_tracks: Include top tracks data (default: true)
    - include_top_artists: Include top artists data (default: true)
    - include_top_albums: Include top albums data (default: true)
    - include_discoveries: Include discoveries data (default: true)
    - include_milestones: Include milestones data (default: true)
    """
    try:
        user_id = get_current_user_id()
        
        # Get recap summary first
        recap_summary = await recap_service.get_recap_summary(user_id, year)
        
        if not recap_summary:
            return error_response(f"No recap found for year {year}", 404)
        
        # Parse include flags
        include_flags = {
            'top_tracks': request.args.get('include_top_tracks', 'true').lower() == 'true',
            'top_artists': request.args.get('include_top_artists', 'true').lower() == 'true',
            'top_albums': request.args.get('include_top_albums', 'true').lower() == 'true',
            'discoveries': request.args.get('include_discoveries', 'true').lower() == 'true',
            'milestones': request.args.get('include_milestones', 'true').lower() == 'true'
        }
        
        # Load full recap data from file
        import json
        from pathlib import Path
        
        recap_file = Path(recap_service.recap_dir) / f"recap_{user_id}_{year}.json"
        
        if not recap_file.exists():
            return error_response(f"Recap data not found for year {year}", 404)
        
        with open(recap_file, 'r') as f:
            full_recap_data = json.load(f)
        
        # Build response based on include flags
        response_data = {
            'year': full_recap_data['year'],
            'stats': full_recap_data['stats'],
            'personality': full_recap_data['personality'],
            'monthly_breakdown': full_recap_data['monthly_breakdown'],
            'created_at': full_recap_data['created_at']
        }
        
        if include_flags['top_tracks']:
            response_data['top_tracks'] = full_recap_data['top_tracks']
        
        if include_flags['top_artists']:
            response_data['top_artists'] = full_recap_data['top_artists']
        
        if include_flags['top_albums']:
            response_data['top_albums'] = full_recap_data['top_albums']
        
        if include_flags['discoveries']:
            response_data['discoveries'] = full_recap_data['discoveries']
        
        if include_flags['milestones']:
            response_data['milestones'] = full_recap_data['milestones']
        
        return success_response({
            'recap': response_data
        })
        
    except Exception as e:
        logger.error(f"Error getting recap details: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/video/<int:year>', methods=['POST'])
@login_required
async def generate_recap_video(year: int):
    """
    Generate recap video for a specific year
    
    Path Parameters:
    - year: Year to generate video for
    
    Request Body:
    {
        "theme": "modern|retro|minimal|vibrant|dark|light",
        "include_audio": true,
        "duration_limit": 180  // Optional: max duration in seconds
    }
    """
    try:
        user_id = get_current_user_id()
        
        # Get request data
        data = request.get_json() or {}
        
        # Validate theme
        theme_name = data.get('theme', 'modern')
        try:
            theme = RecapTheme(theme_name)
        except ValueError:
            return error_response(f"Invalid theme: {theme_name}. Must be one of: {[t.value for t in RecapTheme]}", 400)
        
        # Check if recap exists
        recap_summary = await recap_service.get_recap_summary(user_id, year)
        if not recap_summary:
            return error_response(f"No recap found for year {year}. Generate recap first.", 404)
        
        # Generate video (this is a placeholder - would integrate with Remotion service)
        video_path = await recap_service.generate_recap_video(
            # This would need to load the full recap data
            None,  # recap_data would be loaded here
            theme
        )
        
        return success_response({
            'message': f'Video generation started for {year}',
            'video_path': video_path,
            'theme': theme.value,
            'estimated_completion': '2-5 minutes'
        })
        
    except Exception as e:
        logger.error(f"Error generating recap video: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/available-years', methods=['GET'])
@login_required
async def get_available_years():
    """
    Get list of years for which recaps are available
    """
    try:
        user_id = get_current_user_id()
        
        # Scan recap directory for user's recaps
        import os
        from pathlib import Path
        
        recap_dir = Path(recap_service.recap_dir)
        available_years = []
        
        if recap_dir.exists():
            for file_path in recap_dir.glob(f"recap_{user_id}_*.json"):
                # Extract year from filename
                parts = file_path.stem.split('_')
                if len(parts) >= 3:
                    year = parts[2]
                    try:
                        year_int = int(year)
                        available_years.append(year_int)
                    except ValueError:
                        continue
        
        # Sort years in descending order
        available_years.sort(reverse=True)
        
        return success_response({
            'available_years': available_years,
            'total_recaps': len(available_years)
        })
        
    except Exception as e:
        logger.error(f"Error getting available years: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/share/<int:year>', methods=['POST'])
@login_required
async def create_shareable_link(year: int):
    """
    Create a shareable link for recap
    
    Path Parameters:
    - year: Year to create shareable link for
    
    Request Body:
    {
        "include_personal_data": false,
        "expires_in_days": 30
    }
    """
    try:
        user_id = get_current_user_id()
        
        # Get request data
        data = request.get_json() or {}
        include_personal_data = data.get('include_personal_data', False)
        expires_in_days = data.get('expires_in_days', 30)
        
        # Check if recap exists
        recap_summary = await recap_service.get_recap_summary(user_id, year)
        if not recap_summary:
            return error_response(f"No recap found for year {year}", 404)
        
        # Generate shareable link (this is a placeholder implementation)
        import secrets
        import hashlib
        
        # Generate unique token
        token_data = f"{user_id}_{year}_{datetime.utcnow().timestamp()}"
        share_token = hashlib.sha256(token_data.encode()).hexdigest()[:16]
        
        # Create shareable data
        shareable_data = {
            'year': year,
            'stats': {
                'total_minutes': recap_summary['total_minutes'],
                'total_tracks': recap_summary['total_tracks'],
                'personality_type': recap_summary['personality_type']
            },
            'top_track': recap_summary.get('top_track'),
            'top_artist': recap_summary.get('top_artist'),
            'created_at': recap_summary['created_at']
        }
        
        # Save shareable data (in a real implementation, this would go to database)
        share_file = Path(recap_service.recap_dir) / f"share_{share_token}.json"
        import json
        with open(share_file, 'w') as f:
            json.dump({
                'user_id': user_id,
                'year': year,
                'data': shareable_data,
                'expires_at': (datetime.utcnow() + datetime.timedelta(days=expires_in_days)).isoformat(),
                'created_at': datetime.utcnow().isoformat()
            }, f)
        
        share_url = f"/recap/shared/{share_token}"
        
        return success_response({
            'share_url': share_url,
            'share_token': share_token,
            'expires_in_days': expires_in_days,
            'includes_personal_data': include_personal_data
        })
        
    except Exception as e:
        logger.error(f"Error creating shareable link: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/shared/<token>', methods=['GET'])
async def get_shared_recap(token: str):
    """
    Get shared recap by token (public endpoint)
    
    Path Parameters:
    - token: Share token
    """
    try:
        # Load share data
        share_file = Path(recap_service.recap_dir) / f"share_{token}.json"
        
        if not share_file.exists():
            return error_response("Shared recap not found or expired", 404)
        
        import json
        with open(share_file, 'r') as f:
            share_data = json.load(f)
        
        # Check if expired
        expires_at = datetime.fromisoformat(share_data['expires_at'])
        if datetime.utcnow() > expires_at:
            share_file.unlink()  # Clean up expired share
            return error_response("Shared recap has expired", 410)
        
        return success_response({
            'shared_recap': share_data['data'],
            'year': share_data['year'],
            'created_at': share_data['created_at']
        })
        
    except Exception as e:
        logger.error(f"Error getting shared recap: {e}")
        return error_response("Internal server error", 500)


@recap_bp.route('/compare/<int:year1>/<int:year2>', methods=['GET'])
@login_required
async def compare_years(year1: int, year2: int):
    """
    Compare recaps between two years
    
    Path Parameters:
    - year1: First year to compare
    - year2: Second year to compare
    """
    try:
        user_id = get_current_user_id()
        
        # Get both recaps
        recap1 = await recap_service.get_recap_summary(user_id, year1)
        recap2 = await recap_service.get_recap_summary(user_id, year2)
        
        if not recap1:
            return error_response(f"No recap found for year {year1}", 404)
        
        if not recap2:
            return error_response(f"No recap found for year {year2}", 404)
        
        # Calculate comparisons
        comparison = {
            'year1': year1,
            'year2': year2,
            'listening_time_change': {
                'absolute': recap2['total_minutes'] - recap1['total_minutes'],
                'percentage': ((recap2['total_minutes'] - recap1['total_minutes']) / recap1['total_minutes'] * 100) if recap1['total_minutes'] > 0 else 0
            },
            'tracks_change': {
                'absolute': recap2['total_tracks'] - recap1['total_tracks'],
                'percentage': ((recap2['total_tracks'] - recap1['total_tracks']) / recap1['total_tracks'] * 100) if recap1['total_tracks'] > 0 else 0
            },
            'personality_change': {
                'from': recap1['personality_type'],
                'to': recap2['personality_type'],
                'changed': recap1['personality_type'] != recap2['personality_type']
            }
        }
        
        return success_response({
            'comparison': comparison,
            'recap1': recap1,
            'recap2': recap2
        })
        
    except Exception as e:
        logger.error(f"Error comparing years: {e}")
        return error_response("Internal server error", 500)