"""
S3 Service for managing uploads and standard images
"""
import boto3
import uuid
import base64
from datetime import datetime
from django.conf import settings
from django.core.files.uploadedfile import InMemoryUploadedFile
import logging

logger = logging.getLogger(__name__)

class S3Service:
    """AWS S3 service for handling image uploads and management"""
    
    def __init__(self):
        self.s3_client = boto3.client(
            's3',
            aws_access_key_id=settings.AWS_ACCESS_KEY_ID,
            aws_secret_access_key=settings.AWS_SECRET_ACCESS_KEY,
            region_name=settings.AWS_S3_REGION_NAME
        )
        self.bucket_name = settings.AWS_STORAGE_BUCKET_NAME
        self.custom_domain = settings.AWS_S3_CUSTOM_DOMAIN
    
    def upload_checkin_image(self, image_file, event_code, team_code, cp_number, is_goal=False):
        """
        チェックイン画像またはゴール画像をS3にアップロード
        
        Args:
            image_file: アップロードする画像ファイル
            event_code: イベントコード
            team_code: チームコード
            cp_number: チェックポイント番号
            is_goal: ゴール画像かどうか（デフォルト: False）
        """
        try:
            # ファイル名を生成（UUID + タイムスタンプ）
            file_extension = image_file.name.split('.')[-1] if '.' in image_file.name else 'jpg'
            filename = f"{uuid.uuid4()}-{datetime.now().strftime('%Y-%m-%dT%H-%M-%S')}.{file_extension}"
            
            # S3キーを生成（イベント/チーム/ファイル名）
            # ゴール画像の場合は専用フォルダに保存
            if is_goal:
                s3_key = f"{event_code}/goals/{team_code}/{filename}"
            else:
                s3_key = f"{event_code}/{team_code}/{filename}"
            
            # メタデータをBase64エンコードして設定（S3メタデータはASCIIのみ対応）
            metadata = {
                'event_b64': base64.b64encode(event_code.encode('utf-8')).decode('ascii'),
                'team_b64': base64.b64encode(team_code.encode('utf-8')).decode('ascii'),
                'cp_number': str(cp_number),
                'uploaded_at': datetime.now().strftime('%Y-%m-%dT%H-%M-%S'),
                'image_type': 'goal' if is_goal else 'checkin'
            }
            
            # S3にアップロード
            self.s3_client.upload_fileobj(
                image_file,
                self.bucket_name,
                s3_key,
                ExtraArgs={
                    'ContentType': f'image/{file_extension}',
                    'Metadata': metadata
                }
            )
            
            # S3 URLを生成
            s3_url = f"https://{self.bucket_name}.s3.{settings.AWS_S3_REGION_NAME}.amazonaws.com/{s3_key}"
            
            logger.info(f"{'Goal' if is_goal else 'Checkin'} image uploaded to S3: {s3_url}")
            return s3_url
            
        except Exception as e:
            logger.error(f"Failed to upload image to S3: {e}")
            raise
    
    def upload_standard_image(self, image_file, event_code, image_type):
        """
        規定画像をS3にアップロード
        """
        try:
            # ファイル拡張子を取得
            file_extension = image_file.name.split('.')[-1] if '.' in image_file.name else 'jpg'
            
            # S3キーを生成（イベント/standards/タイプ.拡張子）
            s3_key = f"{event_code}/standards/{image_type}.{file_extension}"
            
            # メタデータをBase64エンコードして設定
            metadata = {
                'event_b64': base64.b64encode(event_code.encode('utf-8')).decode('ascii'),
                'image_type': image_type,
                'uploaded_at': datetime.now().strftime('%Y-%m-%dT%H-%M-%S')
            }
            
            # S3にアップロード
            self.s3_client.upload_fileobj(
                image_file,
                self.bucket_name,
                s3_key,
                ExtraArgs={
                    'ContentType': f'image/{file_extension}',
                    'Metadata': metadata
                }
            )
            
            # S3 URLを生成
            s3_url = f"https://{self.bucket_name}.s3.{settings.AWS_S3_REGION_NAME}.amazonaws.com/{s3_key}"
            
            logger.info(f"Standard image uploaded to S3: {s3_url}")
            return s3_url
            
        except Exception as e:
            logger.error(f"Failed to upload standard image to S3: {e}")
            raise
    
    def get_standard_image_url(self, event_code, image_type):
        """
        Get URL for standard image
        
        Args:
            event_code: Event code
            image_type: Type of image (goal, start, checkpoint, etc.)
            
        Returns:
            str: S3 URL of standard image or None if not found
        """
        # Try common image extensions
        extensions = ['.jpg', '.jpeg', '.png', '.gif']
        
        for ext in extensions:
            s3_key = f"{event_code}/standards/{image_type}{ext}"
            try:
                # Check if object exists
                self.s3_client.head_object(Bucket=self.bucket_name, Key=s3_key)
                return f"https://{self.custom_domain}/{s3_key}"
            except self.s3_client.exceptions.NoSuchKey:
                continue
            except Exception as e:
                logger.error(f"Error checking standard image: {e}")
                continue
        
        return None
    
    def delete_image(self, s3_url):
        """
        Delete image from S3
        
        Args:
            s3_url: Full S3 URL of the image
            
        Returns:
            bool: True if deleted successfully
        """
        try:
            # Extract S3 key from URL
            s3_key = self._extract_s3_key_from_url(s3_url)
            if not s3_key:
                logger.error(f"Invalid S3 URL: {s3_url}")
                return False
            
            # Delete from S3
            self.s3_client.delete_object(Bucket=self.bucket_name, Key=s3_key)
            logger.info(f"Image deleted from S3: {s3_url}")
            return True
            
        except Exception as e:
            logger.error(f"Failed to delete image from S3: {e}")
            return False
    
    def list_event_images(self, event_code, limit=100):
        """
        List all images for an event
        
        Args:
            event_code: Event code
            limit: Maximum number of images to return
            
        Returns:
            list: List of S3 URLs
        """
        try:
            response = self.s3_client.list_objects_v2(
                Bucket=self.bucket_name,
                Prefix=f"{event_code}/",
                MaxKeys=limit
            )
            
            urls = []
            if 'Contents' in response:
                for obj in response['Contents']:
                    url = f"https://{self.custom_domain}/{obj['Key']}"
                    urls.append(url)
            
            return urls
            
        except Exception as e:
            logger.error(f"Failed to list event images: {e}")
            return []
    
    def _get_file_extension(self, filename):
        """Get file extension from filename"""
        if '.' in filename:
            return '.' + filename.split('.')[-1].lower()
        return '.jpg'  # default extension
    
    def _get_timestamp(self):
        """Get current timestamp string"""
        from datetime import datetime
        return datetime.now().strftime("%Y-%m-%dT%H-%M-%S")
    
    def _extract_s3_key_from_url(self, s3_url):
        """Extract S3 key from full S3 URL"""
        try:
            # Remove domain part to get key
            if self.custom_domain in s3_url:
                return s3_url.split(self.custom_domain + '/')[-1]
            return None
        except Exception:
            return None