"""SendGrid email service integration."""

import os
from typing import Any, Dict, List, Optional, Union

try:
    import requests
    HAS_REQUESTS = True
except ImportError:
    HAS_REQUESTS = False

from .base import EmailProvider


class SendGridProvider(EmailProvider):
    """SendGrid email service integration."""
    
    def __init__(
        self,
        api_key: Optional[str] = None,
        credentials_path: Optional[str] = None,
        default_from: Optional[str] = None,
    ):
        """Initialize the SendGrid provider.
        
        Args:
            api_key: SendGrid API key
            credentials_path: Path to credentials file
            default_from: Default sender email address
        """
        if not HAS_REQUESTS:
            raise ImportError(
                "Requests library not installed. "
                "Install with 'pip install requests'"
            )
        
        # Read credentials from environment variables if not provided
        self.api_key = api_key or os.environ.get("SENDGRID_API_KEY")
        self.default_from = default_from or os.environ.get("SENDGRID_DEFAULT_FROM")
        
        if credentials_path:
            # TODO: Implement loading credentials from file
            pass
        
        if not self.api_key:
            raise ValueError(
                "Missing required API key for SendGrid. "
                "Provide api_key or set SENDGRID_API_KEY environment variable."
            )
        
        # Setup API details
        self.base_url = "https://api.sendgrid.com/v3"
        self.headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json"
        }
    
    def send_email(
        self, 
        to: Union[str, List[str]],
        subject: str,
        body: str,
        from_email: Optional[str] = None,
        cc: Optional[Union[str, List[str]]] = None,
        bcc: Optional[Union[str, List[str]]] = None,
        html_body: Optional[str] = None,
        attachments: Optional[List[Dict[str, Any]]] = None,
        **kwargs
    ) -> Dict[str, Any]:
        """Send an email using SendGrid.
        
        Args:
            to: Recipient email address(es)
            subject: Email subject
            body: Plain text email body
            from_email: Sender email address
            cc: Carbon copy recipient(s)
            bcc: Blind carbon copy recipient(s)
            html_body: HTML version of the email body
            attachments: List of attachments
            **kwargs: Additional parameters
            
        Returns:
            Dict containing the send result
        """
        # TODO: Implement email sending using SendGrid API
        # API doc: https://docs.sendgrid.com/api-reference/mail-send/mail-send
        
        # Use default_from if from_email not provided
        from_email = from_email or self.default_from
        
        if not from_email:
            raise ValueError("Sender email address is required")
        
        # Normalize to, cc, bcc to lists
        if isinstance(to, str):
            to = [to]
        if cc and isinstance(cc, str):
            cc = [cc]
        if bcc and isinstance(bcc, str):
            bcc = [bcc]
        
        # TODO: Prepare and send the request to SendGrid API
        
        raise NotImplementedError("SendGrid email sending not implemented yet")
    
    def send_template_email(
        self,
        to: Union[str, List[str]],
        template_id: str,
        template_data: Dict[str, Any],
        from_email: Optional[str] = None,
        cc: Optional[Union[str, List[str]]] = None,
        bcc: Optional[Union[str, List[str]]] = None,
        attachments: Optional[List[Dict[str, Any]]] = None,
        **kwargs
    ) -> Dict[str, Any]:
        """Send an email using a SendGrid template.
        
        Args:
            to: Recipient email address(es)
            template_id: ID of the SendGrid template to use
            template_data: Data to populate the template
            from_email: Sender email address
            cc: Carbon copy recipient(s)
            bcc: Blind carbon copy recipient(s)
            attachments: List of attachments
            **kwargs: Additional parameters
            
        Returns:
            Dict containing the send result
        """
        # TODO: Implement template email sending using SendGrid API
        # API doc: https://docs.sendgrid.com/api-reference/mail-send/mail-send
        
        # Use default_from if from_email not provided
        from_email = from_email or self.default_from
        
        if not from_email:
            raise ValueError("Sender email address is required")
        
        # Normalize to, cc, bcc to lists
        if isinstance(to, str):
            to = [to]
        if cc and isinstance(cc, str):
            cc = [cc]
        if bcc and isinstance(bcc, str):
            bcc = [bcc]
        
        # TODO: Prepare and send the template request to SendGrid API
        
        raise NotImplementedError("SendGrid template email sending not implemented yet")
    
    def get_email_status(
        self,
        message_id: str,
        **kwargs
    ) -> Dict[str, Any]:
        """Get the status of a sent email using SendGrid.
        
        Args:
            message_id: ID of the email to check
            **kwargs: Additional parameters
            
        Returns:
            Dict containing the email status
        """
        # TODO: Implement email status checking using SendGrid API
        # This might require using SendGrid's Event Webhook API or Email Activity API
        
        raise NotImplementedError("SendGrid email status checking not implemented yet") 