import logging
from typing import Any, Dict, Optional

import requests
from fastapi import HTTPException

from config import Config


class KleerAPIError(Exception):
    """Custom exception for Kleer API errors."""
    pass


class KleerAPI:
    """Client for interacting with the Kleer API."""
    
    def __init__(self, api_url: Optional[str] = None, company_id: Optional[str] = None):
        """
        Initialize Kleer API client.
        
        Args:
            api_url: Base URL for the Kleer API
            company_id: Company ID for API requests
            
        Raises:
            ValueError: If API key is not configured
        """
        self.api_url = api_url or Config.API_URL
        self.company_id = company_id or Config.get_company_id()
        self.api_key = Config.get_api_key()
        
        if not self.api_key:
            raise ValueError("KLEER_API_KEY environment variable is not set")
    
    def _get_headers(self) -> Dict[str, str]:
        """Get headers for API requests."""
        return {
            'X-token': self.api_key,
            'Content-Type': 'application/json'
        }
    
    def api_request(
        self,
        endpoint: str,
        method: str = 'GET',
        data: Optional[Any] = None
    ) -> Optional[Any]:
        """
        Make a request to the Kleer API.
        
        Args:
            endpoint: API endpoint path
            method: HTTP method (GET, POST, PUT)
            data: Request payload for POST/PUT requests
            
        Returns:
            JSON response from the API
            
        Raises:
            HTTPException: If the request fails
        """
        url = f"{self.api_url}/{endpoint}"
        headers = self._get_headers()
        
        response = None
        try:
            if method == 'GET':
                response = requests.get(url, headers=headers)
            elif method == 'POST':
                response = requests.post(url, headers=headers, json=data)
            elif method == 'PUT':
                response = requests.put(url, headers=headers, json=data)
            else:
                raise ValueError(f"Unsupported HTTP method: {method}")
            
            response.raise_for_status()
            return response.json()
            
        except requests.HTTPError as e:
            logging.error(f"HTTP error during API request: {e}")
            raise HTTPException(
                status_code=response.status_code if response else 502,
                detail=f"API request failed: {str(e)}"
            )
        except requests.RequestException as e:
            logging.error(f"API request failed: {e}")
            raise HTTPException(status_code=502, detail=f"API request failed: {str(e)}")
    
    def get_events(self, user_id: int, start_date: str, end_date: str) -> Dict[str, Any]:
        """
        Retrieve events for a user within a date range.
        
        Args:
            user_id: User ID
            start_date: Start date in YYYY-MM-DD format
            end_date: End date in YYYY-MM-DD format
            
        Returns:
            Event data from API
        """
        endpoint = (
            f"company/{self.company_id}/event"
            f"?userId={user_id}&startDate={start_date}&endDate={end_date}"
        )
        return self.api_request(endpoint, method='GET') or {}
    
    def approve_events(self, user_id: int, start_date: str, end_date: str) -> Dict[str, Any]:
        """
        Approve events for a user within a date range.
        
        Args:
            user_id: User ID
            start_date: Start date in YYYY-MM-DD format
            end_date: End date in YYYY-MM-DD format
            
        Returns:
            Approval response from API
        """
        endpoint = f"company/{self.company_id}/event/approve"
        payload = {
            "user-id": {"id": user_id},
            "start-date": start_date,
            "end-date": end_date
        }
        return self.api_request(endpoint, method='POST', data=payload) or {}
    
    def put_event(self, event: Dict[str, Any]) -> Optional[Any]:
        """
        Submit a time event to the Kleer API.
        
        Args:
            event: Time event data
            
        Returns:
            API response
            
        Raises:
            HTTPException: If the request fails
        """
        url = f"company/{self.company_id}/event"
        try:
            response = self.api_request(url, method='PUT', data=event)
            logging.info(f"Successfully reported event for date: {event.get('date')}")
            return response
        except HTTPException as e:
            logging.error(
                f"Failed to put event for date {event.get('date')}. "
                f"Status: {e.status_code}, Detail: {e.detail}"
            )
            raise
        except Exception as e:
            logging.error(
                f"Unexpected error while putting event for date {event.get('date')}: {e}"
            )
            raise HTTPException(
                status_code=500,
                detail=f"An unexpected error occurred: {str(e)}"
            )
    
    def get_projects(self, user_id: int) -> Dict[str, Dict[str, Any]]:
        """
        Retrieve active projects for a user.
        
        Args:
            user_id: User ID to filter projects
            
        Returns:
            Dictionary mapping project names to project info
        """
        url = f"company/{self.company_id}/client-project?filter=active"
        data = self.api_request(url, method='GET')
        
        if not data:
            logging.warning("No data received from projects API.")
            return {}
        
        projects_data = data.get('client-project-readables') if isinstance(data, dict) else data
        if not isinstance(projects_data, list):
            logging.error("Unexpected projects data format.")
            return {}
        
        projects = {}
        for project in projects_data:
            if not isinstance(project, dict):
                logging.warning(f"Unexpected project data format: {project}")
                continue
            
            project_id = project.get('id')
            project_name = project.get('name')
            activity_id = None
            
            users = project.get('users', [])
            for user in users:
                if user.get('user', {}).get('id') != user_id:
                    continue
                activities = user.get('activities', [])
                for activity in activities:
                    activity_id = activity.get('activity', {})
                    if activity_id:
                        break
                if activity_id:
                    break
            
            if not project_id or not project_name:
                logging.info(f"Skipping project with missing ID or name: {project}")
                continue
            
            if activity_id:
                projects[project_name] = {"id": project_id, "activity": activity_id}
            else:
                logging.info(
                    f"Project '{project_name}' (ID: {project_id}) has no associated activity."
                )
        
        logging.info(f"Found {len(projects)} valid projects.")
        return projects
    
    def get_user_info(self) -> Optional[Dict[str, Any]]:
        """
        Retrieve user information from the Kleer API.
        
        Returns:
            User information dictionary or None if not found
        """
        url = f"company/{self.company_id}/user"
        data = self.api_request(url, method='GET')
        
        if data and isinstance(data, dict):
            logging.info("User info retrieved from Kleer API.")
            return data
        
        logging.warning("No user information found or data format is incorrect.")
        return None