"""
Image handling and fetching from Unsplash.
"""
import requests
import json 
from io import BytesIO
from PIL import Image 
from logger import logger
from config import UNSPLASH_API_KEY, IMAGE_FEATURED_WIDTH, IMAGE_FEATURED_HEIGHT


class ImageHandler:
    """Handles image fetching from Unsplash API."""

    def __init__(self, api_key=UNSPLASH_API_KEY):
        """Initialize image handler."""
        if not api_key:
            raise ValueError("UNSPLASH_API_KEY not set in environment")
        self.api_key = api_key
        self.base_url = "https://api.unsplash.com/photos/random"
        logger.debug("ImageHandler initialized")

    def fetch_image(self, tags):
        """
        Fetch a random image from Unsplash based on tags. If no image is found, retry by removing one word at a time.
        Args:
            tags (list): List of search tags
        Returns:
            dict: Contains 'url', 'credit', 'filename' keys
        Raises:
            Exception: If API call fails or response is invalid
        """
        if not tags:
            raise ValueError("At least one tag is required")

        tried_queries = set()
        def try_fetch(tags_subset):
            search_query = " ".join(tags_subset)
            if not search_query or search_query in tried_queries:
                return None
            tried_queries.add(search_query)
            logger.info(f"Searching for image with query: '{search_query}'")
            params = {
                "query": search_query,
                "orientation": "landscape",
                "w": IMAGE_FEATURED_WIDTH,
                "h": IMAGE_FEATURED_HEIGHT,
            }
            headers = {"Authorization": f"Client-ID {self.api_key}"}
            logger.debug(f"Unsplash API request: {self.base_url}")
            try:
                response = requests.get(self.base_url, params=params, headers=headers)
                logger.debug(f"Unsplash response status: {response.status_code}")
                if response.status_code != 200:
                    logger.warning(f"No image found for query '{search_query}' (status {response.status_code})")
                    return None
                photo = response.json()
                if "urls" not in photo or "user" not in photo:
                    logger.warning(f"Invalid response structure for query '{search_query}': {json.dumps(photo, indent=2)}")
                    return None
                image_url = photo["urls"].get("regular")
                image_credit = photo["user"].get("name", "")
                image_credit_url = photo["user"].get("links", {}).get("html", "https://unsplash.com")
                filename = f"featured_{search_query.replace(' ', '_')}.avif"
                logger.info(f"Image found by {image_credit}: {image_url}")
                return {
                    "url": image_url,
                    "credit": image_credit,
                    "credit_url": image_credit_url,
                    "filename": filename,
                }
            except requests.RequestException as e:
                logger.error(f"Request failed: {e}")
                return None
            except Exception as e:
                logger.error(f"Failed to fetch image: {e}")
                return None

        # Try with all tags first
        result = try_fetch(tags)
        if result:
            return result

        # Try by removing one word at a time
        for i in range(len(tags)):
            reduced_tags = tags[:i] + tags[i+1:]
            if not reduced_tags:
                continue
            result = try_fetch(reduced_tags)
            if result:
                return result

        # Try each individual tag
        for tag in tags:
            result = try_fetch([tag])
            if result:
                return result

        raise Exception("No image found for any tag combination.")

    def download_image(self, image_url):
        """
        Download image from URL and convert to AVIF format.
        
        Args:
            image_url (str): URL of the imageF
            
        Returns:
            bytes: Image data in AVIF format
            
        Raises:
            Exception: If download or conversion fails
        """
        try:
            logger.info("Downloading image...")
            response = requests.get(image_url)
            response.raise_for_status()
            image_data = response.content
            logger.info(f"Downloaded image: {len(image_data) // 1024} KB")
            
            # Convert to AVIF format
            logger.info("Converting image to AVIF format...")
            try:
                img = Image.open(BytesIO(image_data))
                # Convert RGBA to RGB if needed
                if img.mode in ("RGBA", "LA", "P"):
                    rgb_img = Image.new("RGB", img.size, (255, 255, 255))
                    rgb_img.paste(img, mask=img.split()[-1] if img.mode == "RGBA" else None)
                    img = rgb_img
                
                # Save as AVIF
                avif_buffer = BytesIO()
                img.save(avif_buffer, format="AVIF", quality=85)
                avif_data = avif_buffer.getvalue()
                logger.info(f"Converted to AVIF: {len(avif_data) // 1024} KB")
                return avif_data
            except Exception as e:
                logger.error(f"Failed to convert image to AVIF: {e}")
                logger.info("Returning original image data")
                return image_data
        except requests.RequestException as e:
            logger.error(f"Failed to download image: {e}")
            raise