import os
import io
import time
import random
import logging
import requests
from PIL import Image, UnidentifiedImageError

# --- Logging setup ---
logger = logging.getLogger("flux")
LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO").upper()
logger.setLevel(LOG_LEVEL)
handler = logging.StreamHandler()
handler.setFormatter(logging.Formatter("%(asctime)s [%(levelname)s] %(message)s"))
logger.addHandler(handler)

# --- Configuration ---
IMGBB_API_KEY = os.getenv("IMGBB_API_KEY")
DEFAULT_MODEL = "flux"
DEFAULT_WIDTH = 1920
DEFAULT_HEIGHT = 1080
MAX_RETRIES   = 3
BACKOFF_BASE  = 2  # exponential backoff

def upload_to_imgbb(image_path: str, file_name: str) -> str | None:
    """
    Uploads the image at image_path to ImgBB.
    Returns the public URL or None on failure.
    """
    if not IMGBB_API_KEY:
        logger.warning("IMGBB_API_KEY not set, skipping upload")
        return None

    try:
        with open(image_path, 'rb') as f:
            files = {"image": (file_name, f.read())}
        resp = requests.post(
            "https://api.imgbb.com/1/upload",
            params={"key": IMGBB_API_KEY},
            files=files,
            timeout=15
        )
        resp.raise_for_status()
        data = resp.json().get("data", {})
        url  = data.get("url")
        if url:
            logger.debug(f"Uploaded to ImgBB: {url}")
            return url
        else:
            logger.error("ImgBB response missing URL")
            return None
    except Exception as e:
        logger.error(f"ImgBB upload failed: {e}")
        return None

def generate_image(
    prompt: str,
    request_id: str,
    current_request_id: str,
    image_dir: str,
    model: str = None,
    width: int = None,
    height: int = None
) -> tuple[Image.Image, str, str, str] | None:
    """
    Generate an image via Pollinations API, save locally, upload to ImgBB.

    Returns:
      (PIL.Image, local_path, returned_prompt, image_url) or None on failure.
    """
    model  = model or DEFAULT_MODEL
    width  = width or DEFAULT_WIDTH
    height = height or DEFAULT_HEIGHT

    # if the request has been superseded, bail early
    if request_id != current_request_id:
        logger.info("Request ID mismatch; cancelling generation")
        return None

    seed = random.randint(0, 2**31 - 1)
    url  = (
        f"https://image.pollinations.ai/prompt/{requests.utils.quote(prompt)}"
        f"?nologo=true&safe=false&private=true&model={model}"
        f"&enhance=true&width={width}&height={height}&seed={seed}"
    )
    logger.debug(f"Fetching image (seed={seed}): {url}")

    backoff = 1000 # equivalent to 1 second
    for attempt in range(1, MAX_RETRIES + 1):
        try:
            resp = requests.get(url, timeout=45)
            if resp.status_code != 200:
                raise RuntimeError(f"Status {resp.status_code}")
            break
        except Exception as e:
            logger.warning(f"Attempt {attempt}/{MAX_RETRIES} failed: {e}")
            if attempt == MAX_RETRIES:
                logger.error("Max retries reached, aborting image fetch")
                return None
            time.sleep(backoff)
            backoff *= BACKOFF_BASE

    # verify still the active request
    if request_id != current_request_id:
        logger.info("Request ID mismatch after fetch; discarding result")
        return None

    # load image
    try:
        image = Image.open(io.BytesIO(resp.content))
        logger.debug(f"Image loaded: {image.size[0]}×{image.size[1]}")
    except UnidentifiedImageError as e:
        logger.error(f"Invalid image data: {e}")
        return None

    # try to extract prompt metadata from EXIF
    returned_prompt = prompt
    exif = image.info.get("exif", b"")
    if exif:
        try:
            import re, json as _json
            m = re.search(b'{"prompt":.*}', exif)
            if m:
                meta = _json.loads(m.group(0).decode())
                returned_prompt = meta.get("prompt", prompt)
        except Exception as e:
            logger.debug(f"EXIF parse failed: {e}")

    # ensure output directory
    os.makedirs(image_dir, exist_ok=True)
    filename = f"flux_{int(time.time())}.png"
    path     = os.path.join(image_dir, filename)

    try:
        image.save(path, format="PNG")
        logger.info(f"Image saved to {path}")
    except Exception as e:
        logger.error(f"Failed to save image: {e}")
        return None

    # upload
    image_url = upload_to_imgbb(path, filename) or ""
    return image, path, returned_prompt.split("\n\n", 1)[0], image_url