"""Image and timestamp helpers used by the Ollama/OpenAI request pipeline."""
import base64
import io
import time
from datetime import datetime, timezone

from PIL import Image


def iso8601_ns():
    ns = time.time_ns()
    sec, ns_rem = divmod(ns, 1_000_000_000)
    dt = datetime.fromtimestamp(sec, tz=timezone.utc)
    return (
        f"{dt.year:04d}-{dt.month:02d}-{dt.day:02d}T"
        f"{dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}."
        f"{ns_rem:09d}Z"
    )


def is_base64(image_string):
    try:
        if isinstance(image_string, str) and base64.b64encode(base64.b64decode(image_string)) == image_string.encode():
            return True
    except Exception:
        return False


def resize_image_if_needed(image_data):
    try:
        # Check if already data-url
        if image_data.startswith("data:"):
            try:
                header, image_data = image_data.split(",", 1)
            except ValueError:
                pass
        # Decode the base64 image data
        image_bytes = base64.b64decode(image_data)
        with Image.open(io.BytesIO(image_bytes)) as image:
            if image.mode not in ("RGB", "L"):
                image = image.convert("RGB")

            # Get current size
            width, height = image.size

            # Calculate the new dimensions while maintaining aspect ratio
            if width > 512 or height > 512:
                aspect_ratio = width / height
                if aspect_ratio > 1:  # Width is larger
                    new_width = 512
                    new_height = int(512 / aspect_ratio)
                else:  # Height is larger
                    new_height = 512
                    new_width = int(512 * aspect_ratio)

                image = image.resize((new_width, new_height), Image.Resampling.LANCZOS)

            # Encode the resized image back to base64
            buffered = io.BytesIO()
            image.save(buffered, format="PNG")
            resized_image_data = base64.b64encode(buffered.getvalue()).decode("utf-8")
            return resized_image_data

    except Exception as e:
        print(f"Error processing image: {e}")
        return None