import re
from PIL import Image
import io
import os

TEST_PHOTOS_FOLDER = "/mnt/c/Users/KMult/Desktop/Praca_inzynierska/zdjecia_testowe/" 
TEST_RESULTS_FOLDER = "./results"


def return_image_response(image: Image.Image):
    from fastapi.responses import StreamingResponse
    
    buffer = io.BytesIO()
    image.save(buffer, format="PNG")
    buffer.seek(0)
    return StreamingResponse(buffer, media_type="image/png")


def open_image(file_path: str) -> Image.Image:
    image_path = os.path.join(TEST_PHOTOS_FOLDER, file_path)
    
    if not os.path.exists(image_path):
        raise FileNotFoundError(f"File not found: {image_path}")
    
    try:
        img = Image.open(image_path)
        img.load()
        return img
    except OSError as e:
        raise OSError(f"Could not open file as image: {image_path}") from e


def get_next_result_number(folder_path: str):
    if not os.path.exists(folder_path):
        return 1

    numbers = []
    for filename in os.listdir(folder_path):
        match = re.match(r"result(\d+)\.png", filename)
        if match:
            numbers.append(int(match.group(1)))
    return max(numbers, default=0) + 1


def save_result_file(image: Image.Image):
    os.makedirs(TEST_RESULTS_FOLDER, exist_ok=True)
    next_number = get_next_result_number(TEST_RESULTS_FOLDER)
    output_path = os.path.join(TEST_RESULTS_FOLDER, f"result{next_number}.png")
    
    buffer = io.BytesIO()
    image.save(buffer, format="PNG")
    buffer.seek(0)

    with open(output_path, "wb") as f:
        f.write(buffer.read())

    print(f"Image saved to {output_path}")