import subprocess
from PIL import Image
import os

EXTENSIONS_IMG = ('jpg', 'jpeg', 'png', 'gif', 'webp', 'bmp')
EXTENSIONS_VID = ('mp4', 'webm')
VALID_EXTENSIONS = EXTENSIONS_IMG + EXTENSIONS_VID

def check_ffmpeg():
    try:
        if os.name == 'nt': creationflags = subprocess.CREATE_NO_WINDOW
        else: creationflags = 0
        subprocess.run(["ffmpeg", "-version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True, creationflags=creationflags)
        return True
    except (FileNotFoundError, subprocess.CalledProcessError):
        return False

def video_gen(input_path_file, output_path_file, TARGET_MIN_SIZE):
    vf_scale = f"scale='if(gt(iw,ih),-1,{TARGET_MIN_SIZE})':'if(gt(iw,ih),{TARGET_MIN_SIZE},-1)'"
    cmd = ["ffmpeg", "-y", "-i", input_path_file, "-ss", "00:00:00", "-vframes", "1", "-vf", vf_scale, "-q:v", "2", output_path_file]
    if os.name == 'nt': creationflags = subprocess.CREATE_NO_WINDOW
    else: creationflags = 0
    result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, creationflags=creationflags)
    if result.returncode != 0:
        raise Exception(f"FFmpeg error: {result.stderr.decode('utf-8', errors='ignore')}")

def image_and_gif_gen(input_path_file, output_path_file, TARGET_MIN_SIZE):
    with Image.open(input_path_file) as img:
        img_rgba = img.convert("RGBA")
        background = Image.new("RGB", img_rgba.size, (255, 255, 255))
        background.paste(img_rgba, mask=img_rgba)
        final_img = background
        width, height = final_img.size
        if width <= TARGET_MIN_SIZE and height <= TARGET_MIN_SIZE:
            final_img.save(output_path_file, "JPEG", quality=90)
        else:
            if width < height:
                new_width = TARGET_MIN_SIZE
                new_height = int(TARGET_MIN_SIZE * (height / width))
            else:
                new_height = TARGET_MIN_SIZE
                new_width = int(TARGET_MIN_SIZE * (width / height))
            resized_img = final_img.resize((new_width, new_height), Image.Resampling.LANCZOS)
            resized_img.save(output_path_file, "JPEG", quality=85)

def generate_thumb(input_path_file, THUMB_FOLDER, TARGET_MIN_SIZE):
    ext_file = input_path_file.split(".")[-1]
    if ext_file not in VALID_EXTENSIONS:
        return {"status":False, "message":"Расширение не поддерживаеться!"}
    thumb_filename = f"{os.path.basename(input_path_file).split(".")[-2]}.jpg"
    output_path_file = os.path.join(THUMB_FOLDER, thumb_filename)
    if ext_file in EXTENSIONS_IMG:
        image_and_gif_gen(input_path_file, output_path_file, TARGET_MIN_SIZE)
        return {"status":True}
    else:
        if not check_ffmpeg(): return {"status":False, "message":"ffmpeg не установлен!"}
        video_gen(input_path_file, output_path_file, TARGET_MIN_SIZE)
        return {"status":True}