# video_processor.py
from io import BytesIO
import av
import base64
from PIL import Image
from typing import List
from dataclasses import dataclass

@dataclass
class VideoProcessor:
    frame_format: str = "JPEG"
    frame_skip: int = 10
    group_size: int = 10
    
    def decode(self, video_path: str) -> List[Image.Image]:
        frames = []
        container = av.open(video_path)
        for i, frame in enumerate(container.decode(video=0)):
            if i % self.frame_skip:
                continue
            im = frame.to_image()
            frames.append(im)
        return frames

    def concatenate(self, frames: List[Image.Image], direction: str = "horizontal") -> Image.Image:
        widths, heights = zip(*(frame.size for frame in frames))

        if direction == "horizontal":
            total_width = sum(widths)
            max_height = max(heights)
            concatenated_image = Image.new('RGB', (total_width, max_height))
            x_offset = 0
            for frame in frames:
                concatenated_image.paste(frame, (x_offset, 0))
                x_offset += frame.width
        else:
            max_width = max(widths)
            total_height = sum(heights)
            concatenated_image = Image.new('RGB', (max_width, total_height))
            y_offset = 0
            for frame in frames:
                concatenated_image.paste(frame, (0, y_offset))
                y_offset += frame.height

        return concatenated_image

    def group_and_concatenate(self, frames: List[Image.Image], limit=10) -> List[Image.Image]:
        xs = len(frames) // self.group_size
        groups = [frames[i:i + xs] for i in range(0, len(frames), xs)]
        sampled_groups = []
        for group in groups:
            interval = max(1, len(group) // limit)
            sampled_groups.append([group[i] for i in range(0, len(group), interval)])
        return [self.concatenate(group) for group in sampled_groups]

    def to_base64_list(self, images: List[Image.Image]) -> List[str]:
        base64_list = []
        for image in images:
            buffered = BytesIO()
            image.save(buffered, format=self.frame_format)
            base64_list.append(base64.b64encode(buffered.getvalue()).decode('utf-8'))
        return base64_list