from __future__ import annotations

import os
from pathlib import Path
from typing import Any

import numpy as np
from moviepy import AudioFileClip, VideoClip
from PIL import Image

from engine.config import AppConfig

from .base import BaseVideoGen


class MoviePyVideoGen(BaseVideoGen):
    def __init__(self, cfg: AppConfig):
        self.cfg = cfg

    def generate(self, image_path: str, prompt: dict, output_path: str | Path) -> str:
        output_path = Path(output_path)
        output_path.parent.mkdir(parents=True, exist_ok=True)

        # Required prompt fields for shot rendering.
        duration_s = float(prompt.get("duration_s", 3))
        fps = int(prompt.get("fps", self.cfg.get("video.mock_fps", 24)))
        audio_path = prompt.get("audio_path")

        # Clip resolution.
        size = prompt.get("size")
        if isinstance(size, (list, tuple)) and len(size) == 2:
            w, h = int(size[0]), int(size[1])
        else:
            mock_size = self.cfg.get("video.mock_size", [1024, 576])
            w, h = int(mock_size[0]), int(mock_size[1])

        base_img = Image.open(image_path).convert("RGB")

        def make_frame(t: float):
            progress = float(t) / max(duration_s, 1e-6)
            progress = max(0.0, min(1.0, progress))
            scale = 1.0 + 0.03 * progress
            new_w = max(w, int(w * scale))
            new_h = max(h, int(h * scale))
            frame = base_img.resize((new_w, new_h), Image.LANCZOS)
            left = (new_w - w) // 2
            top = (new_h - h) // 2
            frame = frame.crop((left, top, left + w, top + h))
            return np.array(frame)

        video = VideoClip(make_frame, duration=duration_s, has_constant_size=True)

        # Optional audio.
        if audio_path and os.path.exists(str(audio_path)):
            a = AudioFileClip(str(audio_path))
            video = video.with_audio(a)
        else:
            a = None

        try:
            video.write_videofile(
                str(output_path),
                fps=fps,
                codec="libx264",
                audio_codec="aac",
                preset="veryfast",
                threads=2,
            )
        finally:
            try:
                video.close()
            except Exception:
                pass
            if a is not None:
                try:
                    a.close()
                except Exception:
                    pass

        return str(output_path)