"""
A minimal, self-contained Gradio video editor that allows:
1. Uploading one or more videos.
2. Trimming each video to a start/end time.
3. Concatenating the trimmed clips in the order supplied.
4. Downloading the final edited video.

Requirements (install once):
    pip install gradio moviepy==1.0.3

Run:
    python video_editor.py
"""

import tempfile
import os
from typing import List, Tuple

import gradio as gr
from moviepy.editor import VideoFileClip, concatenate_videoclips


def _time_to_seconds(time_str: str) -> float:
    """Convert HH:MM:SS[.ms] → seconds (float)."""
    parts = list(map(float, reversed(time_str.split(":"))))
    return sum(v * 60 ** idx for idx, v in enumerate(parts))


def edit_videos(
    videos: List[str],
    trims: List[Tuple[str, str]],
) -> str:
    """
    Create a single edited video from the list of uploaded videos
    and corresponding (start, end) times.

    Returns the file path of the final video.
    """

    if not videos:
        raise ValueError("At least one video is required.")

    if len(videos) != len(trims):
        raise ValueError("Each video must have a start/end time pair.")

    clips = []
    for vid_path, (start_str, end_str) in zip(videos, trims):
        start = _time_to_seconds(start_str)
        end = _time_to_seconds(end_str)
        clip = VideoFileClip(vid_path).subclip(start, end)
        clips.append(clip)

    final = concatenate_videoclips(clips)

    # Save to a temporary file with a unique name
    out_path = os.path.join(
        tempfile.gettempdir(),
        "edited_video.mp4"
    )
    final.write_videofile(out_path, codec="libx264", audio_codec="aac")

    # Close clips to release file handles
    for c in clips:
        c.close()
    final.close()

    return out_path


def gradio_interface():
    with gr.Blocks(title="Video Editor") as demo:
        gr.Markdown("## Simple Gradio Video Editor")
        gr.Markdown(
            "Upload one or more videos.  \n"
            "Provide the **start** and **end** time (HH:MM:SS) for each clip.  \n"
            "The clips will be concatenated in the order given."
        )

        with gr.Row():
            with gr.Column(scale=2):
                video_files = gr.File(
                    label="Upload videos",
                    file_count="multiple",
                    file_types=["video"],
                    type="filepath",
                )

                # Dynamic UI for trims
                trim_rows = gr.State([])

                def _update_trim_inputs(videos):
                    rows = []
                    for idx, v in enumerate(videos or []):
                        with gr.Row():
                            start = gr.Textbox(
                                label=f"Start time #{idx+1}",
                                value="00:00:00",
                                scale=1,
                            )
                            end = gr.Textbox(
                                label=f"End time #{idx+1}",
                                value="00:00:05",
                                scale=1,
                            )
                        rows.append((start, end))
                    return rows

                trim_inputs_placeholder = gr.HTML()  # dummy; we will render rows

                # Render trim inputs after file upload
                video_files.change(
                    fn=_update_trim_inputs,
                    inputs=video_files,
                    outputs=trim_inputs_placeholder,
                )

            with gr.Column(scale=1):
                output_video = gr.Video(label="Edited Video")
                edit_btn = gr.Button("Edit & Download", variant="primary")

        # Submit
        def _on_edit(videos):
            # Re-create trim tuples based on current videos
            rows = _update_trim_inputs(videos)
            trims = [
                (start.value, end.value) for start, end in rows
            ]
            out_path = edit_videos(videos, trims)
            return out_path

        edit_btn.click(_on_edit, inputs=[video_files], outputs=output_video)

    demo.launch()


if __name__ == "__main__":
    gradio_interface()