app.py

import gradio as gr
import os
import shutil
from typing import List, Optional

from scripts.generate_scripts import generate_script, generate_title, generate_description
from scripts.generate_voice import generate_voice
from scripts.get_footage import get_video_montage_from_folder
from scripts.edit_video import edit_video
from scripts.generate_subtitles import (
    transcribe_audio_to_subs,
    chunk_text_by_words,
    add_subtitles_to_video,
)

# ──────────────────────────────────────────────────────────────────────────────
# Constants & helper utils
# ──────────────────────────────────────────────────────────────────────────────

WORDS_PER_SECOND = 2.3  # ≃ 140 wpm


def safe_copy(src: str, dst: str) -> str:
    if os.path.abspath(src) == os.path.abspath(dst):
        return src
    shutil.copy(src, dst)
    return dst

# ──────────────────────────────────────────────────────────────────────────────
# Core processing pipeline
# ──────────────────────────────────────────────────────────────────────────────

def process_video(
    context: str,
    instruction: str,
    target_duration: int,
    script_mode: str,
    custom_script: Optional[str],
    lum: float,
    contrast: float,
    gamma: float,
    add_subs: bool,
    accumulated_videos: List[str] | None = None,
    user_music: Optional[str] = None,
    show_progress_bar: bool = True,
):
    """Build the final video using user‑defined visual parameters (brightness, contrast, gamma)."""

    if not accumulated_videos:
        raise ValueError("❌ Please upload at least one background video (.mp4) before generating.")

    approx_words = int(target_duration * WORDS_PER_SECOND)

    # --- 1. Script (AI or custom) ---
    if script_mode == "Use my script":
        if not custom_script or not custom_script.strip():
            raise ValueError("❌ You selected 'Use my script' but the script field is empty!")
        script = custom_script.strip()
        title = generate_title(script)
        description = generate_description(script)
    else:
        prompt = (
            f"You are a video creation expert. Here is the context: {context.strip()}\n"
            f"Instruction: {instruction.strip()}\n"
            f"🔴 Strict target duration: {target_duration}s — ≈ {approx_words} words (must be respected)."
        )
        script = generate_script(prompt)
        title = generate_title(script)
        description = generate_description(script)

    # --- 2. Prepare folders ---
    for folder in ("./assets/audio", "./assets/backgrounds", "./assets/output"):
        os.makedirs(folder, exist_ok=True)

    voice_path = "./assets/audio/voice.mp3"
    final_no_subs = "./assets/output/final_video.mp4"
    final_with_subs = "./assets/output/final_video_subtitles.mp4"

    # --- 3. Copy videos ---
    for f in os.listdir("./assets/backgrounds"):
        if f.lower().endswith(".mp4"):
            os.remove(os.path.join("./assets/backgrounds", f))
    for idx, v in enumerate(accumulated_videos):
        if not os.path.isfile(v) or not v.lower().endswith(".mp4"):
            raise ValueError(f"❌ Invalid file: {v}")
        safe_copy(v, os.path.join("./assets/backgrounds", f"video_{idx:03d}.mp4"))

    # --- 4. AI voice ---
    generate_voice(script, voice_path)

    # --- 5. Video montage ---
    music_path = user_music if user_music and os.path.isfile(user_music) else None
    _, out_no_audio = get_video_montage_from_folder(
        folder_path="./assets/backgrounds",
        audio_path=voice_path,
        output_dir="./assets/video_music",
        lum=lum,
        contrast=contrast,
        gamma=gamma,
        show_progress_bar=show_progress_bar,
    )

    # --- 6. Mixing & subtitles ---
    edit_video(out_no_audio, voice_path, music_path, final_no_subs)

    if add_subs:
        segments = transcribe_audio_to_subs(voice_path)
        subs = chunk_text_by_words(segments, max_words=3)
        add_subtitles_to_video(final_no_subs, subs, final_with_subs)
        return script, title, description, final_with_subs
    else:
        return script, title, description, final_no_subs

# ──────────────────────────────────────────────────────────────────────────────
# Upload helper
# ──────────────────────────────────────────────────────────────────────────────

def accumulate_files(new: List[str], state: List[str] | None):
    state = state or []
    for f in new or []:
        if isinstance(f, str) and os.path.isfile(f) and f.lower().endswith(".mp4") and f not in state:
            state.append(f)
    return state

# ──────────────────────────────────────────────────────────────────────────────
# Gradio UI
# ──────────────────────────────────────────────────────────────────────────────

with gr.Blocks(theme="gradio/soft") as demo:
    gr.Markdown("# 🎬 AI Video Generator — Advanced Controls")

    # ------------------- Parameters -------------------
    with gr.Tab("🛠️ Settings"):
        with gr.Row():
            context_input = gr.Textbox(label="🧠 Context", lines=4)
            instruction_input = gr.Textbox(label="🎯 Instruction", lines=4)

        duration_slider = gr.Slider(5, 120, 1, 60, label="⏱️ Target duration (s)")

        script_mode = gr.Radio([
            "Generate script with AI",
            "Use my script",
        ], value="Generate script with AI", label="Script mode")

        custom_script_input = gr.Textbox(label="✍️ My script", lines=8, interactive=False)

        def toggle_script_input(mode):
            return gr.update(interactive=(mode == "Use my script"))

        script_mode.change(toggle_script_input, inputs=script_mode, outputs=custom_script_input)

        with gr.Accordion("🎨 Video Settings (brightness/contrast/gamma)", open=False):
            lum_slider = gr.Slider(0, 20, 6, step=0.5, label="Brightness (0–20)")
            contrast_slider = gr.Slider(0.5, 2.0, 1.0, step=0.05, label="Contrast (0.5–2.0)")
            gamma_slider = gr.Slider(0.5, 2.0, 1.0, step=0.05, label="Gamma (0.5–2.0)")

        with gr.Row():
            add_subs_checkbox = gr.Checkbox(label="Add dynamic subtitles", value=True)

        with gr.Row():
            show_bar = gr.Checkbox(label="Show progress bar", value=True)

        # Upload videos
        videos_dropzone = gr.Files(label="🎞️ Background videos (MP4)", file_types=[".mp4"], type="filepath")
        videos_state = gr.State([])
        video_list_display = gr.Textbox(label="✅ Selected videos", interactive=False, lines=4)
        videos_dropzone.upload(accumulate_files, [videos_dropzone, videos_state], videos_state, queue=False)
        videos_state.change(lambda s: "\n".join(os.path.basename(f) for f in s), videos_state, video_list_display, queue=False)


        user_music = gr.File(label="🎵 Background music (MP3, optional)", file_types=[".mp3"], type="filepath")

        generate_btn = gr.Button("🚀 Generate the video", variant="primary")

    with gr.Tab("📤 Results"):
        video_output = gr.Video(label="🎬 Generated Video")

        # Script + copy button
        script_output = gr.Textbox(label="📝 Script", lines=6, interactive=False)
        copy_script_btn = gr.Button("📋 Copy")
        copy_script_btn.click(
            None,
            inputs=[script_output],
            outputs=None,
            js="(text) => navigator.clipboard.writeText(text)"
        )

        # Title + copy button
        title_output = gr.Textbox(label="🎬 Title", lines=1, interactive=False)
        copy_title_btn = gr.Button("📋 Copy")
        copy_title_btn.click(None, inputs=title_output, outputs=None, js="(text) => {navigator.clipboard.writeText(text);}")

        # Description + copy button
        desc_output = gr.Textbox(label="📄 Description", lines=3, interactive=False)
        copy_desc_btn = gr.Button("📋 Copy")
        copy_desc_btn.click(None, inputs=desc_output, outputs=None, js="(text) => {navigator.clipboard.writeText(text);}")

    # ------------------- Generation Callback -------------------
    generate_btn.click(
        fn=process_video,
        inputs=[
            context_input,
            instruction_input,
            duration_slider,
            script_mode,
            custom_script_input,
            lum_slider,
            contrast_slider,
            gamma_slider,
            add_subs_checkbox,
            videos_state,
            user_music,
            show_bar,
        ],
        outputs=[script_output, title_output, desc_output, video_output],
    )

    demo.launch()