import streamlit as st
import tempfile
import subprocess
import os
import re

# Page settings
st.set_page_config(page_title="Video Speed Tool", layout="centered")

# CSS styling for mobile
st.markdown("""
    <style>
    /* Center title */
    .title-center {
        text-align: center;
        font-size: 1.8em;
        font-weight: bold;
        margin-bottom: 20px;
    }
    /* Center all buttons */
    div.stButton > button {
        font-weight: bold;
        width: 80%;
        border-radius: 8px;
        padding: 10px 0;
        font-size: 1.1em;
        display: block;
        margin: 0 auto;
    }
    /* Center download button */
    div.stDownloadButton > button {
        font-weight: bold;
        width: 80%;
        border-radius: 8px;
        padding: 10px 0;
        font-size: 1.1em;
        display: block;
        margin: 0 auto;
    }
    /* Bigger + and - buttons in number input */
    div[data-baseweb="input"] button {
        width: 40px !important;
        height: 40px !important;
        font-size: 1.2em !important;
    }
    </style>
""", unsafe_allow_html=True)

# Title
st.markdown('<p class="title-center">🎬 Video Speed Tool</p>', unsafe_allow_html=True)

# Upload file
uploaded_file = st.file_uploader("Upload video", type=["mp4", "mov", "avi", "mkv"])

# Speed input
speed = st.number_input(
    "Speed (0.25x - 4x)",
    min_value=0.25,
    max_value=4.0,
    value=1.5,
    step=0.05
)

if uploaded_file is not None:
    st.video(uploaded_file)

    if st.button("PROCESS VIDEO"):
        with st.spinner("Processing... Please wait"):
            with tempfile.NamedTemporaryFile(delete=False, suffix=".mp4") as tmp_input:
                tmp_input.write(uploaded_file.read())
                input_path = tmp_input.name

            output_path = tempfile.NamedTemporaryFile(delete=False, suffix=".mp4").name

            video_speed = 1 / speed
            audio_speed = speed

            # Always compress
            cmd = [
                "ffmpeg", "-i", input_path,
                "-filter_complex", f"[0:v]setpts={video_speed}*PTS[v];[0:a]atempo={audio_speed}[a]",
                "-map", "[v]", "-map", "[a]",
                "-vcodec", "libx264", "-crf", "28", "-preset", "fast",
                "-movflags", "+faststart",
                "-y", output_path
            ]

            # Progress bar
            progress_text = st.empty()
            progress_bar = st.progress(0)

            # Get video duration
            probe = subprocess.run(
                ["ffprobe", "-v", "error", "-show_entries", "format=duration",
                 "-of", "default=noprint_wrappers=1:nokey=1", input_path],
                stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True
            )
            try:
                total_duration = float(probe.stdout.strip())
            except:
                total_duration = None

            # Run ffmpeg with live progress
            process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True, bufsize=1)

            for line in process.stdout:
                if "time=" in line and total_duration:
                    match = re.search(r"time=(\d+:\d+:\d+\.\d+)", line)
                    if match:
                        h, m, s = match.group(1).split(":")
                        elapsed = int(h) * 3600 + int(m) * 60 + float(s)
                        percent = min(int((elapsed / total_duration) * 100), 100)
                        progress_bar.progress(percent)
                        progress_text.text(f"Processing... {percent}%")

            process.wait()
            progress_bar.progress(100)
            progress_text.text("✅ Processing complete!")

            # Show processed video
            st.video(output_path)

            # Download button centered
            with open(output_path, "rb") as f:
                st.download_button(
                    label="DOWNLOAD VIDEO",
                    data=f,
                    file_name="processed_video.mp4",
                    mime="video/mp4"
                )

            os.remove(input_path)
            os.remove(output_path)