#!/bin/bash

max_file_size=2800
DEFAULT_OFFSET=0

if [ $# -eq 0 ]; then
    echo "No arguments supplied. Please provide the video path."
    exit 1
fi

VIDEO_PATH="$1"

# Get the original video length in seconds
FULL_LENGTH=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$VIDEO_PATH")

DEFAULT_LENGTH=$FULL_LENGTH
DEFAULT_RESOLUTION=$(ffprobe -v error -select_streams v:0 -show_entries stream=width -of csv=p=0 "$VIDEO_PATH")

echo "Please enter an offset from the video beginning (in seconds) [default: $DEFAULT_OFFSET]:"
read OFFSET
OFFSET=${OFFSET:-$DEFAULT_OFFSET}

echo "Please enter the length of the clip (in seconds) [default: $DEFAULT_LENGTH]:"
read LENGTH
LENGTH=${LENGTH:-$DEFAULT_LENGTH}

echo "Enter the preferred video resolution (width:height, e.g., 720:1280 or original) [default: $DEFAULT_RESOLUTION]:"
read RESOLUTION
RESOLUTION=${RESOLUTION:-$DEFAULT_RESOLUTION}

# Now you can use the variables OFFSET, LENGTH, and RESOLUTION in your script
echo "VIDEO_PATH: $VIDEO_PATH"
echo "OFFSET: $OFFSET"
echo "LENGTH: $LENGTH"
echo "RESOLUTION: $RESOLUTION"

OUTPUT_NAME=$(basename "$VIDEO_PATH" | cut -d. -f1)

# Determine output video path
OUTPUT_PATH=$(dirname "${VIDEO_PATH}")

# Use bc for floating-point arithmetic to calculate the bitrate
bitrate=$(echo "scale=2; 8 * $max_file_size / $LENGTH" | bc)

echo "Target bitrate: $bitrate"

ffmpeg -y -ss ${OFFSET} -i ${VIDEO_PATH} -t ${LENGTH} -pass 1 -c:v libvpx -b:v ${bitrate}K -vf scale=${RESOLUTION}:-1 -an -sn -f webm /dev/null && \
ffmpeg -ss ${OFFSET} -i ${VIDEO_PATH} -t ${LENGTH} -pass 2 -c:v libvpx -b:v ${bitrate}K -vf scale=${RESOLUTION}:-1 -an -sn -c:a libvorbis ${OUTPUT_PATH}/${OUTPUT_NAME}-out.webm