#!/bin/bash

# Parse options

while [ $# -gt 0 ]; do
    opt=$1
    case $opt in
        # General options
        -i|--infile)
            infile=$2
            shift 2 ;;
        -o|--outfile)
            outfile=$2
            shift 2 ;;
        -t|--text)
            text=$2
            shift 2 ;;
        -w|--width)
            width=$2
            shift 2 ;;
        # Video options
        # Audio options
        # Text options
        --font)
            fontname=$2
            shift 2 ;;
        --color)
            textcolor=$2
            shift 2 ;;
        *)
            echo "Unknown option: $opt"
            exit 1 ;;
    esac
done

# Check options

if [ -z "$infile" ]; then
    echo "Input file is not specified. use -i option."
    exit 1
fi

if [ ! -f "$infile" ]; then
    echo "Input file '"$infile"' is not found"
    exit 1
fi

if [ -z "$outfile" ]; then
    outfile="$infile.mkv"
    echo "Output file name is not specified. '"$outfile"' will be used"
fi

if [ -z "$text" ]; then
    text="forumsmotri.com"
    echo "Watermark text is not specified. '"$text"' will be used"
fi

# Generate watermark

videowidth=$(ffprobe -hide_banner -v quiet -of default=noprint_wrappers=1 -sexagesimal -select_streams v:0 -show_entries stream=width -i "$infile")
eval "$videowidth"
videowidth=$width
echo "Video width = $videowidth"

wmwidth=$(bc <<< "$videowidth/2")
wmfile="$text.png"
convert -alpha on -background transparent -fill "rgba(255,255,255,0.1)" -strokewidth 2 -stroke "rgba(0,0,0,0.1)" -font Purisa -size ${wmwidth}x label:"$text" "$wmfile"
wmheight=$(identify -ping '%n' "$wmfile")


# Convert video

ffmpeg -hide_banner -i "$infile" -i "$wmfile" \
    -filter_complex "overlay='if(gte(t,1), -w+(mod(t,($videowidth+$wmwidth)/60))*60, NAN)':y='(sin(t)*(main_h-overlay_h))/2+(main_h-overlay_h)/2'" \
    "$outfile"