#!/bin/bash

if [[ -z "$1"  || "$1" == --help || "$1" == "-?" ]]; then
    echo "Usage: mvimg_play MVIMG_20190806_183324.jpg [other files]"
    echo "Plays Google's Motion Photo using mpv. Depends on exiftool, mktemp, bash and mpv."
    exit 0
fi

FOUND=0
ARGS=()

TORM=()
TOKILL=()

function cleanup() {
    for i in "${TORM[@]}"; do
        rm -f "$i"
    done
    for p in ${TOKILL[@]}; do
        wait $p
    done
}

trap "cleanup" EXIT

for i in "$@"; do
    O=$(exiftool -t $i  | grep -F 'Micro Video Offset' | cut -f 2-2)
    if [[ -z "$O" ]]; then
        # wrong file? Just appending to playlist as is
        ARGS+=($i)
    else
        FOUND=1
        S=$(find $i -printf '%s')
        T=`mktemp`

        ARGS+=("$T")
        dd if="$i" skip=$((S-O)) iflag=skip_bytes of="$T" 2> /dev/null &
        TOKILL+=($!)
        TORM+=("$T")
    fi
done

if [[ $FOUND == 0 ]]; then
    echo "EXIF tag wasn't detected in specified files. Maybe exiftool does not work?" >&2
fi

mpv "${ARGS[@]}"