Recover timestamp for images taken out from Google photos

recover_timestamp.fish

function change_ts
    set json $argv[1]
    set img $argv[2]
    set ts_epoch (jq '.photoTakenTime.timestamp' $json | grep --only-matching "[0-9]\+")
    set title (jq '.title' $json | sed 's/^"\(.*\)"$/\1/')
    set ts_fmt (date --utc --date=@$ts_epoch)
    cp $img "../out/$title"
    touch --date="$ts_fmt" "../out/$title"
end

# Under Google Photos directory
set json_list (ls */*.json)
set img_list (ls */* | grep -v json)
set i 0
set len (ls */*.json | wc -l)

while [ $i -lt $len ]
    change_ts $json_list[$i] $img_list[$i]
    set i (expr $i + 1)
end