#!/bin/bash

checkcommand()
{
    local result
    local command="$1"
    which "$command" 1>/dev/null 2>&1
    if [[ $? == 0 ]]; then
        echo "$command requirement OK"
        result=1
    else
        echo "$command requirement MISSING"
        result=0
    fi
    return $result
}

help()
{
    echo "Usage:"
    echo "    tphoto -h              Display help."
    echo "    tphoto                 Rename jpg files from current directory with Exif datetime."
    echo "    tphoto *.jpg           Rename files in parameter with Exif datetime."
    echo "    tphoto -f              Rename jpg files from current directory with Exif datetime or file datetime."
    echo "    tphoto -f *.jpg        Rename files in parameter with Exif datetime or file datetime."
}

renameFromDirectoryWithExifOnly()
{
    find . -maxdepth 1 -type f -iname "*.jpg" | while read path
    do
        filename=$(basename $path)
        #echo "$filename"
        if [[ $(jhead $filename | grep -c Date) == 1 ]]; then
            #echo "yop $filename"
            jhead -n%Y%m%d-%H%M%S "$filename"
        else
            echo "$filename IGNORED"
        fi
    done
}

renameFromDirectory()
{
    find . -maxdepth 1 -type f -iname "*.jpg" | while read path
    do
        filename=$(basename $path)
        #echo "$filename"
        jhead -n%Y%m%d-%H%M%S "$filename"
    done
}


# main
if [[ $# == 0 ]]; then
    renameFromDirectoryWithExifOnly
elif [[ "$1" == "-h" ]]; then
    help
elif [[ "$1" == "-f" && $# == 1 ]]; then
    renameFromDirectory
elif [[ "$1" == "-f" && $# > 1 ]]; then
    for filename do
        if [[ "$filename" != "-f" ]]; then
            #echo "$filename"
            jhead -n%Y%m%d-%H%M%S "$filename"
        fi
    done
else
    for filename do
        #echo "$filename"
        if [[ $(jhead $filename | grep -c Date) == 1 ]]; then
            #echo "yop $filename"
            jhead -n%Y%m%d-%H%M%S "$filename"
        else
            echo "$filename IGNORED"
        fi
    done
fi