shrug-add

#!/bin/dash

root_folder='.shrug'

if [ ! -d $root_folder ]; then
    echo 'shrug-add: error: no .shrug directory containing shrug repository exists'
    exit 1
else
    touch "$root_folder/.git/index"

    for i in $@
    do
        # check if all files in argv are exist, if not, would exit
        # instead of adding first few exist files then found one file behind not exist and exit which would cause workstream conflict
        if [ ! -f "$i" ]; then
            flag=`cat .shrug/.git/index | egrep " $i$"`
            if [ "$flag" = '' ]; then
                echo "shrug-add: error: can not open '$i'"
                exit 1
            else 
                sed -i -e "/$flag/d" ".shrug/.git/index" > /dev/null
            fi
        fi
    done

    for filename in $@
    do
        # if not exit above
        # use sha1sum with the mix of filename and content for filename generation to keep filename unique and avoid ambiguity
        if [ -f "$filename" ]; then
            sha1sum_content=`cat $filename`
            filename_sha1sum=`echo $filename$sha1sum_content | sha1sum | cut -d' ' -f1`
            if [ ! -e "$root_folder/.git/objects/$filename_sha1sum" ]; then
                cp -n $filename "$root_folder/.git/objects/$filename_sha1sum"
            fi
            
            # then keep the sha1sum result(staged filename) and original filename in index file
            r=`cat "$root_folder/.git/index" | egrep " $filename"`
            if [ -z "$r" ]; then
                echo "$filename_sha1sum $filename" >> "$root_folder/.git/index"
            else
                sed -i -e "s/$r/$filename_sha1sum $filename/g" "$root_folder/.git/index"
            fi
        fi
    done
fi