git-ff

#!/usr/bin/env bash

# setup color
# msysgit has no tput, I am looking for getting color codes for mingw32 env
if [ `expr "$(uname)" : "MING"` = 0 ]; then
    underline=$(tput sgr 0 1)
    bold=$(tput bold)
    black=$(tput setaf 0)
    red=$(tput setaf 1)
    green=$(tput setaf 2)
    yellow=$(tput setaf 3)
    blue=$(tput setaf 4)
    magenta=$(tput setaf 5)
    cyan=$(tput setaf 6)
    white=$(tput setaf 7)
    normal=$(tput sgr0)
fi

usage(){
    echo "git ff [remote]"
}

shas_store=""

shas() {
    local key=$1
    local value=$2

    if [ "$value" != "" ]; then
        shas_store="$shas_store $value:$key"
    else
        for pair in $shas_store; do
            local pair_key=${pair##*:}
            local pair_value=${pair%%:*}

            if [ "$pair_key" = "$key" ]; then
                echo $pair_value
                break
            fi
        done
    fi
}

init(){
    local remote=$1
    local pairs=`git show-ref | grep refs/remotes/$remote`
    local pairs=${pairs// /:}

    for pair in $pairs; do
        shas_store="$shas_store $pair"
    done
}

log(){
    echo "$@"
}

is_force_updated(){
    local full_ref=$1
    local fetched=$(shas $full_ref)

    if [ "$fetched" != "" ]; then
        local forced=`echo $(git rev-list $full_ref..$before_fetched | wc -l)`

        if [ "$forced" != "0" ]; then
            echo "0"
        fi
    fi

    echo "-1";
}

is_mergable() {
    local full_ref=$1
    local full_local_ref=$2

    #check for mergable
    local has_merge_base=`git merge-base $full_ref $full_local_ref >> /dev/null; echo $?`

    echo "$has_merge_base"
}

git_ff(){
    local full_ref=$1
    local ref=$2
    local local_ref=$3
    local full_local_ref=$4

    local head="[pass]"
    local body=""
    local distance=''

    body="$cyan$full_ref$normal"
    #has local branch?
    local has_local_ref=`git show-ref --verify --quiet $full_local_ref; echo $?`

    if [ "$has_local_ref" != "0" ]; then
        body="$body: has no local branch"
        continue;
    elif [ "$(is_force_updated $full_ref)" == "0" ]; then
        head="$red[force-updated]"
    elif [ "$(is_mergable $full_ref $full_local_ref)" == "0" ]; then
        local ahead=`echo $(git rev-list $full_ref..$full_local_ref | wc -l)`
        local behind=`echo $(git rev-list $full_local_ref..$full_ref | wc -l)`

        #Remote branch changed
        distance=": $magenta[+$ahead][-$behind]"

        if [ "$behind" != "0" ]; then
            git checkout $local_ref
            if [ "$ahead" != "0" ]; then
                head="$red[rebase]"
                #rebase local changes
                #git rebase $full_ref
            else
                head="$yellow[merged]"
                #fast-forward merge, cos local branch has no changes
                git merge $full_ref
            fi
        fi
    fi

    echo "[ff]$head$body $distance$normal"

}

main() {
    local remote=$1

    if [ "$remote" = "" ]; then
        remote='origin'
    fi

    if [[ -n $(git status -s 2> /dev/null |grep -v ^# |grep -v "working directory clean") ]]; then
        echo "Checkouted branch is dirty!"
        exit 1;
    fi

    ## bakcup current branch.
    local current_branch=$(git symbolic-ref HEAD 2> /dev/null)

    init

    git config svn-remote.svn.url

    if [ "$remote" = "origin" ] && [ "`git config svn-remote.svn.url`" != "" ]; then
        git svn fetch

        git_ff "trunk" "trunk" "master" "refs/heads/master"
    else
        git fetch --prune $remote

        local branches=`git show-ref | awk '{print $2}' | grep $remote`

        for full_ref in $branches; do
            local ref=${full_ref#refs/remotes/}
            local local_ref=${full_ref#refs/remotes/$remote/}
            local full_local_ref="refs/heads/$local_ref"

            git_ff $full_ref $ref $local_ref $full_local_ref
        done
    fi

    ## restore current branch.
    local temp=$(git symbolic-ref HEAD 2> /dev/null)

    if [ "$current_branch" != "" ] && [ "$current_branch" != "temp" ]; then
        git checkout ${current_branch#refs/heads/}
    fi
}

main "$@"