.venv

# (c) 2013 Mike Wadsten. http://github.com/mikewadsten

# Bash wrapper around Python virtualenv functionality.
# Allow for easy activation of virtualenv with command 'venv'
# (includes tab autocompletion!). Also includes the 'mkenv'
# command to easily create a new virtual environment within
# the ENVS_DIR location specified, and 'rmenv' to delete
# virtual environments.

ENVS_DIR=~/.envs

# Handles autocompletion of virtual environment names
_venv() {
    local cur envs

    cur=${COMP_WORDS[COMP_CWORD]}
    envs=$(\ls $ENVS_DIR)

    COMPREPLY=( $( compgen -W "$envs" -- $cur ))

    return 0
}

venv() {
    # Check argument count
    if [ "$#" == "0" ]; then
        echo "usage: $FUNCNAME <environment name>"
        return 1
    fi

    local env envdir env_activate
    env="$1"
    envdir=$ENVS_DIR/$env
    env_activate=$envdir/bin/activate

    # Enter the Matrix
    if [ -d "$envdir" ] ; then
        if [ -f "$env_activate" ] ; then
            source "$env_activate"
        else
            echo "Can't find activate script for virtual environment '$env'"
        fi
    else
        echo "There is no virtual environment '$env'"
    fi
}

mkenv() {
    # Check argument count
    if [ "$#" == "0" ]; then
        echo "usage: $FUNCNAME <new environment name>"
        return 1
    fi

    local dir env
    env="$1"
    dir=$ENVS_DIR/$env

    # Environments starting with . interfere with my cunning plan to prevent deleting directories
    # outside of $ENVS_DIR (or that directory itself) by stopping rmenv if the environment name
    # given starts with .
    case "$env" in
        "."* )
            echo "Please don't try to make environments starting with '.', I could get confused..."
            return 1;;
        *".."* )
            echo "Please don't make environments containing '..', that's just weird!"
            return 1;;
        *"/"* )  # Doesn't mess with the filesystem, just might get weird...
            echo "No slashes, please. ($1)"
            return 1;;
        *"\\"* )  # Doesn't mess with the filesystem, just might get weird...
            echo "No slashes, please. ($1)"
            return 1;;
        *" "* )  # Would make it so you have to wrap arguments in quotes
            echo "No spaces in environment name, please. ($1)"
            return 1;;
    esac

    if [ -d "$dir" ]; then  # already exists
        echo "There is already a virtual environment '$1'"
        return 1
    else
        virtualenv "$dir"
    fi
}

rmenv() {
    # Check argument count
    if [ "$#" == "0" ]; then
        echo "usage: $FUNCNAME <environment name>"
        return 1
    fi

    local dir env
    env="$1"
    dir=$ENVS_DIR/$env

    if [ -d "$dir" ]; then
        case "$env" in
            "."* )
                echo "The given environment ($1) starts with . -- I don't like that."
                return 1;;
            *".."* )
                echo "Looks like you're trying to mess with me ($1) -- son, just don't."
                return 1;;
        esac
        # The virtual environment dir does exist
        read -p "Are you sure you want to delete virtual environment '$1'? (y/n) " -n 1 -r
        echo  # Newline for some spacing
        echo  # Another one for good measure
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            # See if we are already inside the environment
            case $PS1 in
                "($1)"*)
                    echo "Calling $FUNCNAME on active virtual environment! Deactivating..."
                    deactivate
                    # Presumably the virtual environment exists anyway...
                    # Check we're not inside of it
                    case "$(pwd)" in
                        "$dir"* )
                            echo "You're physically inside the environment right now! Leaving it..."
                            builtin cd ~ ;;
                        *) ;;
                    esac ;;
                *) ;;
            esac

            rm "$dir" -rf
            echo "Deleted virtual environment '$1'"
        else
            echo "Never mind then!"
        fi
    else
        echo "There is no virtual environment '$1'"
    fi
}

activate() {
    venv $@
}

complete -F _venv -o nospace venv
complete -F _venv -o nospace rmenv
complete -F _venv -o nospace activate