#!/bin/bash
#
# develop_brew_cask
#
# Called via symlink as:
#  production_brew_cask
#

called_as="$(basename $0)"

###
### settings
###

set -e               # exit on any uncaught error
set +o histexpand    # don't expand history expressions
shopt -s nocasematch # case-insensitive regular expressions

###
### configurable global variables
###

tap_subdir="Library/Taps/caskroom/homebrew-cask"

###
### functions
###

warn () {
    local message="$@"
    message="${message//\\t/$'\011'}"
    message="${message//\\n/$'\012'}"
    message="${message%"${message##*[![:space:]]}"}"
    printf "%s\n" "$message" 1>&2
}

die () {
    warn "$@"
    exit 1
}

cd_to_project_root () {
    local script_dir="$(/usr/bin/dirname "$0")"
    cd "$script_dir"
    local git_root="$(git rev-parse --show-toplevel)"
    if [[ -z "$git_root" ]]; then
        die "ERROR: Could not find git project root"
    fi
    cd "$git_root"
}

cd_to_version_dir () {
    local cellar_dir="$1"
    local version_dir="$2"
    if [[ -z "$version_dir" ]]; then
        die "ERROR: Could not find version dir under $cellar_dir/"
    fi
    cd "$cellar_dir/$version_dir"
}

not_inside_homebrew () {
    local tap_dir="$1"
    local git_root="$2"
    if [[ "$(/usr/bin/stat -L -f '%i' -- "$tap_dir")" -eq "$(/usr/bin/stat -L -f '%i' -- "$git_root")" ]]; then
        die "\nERROR: Run this script in your private repo, not inside Homebrew.\n"
    fi
}

remove_dev_links () {
    local tap_dir="$1"
    /bin/rm -- rubylib Casks
    /bin/mv -- production_rubylib rubylib
    /bin/mv -- production_Casks   Casks
    cd "$tap_dir"
    /bin/rm -- lib Casks
    /bin/mv -- production_lib   lib
    /bin/mv -- production_Casks Casks
    printf "brew-cask is now in production mode\n"
    printf "It is safe to run 'brew update' if you are in production mode for all Caskroom repos.\n"
}

create_dev_links () {
    local tap_dir="$1"
    local git_root="$2"
    /bin/mv -- rubylib production_rubylib
    /bin/mv -- Casks   production_Casks
    /bin/ln -s -- "$git_root/Casks" .
    /bin/ln -s -- "$git_root/lib"   rubylib
    cd "$tap_dir"
    /bin/mv -- lib   production_lib
    /bin/mv -- Casks production_Casks
    /bin/ln -s -- "$git_root/Casks" .
    /bin/ln -s -- "$git_root/lib"   .
    printf "brew-cask is now in development mode\n"
    printf "Note: it is not safe to run 'brew update' while in development mode\n"
}

###
### main
###

_develop_brew_cask_develop_action () {
    die "brew-cask is already set up for development"
}

_develop_brew_cask_production_action () {
    create_dev_links "$tap_dir" "$git_root"
}

_production_brew_cask_develop_action () {
    remove_dev_links "$tap_dir"
}

_production_brew_cask_production_action () {
    die "brew-cask is already set up for production"
}

_main () {

    # initialization
    cd_to_project_root
    local git_root="$(/bin/pwd)"
    local brew_prefix="$(brew --prefix)"
    local cellar_dir="$brew_prefix/Cellar/brew-cask"
    local version_dir="$(/bin/ls -- "$cellar_dir/" | /usr/bin/sort | /usr/bin/tail -1)"
    local tap_dir="$brew_prefix/$tap_subdir"

    # sanity check
    not_inside_homebrew "$tap_dir" "$git_root"

    # action
    cd_to_version_dir "$cellar_dir" "$version_dir"
    if [[ -e "production_rubylib" ]]; then
        eval "_${called_as}_develop_action"
    else
        eval "_${called_as}_production_action"
    fi

}

_develop_brew_cask_usage () {

    printf "develop_brew_cask

Symlink private repo directories into Homebrew's Cellar, so
that the 'brew cask' command will use code and Casks from
the current development branch in your private repo.

Saves the production Homebrew directories under new names.

You can reverse this operation with 'production_brew_cask'.

Note: it is not safe to run 'brew update' while development
mode is in effect.

"

}

_production_brew_cask_usage () {

    printf "production_brew_cask

Undo all symlinks created by 'develop_brew_cask' so that the
'brew cask' command will use only released code and Casks
within Homebrew.

After running this command it is safe to run 'brew update',
unless you are using similar scripts to create symlinks into
other Caskroom development repos.

"

}

# ensure we're called by a valid name
case "${called_as}" in
    develop_brew_cask) ;;
    production_brew_cask) ;;
    *)
        die "ERROR: name ${called_as} not recognized"
        ;;
esac


# process args
if [[ $1 =~ ^-+h(elp)?$ ]]; then
    eval "_${called_as}_usage"
    exit
fi

# dispatch main
_main "${@}"

#