#!/bin/bash
#Script to install emacs 26 from the emacs mirror hosted in github

version="install_emacs_26.0.91"
url="https://github.com/emacs-mirror/emacs/archive/$version.tar.gz"
uninstall_flag=$1

function main {
    if [[ $uninstall_flag == "--uninstall" ]]; then
        uninstall_emacs
    else
        install_dependencies
        install_emacs
        install_success
    fi
}

function install_dependencies {
    sudo apt-get install build-essential \
         texinfo libx11-dev libxpm-dev libjpeg-dev libpng-dev \
         libgif-dev libtiff-dev libgtk2.0-dev libncurses-dev \
         autoconf automake
}

function install_emacs {
    echo "Go $HOME"
    cd $HOME

    echo "Creating the emacs folder..."
    mkdir emacs

    echo "Go to the created emacs folder..."
    cd $HOME/emacs

    echo "Invoque and untar from the mirror hosted in github"
    curl -L $url | tar zx

    echo "Go to to emacs-$version folder"
    cd "emacs-$version"

    echo "Executing the autogen.sh"
    ./autogen.sh

    echo "Executing the default settings"
    ./configure --with-gnutls=no

    echo "Making the installer"
    make

    echo "Execute the installer with superuser mode, "
    echo "basically the binary copy to the path /usr/local/bin"
    sudo make install

    echo "done!"
}

function uninstall_emacs {
    read -p "Are you sure to uninstall emacs? (y/n)" -n 1 -r
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        echo "Go to source folder"
        cd "$HOME/emacs/emacs-$version"
        echo "uninstalling..."
        sudo make uninstall
        cd $HOME
        sudo rm -fr "$HOME/emacs/emacs-$version"
        echo "done."
    else
        exit 1
    fi
}

function install_success {
    echo "emacs has been successfully installed :D"
    emacs --version
}

main