#!/bin/bash

###########################
######  "CONSTANTS"  ######
###########################

DOWNLOAD_DIR=/tmp/KozConfigurator         # Temporary folder for distributives and archives.
INSTALLATION_DIR=/opt/KozConfigurator     # Big programs will be moved here.
BIN_DIR=/usr/local/bin                    # Small programs will be moved here, and symlinks will be created here to big ones.
SHORTCUT_DIR=/usr/share/applications      # Here will be created .desktop files for some programs.

HELP_MESSAGE="
########################################################
#################  kjbupdater v0.1.0  ##################
###  This script is a part of KozConfigurator v0.4.0 ###
########################################################
#########  Leonid Kozarin <kozalo@nekochan.ru  #########
#########  License: MIT                        #########
#########  (c) Copyright Kozalo.Ru, 2018       #########
########################################################

Installation script for products of JetBrains. Use it to install or update their
awesome IDEs!

Basic usage:
    kjbupdater <name of program*> <code of distributive**> [categories for .desktop files***]

    * Actually, it MUST be the same as an executable file! For IntelliJ IDEA,
    for example, it can be 'IDEA', 'Idea', 'idea', but not 'IntelliJ IDEA'.
    ** JetBrains uses a convenient downloading system to get links for the
    latest software using a special code for every product. See
    https://jetbrains.com for them.
    *** 'Development;IDE;' by default.

Shortcuts:
    The script has some IDE names and codes predefined:
        - clion
        - idea
        - idea-community
        - pycharm
        - pycharm-community
        - rubymine
        - phpstorm
        - webstorm
        - datagrip

    So, you may just type, for example:
        kjbupdater -n idea

Deletion:
    kjbupdater -d <name of program>

Pitfalls:
    It's not possible to use this script for managing different installations of
    one type of IDE. By type I mean different editions of IDE for one
    programming laguage. Thus, you cannot install both IntelliJ IDEA Ultimate
    and IntelliJ IDEA Community Edition.
"


################################
######  HELPER FUNCTIONS  ######
################################

# Downloads a file to the special folder we discussed above and changes the working directory to this folder.
# Usage: fetch_dist <name for the file> <link>
# Depends on: $DOWNLOAD_DIR.
function fetch_dist {
    mkdir -p "$DOWNLOAD_DIR/$1"
    cd "$DOWNLOAD_DIR/$1"
    wget -O "$1" "$2"
}

# Creates a .desktop file to let the user run programs via the desktop environment.
# Usage: make_shortcut <path or name of executable file> <name of program> <category (-ies) of program> [path to icon*]
# * If it's not set, "applications-other" is used instead.
# Depends on: $SHORTCUT_DIR.
function make_shortcut {
    if [[ -n "$4" ]]; then
        local ICON_PATH="$4"
    else
        local ICON_PATH="applications-other"
    fi

    local DESKTOP_FILE="
[Desktop Entry]
Encoding=UTF-8
Type=Application
Terminal=false
Categories=$3
Exec=$1
Name=$2
Icon=$ICON_PATH
"

    echo "$DESKTOP_FILE" | sudo tee "$SHORTCUT_DIR/$2.desktop" > /dev/null
}

# Used to let the user change the list of software interactively.
# Usage: confirm <name of variable> <message>
function confirm {
    read -p "$2" mode
    case "$mode" in
        [Yy]* ) eval $1=true;;
        [Nn]* ) eval $1=false;;
        *) echo "Skipped! It's still set to ${!1}."
    esac
}


# As the name of this function says, it's used to check if some program installed or not.
# Usage: check_not_installed <program>
# Returns:
#   0 (true)  - if a checked program is not installed yet;
#   1 (false) - if the program is already installed.
function check_not_installed {
    if hash "$1" 2>/dev/null; then
        return 1
    else
        return 0
    fi
}

function uninstall_jetbrains_ide {
    local LINK=$(which "$1")
    local APP=$(readlink "$LINK")
    local DIR=$(dirname "$APP")

    if [[ $(dirname "$DIR") != "$INSTALLATION_DIR" ]]; then
        echo "Installation directory test failed!"
        return 1
    fi

    rm -rf "$DIR"
    rm -f "$SHORTCUT_DIR/$1.desktop" "$LINK"
    rm "$LINK"

    return 0
}

# Used to install all programs made by JetBrains with only one line of code.
# Usage: install_jetbrains_ide <name of program*> <code of distributive**> <categories for .desktop files>
# * Actually, it MUST be the same as an executable file! For IntelliJ IDEA, for example, it can be "IDEA", "Idea", "idea", but not "IntelliJ IDEA".
# ** JetBrains uses a convenient downloading system to get links for the latest software using a special code for every product. See https://jetbrains.com for them.
# Depends on: fetch_dist, make_shortcut, check_not_installed, $INSTALLATION_DIR, $BIN_DIR.
function install_jetbrains_ide {
    local BIN_NAME=$(echo "$1" | awk '{print tolower($0)}')
    local EXEC_FILENAME="$BIN_NAME.sh"

    if ! check_not_installed "$BIN_NAME"; then
        UPDATE_CONFIRMATION=true
        confirm UPDATE_CONFIRMATION "This program is already installed. Do you want to update it? (Y/n)"
        
        if [[ "$UPDATE_CONFIRMATION" == true ]]; then
            if ! uninstall_jetbrains_ide "$BIN_NAME"; then
                return 2
            fi
        else
            return 1
        fi
    fi

    fetch_dist "$1" "http://data.services.jetbrains.com/products/download?code=$2&platform=linux"
    tar -zxvf "$1"
    rm "$1"
    local DIRNAME=$(ls)
    mkdir -p "$INSTALLATION_DIR/$BIN_NAME"
    rm -rf "$INSTALLATION_DIR/$BIN_NAME/*"
    mv "$DIRNAME"/* "$INSTALLATION_DIR/$BIN_NAME/"
    rmdir "$DIRNAME"

    sudo ln -sf "$INSTALLATION_DIR/$BIN_NAME/bin/$EXEC_FILENAME" "$BIN_DIR/$BIN_NAME"
    make_shortcut "$BIN_NAME" "$1" "${3:-'Development;IDE;'}" "$INSTALLATION_DIR/$BIN_NAME/bin/$BIN_NAME.png"
}


############################
######  MAIN SECTION  ######
############################

if [[ ("$1" == *delete || "$1" == "-d") && -n "$2" ]]; then
    uninstall_jetbrains_ide "$2"
elif [[ ("$1" == *name || "$1" == "-n") && -n "$2" ]]; then
    NAME=$(echo "$2" | awk '{print tolower($0)}')
    case "$NAME" in
        clion) install_jetbrains_ide clion CL;;
        idea) install_jetbrains_ide idea IIU;;
        idea-community) install_jetbrains_ide idea IIC;;
        pycharm) install_jetbrains_ide pycharm PCP;;
        pycharm-community) install_jetbrains_ide pycharm PCC;;
        rubymine) install_jetbrains_ide rubymine RM;;
        phpstorm) install_jetbrains_ide phpstorm PS;;
        webstorm) install_jetbrains_ide webstorm WS;;
        datagrip) install_jetbrains_ide datagrip DG 'Development;';;
    esac
elif [[ -n "$2" ]]; then
    install_jetbrains_ide "$1" "$2" "$3"
else
    echo "$HELP_MESSAGE"
fi