#!/bin/bash
# Simple Note System - Install Script
#    Copyright (C) 2016, Jon Lewis
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License along
#    with this program; if not, write to the Free Software Foundation, Inc.,
#    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# Color codes for messages
readonly RED_COLOR='\033[1;31m'
readonly YELLOW_COLOR='\033[1;33m'
readonly BLUE_COLOR='\033[1;34m'
readonly RESET_COLOR='\033[0m'


# Set variables for header
PROD_STR="Simple Note System"
PROD_SUB="Install Script"
# Set default build directory if none specified
if [ ! -d "$BUILD_ROOT" ]; then BUILD_ROOT="build"; fi

# Set default install prefix according to platform
if [ -z "$INSTALL_DIR" ]; then
    case "$(uname)" in
        "Darwin" )
            INSTALL_ROOT=/usr/local/opt
            ;;
        *)
            INSTALL_ROOT=/opt
            ;;
    esac
    INSTALL_DIR="$INSTALL_ROOT/sns"
fi

function sns_out {
    # Compile SNS from source files and print the resulting script to stdout
    cat ./src/header.src.sh
    printf "%s\n" "# Section: Functions"
    awk 'NR>=17' ./src/libEncryption.src.sh
    awk 'NR>=17' ./src/libStore.src.sh
    awk 'NR>=17' ./src/libSNS.src.sh
    printf "%s\n" "# End Section: Functions"
    awk 'NR>=17' ./src/sns.src.sh
}
function clean {
    if [ -d "$BUILD_ROOT" ]; then rm -rf "$BUILD_ROOT"; fi
}
function build_sns {
    clean
    if [ ! -d ."$BUILD_ROOT" ]; then mkdir $BUILD_ROOT; fi
    sns_out > "$BUILD_ROOT/sns"
    chmod +x "$BUILD_ROOT/sns"
    cp -f ./src/bash-completion.src.sh ./build/bash-completion
}

function check_install_dir_perms {
    STATS=( $(stat -c "%a %u %g" "$INSTALL_ROOT"))
    O=$(echo "${STATS[1]}" | cut -c 1)
    G=$(echo "${STATS[1]}" | cut -c 2)
    E=$(echo "${STATS[1]}" | cut -c 3)

    USER=$(id -u)
    GROUP=$(id -g)

    if    [ "${STATS[2]}" == "$USER"  ] && [ "$O" == "7" ]; then WRITE="1";
    elif  [ "${STATS[3]}" == "$GROUP" ] && [ "$G" == "7" ]; then WRITE="1";
    elif                                    [ "$E" == "7" ]; then WRITE="1";
    else                                                          WRITE="0";
    fi

    if [ "$(id -u)" == "0" ]; then WRITE=1; fi
}
function install_sns {
    # Make sure we can write to "$INSTALL_DIR"
    check_install_dir_perms
    if [ "$WRITE" == "0" ]; then
        printf "$RED_COLOR!$RESET_COLOR - %s %s\n"\
            "Superuser permissions required to install to" "$INSTALL_DIR."
        printf "$YELLOW_COLOR!$RESET_COLOR - %s\n"\
            "Will use sudo as necessary."
        USE_SUDO="sudo"
    else
        USE_SUDO=""
    fi
    # Prepare target environment
    "$USE_SUDO" mkdir -p "$INSTALL_DIR"
    "$USE_SUDO" mkdir -p "$INSTALL_DIR/bin"
    "$USE_SUDO" mkdir -p "$INSTALL_DIR/etc/bash-completion.d"

    # Install files from "$BUILD_ROOT" to "$INSTALL_DIR"
    "$USE_SUDO" install -m 0755 "$BUILD_ROOT/sns"             "$INSTALL_DIR/bin/sns"
    "$USE_SUDO" install -m 0644 "$BUILD_ROOT/bash-completion" "$INSTALL_DIR/etc/bash-completion.d/sns"
}

function verify {
    if [ ! -r "$INSTALL_DIR/bin/sns" ]; then
        printf "$RED_COLOR!$RESET_COLOR - %s\n"\
            "could not write to $INSTALL_DIR/bin/sns"
        exit 15
    else
        printf "$YELLOW_COLOR*$RESET_COLOR - %s $BLUE_COLOR%s$RESET_COLOR\n"\
            "Simple Note System was installed to" "$INSTALL_DIR/bin/sns."
        SNS_INSTALLED=1
    fi

    if [ ! -r "$INSTALL_DIR/etc/bash-completion.d/sns" ]; then
        printf "$RED_COLOR!$RESET_COLOR - %s\n"\
            "could not write to $INSTALL_DIR/etc/bash-completion.d/sns"
        exit 15
    else
        printf "$YELLOW_COLOR*$RESET_COLOR - %s $BLUE_COLOR%s$RESET_COLOR\n"\
            "Bash completion was installed to" "$INSTALL_DIR/etc/bash-completion.d/sns."
    fi

    DEFAULT_SNS="$(which sns 2>/dev/null)"
    if [ -n "$DEFAULT_SNS" ] && [ "$DEFAULT_SNS" != "$INSTALL_DIR/bin/sns" ]; then
        printf "$RED_COLOR!$RESET_COLOR - %s %s %s\n"\
            "Another installation of sns"\
            "($DEFAULT_SNS)"\
            "was detected."
    fi
    if [ -z "$DEFAULT_SNS" ]; then
        printf "\n$YELLOW_COLOR*$RESET_COLOR - %s\n\t$YELLOW_COLOR%s\n$RESET_COLOR    %s\n\n"\
            "sns was not found in PATH. Please add"\
            "export PATH=$INSTALL_DIR/bin:\$PATH"\
            "  to your ~/.bashrc or ~/.bash_profile"
    fi
    if grep "source $INSTALL_DIR/etc/bash-completion.d/sns" < "$BASH_SETTINGS" > /dev/null; then
        SNS_BASH_COMPLETION=1;
    else
        SNS_BASH_COMPLETION=0;
    fi

    if [ "$SNS_BASH_COMPLETION" != "1" ]; then
        printf "\n$YELLOW_COLOR*$RESET_COLOR - %s\n\t$YELLOW_COLOR%s\n$RESET_COLOR    %s\n\n"\
            "To enable bash completion, add"\
            "source $INSTALL_DIR/etc/bash-completion.d/sns"\
            "  to your ~/.bashrc or ~/.bash_profile"
    else
        printf "$YELLOW_COLOR*$RESET_COLOR - %s\n"\
            "Bash completion already enabled."
    fi

    if [ "$SNS_INSTALLED" == "1" ]; then
        printf "$YELLOW_COLOR*$RESET_COLOR - %s $BLUE_COLOR%s$RESET_COLOR %s\n"\
            "Installation succeeded. You should run" "sns -i" "now."
    fi
}

function print_help {
    printf "  %s" "usage: ./install [bchiu]"
    printf "\n%s" "  -b | --build-only : build, but do not install sns"
    printf "\n%s" "  -c | --clean      : clean build directory"
    printf "\n%s" "  -h | --help       : Print this information"
    printf "\n%s" "  -i | --install    : build and install sns"
    printf "\n%s" "  -u | --uninstall  : remove sns from the system (will not remove notes)"
    printf "\n\n%s" "Run Variables:"
    printf "\n  %s  %s" "BUILD_DIR=  " "Directory to build SNS in"
    printf "\n  %s  %s" "INSTALL_DIR=" "Directory to install SNS to"
    printf "\n\n"
}

# Sanity check
if [ -z "$INSTALL_DIR" ]; then
    printf "$RED_COLOR!$RESET_COLOR - %s\n"\
        "Failed to guess optimal install directory please specify with INSTALL_DIR=\n"
    exit 10
fi
if [ -r "$HOME"/.bashrc ]; then
    BASH_SETTINGS="$HOME/.bashrc"
elif [ -r "$HOME"/.bash_profile ]; then
    BASH_SETTINGS="$HOME/.bash_profile"
else
    printf "$RED_COLOR!$RESET_COLOR - %s\n"\
           "Failed to determine bash settings file (e.g. ~/.bashrc)"
    exit 13
fi

# Print header
printf "\n %s\n"     "$PROD_STR"
printf "   %s\n"     "$PROD_SUB"
printf "%s\n\n"      "--------------------"
# Argument Parsing
for ARG in "$@"; do
    case "$ARG" in
        -b|--build-only)
            build_sns
            printf "\n"
            exit
            ;;
        -c|--clean)
            clean
            exit
            ;;
        -u|--uninstall)
            check_install_dir_perms
            if [ "$WRITE" == "1" ]; then
                rm -rf "$INSTALL_DIR"
            else
                sudo rm -rf "$INSTALL_DIR"
            fi
            exit
            ;;
        -i|--install)
            build_sns
            install_sns
            verify
            printf "\n"
            exit
            ;;
        -h|--help)
            print_help
            exit
            ;;
    esac
done

print_help
exit