#!/bin/bash
#
# RaspAP installation functions.
# author: @billz
# license: GNU General Public License v3.0

raspap_dir="/etc/raspap"
raspap_user="www-data"
raspap_sudoers="/etc/sudoers.d/090_raspap"
raspap_dnsmasq="/etc/dnsmasq.d/090_raspap.conf"
raspap_sysctl="/etc/sysctl.d/90_raspap.conf"
webroot_dir="/var/www/html"
git_source_url="https://github.com/$repo"  # $repo from install.raspap.com

# Fetch details for various Linux distros
if type lsb_release >/dev/null 2>&1; then # linuxbase.org
    OS=$(lsb_release -si)
    RELEASE=$(lsb_release -sr)
    CODENAME=$(lsb_release -sc)
    DESC=$(lsb_release -sd)
elif [ -f /etc/os-release ]; then # freedesktop.org
    . /etc/os-release
    OS=$ID
    RELEASE=$VERSION_ID
    CODENAME=$VERSION_CODENAME
    DESC=$PRETTY_NAME
else
    install_error "Unsupported Linux distribution"
fi

# Set php package option based on Linux release version,
# abort if unsupported distro
case $RELEASE in
    "18.04") # Ubuntu 18.04 LTS
        php_package="php7.4-cgi"
        phpcgiconf="/etc/php/7.4/cgi/php.ini" ;;
    "10")
        php_package="php7.3-cgi"
        phpcgiconf="/etc/php/7.3/cgi/php.ini" ;;
    "9")
        php_package="php7.0-cgi"
        phpcgiconf="/etc/php/7.0/cgi/php.ini" ;;
    "8")
        install_error "${DESC} and php5 are not supported. Please upgrade." ;;
    *)
        install_error "${DESC} is unsupported. Please install on a supported distro." ;;
esac

### NOTE: all the below functions are overloadable for system-specific installs

# Prompts user to set options for installation
function config_installation() {
    install_log "Configure installation"
    echo "Detected OS: ${DESC}"
    echo "Using GitHub repository: ${repo} ${branch} branch"
    echo "Install directory: ${raspap_dir}"
    echo -n "Install to lighttpd root: ${webroot_dir}? [Y/n]: "
    if [ "$assume_yes" == 0 ]; then
        read answer < /dev/tty
        if [ "$answer" != "${answer#[Nn]}" ]; then
            read -e -p < /dev/tty "Enter alternate lighttpd directory: " -i "/var/www/html" webroot_dir
        fi
    else
        echo -e
    fi
    echo "Installing to lighttpd directory: ${webroot_dir}"
    echo -n "Complete installation with these values? [Y/n]: "
    if [ "$assume_yes" == 0 ]; then
        read answer < /dev/tty
        if [ "$answer" != "${answer#[Nn]}" ]; then
            echo "Installation aborted."
            exit 0
        fi
    else
        echo -e
    fi
}

# Runs a system software update to make sure we're using all fresh packages
function install_dependencies() {
    install_log "Installing required packages"
    if [ "$php_package" = "php7.4-cgi" ]; then
        echo "Adding apt-repository ppa:ondrej/php"
        sudo add-apt-repository ppa:ondrej/php || install_error "Unable to add-apt-repository ppa:ondrej/php"
    fi
    sudo apt-get install $apt_option lighttpd git hostapd dnsmasq $php_package $dhcpcd_package vnstat qrencode || install_error "Unable to install dependencies"
}

# Enables PHP for lighttpd and restarts service for settings to take effect
function enable_php_lighttpd() {
    install_log "Enabling PHP for lighttpd"

    sudo lighttpd-enable-mod fastcgi-php    
    sudo service lighttpd force-reload
    sudo systemctl restart lighttpd.service || install_error "Unable to restart lighttpd"
}

# Verifies existence and permissions of RaspAP directory
function create_raspap_directories() {
    install_log "Creating RaspAP directories"
    if [ -d "$raspap_dir" ]; then
        sudo mv $raspap_dir "$raspap_dir.`date +%F-%R`" || install_error "Unable to move old '$raspap_dir' out of the way"
    fi
    sudo mkdir -p "$raspap_dir" || install_error "Unable to create directory '$raspap_dir'"

    # Create a directory for existing file backups.
    sudo mkdir -p "$raspap_dir/backups"

    # Create a directory to store networking configs
    sudo mkdir -p "$raspap_dir/networking"
    # Copy existing dhcpcd.conf to use as base config
    cat /etc/dhcpcd.conf | sudo tee -a /etc/raspap/networking/defaults

    sudo chown -R $raspap_user:$raspap_user "$raspap_dir" || install_error "Unable to change file ownership for '$raspap_dir'"
}

# Generate hostapd logging and service control scripts
function create_hostapd_scripts() {
    install_log "Creating hostapd logging & control scripts"
    sudo mkdir $raspap_dir/hostapd || install_error "Unable to create directory '$raspap_dir/hostapd'"

    # Move logging shell scripts 
    sudo cp "$webroot_dir/installers/"*log.sh "$raspap_dir/hostapd" || install_error "Unable to move logging scripts"
    # Move service control shell scripts
    sudo cp "$webroot_dir/installers/"service*.sh "$raspap_dir/hostapd" || install_error "Unable to move service control scripts"
    # Make enablelog.sh and disablelog.sh not writable by www-data group.
    sudo chown -c root:"$raspap_user" "$raspap_dir/hostapd/"*.sh || install_error "Unable change owner and/or group"
    sudo chmod 750 "$raspap_dir/hostapd/"*.sh || install_error "Unable to change file permissions"
}

# Generate lighttpd service control scripts
function create_lighttpd_scripts() {
    install_log "Creating lighttpd control scripts"
    sudo mkdir $raspap_dir/lighttpd || install_error "Unable to create directory '$raspap_dir/lighttpd"

    # Move service control shell scripts
    sudo cp "$webroot_dir/installers/"configport.sh "$raspap_dir/lighttpd" || install_error "Unable to move service control scripts"
    # Make configport.sh writable by www-data group
    sudo chown -c root:"$raspap_user" "$raspap_dir/lighttpd/"*.sh || install_error "Unable change owner and/or group"
    sudo chmod 750 "$raspap_dir/lighttpd/"*.sh || install_error "Unable to change file permissions"
}

# Prompt to install openvpn
function prompt_install_openvpn() {
    install_log "Setting up OpenVPN support (beta)"
    echo -n "Install OpenVPN and enable client configuration? [Y/n]: "
    if [ "$assume_yes" == 0 ]; then
        read answer < /dev/tty
        if [ "$answer" != "${answer#[Nn]}" ]; then
            echo -e
        else
            install_openvpn
        fi
    elif [ "$ovpn_option" == 1 ]; then
        install_openvpn
    fi
}

# Install openvpn and enable client configuration option
function install_openvpn() {
    install_log "Installing OpenVPN and enabling client configuration"
    sudo apt-get install -y openvpn || install_error "Unable to install openvpn"
    sudo sed -i "s/\('RASPI_OPENVPN_ENABLED', \)false/\1true/g" "$webroot_dir/includes/config.php" || install_error "Unable to modify config.php"
    echo "Enabling openvpn-client service on boot"
    sudo systemctl enable openvpn-client@client || install_error "Unable to enable openvpn-client daemon"
    create_openvpn_scripts || install_error "Unable to create openvpn control scripts"
}

# Generate openvpn logging and auth control scripts
function create_openvpn_scripts() {
    install_log "Creating OpenVPN control scripts"
    sudo mkdir $raspap_dir/openvpn || install_error "Unable to create directory '$raspap_dir/openvpn'"

   # Move service auth control shell scripts
    sudo cp "$webroot_dir/installers/"configauth.sh "$raspap_dir/openvpn" || install_error "Unable to move auth control script"
    # Make configauth.sh writable by www-data group
    sudo chown -c root:"$raspap_user" "$raspap_dir/openvpn/"*.sh || install_error "Unable change owner and/or group"
    sudo chmod 750 "$raspap_dir/openvpn/"*.sh || install_error "Unable to change file permissions"
}

# Fetches latest files from github to webroot
function download_latest_files() {
    if [ ! -d "$webroot_dir" ]; then
        sudo mkdir -p $webroot_dir || install_error "Unable to create new webroot directory"
    fi

    if [ -d "$webroot_dir" ]; then
        sudo mv $webroot_dir "$webroot_dir.`date +%F-%R`" || install_error "Unable to remove old webroot directory"
    fi

    install_log "Cloning latest files from github"
    git clone --branch $branch --depth 1 $git_source_url /tmp/raspap-webgui || install_error "Unable to download files from github"

    sudo mv /tmp/raspap-webgui $webroot_dir || install_error "Unable to move raspap-webgui to web root"
}

# Sets files ownership in web root directory
function change_file_ownership() {
    if [ ! -d "$webroot_dir" ]; then
        install_error "Web root directory doesn't exist"
    fi

    install_log "Changing file ownership in web root directory"
    sudo chown -R $raspap_user:$raspap_user "$webroot_dir" || install_error "Unable to change file ownership for '$webroot_dir'"
}

# Check for existing configuration files
function check_for_old_configs() {
    if [ -f /etc/network/interfaces ]; then
        sudo cp /etc/network/interfaces "$raspap_dir/backups/interfaces.`date +%F-%R`"
        sudo ln -sf "$raspap_dir/backups/interfaces.`date +%F-%R`" "$raspap_dir/backups/interfaces"
    fi

    if [ -f /etc/hostapd/hostapd.conf ]; then
        sudo cp /etc/hostapd/hostapd.conf "$raspap_dir/backups/hostapd.conf.`date +%F-%R`"
        sudo ln -sf "$raspap_dir/backups/hostapd.conf.`date +%F-%R`" "$raspap_dir/backups/hostapd.conf"
    fi

    if [ -f $raspap_dnsmasq ]; then
        sudo cp $raspap_dnsmasq "$raspap_dir/backups/dnsmasq.conf.`date +%F-%R`"
        sudo ln -sf "$raspap_dir/backups/dnsmasq.conf.`date +%F-%R`" "$raspap_dir/backups/dnsmasq.conf"
    fi

    if [ -f /etc/dhcpcd.conf ]; then
        sudo cp /etc/dhcpcd.conf "$raspap_dir/backups/dhcpcd.conf.`date +%F-%R`"
        sudo ln -sf "$raspap_dir/backups/dhcpcd.conf.`date +%F-%R`" "$raspap_dir/backups/dhcpcd.conf"
    fi

    if [ -f $raspap_sysctl ]; then
        sudo cp $raspap_sysctl "$raspap_dir/backups/sysctl.d.`date +%F-%R`"
        sudo ln -sf "$raspap_dir/backups/sysctl.d.`date +%F-%R`" "$raspap_dir/backups/sysctl.d"
    fi

    for file in /etc/systemd/network/raspap-*.net*; do
        if [ -f "${file}" ]; then
            filename=$(basename $file)
            sudo cp "$file" "${raspap_dir}/backups/${filename}.`date +%F-%R`"
            sudo ln -sf "${raspap_dir}/backups/${filename}.`date +%F-%R`" "${raspap_dir}/backups/${filename}"
        fi
    done
}

# Move configuration file to the correct location
function move_config_file() {
    if [ ! -d "$raspap_dir" ]; then
        install_error "'$raspap_dir' directory doesn't exist"
    fi

    install_log "Moving configuration file to '$raspap_dir'"
    sudo cp "$webroot_dir"/raspap.php "$raspap_dir" || install_error "Unable to move files to '$raspap_dir'"
    sudo chown -R $raspap_user:$raspap_user "$raspap_dir" || install_error "Unable to change file ownership for '$raspap_dir'"
}

# Set up default configuration
function default_configuration() {
    install_log "Applying default configuration to installed services"
    if [ -f /etc/default/hostapd ]; then
        sudo mv /etc/default/hostapd /tmp/default_hostapd.old || install_error "Unable to remove old /etc/default/hostapd file"
    fi
    sudo cp $webroot_dir/config/default_hostapd /etc/default/hostapd || install_error "Unable to move hostapd defaults file"
    sudo cp $webroot_dir/config/hostapd.conf /etc/hostapd/hostapd.conf || install_error "Unable to move hostapd configuration file"
    sudo cp $webroot_dir/config/dnsmasq.conf $raspap_dnsmasq || install_error "Unable to move dnsmasq configuration file"
    sudo cp $webroot_dir/config/dhcpcd.conf /etc/dhcpcd.conf || install_error "Unable to move dhcpcd configuration file"

    [ -d /etc/dnsmasq.d ] || sudo mkdir /etc/dnsmasq.d

    sudo systemctl stop systemd-networkd
    sudo systemctl disable systemd-networkd
    sudo cp $webroot_dir/config/raspap-bridge-br0.netdev /etc/systemd/network/raspap-bridge-br0.netdev || install_error "Unable to move br0 netdev file"
    sudo cp $webroot_dir/config/raspap-br0-member-eth0.network /etc/systemd/network/raspap-br0-member-eth0.network || install_error "Unable to move br0 member file"

    if [ ! -f "$webroot_dir/includes/config.php" ]; then
        sudo cp "$webroot_dir/config/config.php" "$webroot_dir/includes/config.php"
    fi
}

# Install and enable RaspAP daemon
function enable_raspap_daemon() {
    install_log "Enabling RaspAP daemon"
    echo "Disable with: sudo systemctl disable raspap.service"
    sudo cp $webroot_dir/installers/raspap.service /etc/systemd/system/ || install_error "Unable to move raspap.service file"
    sudo systemctl daemon-reload
    sudo systemctl enable raspap.service || install_error "Failed to enable raspap.service"
}

# Configure IP forwarding, IP tables rules and RaspAP daemon
function configure_networking() {
    install_log "Configuring networking"
    # Enable IP forwarding in /etc/sysctl.d/90_raspap.conf
    if [ ! -f $raspap_sysctl ]; then
        echo "Enabling IP forwarding"
        sudo touch $raspap_sysctl || install_error "Unable to create ${raspap_sysctl}"
        echo "net.ipv4.ip_forward = 1" | sudo tee -a $raspap_sysctl || install_error "Unable to append to ${raspap_sysctl}"
        sudo sysctl -p $raspap_sysctl || install_error "Unable to load sysctl settings from file"
    fi

    echo "Enabling persistent IP tables rules"
    if [ ! -f "/etc/iptables.raspap.rules" ]; then
        sudo cp "$webroot_dir/installers/iptables.rules" /etc/iptables.raspap.rules || install_error "Unable to move iptables.rules"
    fi

    if [ ! -f "/etc/systemd/system/iptables.service" ]; then
        echo "Enabling iptables.service"
        sudo cp "$webroot_dir/installers/iptables.service" /etc/systemd/system/ || install_error "Unable to move iptables.service file"
        sudo update-alternatives --set iptables /usr/sbin/iptables-legacy || install_error "Unable to execute update-alternatives"
        sudo systemctl daemon-reload
        sudo systemctl enable iptables.service || install_error "Failed to enable iptables.service"
        sudo systemctl start iptables.service || install_error "Unable to start iptables.service"
    fi

    # Prompt to install RaspAP daemon
    echo -n "Enable RaspAP control service (Recommended)? [Y/n]: "
    if [ "$assume_yes" == 0 ]; then
        read answer < /dev/tty
        if [ "$answer" != "${answer#[Nn]}" ]; then
            echo -e
        else
            enable_raspap_daemon
        fi
    else
        echo -e
        enable_raspap_daemon
    fi
 }

# Add sudoers file to /etc/sudoers.d/ and set file permissions
function patch_system_files() {

    # Create sudoers if not present
    if [ ! -f $raspap_sudoers ]; then
        install_log "Adding raspap.sudoers to ${raspap_sudoers}"
        sudo cp "$webroot_dir/installers/raspap.sudoers" $raspap_sudoers || install_error "Unable to apply raspap.sudoers to $raspap_sudoers"
        sudo chmod 0440 $raspap_sudoers || install_error "Unable to change file permissions for $raspap_sudoers"
    fi

    # Add symlink to prevent wpa_cli cmds from breaking with multiple wlan interfaces
    install_log "Symlinked wpa_supplicant hooks for multiple wlan interfaces"
    if [ ! -f /usr/share/dhcpcd/hooks/10-wpa_supplicant ]; then
        sudo ln -s /usr/share/dhcpcd/hooks/10-wpa_supplicant /etc/dhcp/dhclient-enter-hooks.d/
    fi

    # Unmask and enable hostapd.service
    install_log "Unmasking and enabling hostapd service"
    sudo systemctl unmask hostapd.service
    sudo systemctl enable hostapd.service
}


# Optimize configuration of php-cgi.
function optimize_php() {
    install_log "Optimize PHP configuration"
    if [ ! -f "$phpcgiconf" ]; then
        install_warning "PHP configuration could not be found."
        return
    fi

    # Backup php.ini and create symlink for restoring.
    datetimephpconf=$(date +%F-%R)
    sudo cp "$phpcgiconf" "$raspap_dir/backups/php.ini.$datetimephpconf"
    sudo ln -sf "$raspap_dir/backups/php.ini.$datetimephpconf" "$raspap_dir/backups/php.ini"

    echo -n "Enable HttpOnly for session cookies (Recommended)? [Y/n]: "
    if [ "$assume_yes" == 0 ]; then
        read answer < /dev/tty
        if [ "$answer" != "${answer#[Nn]}" ]; then
            echo -e
        else
             php_session_cookie=1;
        fi
    fi

    if [ "$assume_yes" == 1 ] || [ "$php_session_cookie" == 1 ]; then
        echo "Php-cgi enabling session.cookie_httponly."
        sudo sed -i -E 's/^session\.cookie_httponly\s*=\s*(0|([O|o]ff)|([F|f]alse)|([N|n]o))\s*$/session.cookie_httponly = 1/' "$phpcgiconf"
    fi

    if [ "$php_package" = "php7.1-cgi" ]; then
        echo -n "Enable PHP OPCache (Recommended)? [Y/n]: "
        if [ "$assume_yes" == 0 ]; then
            read answer < /dev/tty
            if [ "$answer" != "${answer#[Nn]}" ]; then
                echo -e
            else
                php_opcache=1;
            fi
        fi

        if [ "$assume_yes" == 1 ] || [ "$phpopcache" == 1 ]; then
            echo -e "Php-cgi enabling opcache.enable."
            sudo sed -i -E 's/^;?opcache\.enable\s*=\s*(0|([O|o]ff)|([F|f]alse)|([N|n]o))\s*$/opcache.enable = 1/' "$phpcgiconf"
            # Make sure opcache extension is turned on.
            if [ -f "/usr/sbin/phpenmod" ]; then
                sudo phpenmod opcache
            else
                install_warning "phpenmod not found."
            fi
        fi
    fi
}

function install_complete() {
    install_log "Installation completed!"

    if [ "$assume_yes" == 0 ]; then
        # Prompt to reboot if wired ethernet (eth0) is connected.
        # With default_configuration this will create an active AP on restart.
        if ip a | grep -q ': eth0:.*state UP'; then
            echo -n "The system needs to be rebooted as a final step. Reboot now? [y/N]: "
            read answer < /dev/tty
            if [ "$answer" != "${answer#[Nn]}" ]; then
                echo "Installation reboot aborted."
                exit 0
            fi
            sudo shutdown -r now || install_error "Unable to execute shutdown"
        fi
    fi
}

function install_raspap() {
    display_welcome
    config_installation
    update_system_packages
    install_dependencies
    enable_php_lighttpd
    create_raspap_directories
    optimize_php
    check_for_old_configs
    download_latest_files
    change_file_ownership
    create_hostapd_scripts
    create_lighttpd_scripts
    move_config_file
    default_configuration
    configure_networking
    prompt_install_openvpn
    patch_system_files
    install_complete
}