#!/bin/bash

# TODO:
# - More error messages based on exit status value of command (like a failed download)
# - Allow parameters and interactive run to be able to set the server ip, allow / disallow creation of additional configurations (like for Proxmox Containers)

# Define the Zabbix server IP
ZABBIX_SERVER_IP="192.168.8.41"
LOG_FILE="za2ai.log"

# Detect the operating system and version
OS=$(awk -F= '/^NAME/{print $2}' /etc/os-release | tr -d '"')
VERSION=$(awk -F= '/^VERSION_ID/{print $2}' /etc/os-release | tr -d '"')

# Log functions
_info() {
    local message=$1
    echo -e "\e[32m[INF] $message\e[0m" 2>&1 | tee -a "$LOG_FILE"
}

_warn() {
    local message=$1
    echo -e "\e[33m[WRN] $message\e[0m" | tee -a "$LOG_FILE"
}

_error() {
    local message=$1
    echo -e "\033[1m\e[31m[ERR] $message\e[0m" | tee -a "$LOG_FILE"
}

SCRIPT_VERSION="1.0"

_info "┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓"
_info "┃                                                           ┃"
_info "┃     Zabbix Agent 2 Auto-Installer by Zion Networks UG     ┃"
_info "┃                                                           ┃"
_info "┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛"

_info ""

_info "Script Version: $SCRIPT_VERSION"
_info "Detected OS: $OS $VERSION"
_info "Logging to file: $LOG_FILE"

# Check if running as root
if [[ $EUID -ne 0 ]]; then
    _error "This script must be run as root."
    exit 1
fi

_info "Checking dependencies ..."
if [ -x "$(command -v sed)" ]; then _info "sed - OK"; else _error "sed - MISSING" ; exit 1 ; fi
if [ -x "$(command -v hostname)" ]; then _info "hostname - OK"; else _error "hostname - MISSING" ; exit 1 ; fi
if [ -x "$(command -v ip)" ]; then _info "ip - OK"; else _error "ip - MISSING" ; exit 1 ; fi

# Download and install the Zabbix agent
if [[ "$OS" == *"CentOS"* ]]; then
    if [ -x "$(command -v rpm)" ]; then _info "rpm - OK"; else _error "rpm - MISSING" ; exit 1 ; fi
    if [ -x "$(command -v yum)" ]; then _info "yum - OK"; else _error "yum - MISSING" ; exit 1 ; fi

    if [[ "$VERSION" == "6"* ]]; then
        if [ -x "$(command -v service)" ]; then _info "service - OK"; else _error "service - MISSING" ; exit 1 ; fi
        if [ -x "$(command -v chkconfig)" ]; then _info "chkconfig - OK"; else _error "chkconfig - MISSING" ; exit 1 ; fi

        _info "Downloading and installing Zabbix repositories ..."

        rpm -Uvh https://repo.zabbix.com/zabbix/6.4/rhel/6/x86_64/zabbix-release-6.4-1.el6.noarch.rpm &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to download or install Zabbix repository package"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        yum clean all &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _warn "Command 'yum clean all' failed"
            _warn "See logfile at $LOG_FILE for further information"
        fi

        _info "Installing Zabbix Agent 2 ..."

        yum install zabbix-agent2 zabbix-agent2-plugin-* -y &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to install Zabbix 2 Agent"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release-6.4-1.el6.noarch.rpm

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "7"* ]]; then
        if [ -x "$(command -v systemctl)" ]; then _info "systemctl - OK"; else _error "systemctl - MISSING" ; exit 1 ; fi

        _info "Downloading and installing Zabbix repositories ..."

        rpm -Uvh https://repo.zabbix.com/zabbix/6.4/rhel/7/x86_64/zabbix-release-6.4-1.el7.noarch.rpm &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to download or install Zabbix repository package"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        yum clean all &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _warn "Command 'yum clean all' failed"
            _warn "See logfile at $LOG_FILE for further information"
        fi

        _info "Installing Zabbix Agent 2 ..."

        yum install zabbix-agent2 zabbix-agent2-plugin-* -y &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to install Zabbix 2 Agent"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release-6.4-1.el7.noarch.rpm

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "8"* ]]; then
        if [ -x "$(command -v systemctl)" ]; then _info "systemctl - OK"; else _error "systemctl - MISSING" ; exit 1 ; fi

        _info "Downloading and installing Zabbix repositories ..."

        rpm -Uvh https://repo.zabbix.com/zabbix/6.4/rhel/8/x86_64/zabbix-release-6.4-1.el8.noarch.rpm &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to download or install Zabbix repository package"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        dnf clean all &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _warn "Command 'dnf clean all' failed"
            _warn "See logfile at $LOG_FILE for further information"
        fi

        _info "Installing Zabbix Agent 2 ..."

        dnf install zabbix-agent2 zabbix-agent2-plugin-* -y &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to install Zabbix 2 Agent"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release-6.4-1.el8.noarch.rpm

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "9"* ]]; then
        if [ -x "$(command -v systemctl)" ]; then _info "systemctl - OK"; else _error "systemctl - MISSING" ; exit 1 ; fi

        _info "Disable Zabbix packages provided by EPEL ..."

        sed -i '/\[epel\]/a excludepkgs=Zabbix*' /etc/yum.repos.d/epel.repo &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _warn "Failed to disable EPEL source!"
            _warn "See logfile at $LOG_FILE for further information"
        fi

        _info "Downloading and installing Zabbix repositories ..."

        rpm -Uvh https://repo.zabbix.com/zabbix/6.4/rhel/9/x86_64/zabbix-release-6.4-1.el9.noarch.rpm &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to download or install Zabbix repository package"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        dnf clean all &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _warn "Command 'dnf clean all' failed"
            _warn "See logfile at $LOG_FILE for further information"
        fi

        _info "Installing Zabbix Agent 2 ..."

        dnf install zabbix-agent2 zabbix-agent2-plugin-* -y &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Failed to install Zabbix 2 Agent"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release-6.4-1.el9.noarch.rpm

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    else
        _error "Your CentOS version is not supported."
        exit 1
    fi

elif [[ "$OS" == *"Debian"* ]]; then
    if [ -x "$(command -v wget)" ]; then _info "wget - OK"; else _error "wget - MISSING" ; exit 1 ; fi
    if [ -x "$(command -v dpkg)" ]; then _info "dpkg - OK"; else _error "dpkg - MISSING" ; exit 1 ; fi
    if [ -x "$(command -v apt)" ]; then _info "apt - OK"; else _error "apt - MISSING" ; exit 1 ; fi
    if [ -x "$(command -v systemctl)" ]; then _info "systemctl - OK"; else _error "systemctl - MISSING" ; exit 1 ; fi

    if [[ "$VERSION" == "9"* ]]; then
        _info "Downloading Zabbix repositories package ..."

        wget https://repo.zabbix.com/zabbix/6.4/debian/pool/main/z/zabbix-release/zabbix-release_6.4-1+debian9_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "File download failed!"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Installing Zabbix repositories package ..."

        dpkg -i zabbix-release_6.4-1+debian9_all.deb &>> "$LOG_FILE"
        
        if [ $? -ne 0 ]; then
            _error "Repository package installation failed!"
            _error "See logfile at $LOG_FILE for further information"

            _info "Removing repository installation package"

            rm -f zabbix-release_6.4-1+debian9_all.deb

            if [ $? -ne 0 ]; then
                _warn "Failed to remove downloaded temporary files"
                _warn "See logfile at $LOG_FILE for further information"
            fi

            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release_6.4-1+debian9_all.deb

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "10"* ]]; then
        _info "Downloading Zabbix repositories package ..."

        wget https://repo.zabbix.com/zabbix/6.4/debian/pool/main/z/zabbix-release/zabbix-release_6.4-1+debian10_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "File download failed!"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Installing Zabbix repositories package ..."

        dpkg -i zabbix-release_6.4-1+debian10_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Repository package installation failed!"
            _error "See logfile at $LOG_FILE for further information"

            _info "Removing repository installation package"

            rm -f zabbix-release_6.4-1+debian10_all.deb

            if [ $? -ne 0 ]; then
                _warn "Failed to remove downloaded temporary files"
                _warn "See logfile at $LOG_FILE for further information"
            fi

            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release_6.4-1+debian10_all.deb

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "11"* ]]; then
        _info "Downloading Zabbix repositories package ..."

        wget https://repo.zabbix.com/zabbix/6.4/debian/pool/main/z/zabbix-release/zabbix-release_6.4-1+debian11_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "File download failed!"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Installing Zabbix repositories package ..."

        dpkg -i zabbix-release_6.4-1+debian11_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Repository package installation failed!"
            _error "See logfile at $LOG_FILE for further information"

            _info "Removing repository installation package"

            rm -f zabbix-release_6.4-1+debian11_all.deb

            if [ $? -ne 0 ]; then
                _warn "Failed to remove downloaded temporary files"
                _warn "See logfile at $LOG_FILE for further information"
            fi

            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release_6.4-1+debian11_all.deb

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    elif [[ "$VERSION" == "12"* ]]; then
        _info "Downloading Zabbix repositories package ..."

        wget https://repo.zabbix.com/zabbix/6.4/debian/pool/main/z/zabbix-release/zabbix-release_6.4-1+debian12_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "File download failed!"
            _error "See logfile at $LOG_FILE for further information"
            exit 1
        fi

        _info "Installing Zabbix repositories package ..."

        dpkg -i zabbix-release_6.4-1+debian12_all.deb &>> "$LOG_FILE"

        if [ $? -ne 0 ]; then
            _error "Repository package installation failed!"
            _error "See logfile at $LOG_FILE for further information"

            _info "Removing repository installation package"

            rm -f zabbix-release_6.4-1+debian12_all.deb

            if [ $? -ne 0 ]; then
                _warn "Failed to remove downloaded temporary files"
                _warn "See logfile at $LOG_FILE for further information"
            fi

            exit 1
        fi

        _info "Removing repository installation package"

        rm -f zabbix-release_6.4-1+debian12_all.deb

        if [ $? -ne 0 ]; then
            _warn "Failed to remove downloaded temporary files"
            _warn "See logfile at $LOG_FILE for further information"
        fi

    else
        _error "Your Debian version is not supported."
        exit 1
    fi

    _info "Running 'apt update' ..."

    apt update &>> "$LOG_FILE"

    if [ $? -ne 0 ]; then
        _error "Command 'apt update' failed!"
        _error "See logfile at $LOG_FILE for further information"
        exit 1
    fi

    _info "Installing Zabbix Agent 2 ..."

    apt install zabbix-agent2 zabbix-agent2-plugin-* -y &>> "$LOG_FILE"

    if [ $? -ne 0 ]; then
        _error "Failed to install Zabbix 2 Agent"
        _error "See logfile at $LOG_FILE for further information"
        exit 1
    fi

else
    _error "Your operating system is not supported."
    exit 1
fi

_info "Installation done!"

# Get the IP address and hostname
IP=$(ip addr show eth0 | grep 'inet ' | awk '{print $2}' | cut -f1 -d'/')
HOST=$(hostname | tr '[:lower:]' '[:upper:]')

_info "Detected IP: $IP"
_info "Detected Hostname: $HOST"

_info "Updating Zabbix Agent 2 configuration ..."

# Update the Zabbix agent configuration
sed -i "s/# SourceIP=/SourceIP=$IP/g" /etc/zabbix/zabbix_agent2.conf
sed -i "s/Server=127.0.0.1/Server=$ZABBIX_SERVER_IP/g" /etc/zabbix/zabbix_agent2.conf
sed -i "s/ServerActive=127.0.0.1/ServerActive=$ZABBIX_SERVER_IP/g" /etc/zabbix/zabbix_agent2.conf
sed -i "s/# ListenIP=0.0.0.0/ListenIP=0.0.0.0/g" /etc/zabbix/zabbix_agent2.conf
sed -i "s/Hostname=Zabbix server/Hostname=$HOST/g" /etc/zabbix/zabbix_agent2.conf

_info "Updating done!"
_info "Writing additional configuration file for Proxmox Container support"

# Create the zabbix_container.conf file
cat << EOF > /etc/zabbix/zabbix_agent2.d/zabbix_container.conf
UserParameter=ct.memory.size[*],free -b | awk 'NR==2 {total=\$2; used=(\$3+\$5); pused=((\$3+\$5)*100/\$2); free=\$4; pfree=(\$4*100/\$2); shared=\$5; buffers=\$6; cached=\$7; available=\$8; pavailable=(\$8*100/\$2); if("\$1" == "") {printf("%.0f", total )} else {printf("%.0f", \$1 "" )} }'
UserParameter=ct.swap.size[*],free -b | awk 'NR==3 {total=\$2; used=\$3; free=\$4; pfree=(\$4*100/\$2); pused=(\$3*100/\$2); if("\$1" == "") {printf("%.0f", free )} else {printf("%.0f", \$1 "" )} }'
UserParameter=ct.cpu.load[*],cut -d" " -f1-3 /proc/loadavg | awk -F'[, ]+' '{avg1=\$(NF-2); avg5=\$(NF-1); avg15=\$(NF)}{print \$2/'$(nproc)'}'
UserParameter=ct.uptime,cut -d"." -f1 /proc/uptime
EOF

_info "Restarting and enabling service ..."

# Restart and enable service
if [[ $OS == *"CentOS"* ]]; then
    if [[ $VERSION == "6"* ]]; then
        service zabbix-agent restart &>> "$LOG_FILE"
        chkconfig --level 35 zabbix-agent on &>> "$LOG_FILE"
    elif [[ $VERSION == "7"* ]]; then
        systemctl restart zabbix-agent2 &>> "$LOG_FILE"
        systemctl enable zabbix-agent2 &>> "$LOG_FILE"
    elif [[ $VERSION == "8"* ]]; then
        systemctl restart zabbix-agent2 &>> "$LOG_FILE"
        systemctl enable zabbix-agent2 &>> "$LOG_FILE"
    elif [[ $VERSION == "9"* ]]; then
        systemctl restart zabbix-agent2 &>> "$LOG_FILE"
        systemctl enable zabbix-agent2 &>> "$LOG_FILE"
    else
        _error "Your CentOS version is not supported."
        exit 1
    fi
elif [[ $OS == *"Debian"* ]]; then
    systemctl restart zabbix-agent2 &>> "$LOG_FILE"
    systemctl enable zabbix-agent2 &>> "$LOG_FILE"
else
    _error "Your operating system is not supported."
    exit 1
fi

# Display the installation result
_info
_info "Installation of Zabbix Agent 2 successful!"
_info "IP: $IP"
_info "Hostname: $HOST"
_info
_info "Remember to create a new host in your Zabbix Dashboard at https://mon.zion-networks.de/zabbix.php?action=host.edit"