#!/bin/bash

#######
### Update NGINX configuration '<tags>' with proper values and optionally copy
### to updated directory structure
#######


### text formatting ansi codes
err="\e[1;31m"
ok="\e[1;32m"
warn="\e[93m"
mag="\e[95m"
cyan="\e[96m"
norm="\e[0m"


### set variables

# clear variables
unset IP4
unset useCertbot
unset CertbotDomain
unset CertPath
unset KeyPath
unset CAChainPath
unset DHPath

# set variables
regexIP4="(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])"
regexHostname="(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])"
serverNames_working=()
serverNames=()
detectedIP=$(ip route get 1 | sed -n 's/^.*src \([0-9.]*\) .*$/\1/p')
certbotFiles=(cert.pem chain.pem fullchain.pem privkey.pem)
generateDH=0
hostname=$(hostname)
configPath="./etc.${hostname}"

# set tags and files to update
tag_servernames="<server name(s)>"
file_servernames="nginx/snippets/server_names.conf"
tag_sslcert="<path/to/your_ssl_certificate_fullchain>"
tag_sslkey="<path/to/your_certificate_private_key.key>"
file_ssl="nginx/snippets/ssl/ssl_certs.conf"
tag_dhparam="<path/to/your_dhparam.pem>"
tag_cachain="<path/to/your_CA_bundle.crt>"
file_mozmodern="nginx/conf.d/mozModern_ssl.conf"

### quick intro for the user
echo -e "\n${mag}This script will customize the provided NGINX template files for your"
echo "environment.  You will be prompted for all necessary information.  After that,"
echo "default error pages will be copied to your webroot and your NGINX configuration"
echo -e "directory structure will be customized.${norm}\n"
echo -e "${warn}You may accept the default option (listed in brackets) by simply"
echo "pressing ENTER (i.e. no answer)."
echo -e "You may exit this script at any prompt by typing 'X'${norm}\n"


### get local IP address
echo -e "\n${mag}In cases where this server will be acting as a (reverse) proxy, NGINX"
echo "needs to know it's own local IP address so that the logs can properly reflect"
echo -e "the IP of the remote system(s) instead of this server.${norm}\n"
while true; do
    read -p "What is this machine's local IP4 address? (${detectedIP}) " inputIP
    case "${inputIP}" in
        '')
            IP4="${detectedIP}"
            break
            ;;
        [Xx]*)
            echo -e "\n${cyan}---exiting---\n${norm}"
            exit 1
            ;;
        *)
            # check IP for validity
            if [[ "${inputIP}" =~ ^${regexIP4}$ ]]; then
                IP4="${inputIP}"
                break
            else
                echo -e "\n${err}Invalid IP4 format (xxx.xxx.xxx.xxx)${norm}"
            fi
            ;;
    esac
done


### get server names for this installation
echo -e "\n${mag}To which hostnames should NGINX answer?  You can pick as many hostnames as you"
echo "like.  Please ensure you provide fully-qualified domain names unless you"
echo "understand the impact not doing so."
echo -e "\nIf you are setting up SSL on this system, then make sure the hostnames match"
echo "what appears on your certificates!"
echo -e "\n${warn}You will be prompted to enter one hostname at a time."
echo "Provide a blank-entry (hit enter) when you're done."
echo -e "'X' will exit the script, as always${norm}\n"
while true; do
    read -p "Hostname for this server? " inputServerName
    case "${inputServerName}" in
        '')
            # check that at least one name as been provided
            if [ -z "${serverNames_working}" ]; then
                echo -e "\n${err}You must provide at least one hostname${norm}"
            else
                break
            fi
            ;;
        [Xx]*)
            echo -e "\n${cyan}---exiting---\n${norm}"
            exit 1
            ;;
        *)
            # check hostname for validity
            if [[ ! "${inputServerName}" =~ ^${regexHostname}$ ]]; then
                echo -e "\n${err}Invalid hostname${norm}"
            else
                serverNames_working+=("${inputServerName}")
            fi
            ;;
    esac
done
# create new array with unqiue values only
declare -A uniqueSN
for name in "${serverNames_working[@]}"; do
    uniqueSN["${name}"]=""
done
for sn in "${!uniqueSN[@]}"; do
    serverNames+=("${sn}")
done


### SSL related options
# using certbot?
echo -e "\n${mag}If you are using Certbot, you only need to provide the primary domain name"
echo "of your certificate and the script will auto-generate the paths NGINX needs to"
echo "make everything work."
echo -e "\nIf you haven't run Certbot yet, you can enter the domain you intend to use"
echo "as your primary domain and the paths generated by this script will work after"
echo -e "you run Certbot.  In that case, you will have to answer ${warn}'yes'${mag} when asked"
echo -e "${warn}'Do you want to use this domain setting anyways?'${norm}\n"
while true; do
    read -p "Are you using Certbot to handle your SSL certificates? (default: No) " yn
    case "${yn}" in
        [Yy]*)
            useCertbot=1
            break
            ;;
        [Nn]|'')
            useCertbot=0
            unset CertbotDomain
            break
            ;;
        [Xx]*)
            echo -e "\n${cyan}---exiting---\n${norm}"
            exit 1
            ;;
        *)
            echo -e "\n${err}Please answer (Y)es, (N)o, e(X)it or accept default${norm}"
            ;;
    esac
done            

# using Certbot: get primary domain name since that how Certbot determines paths
if [ "${useCertbot}" -eq 1 ]; then
    while true; do
        read -p "What is the primary domain for your Certbot Certificates? " inputCertbotDomain
        case "${inputCertbotDomain}" in
            '')
                echo -e "\n${err}You cannot have an empty domain name${norm}"
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                # check hostname for validity
                if [[ ! "${inputCertbotDomain}" =~ ^${regexHostname}$ ]]; then
                    echo -e "\n${err}Invalid hostname${norm}"
                else
                    # check if Certbot files exist in path implied from hostname
                    echo -e "\n${cyan}Verifying Certbot files..."
                    echo -e "(/etc/letsencrypt/live/${inputCertbotDomain}/...)${norm}"
                    certbotBadFile=()
                    for certbotFile in "${certbotFiles[@]}"; do
                        if [ -f "/etc/letsencrypt/live/${inputCertbotDomain}/$certbotFile" ]; then
                            echo -e "File: ${certbotFile} -- ${ok}OK${norm}"
                        else
                            echo -e "File: ${certbotFile} -- ${err}X${norm}"
                            certbotBadFile+=("${certbotFile}")
                        fi
                    done
                    if [ -z "${certbotBadFile}" ]; then
                        echo -e "${cyan}Certbot files seem intact${norm}\n"
                        CertbotDomain="${inputCertbotDomain}"
                        break
                    else
                        echo -e "\n${err}The following files are missing from ${inputCertbotDomain}:"
                        echo -e "${warn}${certbotBadFile[*]}${norm}"
                        echo -e "${err}These files should all be present in a functional Certbot install.${norm}\n"
                        while true; do
                            read -p "Do you want to use this domain setting anyways? " yn
                            case "${yn}" in
                                    [Yy]*)
                                        CertbotDomain="${inputCertbotDomain}"
                                        break
                                        ;;
                                    [Nn]*)
                                        break
                                        ;;
                                    *)
                                        ;;
                            esac
                        done
                    fi
                    if [ -n "${CertbotDomain}" ]; then
                        break
                    fi
                fi
                ;;
        esac
    done
fi

# Generate paths from CertbotDomain
if [ "${useCertbot}" -eq 1 ]; then
    CertPath="/etc/letsencrypt/live/${CertbotDomain}/fullchain.pem"
    KeyPath="/etc/letsencrypt/live/${CertbotDomain}/privkey.pem"
    CAChainPath="/etc/letsencrypt/live/${CertbotDomain}/chain.pem"
fi

# only process manual certificate paths if NOT using Certbot
if [ "${useCertbot}" -eq 0 ]; then
    echo -e "\n${mag}NGINX requires the full paths to your PEM formatted certificates, private keys"
    echo "and your CA-chain in order to serve pages securely and properly over SSL."
    echo "If you haven't generated/copied your certificates yet, you can enter the"
    echo "paths where they will be located and confirm when prompted by the script."
    # not using Certbot: get location of certificate
    while true; do
        read -p "What is the path to your primary SSL certificate? " inputCertPath
        case "${inputCertPath}" in
            '')
                echo -e "\n${err}You cannot have an empty path to your SSL certificate${norm}"
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                # validate path
                if [ -f "${inputCertPath}" ]; then
                    CertPath="${inputCertPath}"
                    break
                else
                    echo -e "\n${warn}The file you specified doesn't exist${norm}"
                    while true; do
                        read -p "Do you want to use this path anyways? " yn
                        case $yn in
                            [Yy]*)
                                CertPath="${inputCertPath}"
                                break
                                ;;
                            [Nn]*)
                                break
                                ;;
                            *)
                                ;;
                        esac
                    done
                    if [ -n "${CertPath}" ]; then
                        break
                    fi
                fi
                ;;
        esac
    done

    # not using Certbot: get location of private key
    while true; do
        read -p "What is the path to your primary SSL private key? " inputKeyPath
        case "${inputKeyPath}" in
            '')
                echo -e "\n${err}You cannot have an empty path to your SSL private key${norm}"
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                # validate path
                if [ -f "${inputKeyPath}" ]; then
                    KeyPath="${inputKeyPath}"
                    break
                else
                    echo -e "\n${warn}The file you specified doesn't exist${norm}"
                    while true; do
                        read -p "Do you want to use this path anyways? " yn
                        case $yn in
                            [Yy]*)
                                KeyPath="${inputKeyPath}"
                                break
                                ;;
                            [Nn]*)
                                break
                                ;;
                            *)
                                ;;
                        esac
                    done
                    if [ -n "${KeyPath}" ]; then
                        break
                    fi
                fi
                ;;
        esac
    done

    # not using Certbot: get location of CA Certificate Chain
    while true; do
        read -p "What is the path to your primary SSL CA Chain certificate? " inputCAChainPath
        case "${inputCAChainPath}" in
            '')
                echo -e "\n${err}You cannot have an empty path to your SSL CA Chain certificate${norm}"
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                # validate path
                if [ -f "${inputCAChainPath}" ]; then
                    CAChainPath="${inputCAChainPath}"
                    break
                else
                    echo -e "\n${warn}The file you specified doesn't exist${norm}"
                    while true; do
                        read -p "Do you want to use this path anyways? " yn
                        case $yn in
                            [Yy]*)
                                CAChainPath="${inputCAChainPath}"
                                break
                                ;;
                            [Nn]*)
                                break
                                ;;
                            *)
                                ;;
                        esac
                    done
                    if [ -n "${CAChainPath}" ]; then
                        break
                    fi
                fi
                ;;
        esac
    done
fi

# dhparam: get location of DH Parameters file
echo -e "\n${mag}Having your own unique Diffie-Hellman Parameters file makes your SSL"
echo "communication more secure by helping to generate unique safe large prime"
echo "numbers.  You shouldn't use any pre-installed dhparams.pem files. You should"
echo "always generate your own.  If you haven't done that already and would like this"
echo -e "script to do it for you, please type ${warn}generate${mag} at the prompt instead"
echo -e "of a path${norm}\n"
while true; do
    read -p "What is the path to your DH Parameters file? (default: /etc/ssl/certs/dhparam.pem) " inputDHPath
    case "${inputDHPath}" in
        '')
            # verify default path exists
            inputDHPath="/etc/ssl/certs/dhparam.pem"            
            if [ -f "${inputDHPath}" ]; then
                DHPath="${inputDHPath}"
                break
            else
                echo -e "\n${warn}The file you specified doesn't exist${norm}"
                while true; do
                    read -p "Do you want to use this path anyways? " yn
                    case $yn in
                        [Yy]*)
                            DHPath="${inputDHPath}"
                            break
                            ;;
                        [Nn]*)
                            break
                            ;;
                        *)
                            ;;
                    esac
                done
                if [ -n "${DHPath}" ]; then
                    break
                fi
            fi
            ;;
        [Xx]*)
            echo -e "\n${cyan}---exiting---\n${norm}"
            exit 1
            ;;
        [Gg][Ee][Nn][Ee][Rr][Aa][Tt][Ee]*)
            generateDH=1
            break
            ;;
        *)
            # validate path
            if [ -f "${inputDHPath}" ]; then
                DHPath="${inputDHPath}"
                break
            else
                echo -e "\n${warn}The file you specified doesn't exist${norm}"
                while true; do
                    read -p "Do you want to use this path anyways? " yn
                    case $yn in
                        [Yy]*)
                            DHPath="${inputDHPath}"
                            break
                            ;;
                        [Nn]*)
                            break
                            ;;
                        *)
                            ;;
                    esac
                done
                if [ -n "${DHPath}" ]; then
                    break
                fi
            fi
            ;;
    esac
done


### PHP-FPM related options
# get PHP-FPM usage status
echo -e "\n${mag}PHP-FPM allows your server to process and serve dynamic PHP content. If you"
echo "have PHP-FPM installed, NGINX needs to know how to access it. The following"
echo "questions will allow the script to auto-configure that for you."
echo -e "\nIf you have not yet installed PHP-FPM but intend to do so in the future, you"
echo -e "can answer ${warn}yes${mag} and provide details for your intended setup so the script can"
echo -e "generate a configuration that will work once your PHP-FPM is set up.${norm}\n"
while true; do
    read -p "Are you using PHP-FPM? (default: Yes) " yn
    case $yn in
        [Yy]*|'')
            usePHP=1
            break
            ;;
        [Nn]*)
            usePHP=0
            break
            ;;
        [Xx]*)
            echo -e "\n${cyan}---exiting---\n${norm}"
            exit 1
            ;;
        *)
            echo -e "\n${err}Please answer (Y)es, (N)o, e(X)it or accept default${norm}"
            ;;
    esac
done

# get PHP-FPM version
if [ "${usePHP}" -eq 1 ]; then
    while true; do
        read -p "What version of PHP-FPM are you using? (default: 7.2) " inputPHPVersion
        case $inputPHPVersion in
            [[:digit:]]*|+[[:digit:]]*.[[:digit:]]*)
                phpVersion="$inputPHPVersion"
                break
                ;;
            '')
                phpVersion=7.2
                break
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                echo -e "\n${err}That does not seem to be a valid version number${norm}"
                ;;
        esac
    done
fi

# get PHP-FPM TCP or Sockets configuration
if [ "${usePHP}" -eq 1 ]; then
    echo -e "\n${mag}PHP-FPM can be set up to respond to requests via TCP or via UNIX sockets."
    echo "If you have no idea what any of this means, then you're probably using the"
    echo -e "default setup which is sockets${norm}\n"
    while true; do
        read -p "Is your PHP-FPM set up to listen via 'TCP' or 'sockets'? (default: sockets) " inputPHPType
        case "${inputPHPType}" in
            [Ss][Oo][Cc][Kk][Ee][Tt][Ss]*|'')
                phpType='sockets'
                break
                ;;
            [Tt][Cc][Pp]*)
                phpType='tcp'
                break
                ;;
            [Xx]*)
                echo -e "\n${cyan}---exiting---\n${norm}"
                exit 1
                ;;
            *)
                echo -e "\n${err}Please enter either 'tcp' or 'sockets' or 'X' to exit script${norm}"
                ;;
        esac
    done
fi



### Write configurations to template files
# let user know what's happening
echo -e "\n${mag}---------------------${norm}"
echo -e "${cyan}Updating template files now"

# copy template files to working versions
echo "copying files to dedicated directory for customization"
echo -e "${warn}${configPath}${norm}\n"
rm -rf "${configPath}"
cp -R ./etc "${configPath}"

# process server_names snippet
echo -e "updating ${warn}${configPath}/${file_servernames}${norm}"
for name in "${serverNames[@]}"; do
    sed -i "/${tag_servernames}/a \   \ ${name}" "${configPath}/${file_servernames}"
done
sed -i "/${tag_servernames}/d" "${configPath}/${file_servernames}"

# process SSL snippet
echo "updating ${warn}${configPath}/${file_ssl}${norm}"
sed -i -e "s%${tag_sslcert}%${CertPath}%" "${configPath}/${file_ssl}"
sed -i -e "s%${tag_sslkey}%${KeyPath}%" "${configPath}/${file_ssl}"

# process mozModern SSL configuration
echo "updating ${warn}${configPath}/${file_mozmodern}${norm}"
echo -i -e "s%${tag_dhparam}%${DHPath}%" "${configPath}/${file_mozmodern}"
echo -i -e "s%${tag_cachain}%${CAChainPath}%" "${configPath}/${file_mozmodern}"



# debug section
echo -e "\n${mag}---------------------${norm}"
echo "Local IP4: $IP4"
echo -e "${cyan}--------------------${norm}"
echo "Using Certbot: $useCertbot"
echo "CertbotDomain: $CertbotDomain"
echo -e "${cyan}--------------------${norm}"
echo "CertPath: $CertPath"
echo "KeyPath: $KeyPath"
echo "CA-Chain: $CAChainPath"
echo "DHPath: $DHPath"
echo "Generating DH Params? $generateDH"
echo -e "${cyan}--------------------${norm}"
echo "usePHP: $usePHP"
echo "PHP Version: $phpVersion"
echo "PHP listen type: $phpType"
echo -e "${mag}---------------------${norm}\n"



exit 0