#!/bin/bash

#Export to be based on user preference
#Enviromental  Variables for certificate paths, this is to make sure certificates are always issued in same path
#if cert in used by multiple applications. can be placed in central path
#Can be run without root - root only needed to install dependencies from apt

#should be folder that doesn't have root permission
export CERT_PATH=/etc/nginx/ssl
export CONTACT_MAIL=xxxxxxxxxxxxxxxxxxxxxxxx

#Use case - namecheap (environment variable depends on dns provider)
#check out https://go-acme.github.io/lego/dns/index.html for dns provider variables
export DNS_PROVIDER=namecheap
export NAMECHEAP_PROPAGATION_TIMEOUT=60
export NAMECHEAP_POLLING_INTERVAL=2
export NAMECHEAP_API_USER=xxxxxxxxxxxxxxxxxxxxxxxx
export NAMECHEAP_API_KEY=xxxxxxxxxxxxxxxxxxxxxxxx

install_as_sudo() {

  if [ -z "$SUDO_PASS"] && [ $EUID -ne 0 ]; then

    echo 'Sudo access needed to install dependencies'
    read -sp "Enter Sudo Password:" SUDO_PASS
    printf "\n\n"

  fi
  env_file=~/.profile
}

check_dependencies() {

  echo "Checking dependencies..."
  check_install_curl
  check_install_jq
  check_install_go
  check_install_lego
  echo "Check compelete"
  if [ "$dependency_install" == "yes" ]; then
    echo "restart shell session"
    exit 0
  fi

}

check_install_curl() {

  if ! command -v curl 2>&1 >/dev/null; then
    install_as_sudo
    echo 'curl module not installed'
    echo "now installing curl..."

    ###download and install curl
    eval "sudo apt install curl -y"
    echo "curl succcesfully installed"
    eval "curl -V"
    dependency_install=yes
  fi
}

check_install_jq() {

  if ! command -v jq 2>&1 >/dev/null; then
    install_as_sudo
    echo 'jq module not installed'
    echo "now installing jq..."

    ###download and install curl
    eval "sudo apt install jq -y"
    echo "jq succcesfully installed"
    eval "jq -V"
    dependency_install=yes
  fi
}

check_install_go() {

  if ! command -v go 2>&1 >/dev/null; then
    install_as_sudo
    echo 'go module not installed'

    echo "now installing go..."
    echo "export GOPATH=$""HOME/go" >>$env_file
    echo "export GO_HOME=/usr/local/go" >>$env_file
    echo "export PATH=$""PATH:$""GO_HOME/bin:$""GOPATH/bin" >>$env_file
    eval "source $env_file"

    ###download and install go
    get_system_information
    eval "sudo rm -rf $GO_HOME"
    command=$(curl $url | sudo tar -xz -C /usr/local)
    eval "$command"

    echo "go succcesfully installed"
    eval "source $env_file"
    eval "go version"
    dependency_install=yes
  fi
}

check_install_lego() {

  if ! command -v lego 2>&1 >/dev/null; then

    echo 'lego could not be found'

    echo 'now installing lego...'
    export GO111MODULE=on

    if [ ! -d $CERT_PATH ]; then
      sudo mkdir -p $CERT_PATH
      sudo chown $USER:$USER -R $CERT_PATH
    fi

    echo "export LEGO_PATH=$CERT_PATH/lego" >>$env_file
    eval "source $env_file"
    eval "go install github.com/go-acme/lego/v4/cmd/lego@latest"

    #add crontab for auto renewal of certificates (occurence is at monday,thursdays - can be changed)
    eval "(crontab -l 2>/dev/null || true; echo '0 0 * * 1,4 $0 autorenew') | sort -u |crontab - "
    printf "\n"
    echo "lego succcesfully installed"
    eval "lego -version"
    dependency_install=yes
  fi
}

get_system_information() {

  ##go1.24.3.linux-amd64.tar.gz
  ##https://dl.google.com/go/go1.24.3.linux-amd64.tar.gz
  ###As at writing script - go version is 1.24.3 (could find api to get current version)
  version="1.24.3"

  #Get System Information (Adapted to Debian - This would need changes for other OS's)
  sys=$(uname -s)
  system=$(echo $sys | tr '[:upper:]' '[:lower:]')
  archictecture=$(dpkg --print-architecture)

  #Form URL Based on system information
  url="https://dl.google.com/go/go$version.$system-$archictecture.tar.gz"
  printf "\n"
  echo $url
  printf "\n"

}

run() {
  read -p 'enter domain name(s) seperate with ,: ' -a domains
  for domain in "${domains[@]}"; do
    command+="-d $domain "
  done
  eval " $command run"
  exit 0
}

revoke() {

  read -p 'enter domain name(s) seperate with ,: ' -a domains
  for domain in "${domains[@]}"; do
    command+="-d $domain "
  done
  eval " $command revoke"
  exit 0
}

renew() {

  read -p 'enter domain name(s) seperate with ,: ' -a domains
  for domain in "${domains[@]}"; do
    command+="-d $domain "
  done
  eval " $command renew"
  exit 0
}

list() {
  eval " $command list"
  exit 0
}

autorenew() {

  ###to be used to store output from crontab renewals
  LOG_FILE="$CERT_PATH/log"
  if [ ! -d $LOG_FILE ]; then
    mkdir -p $LOG_FILE
  fi

  for files in $(find $LEGO_PATH/certificates/*.json -type f); do
    IFS=$'\n'
    for file in $files; do
      temp_domain=$(cat $file | jq .domain | sed -e 's/^"//' -e 's/"$//')
      renew_command="$command -d $temp_domain renew"
      eval $renew_command
    done
  done

  exit 0

}

functionlist() {
  echo "Usage: {run, renew, revoke, list}"
  PS3="Select Option to enter option or and key to exit: "
  options=("run" "revoke" "renew" "list")
  select option in "${options[@]}"; do
    case $option in
    "run")
      run
      ;;
    "revoke")
      revoke
      ;;
    "renew")
      renew
      ;;
    "list")
      list
      ;;
    *)
      exit 0
      ;;
    esac
  done
}

functionvar() {

  case $1 in
  "run")
    run
    ;;
  "revoke")
    revoke
    ;;
  "renew")
    renew
    ;;
  "list")
    list
    ;;
  "autorenew")
    autorenew
    ;;
  esac
}

check_dependencies

cd $CERT_PATH
echo "Acme Script for $DNS_PROVIDER"
## If no parameters are given, print which are avaiable.
echo "Usage: only dns challenge function available"
command="lego --email $CONTACT_MAIL --dns $DNS_PROVIDER "
IFS=","
###TODO###
#available functions - can be used as a function list or a  direct execute by passing action
#would write domains into file/list on issuance so it can be used for renewal
#revoked certificate names would be removed from existing list of issued certificates
#cron jobs would be created for renew function
if [ -z "$1" ]; then
  functionlist
  exit 0
else
  functionvar $1
  exit 0
fi