#!/bin/bash
#!/bin/bash

echo_rgb() {
  # Echo a colored string to the terminal based on rgb values
  #
  # Positional Arguments:
  #
  #   message <type: string> <position: 1> <required: true>
  #     - The message to be printed to stdout
  #   red <type: int> <position: 2> <required: true>
  #     - The red value from 0 to 255
  #   green <type: int> <position: 3> <required: true>
  #     - The green value from 0 to 255
  #   blue <type: int> <position: 4> <required: true>
  #     - The blue value from 0 to 255
  #
  # Usage:
  #   echo_rgb "Yep" 10 8 30
  #
  # POSIX Compliant:
  #   N/A
  #

  local red
  local green
  local blue
  local input

  input="${1}"
  red="${2}"
  green="${3}"
  blue="${4}"

  printf "\e[0;38;2;%s;%s;%sm%s\e[m\n" "${red}" "${green}" "${blue}" "${input}"
}

important() {
  echo_rgb "${1}" 135 195 255
}

log() {
  # Print a message and send it to stdout or stderr depending upon log level, also configurable with debug etc.
  #
  # Arguments:
  #   level <type: string> <position: 1> <required: true>
  #     - The log level, defined within a case check in this function
  #   message <type: string> <position: 2> <required: true>
  #     - The info message
  #   line_number <type: int> <position: 3> <required: false>
  #     - The line number of the calling function (${LINNO})
  #
  # Usage:
  #   log "info" "Could not find that directory"
  #
  # POSIX Compliant:
  #   Yes
  #

  # Set debug status depending if a global debug variable has been set to either 1 or 0
  local debug
  if [ ${DEBUG} ]; then
    debug=${DEBUG}
  else
    debug=0
  fi

  local FORMAT
  FORMAT="[$(echo_rgb "$(date +%Y-%m-%dT%H:%M:%S)" 180 140 255)]"

  # Convert the level to uppercase
  local level
  level=$(echo "${1}" | tr '[:lower:]' '[:upper:]')

  local message
  message="${2}"

  case "${level}" in
    INFO)
      # Output all info log levels to stdout
      printf "${FORMAT}[$(echo_rgb "INFO" 0 140 255)] %s\n" "${message}" >&1
      return 0
      ;;
    WARN | WARNING)
      # Output all warning log levels to stdout
      printf "${FORMAT}[$(echo_rgb "WARNING" 255 255 0)] %s\n" "${message}" >&1
      return 0
      ;;
    DEBUG)
      # Output all debug log levels to stdout
      if [ "${DEBUG}" ]; then
        printf "${FORMAT}[$(echo_rgb "DEBUG" 0 160 110)] %s\n" "${message}" >&1
      fi
      return 0
      ;;
    ERROR)
      # Output all error log levels to stderr
      printf "${FORMAT}[$(echo_rgb "ERROR" 255 0 0)] %s\n" "${message}" >&2
      return 0
      ;;
    # Further log levels can be added by extending this switch statement with more comparisons

    *) # Default case, no matches
      # Returns non-zero code as an improper log option was passed, this helps with using `set -e`
      printf "${FORMAT}[ERROR] %s\n" "Invalid log level passed, received level \"${level}\" with message \"${message}\"" >&2
      return 1
      ;;
  esac
}


get_available_disks() {
  local available_disks
  available_disks=()

  local disk_line
  while read -r; do
    # tr is used to change multiple whitespaces into a single space for processing by cut
    disk_line="$(echo "${REPLY}" | tr -s " " | cut -d " " -f6)"
    if [[ "${disk_line}" = "disk" ]]; then
      # Add the found disk to our array
      available_disks+=("$(echo "${REPLY}" | cut -d " " -f1)")
    fi

  done <<< "$(lsblk)"

  local ret_val
  # Build the array into a string, yes this is less efficient, but easier to modify in the future if something changes
  for disk in "${available_disks[@]}"; do
    ret_val="${ret_val} ${disk}"
  done

  echo "${ret_val}"
}

install() {

  local available_disks

  log "info" "Querying system for available disks..."
  available_disks="$(get_available_disks)"

  log "info" "Available disks: "
  for disk in ${available_disks}; do
    echo "- $(important "${disk}")"
  done

}

main() {
  install
}

main "$@"