#!/usr/bin/env bash

# CONSTANTS

BASEDIR=$(dirname "$0") 
DEFAULT_CONFIG="$BASEDIR/../config/default.conf"
ARG1="${1:-}"

# FUNCTIONS

function usage {
	echo "$(basename "$0") [--edit | --config]"
}

function parse_options {
  COMMAND=show
  while [[ $# -gt 0 ]]; do
    case "$1" in
    --edit)
      COMMAND=edit
      ;;    	
    --config)
      COMMAND=config
      ;;    	
    --help | -h)
      usage && exit 0
      ;;
    *)
      echo >&2 "Unknown option: $1" && usage && exit 2
      ;;
    esac

    shift 1 # Move to the next argument
  done
}

function show_defaults {
	[[ ! -f $DEFAULT_CONFIG ]] && echo >&2 "config file missing: $DEFAUL_CONFIG" && exit 3

	source "$DEFAULT_CONFIG"
	echo "STORAGE_DISK=$STORAGE_DISK"
	echo "STORAGE_SIZE=$STORAGE_SIZE"
	echo "BRIDGE=$BRIDGE"
	echo "MEMORY=$MEMORY"
	echo "SWAP=$SWAP"
	echo "CPU=$CPU"
}

function compute_cpu_cores {
	nproc=$(nproc)
	[[ $nproc -ge 16 ]] && cores=4
	[[ $nproc -ge 8 ]] && cores=2
	[[ $nproc -lt 8 ]] && cores=1
	echo $cores
}

function choose_from_selection {
	local name=$1[@]
	local selection=("${!name}")
	local length=${#selection[@]}
	[[ $length == 0 ]] && echo >&2 'no values from selection!' && exit 7
	[[ $length == 1 ]] && chosen=${selection[0]} && return

	echo "$2:"
	echo -----------------
	
	PS3="Choose number: "
	select chosen in "${selection[@]}"; do
		[[ -n $chosen ]] && break
	done < /dev/tty
}

function choose_default {
	echo 'initializing default values...'
	storage_size='20G'
	memory='2G'
	swap='2G'
	cpu=$(compute_cpu_cores)

	mapfile -t storages <<< $(pct-info list-zfs-pools)
	choose_from_selection storages "TYPE=ZFSPOOL STORAGE LIST"
	storage_disk=$chosen

	mapfile -t bridges <<< $(pct-info list-bridges)
	choose_from_selection bridges "BRIDGE LIST"
	bridge=$chosen

	cat >$DEFAULT_CONFIG <<EOF
STORAGE_DISK=\${STORAGE_DISK:-$storage_disk}
STORAGE_SIZE=\${STORAGE_SIZE:-$storage_size}
BRIDGE=\${BRIDGE:-$bridge}
MEMORY=\${MEMORY:-$memory}
SWAP=\${SWAP:-$swap}
CPU=\${CPU:-$cpu}
EOF
}

function perform {
	case "$COMMAND" in
    show)
      show_defaults
      ;;
    edit)
      editor $DEFAULT_CONFIG
      ;;
    config)
      choose_default    	
      ;;
    esac
}

# MAIN

set -Eue
parse_options $* 
perform