#!/bin/bash

FIELD_TYPES=(string str integer int raw)

function show_help() {
	echo "usage: twnet [action] [options]"
	echo "options:"
	echo "  --help | -h    show this help"
	echo "actions:"
	echo "  generate | g   generate a ruby file. See $(tput bold)twnet g --help$(tput sgr0)"
}

function is_camel_case() {
	[[ "$1" =~ ^([A-Z][a-z]+)+$ ]] && return 0
	return 1
}

function is_snake_case() {
	[[ "$1" =~ ^[a-z][a-z_]*[a-z]$ ]] && return 0
	return 1
}

function split_camel_case() {
	local str="$1"
	local words=()
	local word=''
	while read -n1 -r c
	do
		if [[ "$c" =~ [A-Z] ]]
		then
			if [ "$word" != "" ]
			then
				words+=("${word,}")
				word=''
			fi
		fi
		word+="$c"
	done < <(echo -n "$str")
	if [ "$word" != "" ]
	then
		words+=("${word,}")
		word=''
	fi
	echo "${words[*]}"
}

function split_snake_case() {
	local str="$1"
	local words=()
	local word=''
	while read -n1 -r c
	do
		if [[ "$c" == '_' ]]
		then
			if [ "$word" != "" ]
			then
				words+=("${word,}")
				word=''
			fi
		else
			word+="$c"
		fi
	done < <(echo -n "$str")
	if [ "$word" != "" ]
	then
		words+=("${word,}")
		word=''
	fi
	echo "${words[*]}"
}

function camel_to_snake_case() {
	local camel="$1"
	local w
	local snake=''
	for w in $(split_camel_case "$camel")
	do
		snake+="_$w"
	done
	echo "${snake:1}"
}

function snake_to_camel_case() {
	local snake="$1"
	local w
	local camel=''
	for w in $(split_snake_case "$snake")
	do
		camel+="${w^}"
	done
	echo "$camel"
}

function action_generate_help() {
	echo "usage: twnet generate <type> <name> [fields..]"
	echo "options:"
	echo "  --help | -h       show this help"
	echo "type:"
	echo "	server_packet | srv_pck | sp     packet sent from server to client"
	echo "	client_packet | cl_pck | cp      packet sent from client to server"
	echo "name:"
	echo "  will be the packet name use UpperCamelCase"
	echo "  for example ClSay"
	echo "fields:"
	echo "  the formate is field_name:field_type"
	echo "  the allowed types are: ${FIELD_TYPES[*]}"
	echo "  examples:"
	echo "   target_id:int"
	echo "   message:str"
	echo "examples:"
	echo "  generate a cl_say.rb file describing a packet that"
	echo "  is sent from the client to the server has the class name ClSay"
	echo "  and two fields first target_id (integer) then message (string)"
	echo ""
	tput bold
	echo "    twnet generate cp ClSay target_id:int message:str"
	tput sgr0
}

function action_generate() {
	local arg
	local arg_type=''
	local arg_name=''
	local field_name
	local field_type
	local fields
	local valid_type
	declare -A fields
	if [ "$#" -eq "0" ]
	then
		action_generate_help
		exit 1
	fi
	while true
	do
		[[ "$#" -eq "0" ]] && break

		arg="$1"
		shift

		if [ "${arg::1}" == "-" ]
		then
			if [ "$arg" == "--help" ] || [ "$arg" == "-h" ]
			then
				action_generate_help
				exit 0
			fi
		else
			if [ "$arg_type" == "" ]
			then
				arg_type="$arg"
			elif [ "$arg_name" == "" ]
			then
				arg_name="$arg"
				# tried to be smart with regex and failed
				# if [[ "$arg_name" =~ ([A-Z][a-z]*)+ ]]
				# then
				# 	for b in "${BASH_REMATCH[@]}"
				# 	do
				# 		echo "b: $b"
				# 	done
				# else
				# 	echo "Error: name '$arg_name' has to be UpperCamelCase"
				# 	exit 1
				# fi
				if ! is_camel_case "$arg_name"
				then
					echo "Error: name '$arg_name' has to be UpperCamelCase"
					exit 1
				fi
				# local w
				# for w in $(split_camel_case "$arg_name")
				# do
				# 	echo "w: $w"
				# done
			elif [[ "$arg" =~ (.*):(.*) ]]
			then
				field_name="${BASH_REMATCH[1]}"
				field_type="${BASH_REMATCH[2]}"
				fields["$field_name"]="$field_type"
				local valid=0
				for valid_type in "${FIELD_TYPES[@]}"
				do
					if [ "$valid_type" == "$field_type" ]
					then
						valid=1
						break
					fi
				done
				if [ "$valid" == "0" ]
				then
					echo "Error: '$field_type' is not a valid field type"
					echo "       valid types are: ${FIELD_TYPES[*]}"
					exit 1
				fi
				if ! is_snake_case "$field_name"
				then
					echo "Error: '$field_name' is not a valid field name"
					echo "       field names have to be lower_snake_case"
					exit 1
				fi
			else
				echo "Error: unkown argument '$arg' try $(tput bold)twnet g --help$(tput sgr0)"
				exit 1
			fi
		fi
	done
	if [ "$arg_type" == "" ]
	then
		echo "Error: type can not be empty $(tput bold)twnet g --help$(tput sgr0)"
		exit 1
	fi
	if [ "$arg_name" == "" ]
	then
		echo "Error: name can not be empty $(tput bold)twnet g --help$(tput sgr0)"
		exit 1
	fi
	for field_name in "${!fields[@]}"
	do
		field_type="${fields[$field_name]}"
		# echo "field"
		# echo "  name: $field_name"
		# echo "  type: $field_type"
	done
}

function parse_args() {
	local arg
	while true
	do
		[[ "$#" -eq "0" ]] && break

		arg="$1"
		shift

		if [ "${arg::1}" == "-" ]
		then
			if [ "$arg" == "--help" ] || [ "$arg" == "-h" ]
			then
				show_help
				exit 0
			fi
		else
			if [ "$arg" == "generate" ] || [ "$arg" == "g" ]
			then
				action_generate "$@"
				exit
			else
				echo "Error: unkown action '$arg'"
				exit 1
			fi
		fi
	done
}

if [ "$#" -eq "0" ]
then
	show_help
	exit 1
fi

parse_args "$@"