#!/bin/bash
set -euo pipefail

# =====================================================
# bash-ini v1.0.0 | (c) 2024 DrMaxNix | www.drmaxnix.de
# =====================================================

#
# Parse a ini config file.
#
# @param $1		Path to ini file.
# @param $2		(Optional) prefix for output variable names.
#
ini_parse(){
	## VALIDATE PATH ##
	# get from param
	local path="$1"
	
	# make sure it is readable
	if [[ ! -r "$path" ]]; then
		ini_log_error "Unable to read config file '$path'"
	fi
	
	
	## VAR PREFIX ##
	# get from param or fallback
	local var_prefix="${2:-ini}"
	
	# validate format
	if [[ ! "$var_prefix" =~ ^[a-z0-9]+(_[a-z0-9]+)*$ ]]; then
		ini_log_error "Invalid variable prefix '$var_prefix'"
	fi
	
	# build global var names
	local -n out_section_list="${var_prefix}"
	
	
	local line
	local section_name
	while IFS= read -r line; do
		## TRIM WHITESPACES ##
		line=$(echo "$line" | sed -E "s/^\s*//g" | sed -E "s/\s*$//g")
		
		
		## IGNORE LINES ##
		# empty lines
		if [[ "$line" == "" ]]; then
			# ignore
		continue; fi
		
		# comments
		if [[ "$line" =~ ^# || "$line" =~ ^\; ]]; then
			# ignore
		continue; fi
		
		
		## MATCH SECTION HEADER ##
		if [[ "$line" =~ ^\[.*\]$ ]]; then
			# get section name
			section_name=$(echo "$line" | sed -E "s/^\[(.*)\]$/\1/g")
			
			# trim whitespaces
			section_name=$(echo "$section_name" | sed -E "s/^\s*//g" | sed -E "s/\s*$//g")
			
			# validate format
			if [[ ! "$section_name" =~ ^[A-Za-z0-9]+([\._-][A-Za-z0-9]+)*$ ]]; then
				ini_log_error "Invalid section name '$section_name'"
			fi
			
			# rewrite section name
			section_name=$(echo "$section_name" | tr 'A-Z' 'a-z' | tr '-' '_' | tr '.' '_')
			
			# maybe add to section list
			local found="no"
			for s in ${out_section_list[*]:-}; do
				if [[ "$s" == "$section_name" ]]; then found="yes"; break; fi
			done
			if [[ "$found" != "yes" ]]; then
				out_section_list=(${out_section_list[@]:-""} "$section_name")
			fi
			
			# declare section map
			section_map_varname="${var_prefix}__${section_name}"
			declare -g -A ${section_map_varname}
		continue; fi
		
		
		## MATCH ASSIGNMENT ##
		if [[ "$line" =~ ^([A-Za-z0-9]+([\._-][A-Za-z0-9]+)*)[[:space:]\t]*=[[:space:]\t]*(.*)$ ]]; then
			# maybe enter root section
			if [[ ! "${section_name:+x}" ]]; then
				section_name="_root"
				out_section_list=(${out_section_list[@]:-""} "$section_name")
				section_map_varname="${var_prefix}__${section_name}"
				declare -g -A ${section_map_varname}
			fi
			
			# get key and value
			local key=$(echo "$line" | sed -E "s/^([A-Za-z0-9]+([\._-][A-Za-z0-9]+)*)[ \t]*=[ \t]*(.*)$/\1/g")
			local value=$(echo "$line" | sed -E "s/^([A-Za-z0-9]+([\._-][A-Za-z0-9]+)*)[ \t]*=[ \t]*(.*)$/\3/g")
			
			# maybe trim quote marks
			if [[ "$value" =~ ^\".*\"$ ]]; then
				value=$(echo "$value" | sed -E "s/^\"(.*)\"$/\1/g")
			elif [[ "$value" =~ ^\'.*\'$ ]]; then
				value=$(echo "$value" | sed -E "s/^'(.*)'$/\1/g")
			fi
			
			# maybe add key to key list
			local -n out_section_key_list="${var_prefix}__${section_name}__key_list"
			local found="no"
			for k in ${out_section_key_list[*]:-}; do
				if [[ "$k" == "$key" ]]; then found="yes"; break; fi
			done
			if [[ "$found" != "yes" ]]; then
				out_section_key_list=(${out_section_key_list[@]:-""} "$key")
			fi
			
			# set value in section map
			local -n out_section_map="${var_prefix}__${section_name}"
			out_section_map[$key]="$value"
		continue; fi
		
		
		## UNKNOWN ##
		ini_log_error "Unknown config string '$line'"
	done < "$path"
}



#
# HELPER: try calling external logger, else use fallback.
#
# @param $1		Message to print.
#
ini_log_debug(){
	if [[ "$(type -t log_debug)" == "function" ]]; then log_debug "$1"; return; fi
	echo "[DEBUG] $1" 1>&2
}
ini_log_info(){
	if [[ "$(type -t log_info)" == "function" ]]; then log_info "$1"; return; fi
	echo "[INFO ] $1" 1>&2
}
ini_log_warn(){
	if [[ "$(type -t log_warn)" == "function" ]]; then log_warn "$1"; return; fi
	echo "[WARN ] $1" 1>&2
}
ini_log_error(){
	if [[ "$(type -t log_error)" == "function" ]]; then log_error "$1"; return; fi
	echo "[ERROR] $1" 1>&2
	exit 1
}