#!/bin/bash
# Общественное достояние, 2024, Алексей Безбородов (Alexei Bezborodov) <AlexeiBv+mirocod_parse_arg_lib@narod.ru> 

# Обработка входных параметров

# Формат:
# "Однобуквенная команда|Расширенная команда|Справка|Параметр|Значение по умолчанию|Команда на исполнение"
# Параметр: Пусто - нет параметров, : - есть параметр, :: - параметр не обязателен

# Пример
#common_params=(
#    "i|input|Входной текстовый файл.|:|'1.txt'|"
#    )

function ProcessParams {
    local iparams=$1[@]
    local work_func=$2
    local params=("${!iparams}")
    local custom_arg1="$3"
    local custom_arg2="$4"

    SAVE_IFS=$IFS
    IFS=""

    for (( i=0; i< ${#params[*]}; i++))
    do
        p="${params[i]}"
        readarray -d "|" -t cur_params <<< "$p"
        small_cmd="${cur_params[0]}"
        large_cmd="${cur_params[1]}"
        comment="${cur_params[2]}"
        use_param="${cur_params[3]}"
        default="${cur_params[4]}"
        custom_cmd="${cur_params[5]}"

        $work_func "$small_cmd" "$large_cmd" "$comment" "$use_param" "$default" "$custom_cmd"  "$custom_arg1" "$custom_arg2"
    done

    IFS=$SAVE_IFS
}

param_var='local small_cmd="$1";local large_cmd="$2";local comment="$3";local use_param="$4";local default="$5";local custom_cmd="$6";local custom_arg1="$7";local custom_arg2="$8";'

function Params2InitVar {
    eval "$param_var"

    if [ "$use_param" != '' ]; then
        eval "${large_cmd}=${default}"
    fi
}

function Params2Help {
    eval "$param_var"

    echo "-${small_cmd}, -${large_cmd}, --${large_cmd}"
    echo "        ${comment/"!DEFAULT!"/"${!large_cmd}"}"
}

function Params2small_list {
    eval "$param_var"

    echo -n "${small_cmd}${use_param}"
}

function Params2large_list {
    eval "$param_var"

    echo -n ",${large_cmd}${use_param}"
}

function Params2Case {
    eval "$param_var"

    if [ "$custom_arg1" = "-${small_cmd}" ] || [ "$custom_arg1" = "-${large_cmd}" ] || [ "$custom_arg1" = "--${large_cmd}" ]; then
        clear_custom_cmd="${custom_cmd//[$'\t\r\n ']/}" 
        if [ "${clear_custom_cmd}" != "" ]; then
            eval "${custom_cmd}"
        else
            eval "${large_cmd}=\"$custom_arg2\""
        fi
    fi
}

# Инициализация переменных
ProcessParams all_params Params2InitVar

# $@ is all command line parameters passed to the script.
# -o is for short options like -v
# -l is for long options with double dash like --version
# the comma separates different long options
# -a is for long options with single dash like -version
# Example
# 'h' is a no-value option.
# 'v:' implies that option -v has value and is a mandatory option. ':' means has a value.
# 't::' implies that option -t has value but is optional. '::' means optional.
small_params_list=$(ProcessParams all_params Params2small_list)
small_params_list="${small_params_list:1}"

large_params_list=$(ProcessParams all_params Params2large_list)
large_params_list="${large_params_list:1}"

options=$(getopt --long "$large_params_list" -o "$small_params_list" -a -- "$@")

# set --:
# If no arguments follow this option, then the positional parameters are unset. Otherwise, the positional parameters 
# are set to the arguments, even if some of them begin with a ‘-’.
eval set -- "$options"