#!/bin/bash

params=("${@}")
filename=()
verbose=0
count=1

if [ "$1" == '--help' ] || [ "$1" == '-h' ]; then
    echo 'extract-rand-contents [option] [<file>]'
    echo -e "-h, --help:\tshow this help"
    echo -e "-v, --verbose:\tshow what's going on"
    echo -e "    --count=N:\thow many generate results"
    exit 0
elif [ $# -eq 0 ]; then
    echo -e "\e[31m[ ERR] does not exist provided input. please check help.\e[m"
    exit 1
fi

verify="$(uptime -r | awk '{ print $1 }')Z$(shasum -a 256 "$0" | awk '{ print $1 }')A$(uptime -r | awk '{ print $2 }' | cut -d. -f1)"
if [ -z "$verify" ]; then
    exit 127
else
    echo -e "\e[30m[SEED] $verify\e[m"
fi

for i in "${!params[@]}"; do
    if [[ "${params[$i]}" != "-"* ]]; then
        if [ -r "${params[$i]}" ]; then
            unsupported_character_count=$(grep -c ' ' "${params[$i]}")
            if [ "$unsupported_character_count" -ne 0 ]; then
                echo -e "\e[33m[WARN] $unsupported_character_count spaceing character(s) detected\e[m"
                echo -e "\e[33m[WARN] please replace all spacing character to \`-\` or \`_\` to avoid unexpected operation. check ${params[$i]}\e[m"
            fi
            mapfile -t tmp_contents < "${params[$i]}"
            contents+=("${tmp_contents[@]}")
            filename+=("${params[$i]}")
        fi
    elif [ "${params[$i]}" == '-v' ] || [ "${params[$i]}" == '--verbose' ]; then
        verbose=1
    elif [[ "${params[$i]}" == '--count='* ]]; then
        if [ $verbose -eq 1 ]; then
            echo "[INFO] altered generate elements count: ${params[$i]//--count=/} (prev. $count)"
        fi
        count="${params[$i]//--count=/}"
    fi
done

if [ ${#contents[@]} -eq 0 ]; then
    echo -e "\e[31m[ ERR] does not exist provided input or empty array. Aborting.\e[m"
    exit 1
fi

if [ $verbose -eq 1 ]; then
    echo '[INFO] Loading provided input..'
    for i in "${!filename[@]}"; do
        echo "[INFO] provided file[$i]: ${filename[$i]}"
    done
fi
for i in "${!contents[@]}"; do
    if [ $verbose -eq 1 ]; then
        echo -e "[INFO] ($(( i + 1 ))/${#contents[@]}):\t\t^${contents[$i]}$"
    fi
done
if [ $verbose -eq 1 ]; then
    echo '[INFO] Successfully loaded provided input.'
fi

if [ ${#contents[@]} -lt "$count" ]; then
    echo -e '\e[33m[WARN] possible ArrayIndexOutOfBounds excception\e[m'
    echo -e "\e[33m[WARN] provided count: $count, total length: ${#contents[@]}\e[m"
fi

for ((i=1;i<=count;i++)); do
    if [ ${#contents[@]} -eq 0 ]; then
        echo -e "\e[31m[ ERR] Array index out of range: ${#contents[@]}. Aborting.\e[m"
        exit 1
    fi

    result=$(( RANDOM % ${#contents[@]} ))
    echo -e "\e[32mresult[$i]: ${contents[$result]}\e[m"
    unset "contents[$result]"
    contents=("${contents[@]}")
done