#!/bin/sh

all_processors() {
    grep -E '(processor|core id)' /proc/cpuinfo | while : ; do
        read -r line0 || break
        read -r line1 || break
        if echo "$line0" | grep -q 'processor'; then
            processor="$(echo "$line0" | sed -En 's/^[^0-9]*([0-9]+)$/\1/p')"
            core="$(echo "$line1" | sed -En 's/^[^0-9]*([0-9]+)$/\1/p')"
        elif echo "$line1" | grep -q 'processor'; then
            processor="$(echo "$line1" | sed -En 's/^[^0-9]*([0-9]+)$/\1/p')"
            core="$(echo "$line0" | sed -En 's/^[^0-9]*([0-9]+)$/\1/p')"
        fi
        echo "$processor $core"
    done
}

take_host_processors() {
    all_processors | sort -hk2 | head -n$1
}

take_vm_processors() {
    all_processors | sort -hk2 | tail -n+$(($1+1))
}

_compress_seq_sub() {
    first="$(echo "$@" | awk '{print $1}')"
    last="$(echo "$@" | awk '{print $NF}')"
    if [ $first = $last ]; then
        printf '%s,' "$first"
    else
        printf '%s-%s,' "$first" "$last"
    fi
}

_compress_seq() {
    buffer=
    while read -r item; do
        if [ -z "$buffer" ]; then
            buffer=$item
            continue
        fi
        if [ $(($(echo "$buffer" | awk '{print $NF}')+1)) -eq $item ]; then
            buffer="$buffer $item"
        else
            _compress_seq_sub $buffer
            buffer=$item
        fi
    done
    _compress_seq_sub $buffer
    echo
}

compress_seq() {
    _compress_seq | rev | cut -c2- | rev
}

_decompress_seq() {
    (
        IFS=,
        for item in $@; do
            if echo "$item" | grep -q '-'; then
                num0="$(echo "$item" | awk -F- '{print $1}')"
                num1="$(echo "$item" | awk -F- '{print $2}')"
                printf '%s ' "$(seq $num0 $num1 | xargs echo)"
            else
                printf '%s ' $item
            fi
        done
        echo
    )
}

decompress_seq() {
    _decompress_seq "$1" | rev | cut -c2- | rev
}

check_argument_is_number() {
    if [ -z "$1" ]; then
        echo "Error: must specify number of processors" >&2
        return 1
    fi
    if [ "$1" -eq "$1" ] 2>/dev/null; then
        true
    else
        echo "Error: provided argument '$1' is not a number" >&2
        return 1
    fi
}

compute_all() {
    all_processors | sort -hk1 | awk '{print $1}' | compress_seq
}

compute_host() {
    if ! check_argument_is_number $1; then
        return $?
    fi
    take_host_processors $1 | sort -hk1 | awk '{print $1}' | \
        compress_seq
}

compute_vm() {
    if ! check_argument_is_number $1; then
        return $?
    fi
    take_vm_processors $1 | sort -hk1 | awk '{print $1}' | \
        compress_seq
}

processors_per_core() {
    processor_count=$(all_processors | awk '{print $1}' | sort -h | uniq | wc -l)
    core_count=$(all_processors | awk '{print $2}' | sort -h | uniq | wc -l)
    echo $((processor_count/core_count))
}

"$@"