#!/usr/bin/env bash

add_email() {
    local alias="<${newAlias% *}"
    local emailAddress="<${newAlias##*<}"
    local ignoreList=(
        'amazon.com'
        'billing@'
        'do-not-reply'
        'donotreply'
        'github.com'
        'gitlab.com'
        'mailto'
        'no-reply'
        'noreply'
        'paypal.com'
        'walmart.com'
    )
    # Make the list into a format that works with bash regexp.
    ignoreList="${ignoreList[*]}"
    ignoreList="${ignoreList// /|}"
    # Do not add aliases with no alias-name
    if [[ "$alias" == "UNNAMED" ]]; then
        return
    fi
    # Try to filter out addresses that do not receive replies.
    if [[ "${emailAddress,,}" =~ ${ignoreList} ]]; then
        return
    fi
    # Do not add the same address twice.
    if grep -Fq "$emailAddress" $HOME/.mutt/aliases ; then
        return
    fi
    # Try to not use the same alias-name
    if grep -Fq " $alias " $HOME/.mutt/aliases; then
        alias="${alias}-${emailAddress#*@}"
        alias="${alias%.*}"
    fi
    if grep -Fq "$alias" $HOME/.mutt/aliases; then
        return
    fi
    echo "$newAlias" >> $HOME/.mutt/aliases
    sort -u ~/.mutt/aliases -o ~/.mutt/aliases
}

message=$(cat)
newAlias=$(echo "${message}" | grep ^"From: " | sed -e s/[\,\"\']//g -e s/'From: '//g | awk -F" " '{if (NF == 1) {print "alias UNNAMED UNNAMED " $0;} else if (NF == 2) {print "alias " $1" " toupper(substr($0,1,1)) tolower(substr($0,2));} else if (NF >= 3) {print "alias ", tolower($1)"-"tolower($(NF-1))" " toupper(substr($0,1,1)) tolower(substr($0,2));}}')
add_email
echo "${message}"