#!/bin/bash

# This script has the lofty goal of becoming a full configuration utility for mutt.
# Written by Storm Dragon: https://social.stormdragon.tk/storm
# Written by Michael Taboada: https://2mb.social/mwtab
# This is a 2MB Solutions project: https://2mb.solutions
# Released under the terms of  the WTFPL: http://wtfpl.net

# Variables
muttHome=~/.muttest

# Functions
check_dependancies()
{
   if ! command -v gpg &> /dev/null ; then
        echo "gpg is not installed. Please install gnupg and run this script again."
        exit 1
     fi
    if ! [ -d ~/.gnupg ]; then
        read -p "No configuration for GPG was found. to have ${0##*/} configure this for you, select Configure GPG from the main menu. Press enter to continue. " continue
    fi
}

initialize_directory()
{
    if ! [ -d "$muttHome" ]; then
        mkdir -p "$muttHome"
    fi
    if ! [ -f "$muttHome/mailcap" ]; then
        # Find desired browser
        local x=0
        for i in\
        chromium\
        elinks\
        epiphany\
        firefox\
        google-chrome\
        links\
        lynx\
        midori\
        seamonkey
        do
            unset browserPath
            browserPath="$(command -v $i)"
            if [ -n "$browserPath" ]; then
                browsers[$x]="$browserPath"
                ((x++))
            fi
        done
        echo "Select browser for viewing html email:"
        select i in "${browsers[@]##*/}" ; do
            browserPath="$i"
            if [ -n "$browserPath" ]; then
                break
            fi
        done
        case "${browserPath##*/}" in
            "elinks")
                echo "text/html; $browserPath -dump -force-html -dump-charset utf-8 -no-numbering %s; nametemplate=%s.html; copiousoutput" > "$muttHome/mailcap"
            ;;
            "lynx")
                echo "text/html; $browserPath -dump %s; nametemplate=%s.html; copiousoutput" > "$muttHome/mailcap"
            ;;
            *)
                echo "text/html; $browserPath %s; nametemplate=%s.html; copiousoutput" > "$muttHome/mailcap"
        esac
        if command -v antiword &> /dev/null ; then
            echo "application/msword; $(command -v antiword) %s; copiousoutput" >> "$muttHome/mailcap"
        fi
    fi
    if ! [ -f "$muttHome/gpg.rc" ]; then
        cp "/usr/share/doc/mutt/samples/gpg.rc" "$muttHome/"
        echo "set pgp_autosign=yes" >> "$muttHome/gpg.rc"
        echo "set crypt_autosign=yes" >> "$muttHome/gpg.rc"
        echo "set pgp_replyencrypt=yes" >> "$muttHome/gpg.rc"
        echo "set pgp_timeout=1800" >> "$muttHome/gpg.rc"
        if ! gpg --list-secret-keys | grep '.*@.*' &> /dev/null ; then
            read -p "No gpg key was found. Press enter to generate one now, or control+c if you would like to do so manually. Note, the default values are usually what you want." continue
            gpg --gen-key
        fi
        echo "Select the key you want to use for encryption/signing:"
        select key in $(gpg --list-secret-keys | grep '.*@.*' | cut -d '<' -f2 | cut -d '>' -f1) ; do
            if [ -n "$key" ]; then
                break
            fi
        done
        keyName="$(gpg --fingerprint $key | head -n 2 | tail -n 1 | rev | cut -d ' ' -f-2 | tr -d "[:space:]" | rev)"
        echo "set pgp_sign_as=$keyName" >> "$muttHome/gpg.rc"
    fi
}

configure_gpg()
{
    # GPG stuff in .bashrc:
    if ! grep 'GPG_TTY=$(tty)'  ~/.bashrc ; then
        echo -e 'GPG_TTY=$(tty)\nexport GPG_TTY' >> ~/.bashrc
    fi
    # Make sure the configuration directory exists
if ! [ -d !/.gnupg/ ]; then
        mkdir -p ~/.gnupg
    fi
    if [ -f !/.gnupg/gpg.conf ]; then
        read -p "This will overwrite your existing ~/.gnupg/gpg.conf file. Press enter to continue or control+c to abort. " continue
    fi
    cat << EOF > ~/.gnupg/gpg.conf
charset utf-8
require-cross-certification
no-escape-from-lines
no-mangle-dos-filenames
personal-digest-preferences SHA512
cert-digest-algo SHA512
use-agent
default-preference-list SHA512 SHA384 SHA256 SHA224 AES256 AES192 AES CAST5 ZLIB BZIP2 ZIP Uncompressed
keyserver wwwkeys.pgp.net
keyserver hkp://pool.sks-keyservers.net
keyserver pgp.zdv.uni-mainz.de
keyserver-options auto-key-retrieve
EOF
}

add_email_address()
{
    read -p "Please enter your email address: " emailAddress
    if ! [[ "$emailAddress" =~ .*@.*\..* ]]; then
        read -p "this appears to be an invalid email address. Continue anyway? " continue
        if [ "${continue^}" != "Y" ]; then
            exit 0
        fi
    fi
    if [ -f "$muttHome/$emailAddress" ]; then
        read -p "This email address already exists. Overwrite the existing settings? " continue
        if [ "${continue^}" != "Y" ]; then
            exit 0
        fi
    fi
    case "$emailAddress" in
        *gmail.com)
            configure_gmail "$emailAddress"
        ;;
        *hotmail.com)
            configure_hotmail "$emailAddress"
        ;;
    esac
    # Password encryption with gpg
    passOne=a
    passTwo=b
    until [ "$passOne" = "$passTwo" ]; do
        read -sp "Please enter the password for $emailAddress: " passOne
        echo
        read -sp "Please enter the password again: " passTwo
        echo
        if [ "$passOne" != "$passTwo" ]; then
            echo "The passwords do not match."
        fi
    done
    keyName="$(grep 'pgp_sign_as=' "$muttHome/gpg.rc" | cut -d '=' -f2)"
    keyName="$(gpg --list-secret-keys $keyName | grep '.*@.*' | cut -d '<' -f2 | cut -d '>' -f1)"
    # I wish it were possible to just echo the password through gpg and not have an unencrypted file at all.
    # but either it's not, or I just can't figure out how to do it. So we'll use mktemp and shred.
    passwordFile="$(mktemp)"
    echo -e "set imap_pass=\"$passOne\"\nset smtp_pass=\"$passOne\"" > "$passwordFile"
    gpg -r $keyName -e "$passwordFile"
    mv "$passwordFile.gpg" "$muttHome/$emailAddress.gpg"
    shred -fuzn 10 "$passwordFile" 
    echo "Email address added, press enter to continue."
}

configure_gmail()
{
    # This is just to create the base file with settings common to all gmail accounts
    # I decided to do these in functions so as to not have a truly giagantic case statement in the add email function
    echo "unset imap_passive" > "$muttHome/$1"
echo "unset record" >> "$muttHome/$1"
echo "set imap_user=$1" >> "$muttHome/$1"
echo "set smtp_url=\"smtp://${1%@*}@smtp.gmail.com:587/" >> "$muttHome/$1"
echo "set folder=imaps://${1%@*}@imap.gmail.com/" >> "$muttHome/$1"
echo "mailboxes=+INBOX" >> "$muttHome/$1"
echo "set postponed=+[Gmail]/Drafts" >> "$muttHome/$1"
echo "set imap_keepalive=300" >> "$muttHome/$1"
echo "set mail_check=300" >> "$muttHome/$1"
echo "bind editor <Tab> complete-query" >> "$muttHome/$1"
    unset continue
    if command -v goobook &> /dev/null ; then
        read -p "Goobook is installed, would you like to use it as your addressbook for the account $1? " continue
    fi
    if [ "${continue^}" = "Y" ]; then
        echo "set query_command=\"goobook query %s\"" >> "$muttHome/$1"
        # Normally macros go in muttHome/macros, but this may be a gmail specific setting
        echo "macro index,pager a \"<pipe-message>goobook add<return>\" \"add sender to google contacts\"" >> "$muttHome/$1"
    else
        echo "source ~/${muttHome#/home/*/}/aliases" >> "$muttHome/$1"
    fi
}

configure_hotmail()
{
    # This is just to create the base file with settings common to all hotmail accounts
    # I decided to do these in functions so as to not have a truly giagantic case statement in the add email function
    echo "unset imap_passive" > "$muttHome/$1"
echo "unset record" >> "$muttHome/$1"
    echo "set from=$1" >> "$muttHome/$1"
echo "set imap_user=$1" >> "$muttHome/$1"
echo "set smtp_url=\"smtp://$1@smtp-mail.outlook.com:587/" >> "$muttHome/$1"
echo "set folder=imaps://$1@imap-mail.outlook.com/" >> "$muttHome/$1"
echo "set ssl_force_tls=yes" >> "$muttHome/$1"
echo "mailboxes=+INBOX" >> "$muttHome/$1"
echo "set postponed=+[hotmail]/Drafts" >> "$muttHome/$1"
echo "set imap_keepalive=300" >> "$muttHome/$1"
echo "set mail_check=300" >> "$muttHome/$1"
echo "bind editor <Tab> complete-query" >> "$muttHome/$1"
    echo "source ~/${muttHome#/home/*/}/aliases" >> "$muttHome/$1"
}

# This is the main loop of the program
# Call functions to be ran every time the script is ran.
check_dependancies
initialize_directory
# Let's make a mainmenu variable to hold all the options for the select loop.
mainmenu=('Add Email Address' 'Configure GPG' 'Exit')
echo "Main menu:"
select i in "${mainmenu[@]}" ; do
    functionName="${i,,}"
    functionName="${functionName// /_}"
    functionName="${functionName/exit/exit 0}"
    $functionName
done

exit 0