#! /bin/bash

# This function reads tags of xml in the same way read normally reads lines.
function rdom
{
    local IFS=\>
    read -d \< element content
}

function tell_fact # thing channel
{
    thing="${1}"
    declare -l lower_case_thing="${thing}"
    channel="${2}"

    if [[ -s "info/${lower_case_thing}" ]]
    then
        # For the first entry we will say like: `thing is: '
        first="${thing} is: "

        uniq "info/${lower_case_thing}" |
        while read line
        do
            send_msg "${channel}" "${first}${line}"
            first=''
        done

        return
    else
        return 1
    fi
}

source common_codez

function remember_fact
{
    if grep "^${is}$" "info/${thing}" &>/dev/null
    then
        send_msg "${channel_it_came_from}" "${personoslash}: I know."
    else
        echo "${is}" >> "info/${thing}"
        send_msg "${channel_it_came_from}" "${personoslash}: Remembered."
    fi
}

function forget_fact
{
    number_of_matching_lines=$(grep -c "^${isnt}" "info/${thing}")

    case "${number_of_matching_lines}" in
        0 )
            send_msg "${channel_it_came_from}" "${personoslash}: I know."
            ;;
        1 )
            grep -v "^${isnt}" "info/${thing}" | sponge "info/${thing}"
            send_msg "${channel_it_came_from}" "${personoslash}: OK, entry removed."
            ;;
        * )
            send_msg "${channel_it_came_from}" "${personoslash}: Ambiguos."
            ;;
    esac
}

function translate_user
{
    send_msg "${channel_it_came_from}" "(not yet implemented)"
}

function translate_message
{
    # translate $message from english to spanish
    local translated_message=$(echo "${message}" | apertium en-es)

    [[ "${translated_message}" ]] && send_msg "${channel_it_came_from}" "$person said: ${translated_message}"
}

function process_event
{
    my_own_name='pbot'

    person="${sender%%!*}"

    # Remove any forward slashes.
    personoslash="${person//\/}"
    declare -l personoslashlower="${personoslash}"

    channel_it_came_from="$( echo ${line} | cut -d ' ' -f 3 )"

    # If it's a private message
    [[ "${channel_it_came_from}" == "${my_own_name}" ]] && channel_it_came_from="${personoslash}"


    ######################
    # Echo injected data #
    ######################

    # Should send a message like: echo 'This is the message' > /tmp/un-provoked-message-store
    injected_data=0
    line_filtered=${line##*PRIVMSG +([![:space:]]) :}

    if [[ ${personoslash} == ${INJECT_NICK} ]]
    then
        send_msg "${channel_it_came_from}" "${line_filtered}"
        injected_data=1
    fi
    # NOTE: this 'injected_data' clause is apparently the IPC mechanism
    #         used by the ./labs_change_detector script
    #         see ./labs_change_detector, transport/socat.sh, and transport/dev-tcp.sh
    #       the clause above was originally mutually exclusive
    #         with the remaining entirety of this function
    #         and it is the only place where 'injected_data' is set
    #       yet, 'injected_data' is tested below in the 'Page title getter' section
    #         so, presumably this 'injected_data' was intended to fall through?


    ###############################################################
    # This is a message from a user. Make preperations to process #
    ###############################################################

    the_time_now=$(date +%s)

    # Make this person a folder if they don't already have one.
    if ! [[ -d "announcements/people/${personoslashlower}" ]]
    then
        mkdir -p "announcements/people/${personoslashlower}"
    fi

    # Record that the person has been seen, and when.
    touch "announcements/people/${personoslashlower}/seen"

    shopt -s extglob

    # We want to get only the message part of the line
    sentence="${line#* }"
    sentence="${sentence#* }"
    sentence="${sentence#* :}"


    ##########################
    # Shared libraries error #
    ##########################

    # If someone complains about error while loading shared libraries error
    # then recomend them to the bug tracker.
    if [[ ${sentence} == *"error while loading shared libraries"* ]]
    then
        # Make sure they have not already been recommended to the bug
        # tracker less than one day ago.
        sharlibsrecfile="announcements/people/${personoslashlower}/shared_libs"

        # Have we recommended them to the bug tracker before?
        if [[ -f ${sharlibsrecfile} ]]
        then
            last_time=$( stat -c %Y ${sharlibsrecfile} )

            (( last_time > the_time_now - 86400 )) && rec_recent=1 || rec_recent=0
        else
            rec_recent=0
        fi

        if ! (( rec_recent ))
        then
            send_msg "${channel_it_came_from}" "${person}: please report a bug, specifying the exact error message, package of the failing command and architecture: http://labs.parabola.nu"
            touch "${sharlibsrecfile}"
        fi
    fi


    ##########
    # Repeat #
    ##########

    [[ ${sentence} != ${i_repeated} ]] && say_again=yesyes

    # If two different people say the same thing in a row then say it again for fun;
    # unless it was directed at me.
    if [[ ${sentence} == ${lastline} ]] && [[ ${person} != ${lastsender} ]] && \
       [[ ${say_again} != nono ]] && [[ ${sentence} != "${my_own_name}: "* ]]
    then
        send_msg "${channel_it_came_from}" "${sentence}"
        i_repeated="${sentence}"
        say_again=nono
    fi

    lastline="${sentence}"
    lastsender="${person}"


    #################
    # Announcements #
    #################

    # If someone has sent this person a message then echo it to them.
    if [[ -f "announcements/people/${personoslashlower}/messages" ]]
    then
        uniq "announcements/people/${personoslashlower}/messages" |
        while read line
        do
            # The first field is the time, in *nix seconds, that
            # the message was sent. The second is the name of the
            # sender. And the rest is the message.
            intermediate="${line#* }"
            sender_u="${intermediate%% *}"
            message_u="${intermediate#* }"
            time_sent="${line%% *}"

            seconds_ago_seen="$(( the_time_now - time_sent ))"
            minutes_ago_seen="$(( ( the_time_now - time_sent ) / 60 ))"
            hours_ago_seen="$(( ( the_time_now - time_sent ) / 3600 ))"
            days_ago_seen="$(( ( the_time_now - time_sent ) / 86400 ))"
            months_ago_seen="$(( ( the_time_now - time_sent ) / 2592000 ))"
            years_ago_seen="$(( ( the_time_now - time_sent ) / 31104000 ))"
            if (( seconds_ago_seen < 120 ))
            then
                units="${seconds_ago_seen} seconds"
            elif (( minutes_ago_seen < 120 ))
            then
                units="${minutes_ago_seen} minutes"
            elif (( hours_ago_seen < 48 ))
            then
                units="${hours_ago_seen} hours"
            elif (( days_ago_seen < 60 ))
            then
                units="${days_ago_seen} days"
            elif (( months_ago_seen < 24 ))
            then
                units="${months_ago_seen} months"
            else
                units="${years_ago_seen} years"
            fi

                send_msg "${channel_it_came_from}" "${personoslash}: ${sender_u} told me to tell you, (${units} ago): ${message_u}"
        done
        rm "announcements/people/${personoslashlower}/messages"
    fi


    #####################
    # Page title getter #
    #####################

    # We don't want to get the page title if it's injected data
    # nor if it probably came from a spambot
    if [[ ${line} =~ http://[^\ ]+ ]] || [[ ${line} =~ https://[^\ ]+ ]] && (( ! injected_data ))
    then
        url_to_get="${BASH_REMATCH}"
        the_title=$(
            curl -L --compressed "${url_to_get}" 2> /dev/null |
            while rdom
            do
                if [[ ${element} = title ]] || [[ ${element} = TITLE ]]
                then
                    sed 's/  / /g' <<< "${content}" | replace_wierd_html_chars
                fi
            done
        )

        if ! [[ -z ${the_title} ]]
        then
            send_msg "${channel_it_came_from}" "Page title: \`${the_title}'"
        fi
    fi


    ######################
    # main chat triggers #
    ######################

    case "${sentence}" in


        #########
        # hello #
        #########

        hello|hi)
            send_msg "${channel_it_came_from}"  "hello ${person}, it works!!!"
            ;;


        ########
        # Seen #
        ########

        "${my_own_name}: when did you last see"* )
            subject="${sentence##${my_own_name}: when did you last see }"
            subject="${subject##${my_own_name}: when did you last see: }" # If there's an `:', we can still handle it.
            subject="${subject%\?}"
            subject="${subject%% *}"
            declare -l subjectlower="${subject}"

            if [[ "${subject}" == ${my_own_name} ]]
            then
                send_msg "${channel_it_came_from}" "I last saw ${subject} speak 0 seconds ago."
            elif [[ -f "announcements/people/${subjectlower}/seen" ]]
            then
                seconds_ago_seen="$(( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ))"
                minutes_ago_seen="$(( ( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ) / 60 ))"
                hours_ago_seen="$(( ( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ) / 3600 ))"
                days_ago_seen="$(( ( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ) / 86400 ))"
                months_ago_seen="$(( ( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ) / 2592000 ))"
                years_ago_seen="$(( ( the_time_now - $( stat -c %Y announcements/people/${subjectlower}/seen ) ) / 31104000 ))"
                if (( seconds_ago_seen < 120 ))
                then
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${seconds_ago_seen} seconds ago."
                elif (( minutes_ago_seen < 120 ))
                then
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${minutes_ago_seen} minutes ago."
                elif (( hours_ago_seen < 48 ))
                then
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${hours_ago_seen} hours ago."
                elif (( days_ago_seen < 60 ))
                then
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${days_ago_seen} days ago."
                elif (( months_ago_seen < 24 ))
                then
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${months_ago_seen} months ago."
                else
                    send_msg "${channel_it_came_from}" "I last saw ${subject} speak ${years_ago_seen} years ago."
                fi
            else
                send_msg "${channel_it_came_from}" "I never saw ${subject} speak."
            fi
            ;;


        ########
        # tell #
        ########

        "${my_own_name}: tell "+([![:space:]])":"+([[:space:]])+([![:space:]])* )
            # The line will be something such as:
            # pbot: tell fauno: you suck
            process="${sentence##${my_own_name}: tell }"
            subject="${process%%:*}"
            message="${process#*:}"
            message="${message# }"

            if [[ "${subject}" == "${my_own_name}" ]]
            then
                send_msg "${channel_it_came_from}" "${my_own_name}: ${personoslash} told me to tell you, (0 seconds ago): ${message}"
            else
                declare -l subjectlower="${subject}"

                [[ -d "announcements/people/${subjectlower}" ]] || mkdir -p "announcements/people/${subjectlower}"
                # The time in *nix seconds is saved there so that
                # pbot can say how long ago the massage was sent
                # when he gives it to it's recipient.
                echo "$(date +%s) ${personoslash} ${message}" >> "announcements/people/${subjectlower}/messages"

                response='certainly'

                send_msg "${channel_it_came_from}" "${personoslash}: ${response}"

                if ! [[ -f "announcements/people/${subjectlower}/seen" ]]
                then
                    send_msg "${channel_it_came_from}" "${personoslash}: WARNING: I HAVE NEVER SEEN \"${subject}\" HERE BEFORE. CHECK YOUR SPELLING."
                fi
            fi
            ;;


        ############
        # factoids #
        ############

        "${my_own_name}: "+([!/])" is "+([![:space:]])* )
            declare -l thing="${sentence#${my_own_name}: }"
            thing="${thing%% is *}"
            is="${sentence#* is }"

            remember_fact
            ;;
        "${my_own_name}: "+([!/])" is: "+([![:space:]])* )
            declare -l thing="${sentence#${my_own_name}: }"
            thing="${thing%% is: *}"
            is="${sentence#* is: }"

            remember_fact
            ;;
        "${my_own_name}: "+([![:space:]])" isn't "+([![:space:]])* )
            declare -l thing="${sentence#${my_own_name}: }"
            thing="${thing%% isn\'t *}"
            isnt="${sentence#* isn\'t }"

            forget_fact
            ;;
        "${my_own_name}: "+([![:space:]])" isn't: "+([![:space:]])* )
            declare -l thing="${sentence#${my_own_name}: }"
            thing="${thing%% isn\'t: *}"
            isnt="${sentence#* isn\'t: }"

            forget_fact
            ;;
        ','+([!/]) )
            thing="${sentence#,}"

            tell_fact "${thing}" "${channel_it_came_from}"
            ;;


        #############
        # Footnotes #
        #############

        *\[[[:digit:]]\]* )
            declare -a fn

            while read -d $'\0' file
            do
                #if match = grep "${file##*/}[ ]\?\[[[:digit:]]\]" <<< "${sentence}"
                filename="${file##*/}"

                declare -l lowersentence="${sentence}"

                if [[ " ${lowersentence}" =~ [^[:alnum:]]${filename}[\ ]?\[[[:digit:]]\] ]]
                then
                    index="${BASH_REMATCH: -2:1}"

                    fn[${index}]=$(head -1 "${file}")
                fi
            done < <(find info -print0)

            for (( n=0 ; n<50 ; n++ ))
            do
                str="${fn[${n}]}"

                [[ -z "${str}" ]] && continue

                send_msg "${channel_it_came_from}" "[${n}] ${str}"
            done
            ;;


        #############
        # translate #
        #############

        "${my_own_name}: translate "+([![:space:]])* )
            local message="${sentence#* translate }"
            local nick="$(echo "${message%% *}" | tr -d '/')"

            if   [[ -n "${nick}" ]] && [[ ${nick} != ${my_own_name} ]]
            then if [[ -d announcements/people/${nick} ]]
                  then translate_user
                  else translate_message
                  fi
            fi
            ;;


        ########################
        # unrecognised command #
        ########################

        ${my_own_name}:* | ','* )
            while read line
            do
                send_msg "${personoslash}" "${line}"
            done <<< cat << EOF
Command not recognised. Example commands:
${my_own_name}: tell Jack: hi Jack
${my_own_name}: when did you last see Jill?
${my_own_name}: lemon is yummy
${my_own_name}: lemon isn't yummy
,lemon
EOF
            ;;
    esac

# ' this comment fixes a bug in emacs shell-script-mode that messes up the syntax highlighting

    # I'm dissabling this feature for now as it was being abused
    # and would need an overhaul to be abuse-proof + nobody uses it afaik
    # ##########################
    # # tell someone something #
    # ##########################

    # # TODO: this should be in the case statement

    # if [[ "${sentence}" =~ ${my_own_name}: tell\ [^\ ]+\ about\ [^\ ]+ ]]
    # then
    #     # TODO: There should be the following three constraints to
    #     # prevent abuse.
    #     # 1. People may only ask the bot to tell someone about
    #     #    something in the #parabola channel, not by query.
    #     # 2. pbot will only tell someone something if they're a user
    #     #    he has seen in the past week
    #     # 3. each person may use tell no more than 10 times in
    #     #    three hours.

    #     gotit="${BASH_REMATCH}" # will be like: `,tell jack about blah'

    #     dudep1="${gotit#,tell }"
    #     dude="${dudep1%% *}"
    #     thing="${gotit##* }"

    #     if [[ -n "${dude}" ]] && [[ -n "${thing}" ]]
    #     then
    #         tell_fact "${thing}" "${dude}" || send_msg "${channel_it_came_from}" "${personoslash}: Error, failed to tell ${dude} about ${thing}"
    #     fi
    # fi

    # TODO: add a birthday announcement feature, cointoss feature, timer
    # feature.

    #########
    # Tests #
    #########

    #echo "${line}"
}