#!/bin/bash

fgaddon_url=https://sourceforge.net/p/flightgear/fgaddon/HEAD/tree/trunk/Aircraft

fgaddon_svn=https://svn.code.sf.net/p/flightgear/fgaddon/trunk/Aircraft

fgaddon_path=$HOME/.fgfs/flightgear-addons/Aircraft

attribute_regex='s/^.*id="l[0-9]+" class="code_block">.*<span class="nt">&lt;__attribute__&gt;<.span>(.+)<span class="nt">&lt;.__attribute__&gt;<.span>.*$/\1/p'

aircrafts=$(mktemp --dry-run /dev/shm/Aircraft-XXXXXXXXX)

aircraft=$(mktemp --dry-run /dev/shm/aircraft-XXXXXXX)

setxml=$(mktemp --dry-run /dev/shm/setxml-XXXXXXXX)

in_ram_database=$(mktemp --dry-run /dev/shm/XXXXXXX)

database=${DB:-$0.db}

attributes=(description long_description author flight_model)

function get_attribute () {

    eval "unset $1"

    result=$(sed -rn "${attribute_regex//__attribute__/${1//_/-}}" $setxml)

    eval "$1=\$\"$result\""

}

function sqlite_request () {

    sqlite3 "$in_ram_database" <<< "$1"

}

function trap_exit () {

    if test -r "$database" && md5sum $in_ram_database | sed "s,$in_ram_database,$database," | md5sum --status -c -; then

        rm -f $in_ram_database

    elif test -w "$database"; then

        mv -f $in_ram_database "$database"

    elif ! test -e "$database"; then

        mv $in_ram_database "$database"

    else

        rm -f $in_ram_database

    fi

    rm -f $aircrafts $aircraft $setxml

}

update_database () {

    let progress++

    echo "[ ${progress}${total:+/$total} ] $ac"

    dbupdate=$(sqlite_request "select date from aircrafts where name is '$ac'")

    if test -z "$dbupdate"; then

        sqlite_request "insert into aircrafts (name, date) values ('$ac', $update)"

    elif test $dbupdate -ne $update; then

        sqlite_request "update aircrafts set date = $update where name is '$ac'"

    fi

    id=$(sqlite_request "select id from aircrafts where name is '$ac'")

    wget -qO- $fgaddon_url/$ac > $aircraft

    for sx in $(sed -rn 's/<a class="icon" href="(.+-set.xml)" title=".+"><i class="fa fa-file-o">.+$/\1/p' $aircraft); do

        echo " -> ${sx/-set.xml}"

        wget -qO- $fgaddon_url/$ac/$sx > $setxml

        for attribute in ${attributes[@]}; do

            get_attribute $attribute

        done

        test -e $fgaddon_path/$ac/$sx

        installed=$?

        if test -n "$description" -a -z "$flight_model"; then

            grep -qi 'jsbsim' <<< "$description" && flight_model='jsb'

            grep -qi 'yasim' <<< "$description" && flight_model='yasim'

        fi

        known=$(sqlite_request "select variantof from setxml where file is '$sx'")

        if test -n "$known"; then

            for attribute in ${attributes[@]}; do

                dbvalue=$(sqlite_request "select $attribute from setxml where file is '$sx'")

                eval "wgvalue=\$$attribute"

                if test "$dbvalue" != "$wgvalue"; then

                    sqlite_request "update setxml set $attribute = '$wgvalue' where file is '$sx'"

                fi

            done

        else

            sqlite_request "insert into setxml values ('$sx', $id, '$description', '$long_description', '$author', '$type', '$flight_model', $installed)"

        fi

    done

}

trap trap_exit EXIT

test -e $database && cp $database $in_ram_database

sqlite_request "create table if not exists aircrafts (id integer primary key, name text, date integer)"

sqlite_request "create table if not exists setxml (file text, variantof integer, description text, long_description text, author text, type text, flight_model text, installed integer)"

test -z "$1" && echo "mode RSS"

case ${1:-rss} in

    'full')

        echo "downloading the FGADDON list"

        wget -qO- $fgaddon_url > $aircrafts

        total=$(grep -c '<a class="icon" href=".*class="fa fa-folder".*i>&nbsp;' $aircrafts)

        for ac in $(sed -rn 's/^\s*<a class="icon" href="(.+)" title=.* class="fa fa-folder".+$/\1/p' $aircrafts); do

            update=$(grep -A3 '<a class="icon" href=".*class="fa fa-folder".*i>&nbsp;'$ac'<' $aircrafts | sed -rn '$s/^\s*<span title="(.+)">.*$/\1/p')

            update=$(date +%s -d"$update")

            update_database

        done

    ;;

    'rss')

        xmlgetnext () {                                                         

           local IFS='>'

           read -d '<' TAG VALUE

        }

        get_updates_from_rss () {

            wget -qO- https://sourceforge.net/p/flightgear/fgaddon/feed | while xmlgetnext; do

                case "$TAG" in

                    'lastBuildDate')

                        if test ${latest_update:-0} -ge $(date +%s -d "$VALUE"); then

                            echo "no new updates"

                            exit

                        fi

                    ;;

                    'item')

                        unset link pubDate revision title file;;

                    'link')

                        link="$VALUE";;

                    'title')

                        title="$VALUE";;

                    'guid isPermaLink="false"')

                        revision=$(sed -r 's,^.+/([0-9]+)/$,\1,' <<< $VALUE);;

                    'pubDate')

                        pubDate=$(date +%s -d "$VALUE");;

                    '/item')

                        echo "checking $revision ($(date +"%d %B" -d@$pubDate)): $title" >&2

                        wget -qO- "$link" > $aircrafts

                        for file in $(egrep '/trunk/Aircraft/.*/.*-set.xml$' $aircrafts); do

                            file=${file/\/trunk\/Aircraft\/}

                            echo ${file%/*}

                            echo $pubDate

                        done

                    ;;

                    '/channel')

                        if test ${latest_update:-0} -lt $pubDate; then

                            echo "WARNING: $(( ($pubDate - ${latest_update:-0}) / 86400 )) days between the oldest RSS entry and last DB entry" >&2

                            echo "a $0 full may be useful" >&2

                        fi

                    ;;

                esac

            done

        }

        latest_update=$(sqlite_request "select max(date) from aircrafts")

        ac_list=($(get_updates_from_rss))

        total=$(( ${#ac_list[@]} / 2 ))

        for ((i=0; i < ${#ac_list[@]}; i=i+2)); do

            ac=${ac_list[i]}

            update=${ac_list[ac+1]}

            update_database

        done

    ;;

        *)

            echo "usage: [DB=path/to/database] $0 [rss|full]"

            echo

            echo "rss: updates only last repo changes"

            echo "full: updates from all repo"

    ;;

esac