#!/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 () {

    echo "updating installation status"

    for ac in $(sqlite_request 'select printf("%i:%s/%s", aircrafts.id, aircrafts.name, setxml.file) from aircrafts inner join setxml where aircrafts.id = setxml.variantof;'); do

        ac_path=${ac#*:}

        test ! -e $fgaddon_path/$ac_path

        installed=$?

        sqlite_request "update setxml set installed = $installed where file = '${ac_path#*/}' and variantof = ${ac%:*}"

    done

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

        rm -f $in_ram_database

        echo "no changes in $database"

    elif test -w "$database"; then

        mv -f $in_ram_database "$database"

        echo "database $database updated"

    elif ! test -e "$database"; then

        mv $in_ram_database "$database"

        echo "database $database created"

    else

        rm -f $in_ram_database

        echo "nothing can be done with $database !"

    fi

    rm -f $aircrafts $aircraft $setxml

}

update_database () {

    let progress++

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

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

    if test -z "$dbupdate"; then

        sqlite_request "insert into aircrafts (name, revision, date, author) values ('$ac', $revision, $revdate, '$revauthor')"

    elif test $dbupdate -lt $revision; then

        sqlite_request "update aircrafts set revision = $revision, author = '$revauthor' 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

        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

            test ! -e $fgaddon_path/$ac/$sx

            installed=$?

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

        fi

    done

}

xmlgetnext () {

   local IFS='>'

   read -d '<' TAG VALUE

}

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, revision integer, date integer, author text)"

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 | sed -n '/<table>/,/<\/table>/p' > $aircrafts

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

        while xmlgetnext; do

            case "$TAG" in

                'tr')

                    unset ac revision revauthor

                    ;;

                'a class="icon" href='*)

                    eval $(echo "${TAG#* }")

                    ac=$href

                    ;;

                'span title='*)

                    eval $(echo "${TAG#* }")

                    revdate=$(date +%s -d "$title")

                    ;;

                'a href="/p/flightgear/fgaddon/'*)

                    eval $(echo "${TAG#* }")

                    revision=$(tr -cd '[:digit:]' <<< $href)

                    ;;

                'span class="icon emboss x16" style="text-align:center;" title="User"'*)

                    user=1

                    ;;

                '/span')

                    test -n "$user" && revauthor=$(tr -cd '[:alnum:]' <<< $VALUE) && unset user

                    ;;

                '/tr')

                    test -n "$revision" -a -n "$revauthor" -a -n "$ac" -a -n "$revdate" && update_database

                    ;;

            esac

        done < $aircrafts

    ;;

    'rss')

        get_updates_from_rss () {

            while xmlgetnext; do

                case "$TAG" in

                    'item')

                        let entry++

                        unset link revdate revauthor revision title;;

                    'link')

                        link="$VALUE";;

                    'title')

                        title="$VALUE";;

                    'dc:creator'*)

                        revauthor="$VALUE";;

                    'guid isPermaLink="false"')

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

                        if test $entry -eq 1 -a $revision -eq ${latest_revision:-0}; then

                            echo "no new updates" >&2

                            break

                        fi

                    ;;

                    'pubDate')

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

                    ;;

                    '/item')

                        echo "$revision ($(date +"%d %B" -d@$revdate), $revauthor): $title" >&2

                        wget -qO- "$link" | awk -v data="revision=$revision revdate=$revdate revauthor=$revauthor" '

                            />\/trunk\/Aircraft\/.+</ {

                                ac[gensub("^.+>/trunk/Aircraft/([^/]+).+<.*$", "ac=\\1", "1", $0)]++

                            }

                            END {

                                for (i in ac) print data " " i

                            }'

                    ;;

                    '/channel')

                        if test ${latest_revision:-0} -lt $revision; then

                            echo "WARNING: $(( ($revision - ${latest_revision:-0}) )) revisions between the oldest RSS entry and last DB entry" >&2

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

                        fi

                    ;;

                esac

            done < $aircrafts | awk '

                {

                    if (a[$4] == "") a[$4]=$0

                }

                END {

                    for (i in a) {

                        total++

                        command = command a[i] " update_database;"

                    }

                    printf("total=%i;%s", total, command)

                }'

        }

        latest_revision=$(sqlite_request "select max(revision) from aircrafts")

        wget -qO- https://sourceforge.net/p/flightgear/fgaddon/feed > $aircrafts

        eval "$(get_updates_from_rss)"

    ;;

        *)

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

            echo

            echo "rss: updates only last repo changes"

            echo "full: updates from all repo"

            exit 1

    ;;

esac