#!/bin/sh
set -e

if [ -z "$CODENAME" ]; then
    echo "update_tasks: codename not specified" >&2
    exit 1
fi

if [ "$MIRROR"x = ""x ] ; then
    echo "update_tasks: mirror dir not specified" >&2
    exit 1
fi

if [ "$BDIR"x = ""x ] ; then
    echo "update_tasks: temp dir not specified" >&2
    exit 1
fi
TDIR=$BDIR/update_tasks
mkdir -p $TDIR


update_full_list () {
    file=$1
    tasklist=$2
    pkgfile=$3

    (grep -Ev "^(#.*)?[[:space:]]*$" $tasklist ; echo DONE ; cat $pkgfile) | mawk '
    /DONE/ {
        in_packages = 1
        next
    }
    /.*/ {
        if (!in_packages) {
            tasklist[$1] = num_tasks
            num_tasks++
        }
    }
    /^Package: / {
        if (in_packages) {
            pkgname = $2
            next
        }
    }
    /^Task: / {
        if (in_packages) {
            # Parse the Tasks: line, splitting into array "these"
            gsub("Task: ", "", $0)
            gsub(",", "", $0)
            split($0, these)

            # And see if we have any matches
            for (task in these) {
                for (taskname in tasklist) {
                    if (these[task] == taskname) {
                        printf("%d:%s\n", tasklist[taskname], pkgname)
                        next
                    }
                }
            }
        }
        next
    }' | sort -n | cut -d: -f2 > $file
}

update_essential_list () {
    file=$1
    tasklist=$2
    desktoptasks=$3
    tasksel=$4

    (grep -Ev "^(#.*)?[[:space:]]*$" $tasklist ;
		echo DONE ;
		cat $tasksel/usr/share/tasksel/debian-tasks.desc) | mawk -v DT=$desktoptasks '

    BEGIN {
        split(DT, d_tasks, ",")
    }

    /DONE/ {
        in_tasks = 1
        next
    }
    /^ / {
        if (in_key) {
            printf("%d:%s\n", tasklist[cur_task], $1)
            next
        }
    }
    /.*/ {
        if (!in_tasks) {
            tasklist[$1] = num_tasks
            num_tasks++
        }
        if (in_key) {
            in_key = 0
        }
    }
    /^Task: / {
        if (in_tasks) {
            cur_task = $2
            next
        }
    }
    /^Key: / {
        if (in_tasks) {
            for (taskname in tasklist) {
                if (taskname == cur_task) {
                    if ((cur_task != "gnome-desktop") &&
                        (cur_task != "kde-desktop") &&
                        (cur_task != "xfce-desktop")) {
                        in_key = 1
                    }
                    for (dt_num in d_tasks) {
                        if (cur_task == d_tasks[dt_num]) {
                            in_key = 1
                        }
                    }
                }
            }
        }
        next
    }' | sort -s -n -k1 | cut -d: -f2 > $file
}

# We need to gunzip a copy of the appropriate Packages.gz file
# Assume i386, use the $CODENAME main Packages file
TMP_PKG=$TDIR/Packages
zcat $MIRROR/dists/$CODENAME/main/binary-i386/Packages.gz > $TMP_PKG

# Now grab the appropriate tasksel package
TASKSEL_DEB=$MIRROR/`mawk '
    /^Package: tasksel-data$/ { found=1 }
    /^Filename:/              { if (found==1) { print $2; exit } }' $TMP_PKG`

dpkg -x $TASKSEL_DEB $TDIR/tasksel

update_essential_list task-essential task.list gnome-desktop \
    $TDIR/tasksel

update_essential_list task-essential-kde task.list.kde kde-desktop \
    $TDIR/tasksel

update_essential_list task-essential-xfce task.list.xfce xfce-desktop \
    $TDIR/tasksel

update_full_list task-full task.list $TMP_PKG

update_full_list task-full-kde task.list.kde $TMP_PKG

update_full_list task-full-xfce task.list.xfce $TMP_PKG

rm -rf $TDIR