#!/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

# Sort primary and secondary tasks and add language tasks for both
# Secondary tasks are indicated by a "-" suffix in the task.list file
# When adding language tasks, 'desktop' is sorted before '*-desktop'
expand_task_list () {
    tasklist=$1
    langlist=$2

    # Filter out comments, empty lines and secondary tasks
    task_essential="$(grep -Ev "^(#.*)?(.*-)?[[:space:]]*$" $tasklist)"
    # Select only secondary tasks
    task_extra="$(grep -Ev "^(#.*)?[[:space:]]*$" $tasklist | \
        grep -E "(.*-)[[:space:]]*$" | sed "s/[[:space:]]*-.*$//")"

    echo "# Main tasks" >$tasklist.essential
    echo "$task_essential" >>$tasklist.essential

    echo >>$tasklist.essential
    echo "# Main language tasks" >>$tasklist.essential
    for task in "" $(echo "$task_essential" | grep "^desktop" || true) \
                $(echo "$task_essential" | grep -- "-desktop" || true); do
        for language in $(cat $langlist); do
            echo $language${task:+-$task}
        done
    done >>$tasklist.essential

    cp $tasklist.essential $tasklist.full

    if [ "$task_extra" ]; then
        echo >>$tasklist.full
        echo "# Extra tasks" >>$tasklist.full
        echo "$task_extra" >>$tasklist.full

        echo >>$tasklist.full
        echo "# Extra language tasks" >>$tasklist.full
        for task in $(echo "$task_extra" | grep "^desktop" || true) \
                    $(echo "$task_extra" | grep -- "-desktop" || true); do
            for language in $(cat $langlist); do
                echo $language${task:+-$task}
            done
        done >>$tasklist.full
    fi
}

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
    tasksel=$3

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

    /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) {
                    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

[ -e task.languages ] || exit 1
grep -Ev "^(#.*)?[[:space:]]*$" task.languages > $TDIR/languages

for variant in "" kde lxde xfce light all; do
    if [ ! -e task.list${variant:+.$variant} ]; then
        echo "Warning: task.list${variant:+.$variant} does not exist; skipping"
	continue
    fi

    expand_task_list \
        task.list${variant:+.$variant} \
        $TDIR/languages

    update_essential_list \
        task-essential${variant:+-$variant} \
        task.list${variant:+.$variant}.essential \
        $TDIR/tasksel

    update_full_list \
        task-full${variant:+-$variant} \
        task.list${variant:+.$variant}.full \
        $TMP_PKG
done

rm -rf $TDIR