#!/bin/sh
# Find redundant dependencies
# Johannes Winkelmann <jw at tks6 dot net>

# $ cd /usr/ports/contrib
# $ findredundantdeps *
# $ findredundantdeps bmp


usage()
{
    echo "usage: ${0##*/} [-vfsh] <package>" >&2
    exit 1
}

find_deps()
{
    if blaat=$(prt-get quickdep $1 2>/dev/null); then
	result=${blaat%$1*}
	if  [ -n "$result" ]; then
	    echo "$result"
	    return 0
	else
	    return 1
	fi
    fi
}

get_directdeps()
{
    prt-get info $1 | gawk '
    /^Dependencies:/ {  
        split($2,a,",")
        # remove duplicates
        for (i in a) b[a[i]]
        for (i in b) print i
    }'
}

sortvar()
{
    for d in $*; do
	echo $d
    done | sort -u
}

sortvar_d()
{
    for d in $*; do
	echo $d
    done | sort| uniq -d
}

sortvar_u()
{
    for d in $*; do
	echo $d
    done | sort| uniq -u
}

verbose=false
fixit=false
suggest=false

while [ $# -gt 0 ]; do
    case $1 in
	-v)
	    shift
	    verbose=true
	    ;;
	-f)
	    shift
	    fixit=true
	    ;;
	-s)
	    shift
	    suggest=true
	    ;;
	--*)
	    echo "${0##*/} doesn't recognize -- gnu-longopts."
            usage
            exit 1
	    ;;
	-[a-zA-Z][a-zA-Z]*)
            # split concatenated single-letter options apart
            FIRST="$1"; shift
            set -- `echo "$FIRST" | sed 's/^-\(.\)\(.*\)/-\1 -\2/'` "$@"
            ;;
	''|-*)
	    usage
	    ;;
	*)
	    break
	    ;;
    esac
done

for package in $*; do
    if prt-get info $package >/dev/null; then
	deps=$(find_deps $package)
	unset subdeps
	for d in $deps; do
	    if dep=$(find_deps $d); then
		subdeps="$subdeps $dep"
		# 	else
		# 	    echo "Ignoring unknown dependency '$d' for '$package'"
	    fi
	done
	deps=$(sortvar $deps)
	subdeps=$(sortvar $subdeps)

	res=$(sortvar_d $deps $subdeps)
	directdeps=$(get_directdeps $package)

	redundant=$(sortvar_d $res $directdeps)
	# tranform \n in ' '
	set -- $redundant
	redundant=$*

	if [ -n "$redundant" ]; then
	    right=$(sortvar_u $redundant $directdeps)
	    set -- $right
	    right=$*
	    echo "Redundant deps for $package are: $redundant"
	    if [ "$suggest" = true ]; then
		echo "Right is: # Depends on: $right"
	    fi
	    if [ "$fixit" = true ]; then
		Pkgfile="$(prt-get info $package|awk '/Path:/ {print $2}')/$package/Pkgfile"
		cp $Pkgfile ${Pkgfile}.orig
		sed -i "s|^#.*Depends on:.*|# Depends on: $right|" $Pkgfile
		echo " * Fixed $package"
	    fi
	else
	    [ "$verbose" = true ] && echo " * $package is fine."
	fi
    fi
done