#!/usr/bin/awk -f
#
# $NetBSD: reduce-depends.awk,v 1.3 2014/10/08 10:04:45 jperkin Exp $
#
# Copyright (c) 2006 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Johnny C. Lam.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#        This product includes software developed by the NetBSD
#        Foundation, Inc. and its contributors.
# 4. Neither the name of The NetBSD Foundation nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

######################################################################
#
# NAME
#	reduce-depends.awk -- reduce a list of dependencies
#
# SYNOPSIS
#	reduce-depends.awk "depends_list"
#
# DESCRIPTION
#	reduce-depends.awk removes some extraneous dependencies from the
#	dependency list.  The dependency list should be passed as a single
#	argument, and the output will be a list of the reduced dependencies,
#	echo one on a new line.
#
# ENVIRONMENT
#	CAT
#	PKG_ADMIN
#	PWD_CMD
#	TEST
#
######################################################################

BEGIN {
	CAT = ENVIRON["CAT"] ? ENVIRON["CAT"] : "cat"
	PKG_ADMIN = ENVIRON["PKG_ADMIN"] ? ENVIRON["PKG_ADMIN"] : "pkg_admin"
	PWD_CMD = ENVIRON["PWD_CMD"] ? ENVIRON["PWD_CMD"] : "pwd -P"
	TEST = ENVIRON["TEST"] ? ENVIRON["TEST"] : "test"

	PROGNAME = "reduce-depends.awk"
	ERRCAT = CAT " 1>&2"

	# Gather all dependencies into the depends array.  Index 0 of the
	# depends[pkgpath] array is the number of patterns associated with
	# that pkgpath.
	#
	args = ARGV[1]
	ARGC = split(args, ARGV); ARGC++
	for (i = 1; i < ARGC; i++) {
		pattern = ARGV[i];	sub(":.*", "", pattern)
		dir = ARGV[i];		sub(".*:", "", dir)
		if (pattern ":" dir != ARGV[i]) {
			print "ERROR: [" PROGNAME "] invalid dependency pattern: " ARGV[i] | ERRCAT
			exit 1
		}
		cmd = TEST " -d " dir
		if (system(cmd) == 0) {
			cmd = "cd " dir " && " PWD_CMD
			while ((cmd | getline pkgpath) > 0) {
				if (!(pkgpath in pkgsrcdirs)) {
					pkgpaths[P++] = pkgpath
					pkgsrcdirs[pkgpath] = dir
				}
				depends[pkgpath, 0]++;
				depends[pkgpath, depends[pkgpath, 0]] = pattern
			}
			close(cmd)
		} else {
			print "ERROR: [" PROGNAME "] " dir " does not exist." | ERRCAT
			exit 1
		}
	}

	# Reduce dependencies to the strictest set of dependencies it
	# can derive from all of depends[...].  It only understands
	# dependencies of the form foo>=1.0, and leaves the other
	# dependencies undisturbed.
	#
	# The algorithm takes dependencies of the form foo>=1.0 and
	# converts them to foo-1.0.  It then compares this pkg name against
	# each dependency to see if it satisfies them all.  The key fact
	# is the the strictest dependency, when converted to a pkg name,
	# will satisfy every dependency.
	#
	for (p = 0; p < P; p++) {
		pkgpath = pkgpaths[p]
		D = depends[pkgpath, 0];
		match_all = 1;
		for (d = 1; d <= D; d++) {
			dep = depends[pkgpath, d]
			if (dep ~ /[{]/ || \
			    dep ~ />=[0-9][0-9\.]*(nb[0-9]+)?<[0-9]+/ || \
			    dep !~ />=[0-9]+/)
			{
				reduced[N++] = dep ":" pkgsrcdirs[pkgpath]
				continue
			}
			ge_depends[dep] = dep
		}
		for (dep in ge_depends) {
			dep2pkg = dep; sub(">=", "-", dep2pkg)
			match_all = 1
			for (pattern in ge_depends) {
				cmd = PKG_ADMIN " pmatch \"" pattern "\" " dep2pkg
				if (system(cmd) != 0) {
					match_all = 0
					break
				}
			}
			if (match_all == 0) continue
			reduced[N++] = dep ":" pkgsrcdirs[pkgpath]
			break
		}
		#
		# If there are conflicting dependencies, then just pass them
		# through and let the rest of the pkgsrc machinery handle it.
		#
		if (match_all == 0) {
			for (d = 1; d <= D; d++) {
				dep = depends[pkgpath, d]
				reduced[N++] = dep ":" pkgsrcdirs[pkgpath]
			}
		}
		for (dep in ge_depends)
			delete ge_depends[dep]
	}

	# Output reduced dependencies.
	for (n = 0; n < N; n++)
		print reduced[n];
}