#!/bin/sh -efu
#
# This file provides FindPackage() function which maps paths and
# commands, such as found in shell scripts, to rpm dependencies.
#
# Usage:
#	. @RPMCONFIGDIR@/find-package
#	FindPackage src [path...] [command...]
#
# Arguments:
#	src - the file being processed, used for diagnostics;
#		also, if the file appears to reside under */sbin/
#		directory, the PATH search order is adjusted
#		so as to better match root code
#	path - absolute path to file, e.g. /bin/cat
#	command - executable expected to reside under standard
#		PATH directories, e.g. cat
#
# Copyright (C) 2002-2003  Dmitry V. Levin <ldv@altlinux.org>
# Copyright (C) 2007,2008  Alexey Tourbin <at@altlinux.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

. @RPMCONFIGDIR@/functions

# We use different PATHs for */sbin/ and non-/sbin scripts.  However,
# the distinction is not quite reliable -- there is simply no easy way
# to discriminate between root-only and user-capable shell code.  Thus
# we must use rather conservative path adjustment: 1) the set of user
# and root directories is the same, it is only the order that differs;
# 2) / has main priority over /usr, while as "bin vs sbin" distinction has
# only secondary priority.  The reason is that / has only "most important"
# contents, and /usr is used virtually "for everything else", whatever it is.
# Now that / has a boost, there are simply less chances to end up with
# unrelated dependencies.
DEF_RPM_FINDPACKAGE_USER_PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/usr/games
DEF_RPM_FINDPACKAGE_ROOT_PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/usr/games

# RPM_FINDPACKAGE_PATH is exported by rpm-build
RPM_FINDPACKAGE_USER_PATH="$(IFS="$IFS:"; set -f; echo '' ${RPM_FINDPACKAGE_PATH-} $DEF_RPM_FINDPACKAGE_USER_PATH |sed -e 's/  */:/g; s/^://')"
RPM_FINDPACKAGE_ROOT_PATH="$(IFS="$IFS:"; set -f; echo '' ${RPM_FINDPACKAGE_PATH-} $DEF_RPM_FINDPACKAGE_ROOT_PATH |sed -e 's/  */:/g; s/^://')"
Debug "RPM_FINDPACKAGE_USER_PATH=$RPM_FINDPACKAGE_USER_PATH"
Debug "RPM_FINDPACKAGE_ROOT_PATH=$RPM_FINDPACKAGE_ROOT_PATH"

# By default, FindPackage prefers virtual (most common) dependencies,
# e.g. /usr/bin/perl -> /usr/bin/perl.  This is good for executables.
# However, some binary dependencies should explicitly map to host-system
# package names, e.g. /usr/lib/libdb.so -> libdb4.4-devel.  Localizing
# the following variable with non-empty value will tweak FindPackage
# to use the latter plan.
RPM_FINDPACKAGE_HOST_PKG_NAMES=

# When an interpreter is invoked by name, as in "#!/usr/bin/env python32",
# and is missing, this can force the dependency on /usr/bin/python32.
RPM_FINDPACKAGE_MANDATORY=

# Below we use 'local Verbose=Info' to increase per-case verbosity.
Verbose=Verbose

FindByFileUnderBuildroot()
{
	local f="$1" rep="$2" xbrep; shift 2 || return
	[ -n "${RPM_BUILD_ROOT-}" ] || return 0

	MatchBuildroot()
	{
		[ -n "$1" ] &&
		[ -z "${1##$RPM_BUILD_ROOT/*}" ]
	}
	StatPrint()
	{
		[ -e "$1" -o -L "$1" ] &&
		printf '%s\n' "${1#$RPM_BUILD_ROOT}"
	}

	xbrep=$(CanonPath "$RPM_BUILD_ROOT$rep")
	if MatchBuildroot "$xbrep"; then
		# Good.  The path was canonicalized against buildroot.
		StatPrint "$xbrep" && return 0
	else
		# Too bad.  The path was canonicalized outside buildroot.
		# They should fix their symbolic links.
		Warning "$f: $rep cannot be canonicalized under RPM_BUILD_ROOT"
		# Consider this: RPM_BUILD_ROOT/A/B/C -> /D/C
		#				  `-> /D
		# It still makes sense to check /D/C under RPM_BUILD_ROOT.
		xbrep=$(CanonPath "$RPM_BUILD_ROOT$xbrep")
		MatchBuildroot "$xbrep" && StatPrint "$xbrep" && return 0
	fi

	# They might also ask if /etc/init.d/foo is under RPM_BUILD_ROOT.
	# That would be /etc/rc.d/init.d/foo.
	xbrep=$(CanonPath "$rep")
	xbrep=$(CanonPath "$RPM_BUILD_ROOT$xbrep")
	MatchBuildroot "$xbrep" && StatPrint "$xbrep" && return 0

	# Not there.  Not now.
	:
}

FindByFile()
{
	# Dependence name starts with `/'.
	local f="$1" rep="$2" package; shift 2 || return

	# Does it start with %_builddir or %buildroot?
	if [ -n "${RPM_BUILD_DIR-}" ] && [ -z "${rep##$RPM_BUILD_DIR*}" ]; then
		Info "$f: invalid dependency: $rep"
		return 1
	fi
	if [ -n "${RPM_BUILD_ROOT-}" ] && [ -z "${rep##$RPM_BUILD_ROOT*}" ]; then
		Info "$f: invalid dependency: $rep"
		return 1
	fi

	# Does it belong to buildroot?
	local xbrep
	xbrep=$(FindByFileUnderBuildroot "$f" "$rep")
	if [ -n "$xbrep" ]; then
		# The file is under buildroot.  We emit file-level dependency.
		# If the file is in the same package, rpm-build will optimize
		# out the dependency.  Otherwise, the file is to be packaged
		# into another subpackage, and we get something like more strict
		# dependencies between subpackages.
		if [ ! -L "$RPM_BUILD_ROOT$xbrep" -a -d "$RPM_BUILD_ROOT$xbrep" ]; then
			# They require a directory.  Here we do only "weak" directory
			# dependencies (i.e. sometimes we prefer to omit such dependencies).
			# We only need to make sure that the directory actually exists after
			# install, which is the case if there are packaged files under the
			# directory.
			local dirfiles
			if dirfiles=$(PackagedFiles |grep -F "$xbrep") &&
			   dirfiles=$(echo '' $dirfiles '') &&
			   [ -n "${dirfiles##* $xbrep *}" ] &&
			   [ -z "${dirfiles##* $xbrep/*}" ]; then
				Warning "$f: directory $xbrep not owned by the package"
				return 0
			fi
		fi
		$Verbose "$f: $rep -> \$RPM_BUILD_ROOT$xbrep"
		printf '%s\n' "$xbrep"
		return 0
	fi

	# Is it an alternative?  Path components can be alternatives, too.
	local alt_break= alt xalt xrep p
	xrep=$(readlink -vm "$rep")
	# Blind cleanup-only canonicalization required (the same as CanonPath first pass),
	# to fold intermediate path components.  E.g. in /usr/share/foo/../java/rt.jar,
	# /usr/share/foo might not exist, but [ -L .../rt.jar ] test should still work.
	# XXX This "blind" technique is basically wrong -- one cannot always fold ".."
	# along with previous path component, specifically if the previous path component
	# is a symbolic link.
	p=$(readlink -vm "/-$$-/$rep")
	p=${p##/-$$-}
	while [ -n "$p" ]; do
		# Check each path component whether it is an alternative.
		if [ -L "$p" ] && readlink -v "$p" |grep -qs '^/etc/alternatives/'; then
			alt=$(CanonPath "$p")
			Verbose "$f: $rep -> $p -> $alt (alternative)"
			printf '%s\n' "$alt"
			# Now we have to decide if this alternative should eventually
			# prevent final $rep dependency resolution.
			xalt=$(readlink -vm "$p")
			case "$xrep" in
				"$xalt")
					# alternative and $rep are more or less the same
					alt_break=1 ;;
				"$xalt"/*)
					# $rep is under alternative dir, too bad
					Info "$f: alternative $alt prevents $rep dependency resolution"
					alt_break=1 ;;
			esac
		fi
		p=${p%/*}
	done
	[ -z "$alt_break" ] || return 0
	unset p alt_break alt xalt xrep ||:

	# Hard time checking $rep path components is over.
	# Now we are ready to apply our know-how.
	rep=$(CanonPath "$rep")

	# Ignore pseudo-filesystem dependencies.
	local dir="${rep#/}"; dir="${dir%%/*}"
	case "$dir" in
		dev | proc | sys )
			$Verbose "$f: $rep -> /$dir (skip)"
			return ;;
	esac
	unset dir

	if [ -n "$RPM_FINDPACKAGE_HOST_PKG_NAMES" ] &&
	   package=$(rpmquery --whatprovides --queryformat='%{NAME}\n' -- "$rep" 2>/dev/null); then
		package=$(printf %s "$package" |LC_COLLATE=C sort -u)
		local n="$(IFS=$'\n'; set -- $package; echo $#)"
		if [ "$n" = 1 ]; then
			# Prune generic devel deps generated by pkgconfiglib.req and cpp.req.
			case $package in
				gcc | gcc-c++ | \
				gcc[34].[0-9] | gcc[34].[0-9]-c++ | \
				gcc[5-9] | gcc[5-9]-c++ | \
				libstdc++-devel | \
				libstdc++[34].[0-9]-devel | \
				libstdc++[5-9]-devel | \
				glibc-devel )
					$Verbose "$f: $rep -> $package (skip, generic devel)"
					;;
				*)
					$Verbose "$f: $rep -> $package (via rpmdb)"
					printf %s\\n "$package"
					;;
			esac
			return
		elif [ "$n" -gt 1 ]; then
			Info "$f: $rep provided by:$(echo '' $package)"
			Info "$f: $rep -> $rep (raw, ambiguous, via rpmdb)"
			printf %s\\n "$rep"
			return
		fi
	fi

	if [ -e "$rep" ] || rpmquery --whatprovides -- "$rep" >/dev/null 2>&1; then
		$Verbose "$f: $rep -> $rep (raw)"
	else
		Info "$f: $rep -> $rep (raw, not installed)"
	fi

	printf %s\\n "$rep"
}

FindByName()
{
	local f="$1" r="$2" rep package; shift 2 || return

	local dir="${f%/*}"; dir="${dir#${RPM_BUILD_ROOT-}}"
	local findpackage_path="$RPM_FINDPACKAGE_USER_PATH"
	case "$dir" in
		*/sbin | "" ) # %buildroot dir is used to save scriptlets
			findpackage_path="$RPM_FINDPACKAGE_ROOT_PATH" ;;
		/etc/*)
			dir="${dir#/etc/}"; dir="${dir%%/*}"
			case "$dir" in
				# The sbin-ish places.  WARNING: Explicit Content!
				rc.d | init.d | control.d | chroot.d | net | ppp | cron* | hotplug* )
					Debug "$f: root PATH on"
					findpackage_path="$RPM_FINDPACKAGE_ROOT_PATH" ;;
			esac
			;;
	esac
	unset dir

	# Check buildroot first.
	if [ -n "${RPM_BUILD_ROOT-}" ]; then
		rep=$(IFS="$IFS:"; set -f
			for dir in $findpackage_path; do
				rep="$dir/$r"
				BR_rep="$RPM_BUILD_ROOT/$rep"
				if [ -f "$BR_rep" -o -L "$BR_rep" ]; then
					printf '%s\n' "$rep"
					break
				fi
			done)
		if [ -n "$rep" ]; then
			$Verbose "$f: $r -> \$RPM_BUILD_ROOT$rep"
			printf '%s\n' "$rep"
			return
		fi
	fi

	# Record each command name we search.
	if [ -n "${RPM_FINDPACKAGE_COMMANDS_LOG-}" ]; then
		printf '%s\n' "$r" >>"$RPM_FINDPACKAGE_COMMANDS_LOG"
	fi

	# Check for pkg contents binary index.
	local save_rep= save_package=
	if [ -n "${RPM_PKG_CONTENTS_INDEX_BIN-}" ] && [ -s "$RPM_PKG_CONTENTS_INDEX_BIN" ] && [ -r "$RPM_PKG_CONTENTS_INDEX_BIN" ]; then
		local out="$(awk -v r="$r" -v findpackage_path="$findpackage_path" '
			BEGIN {
				# Here we enumerate all possible paths to keep the order;
				# later we sort the result with "sort -n".
				n = split(findpackage_path, ary, ":")
				for (i = 1; i <= n; i++) {
					dir = ary[i]
					sub("/+$", "", dir)
					file = dir "/" r
					if (dir && !(file in FILES))
						FILES[file] = i
				}
				# By now FILES is normally something like this:
				#	/bin/r		1
				#	/sbin/r		2
				#	/usr/bin/r	3
				#	/usr/sbin/r	4
				#	...
			}
			NF==2 && ($1 in FILES) {
				# Possible output is like this:
				#	3	/usr/bin/r	pkgA
				#	1	/bin/r		pkgB
				print FILES[$1] "\t" $1 "\t" $2
			}
			' "$RPM_PKG_CONTENTS_INDEX_BIN" |
				# Best paths go first:
				sort -n |
				# For each package, keep only the best path:
				sort -u -k3 |
				# Best paths still go first:
				sort -n |
				# Well done, discard numbers.
				cut -f2-)"
		local n="$(IFS=$'\n'; set -- $out; echo $#)"
		if [ "$n" = 1 ]; then
			rep="$(IFS=$'\t\n'; set -- $out; printf %s "$1")"
			package="$(IFS=$'\t\n'; set -- $out; printf %s "$2")"
			$Verbose "$f: $r -> $rep -> $package (via contents_index_bin)"
			printf %s\\n "$package"
			return
		elif [ "$n" -gt 1 ]; then
			# Content index search produced a confict: we have 2 or more paths
			# from different packages.  Consider this case:
			#	/usr/bin/r	pkgA
			#	/usr/bin/r	pkgB
			#	/usr/sbin/r	pkgC
			# Remember that best paths go first, and each package has only the best path.
			# Now if the first two paths are the same, we produce raw dependency on /usr/bin/r.
			local Verbose=Info
			Info "$f: $r indexed by:$(printf %s "$out" |sed -e 's/\t/ -> /; s/$/,/; $s/,$//' |xargs echo '')"
			rep="$(IFS=$'\t\n'; set -- $out; printf %s "$1")"
			package="$(IFS=$'\t\n'; set -- $out; printf %s "$2")"
			# Actually our contents_index generator already handles path dups,
			# so the above example is likely to transform into this:
			#	/usr/bin/r	/usr/bin/r
			#	/usr/sbin/r	pkgC
			# So we first check if path = package.
			if [ "$rep" = "$package" ]; then
				Info "$f: $r -> $rep -> $rep (ambiguous, via contents_index_bin)"
				printf %s\\n "$rep"
				return
			fi
			# And then we check if the first two paths are the same.
			local rep2="$(IFS=$'\t\n'; set -- $out; printf %s "$3")"
			if [ "$rep" = "$rep2" ]; then
				Info "$f: $r -> $rep -> $rep (raw, ambiguous, via contents_index_bin)"
				printf %s\\n "$rep"
				return
			fi
			# However, consider yet worse real-life case:
			#	/usr/bin/arpsend	arpsend
			#	/usr/sbin/arpsend	vzctl
			# In this case, we perfer to put aside the conflict for a while, and query
			# the host system first.  There's a good chance that the right package, either
			# arpsend or vzctl, IS installed, and other unrelated packages are NOT installed.
			# However, if the host system does not provide any candidate, we have to produce
			# the dependency on /usr/bin/arpsend -> arpsend.
			save_rep="$rep" save_package="$package"
		fi
	fi

	# Lookup in the host system.
	rep=$(IFS="$IFS:"; set -f
		for dir in $findpackage_path; do
			rep="$dir/$r"
			if [ -f "$rep" ]; then
				printf '%s\n' "$rep"
			fi
		done)
	if [ -n "$rep" ]; then
		local n="$(IFS=$'\n'; set -- $rep; echo $#)"
		if [ "$n" -gt 1 ]; then
			# We've got a few paths, e.g. awk -> {/bin/awk,/usr/bin/awk};
			# we check if all paths really point to the same file.
			n="$(IFS=$'\n'; for f in $rep; do readlink -vm "$f"; done |sort -u |wc -l)"
			if [ "$n" -gt 1 ]; then
				local Verbose=Info
				Info "$f: host_env $r:$(echo '' $rep)"
			fi
			# But we select the first path, which is the best, anyway.
			rep="$(IFS=$'\n'; set -- $rep; printf %s "$1")"
		fi
		if [ -n "$rep" ]; then
			$Verbose "$f: $r -> $rep -> ... (via host_env)"
			local RPM_FINDPACKAGE_HOST_PKG_NAMES=1
			FindByFile "$f" "$rep"
			return
		fi
	fi

	# Reconsult package binary index.
	if [ -n "$save_rep" ] && [ -n "$save_package" ]; then
		rep="$save_rep" package="$save_package"
		$Verbose "$f: $r -> $rep -> $package (via contents_index_bin)"
		printf %s\\n "$package"
		return
	fi

	# Not found.
	local maybe_function=
	case "$r" in
		*[!A-Za-z0-9_]*) ;;
		[!A-Za-z_]*) ;;
		*[A-Z_]*) maybe_function=1 ;;
	esac
	if [ -n "$RPM_FINDPACKAGE_MANDATORY" ]; then
		Info "$f: $r not found, forcing /usr/bin/$r"
		printf '%s\n' "/usr/bin/$r"
	elif [ -n "$maybe_function" ]; then
		$Verbose "$f: $r not found (skip, maybe function)"
	else
		Info "$f: $r not found (skip)"
	fi
}

FindPackage()
{
	local f="$1" r; shift || return
	for r; do
		local Verbose=Verbose
		# Only these characters are allowed for pathnames or commands:
		valid='A-Za-z0-9/@=.,:_+-'
		case "$r" in
			/*[!$valid]*)
				Info "$f: invalid pathname: $r" ;;
			/*[!/.]*)
				FindByFile "$f" "$r" ;;
			*/*)
				Info "$f: invalid pathname: $r" ;;
			-*)
				Info "$f: invalid command: $r" ;;
			*[!$valid]*)
				Info "$f: invalid command: $r" ;;
			'')
				Verbose "$f: empty command?" ;;
			*)
				FindByName "$f" "$r" ;;
		esac
	done
}