#!/bin/bash
#   pbuilder -- personal Debian package builder
#   Copyright (C) 2001,2002,2003,2005-2007 Junichi Uekawa
#
#   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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

#
# module to satisfy dependency.

set -e

function package_versions() {
	local PACKAGE="$1"
	( $CHROOTEXEC /usr/bin/apt-cache show "$PACKAGE" ) | sed -n 's/^Version: \(.*\)$/\1/p'
}

function candidate_version() {
	local PACKAGE="$1"
	LC_ALL=C $CHROOTEXEC apt-cache policy "$PACKAGE" | sed -n 's/ *Candidate: *\(.*\)/\1/p'
}

function checkbuilddep_versiondeps () {
    local PACKAGE="$1"
    local COMPARESTRING="$2"
    local DEPSVERSION="$3"
    local PACKAGEVERSIONS=$( package_versions "$PACKAGE" | xargs)
    # no versioned provides.
    if [ "${FORCEVERSION}" = "yes" ]; then
	return 0;
    fi
    for PACKAGEVERSION in $PACKAGEVERSIONS ; do
      if dpkg --compare-versions "$PACKAGEVERSION" "$COMPARESTRING" "$DEPSVERSION"; then
	# satisfies depends
	return 0;
      fi
    done
    echo "      Tried versions: $PACKAGEVERSIONS"
    # cannot satisfy depends
    return 1;
}

function expand_arch () {
    local ARCH="$1"
    local EXPANDED_ARCH
    
    # just keep the original behavior.
    echo "$ARCH"
    return

    # the following may be used if dpkg change is set to stone.
    if echo "$ARCH" | grep "-" > /dev/null; then
        EXPANDED_ARCH=$ARCH
    else
        EXPANDED_ARCH="linux-$ARCH"
    fi
    local WC1=$(echo $EXPANDED_ARCH | sed 's/^[^-]*/any/')
    local WC2=$(echo $EXPANDED_ARCH | sed 's/[^-]*$/any/')
    echo "$ARCH\\|$EXPANDED_ARCH\\|$WC1\\|$WC2"
}

function checkbuilddep_archdeps () {
    # returns FALSE on INSTALL
    local INSTALLPKG="$1"
    local ARCH="$2"
    if echo "$INSTALLPKG" | sed 's/.*\(\[.*\]\)/\1/' | grep "[[/][!]\($(expand_arch $ARCH)\)[]/]" > /dev/null; then
	# if !$ARCH exists in there, ERROR.
	return 0;
    fi
    if ! echo "$INSTALLPKG" | sed 's/.*\(\[.*\]\)/\1/' | grep "[!]" > /dev/null; then
	if ! echo "$INSTALLPKG" | sed 's/.*\(\[.*\]\)/\1/' | grep "[[/]\($(expand_arch $ARCH)\)[]/]" > /dev/null; then
	# if $ARCH does not exist, ERROR.
	    return 0;
	fi
    fi
    return 1;
}

function checkbuilddep_provides () {
    local PACKAGENAME="$1"
    # PROVIDED needs to be used outside of this function.
    PROVIDED=$($CHROOTEXEC /usr/bin/apt-cache showpkg $PACKAGENAME | awk '{p=0}/^Reverse Provides:/,/^$/{p=1}{if(p && ($0 !~ "Reverse Provides:")){PACKAGE=$1}} END{print PACKAGE}')
}

# returns either "package=version", to append to an apt-get install line, or
# package
function versioneddep_to_aptcmd () {
	local INSTALLPKG="$1"

	local PACKAGE
	local PACKAGE_WITHVERSION
	local PACKAGEVERSIONS
	local CANDIDATE_VERSION
	local COMPARESTRING
	local DEPSVERSION

	PACKAGE="$(echo "$INSTALLPKG" | sed -e 's/^[/]*//' -e 's/[[/(].*//')"
	PACKAGE_WITHVERSION="$PACKAGE"

	# if not versionned, we skip directly to outputting $PACKAGE
	if echo "$INSTALLPKG" | grep '[(]' > /dev/null; then
	    # package versions returned by APT, in reversed order
	    PACKAGEVERSIONS="$( package_versions "$PACKAGE" | tac | xargs )"
	    CANDIDATE_VERSION="$( candidate_version "$PACKAGE" )"

	    COMPARESTRING="$(echo "$INSTALLPKG" | tr "/" " " | sed 's/^.*([ ]*\(<<\|<=\|>=\|=\|<\|>>\|>\)[ ]*\(.*\)).*$/\1/')"
	    DEPSVERSION="$(echo "$INSTALLPKG" | tr "/" " " | sed 's/^.*([ ]*\(<<\|<=\|>=\|=\|<\|>>\|>\)[ ]*\(.*\)).*$/\2/')"
	    # if strictly versionned, we skip to outputting that version
	    if [ "=" = "$COMPARESTRING" ]; then
		PACKAGE_WITHVERSION="$PACKAGE=$DEPSVERSION"
	    else
		# try the candidate version, then all available versions (asc)
		for VERSION in $CANDIDATE_VERSION $PACKAGEVERSIONS; do
		    if dpkg --compare-versions "$VERSION" "$COMPARESTRING" "$DEPSVERSION"; then
			if [ $VERSION != $CANDIDATE_VERSION ]; then
			    PACKAGE_WITHVERSION="$PACKAGE=$VERSION"
			fi
			break;
		    fi
		done
	    fi
	fi

	echo "$PACKAGE_WITHVERSION"
}

function checkbuilddep_internal () {
# Use this function to fulfill the dependency (almost)

    local ARCH=$(dpkg-architecture -qDEB_HOST_ARCH)
    local INSTALLPKG
    local INSTALLPKGLIST
    local INSTALLPKGMULTI
    local CURRENTREALPKGNAME
    local SATISFIED
    local PACKAGEVERSIONS
    local CANDIDATE_VERSION
    echo " -> Attempting to parse the build-deps $Id$"
    for INSTALLPKGMULTI in $(cat ${DEBIAN_CONTROL} | \
	awk '
BEGIN{source=1} 
/^$/      {source=0} 
/^Source:/      {source=1} 
/^[^ ]*:/ {p=0} 
tolower($0) ~ /^'"${BD_REGEXP}"':/   {p=1} 
{if(p && source) {print $0}}'  | \
	sed 's/^[^: ]*://' | \
	tr " " "/" | \
	awk 'BEGIN{RS=","} {print}'); do
      echo " -> Considering build-dep$(echo "$INSTALLPKGMULTI" | tr "/" " " )"
      SATISFIED="no"
      for INSTALLPKG in $(echo "$INSTALLPKGMULTI" | \
	  awk 'BEGIN{RS="|"} {print}'); do
	CURRENTREALPKGNAME=$(echo "$INSTALLPKG" | sed -e 's/^[/]*//' -e 's/[[/(].*//')
	if echo "$INSTALLPKG" | grep '\[' > /dev/null ; then
	    if checkbuilddep_archdeps "$INSTALLPKG" "$ARCH"; then
		SATISFIED="yes"
		echo "   -> This package is not for this architecture"
		continue;
	    fi
	fi

	CURRENT_APT_COMMAND="$(versioneddep_to_aptcmd "$INSTALLPKG")"

	while [ "$SATISFIED" = "no" ]; do
	    echo "   -> Trying to add ${CURRENT_APT_COMMAND}"
	    if APT_OUTPUT="$( exec 2>&1; LC_ALL=C $CHROOTEXEC /usr/bin/apt-get -s install ${INSTALLPKGLIST} ${CURRENT_APT_COMMAND} )"; then
		# success, we're done
		SATISFIED="yes"
		INSTALLPKGLIST="${INSTALLPKGLIST} ${CURRENT_APT_COMMAND}"
		break
	    fi
	    # try to parse APT's output to recognize lines such as:
	    #   libfoo-dev: Depends: bar (>= xyz) but www is to be installed
	    DEP_INSTALLPKG="$(echo "$APT_OUTPUT" | \
		sed -n \
		    -e "s/^ *.*: *Depends: *\(.*\) but.*is to be installed\$/\\1/p" \
		    -e "s/^ *.*: *Depends: *\(.*\) but it is not going to be installed\$/\\1/p" \
		    -e "s/^ *.*: *Depends: *\(.*\)\$/\\1/p" | \
		head -1 | \
		tr " " "/")"
	    APT_ADD_COMMAND="$(versioneddep_to_aptcmd "$DEP_INSTALLPKG")"
	    if echo "$CURRENT_APT_COMMAND" | grep -q "$APT_ADD_COMMAND"; then
		# loop detected, give up with real packages
		echo "   -> Loop detected, last APT error was: ======"
		echo "$APT_OUTPUT"
		echo "   -> ========================================="
		echo "   -> (not adding $APT_ADD_COMMAND to $CURRENT_APT_COMMAND)"
		break
	    fi
	    CURRENT_APT_COMMAND="$CURRENT_APT_COMMAND $APT_ADD_COMMAND"
	done
	if [ "$SATISFIED" = "yes" ]; then
	    break;
	fi

	echo "       -> Cannot install ${CURRENT_APT_COMMAND}; apt errors follow:"
	if $CHROOTEXEC /usr/bin/apt-get -s install ${INSTALLPKGLIST} "${CURRENT_APT_COMMAND}"; then
	    :
	fi
	# package could not be found. -- looking for alternative.
	PROVIDED=""
	checkbuilddep_provides "${CURRENTREALPKGNAME}"
	if [ -n "$PROVIDED" ]; then
	    # something provides this package
	    echo "     -> Considering $PROVIDED to satisfy the dependency "
	    if $CHROOTEXEC /usr/bin/apt-get -s install ${INSTALLPKGLIST} ${PROVIDED} >& /dev/null; then
		SATISFIED="yes";
		INSTALLPKGLIST="${INSTALLPKGLIST} ${PROVIDED}"
	    else
		# show the error for diagnostic purposes
		echo "       -> Cannot install $PROVIDED; apt errors follow:"
		if $CHROOTEXEC /usr/bin/apt-get -s install ${INSTALLPKGLIST} ${PROVIDED}; then
		    :
		fi
	    fi
	fi
	if [ "$SATISFIED" = "yes" ]; then
	    break;
	fi
      done;
      if [ "$SATISFIED" = "no" ]; then
	  echo "E: Could not satisfy build-dependency." >&2
	  if [ "$CONTINUE_FAIL" != "yes" ]; then
	      exit 2
	  fi
      fi
    done;
    
    # now actually install the packages
    echo " -> Installing ${INSTALLPKGLIST}"
    if ! $CHROOTEXEC apt-get -y --force-yes install ${INSTALLPKGLIST}; then
	echo " -> Trying to fix apt error"
	# Work around an apt bug which causes configure to fail.
	if $CHROOTEXEC dpkg --configure --pending && $CHROOTEXEC apt-get -y --force-yes install ${INSTALLPKGLIST}; then
	    echo " -> Apt bug workaround succeeded"
	elif [ "$CONTINUE_FAIL" != "yes" ]; then
	    echo "E: Unrecoverable error installing build-dependencies." >&2
	    exit 1
	fi
    fi

    # start processing build-conflicts.
    for INSTALLPKG in $(cat "${DEBIAN_CONTROL}" | \
	awk 'BEGIN{source=1} 
/^$/      {source=0} 
/^Source:/      {source=1} 
/^[^ ]*:/{p=0} 
tolower($0) ~ /^'"${BC_REGEXP}"':/   {p=1} 
{if(p && source) {print $0}}'  | \
	sed 's/^[^: ]*://' | \
	tr " " "/" | \
	awk 'BEGIN{RS=","} {print}'); do
      CURRENTREALPKGNAME=$(echo "$INSTALLPKG" | sed -e 's/^[/]*//' -e 's/[[/(].*//')
      echo " -> Considering ${CURRENTREALPKGNAME}"
      
      if echo "$INSTALLPKG" | grep '\[' > /dev/null ; then
	  # this package has arch-conflicts.
	  if checkbuilddep_archdeps "$INSTALLPKG" "$ARCH"; then
	      echo "I: Ignoring other-arch"
	      continue;
	  fi
      fi
      if echo "$INSTALLPKG" | grep '[(]' > /dev/null ; then
	  # this package has version-conflicts
	  if ! checkbuilddep_versiondeps ${CURRENTREALPKGNAME} \
		$(echo "$INSTALLPKG" | tr "/" " " | sed 's/^.*([ ]*\(<<\|<=\|>=\|=\|<\|>>\|>\)[ ]*\(.*\)).*$/\1/') \
		$(echo "$INSTALLPKG" | tr "/" " " | sed 's/^.*([ ]*\(<<\|<=\|>=\|=\|<\|>>\|>\)[ ]*\(.*\)).*$/\2/'); then
	      echo "I: Satisfies version, not trying"
	      continue;
	  fi
      fi

      # if package exists, remove it.
      if $CHROOTEXEC /usr/bin/dpkg -s $(echo "$INSTALLPKG" | tr "/" " " | awk '{print $1}') 2>&1 | grep ^Package: > /dev/null; then
	  if ! $CHROOTEXEC /usr/bin/apt-get -y remove ${CURRENTREALPKGNAME} ; then
	      echo "E: Could not satisfy build-conflicts" >&2
	      exit 1
	  fi
      else
	  echo "I: ${CURRENTREALPKGNAME} package is not installed, no need to remove"
      fi
    done
    echo " -> Finished parsing the build-deps"
}


function print_help () {
    # print out help message
    cat <<EOF
pbuilder-satisfydepends -- satisfy dependencies
Copyright 2002-2007  Junichi Uekawa <dancer@debian.org>

--help:        give help
--control:     specify control file (debian/control, *.dsc)
--chroot:      operate inside chroot
--binary-all:  include binary-all
--binary-arch: include binary-arch only
--echo:        echo mode, do nothing. (--force-version required for most operation)
--force-version: skip version check.
--continue-fail: continue even when failed.

EOF
}


DEBIAN_CONTROL=debian/control
CHROOTEXEC=""
BD_REGEXP="build-(depends|depends-indep)"
BC_REGEXP="build-(conflicts|conflicts-indep)"
FORCEVERSION=""
CONTINUE_FAIL="no"


while [ -n "$1" ]; do
    case "$1" in
	--control|-c)
	    DEBIAN_CONTROL="$2"
	    shift; shift
	    ;;
	--chroot)
	    CHROOTEXEC="chroot $2 "
	    shift; shift
	    ;;
	--internal-chrootexec)
	    CHROOTEXEC="$2"
	    shift; shift 
	    ;;
	--binary-all)
	    BD_REGEXP='build-(depends|depends-indep)'
	    BC_REGEXP='build-(conflicts|conflicts-indep)'
	    shift
	    ;;
	--binary-arch)
	    BD_REGEXP='build-depends'
	    BC_REGEXP='build-conflicts'
	    shift
	    ;;
	--echo)
	    CHROOTEXEC="echo $CHROOTEXEC"
	    shift
	    ;;
	--continue-fail)
	    CONTINUE_FAIL="yes"
	    shift
	    ;;
	--force-version)
	    FORCEVERSION="yes"
	    shift;
	    ;;
	--help|-h|*)
	    print_help
	    exit 1
	    ;;
    esac
done


checkbuilddep_internal