###
### postgresql bindings for dbconfig-common
###
###	all variables and functions fall under the namespace "dbc_foo" and
###	"_dbc_foo", depending on whether or not they are "external"
###

# get some common functions
. /usr/share/dbconfig-common/internal/common

_dbc_psql_local_username(){
	# determine proper local system user as whom to run commands.
	#	- if _dbc_asuser set and ident/localhost,  
	#	  - if $dbc_dbuser exists as a system account, use it
	#	- else ident/localhost: $dbc_dbadmin
	#	- all others: no change (root)
	if [ "${_dbc_asuser:-}" ]; then
		if [ "${dbc_authmethod_user:-}" = "ident" ] && [ ! "${dbc_dbserver:-}" ]; then
			if [ "${dbc_dbuser:-}" ] && id $dbc_dbuser >/dev/null 2>&1; then
				echo $dbc_dbuser
				return 0
			else
				dbc_logline "warning: ident method specified but local account doesn't exist"
			fi
		fi
	elif [ "${dbc_authmethod_admin:-}" = "ident" ] && [ ! "${dbc_dbserver:-}" ]; then
		echo $dbc_dbadmin
		return 0
	fi
	echo root
}

_dbc_psql_remote_username(){
	# determine proper remote user for connection requests
	#	- if _dbc_asuser set: $dbc_dbuser
	#	- else: $dbc_dbadmin
	if [ "${_dbc_asuser:-}" ]; then
		echo $dbc_dbuser
	else
		echo $dbc_dbadmin
	fi
}

_dbc_psql_cmd_setup(){
	local localuser remoteuser remotepass
	localuser=`_dbc_psql_local_username`
	remoteuser=`_dbc_psql_remote_username`
	_dbc_pgsql_tmpdir=`mktemp -dt dbconfig-common.psql_home.XXXXXX`
	if [ $? -ne 0 ]; then return 1; fi
	if [ "$remoteuser" = "$dbc_dbadmin" ]; then
		remotepass="$dbc_dbadmpass"
	else
		remotepass="$dbc_dbpass"
	fi
	touch "${_dbc_pgsql_tmpdir}/.pgpass"
	chmod 600 "${_dbc_pgsql_tmpdir}/.pgpass"
	cat << EOF > "${_dbc_pgsql_tmpdir}/.pgpass"
*:*:*:$remoteuser:$remotepass
EOF
	if [ "$localuser" ] && [ "$localuser" != "root" ]; then
		chown -R "$localuser" "$_dbc_pgsql_tmpdir"
	fi
}

_dbc_psql_cmd_args(){
	local extra remoteuser

	# if a dbserver is specified, use it
	if [ "$dbc_dbserver" ]; then
		extra="-h '$dbc_dbserver'"; 
	# but if they specify a password, we should add the host explictly too
 	elif [ "${_dbc_asuser:-}" ] && [ "$dbc_dbpass" ]; then 
		extra="-h localhost"; 
	elif [ "$dbc_dbadmpass" ]; then
		extra="-h localhost"; 
	fi
	# add port settings if nonempty
	if [ "$dbc_dbport" ]; then extra="$extra -p '$dbc_dbport'"; fi
	# determine the database user name
	extra="$extra -U '`_dbc_psql_remote_username`'"

	echo $extra
}

_dbc_psql_cmd_cleanup(){
	if [ "$_dbc_pgsql_tmpdir" ] && [ -d "$_dbc_pgsql_tmpdir" ]; then
		rm -f "${_dbc_pgsql_tmpdir}/.pgpass"
		rmdir "$_dbc_pgsql_tmpdir"
	fi
}

_dbc_psql(){
	local extra retval PGSSLMODE localuser
	localuser=`_dbc_psql_local_username`
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "${dbc_ssl:-}" ]; then PGSSLMODE="require"; fi
	extra=`_dbc_psql_cmd_args`
	_dbc_debug "su -s /bin/sh $localuser -c \"env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' psql --set \"ON_ERROR_STOP=1\" -q $extra $*\" 2>&1"
	dbc_error=`su -s /bin/sh $localuser -c "env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' psql --set "ON_ERROR_STOP=1" -q $extra $*" 2>&1` || retval=$?
	_dbc_psql_cmd_cleanup
	return $retval
}

_dbc_createdb(){
	local extra extrasql retval PGSSLMODE localuser _dbc_asuser template
	local _dbc_nodb
	localuser=`_dbc_psql_local_username`
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "${dbc_ssl:-}" ]; then PGSSLMODE="require"; fi
	extra=`_dbc_psql_cmd_args`
	if [ "${dbc_pgsql_createdb_encoding:-}" ]; then 
		extrasql=" WITH TEMPLATE = \"template0\""; 
		extrasql="$extrasql ENCODING = '$dbc_pgsql_createdb_encoding'"; 
	fi
	_dbc_nodb="yes"
	_dbc_pgsql_exec_command "CREATE DATABASE \"$dbc_dbname\"${extrasql:-}"
	retval=$?
	_dbc_nodb=""
	_dbc_psql_cmd_cleanup
	return $retval
}

_dbc_dropdb(){
	local extra retval PGSSLMODE localuser _dbc_asuser
	localuser=`_dbc_psql_local_username`
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "$dbc_ssl" ]; then PGSSLMODE="require"; fi
	extra=`_dbc_psql_cmd_args`
	_dbc_debug "su -s /bin/sh $localuser -c \"env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' dropdb $extra $*\" 2>&1"
	dbc_error=`su -s /bin/sh $localuser -c "env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' dropdb $extra $*" 2>&1` || retval=$?
	_dbc_psql_cmd_cleanup
	return $retval
}

_dbc_createuser_majorversion(){
	createuser --version | sed -e 's,.* ,,g' | sed -e 's,\..*,,g'
}

_dbc_createuser(){
	local extra dbc_dbname retval PGSSLMODE localuser _dbc_asuser
	localuser=`_dbc_psql_local_username`
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "$dbc_ssl" ]; then PGSSLMODE="require"; fi
	extra=`_dbc_psql_cmd_args`
	dbc_dbname="template1"
	_dbc_pgsql_exec_command "CREATE USER \"$dbc_dbuser\" WITH PASSWORD '`dbc_pgsql_escape_str $dbc_dbpass`'" || retval=$?
	_dbc_psql_cmd_cleanup
	return $retval
}

_dbc_dropuser(){
	local extra retval PGSSLMODE localuser _dbc_asuser
	localuser=`_dbc_psql_local_username`
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "$dbc_ssl" ]; then PGSSLMODE="require"; fi
	extra=`_dbc_psql_cmd_args`
	_dbc_debug "su -s /bin/sh $localuser -c \"env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' dropuser $extra $*\" 2>&1"
	dbc_error=`su -s /bin/sh $localuser -c "env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' dropuser $extra $*" 2>&1` || retval=$?
	_dbc_psql_cmd_cleanup
	return $retval
}

_dbc_pg_dump(){
	local extra retval PGSSLMODE localuser _dbc_asuser dumpfile old_umask
	dumpfile=$1
	localuser=`_dbc_psql_local_username`
	touch $dumpfile
	chown $localuser $dumpfile
	PGSSLMODE="prefer"
	retval=0
	_dbc_psql_cmd_setup
	if [ "$dbc_ssl" ]; then PGSSLMODE="require"; fi
	old_umask=`umask`
	umask 0066
	extra=`_dbc_psql_cmd_args`
	extra="-f \"$dumpfile\" $extra"
	_dbc_debug "su -s /bin/sh $localuser -c \"env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' pg_dump $extra $dbc_dbname\" 2>&1"
	dbc_error=`su -s /bin/sh $localuser -c "env HOME='$_dbc_pgsql_tmpdir' PGPASSFILE='$_dbc_pgsql_tmpdir/.pgpass' PGSSLMODE='$PGSSLMODE' pg_dump $extra $dbc_dbname" 2>&1` || retval=$?
	umask $old_umask
	_dbc_psql_cmd_cleanup
	return $retval
}

##
## check that we can actually connect to the specified postgres server
##
_dbc_pgsql_check_connect(){
	local constat extra _dbc_asuser
	constat="bad"
	if ! _dbc_psql $extra template1 < /dev/null; then
		dbc_logline "unable to connect to postgresql server"
		return 1
	fi
}

##
## execute a file with pgsql commands
##
##	note this is done without passing any sensitive info on the cmdline
##
dbc_pgsql_exec_file(){
	local l_sqlfile retval
	l_sqlfile=$1

	if [ ! "$l_sqlfile" ]; then
		dbc_error="no file supplied to execute"
		dbc_log="no file supplied to execute"
		return 1
	fi

	_dbc_psql $dbc_dbname < "$l_sqlfile"
	retval=$?
	return $retval
}

##
## execute a specific pgsql command
##
##	note this is done without passing any sensitive info on the cmdline,
##	including the sql command itself
##
_dbc_pgsql_exec_command(){
	local statement l_sqlfile l_dbname retval
	retval=0
	statement=$@
	l_sqlfile=`dbc_mktemp dbconfig-common_sqlfile.XXXXXX`
	if [ -z "${_dbc_nodb:-}" ]; then
		l_dbname="$dbc_dbname"
	fi

	cat << EOF > "$l_sqlfile"
$statement
EOF
	_dbc_psql $extra ${l_dbname:-} < "$l_sqlfile" || retval=$?
	rm -f "$l_sqlfile"
	return $retval
}

##
## check for the existance of a specified database
##
_dbc_pgsql_check_database(){
	local dbc_dbname _dbc_asuser extra
	dbc_dbname=$1
	_dbc_psql $extra $dbc_dbname </dev/null 2>/dev/null
	return $?
}

##
## check for access for a specific user
##
##	this works by checking the grants for the user, so we can verify that
##	not only does the user exist, but that it should be able to connect
##
dbc_pgsql_check_user(){
	local dbc_dbname l_retval _dbc_asuser extra
	dbc_dbname="template1"
	_dbc_pgsql_exec_command "ALTER USER \"$dbc_dbuser\""
	l_retval=$?
	return $l_retval
}

###
### externally supplied functions
###
###	included inline are some slightly modified / corrected comments from 
###	the respective original	functions provided by wwwconfig-common, and
###	comments of similar style for now functions
###
###	all functions return non-zero on error
###

# File:         pgsql-createdb.sh
# Description:  Creates a database.
# Needs:        $dbc_dbname
#               $dbc_dbadmin
# Sets:         $dbc_error = error message

dbc_pgsql_createdb(){
	_dbc_sanity_check dbname dbadmin psql dbuser createdb || return 1
	_dbc_pgsql_check_connect || return 1

	dbc_logpart "creating database $dbc_dbname:"

	if _dbc_pgsql_check_database "$dbc_dbname"; then
		dbc_logline "already exists"
	else
		if _dbc_createdb $dbc_dbname ; then
			dbc_logline "success"
			dbc_logpart "verifying database $dbc_dbname exists:"
			if ! _dbc_pgsql_check_database "$dbc_dbname"; then
				dbc_logline "failed"
				return 1
			else
				dbc_logline "success"
			fi
		else
			dbc_logline "failed"
			return 1
		fi
	fi

}

# File:		pgsql-dropdb.sh
# Needs:	$dbc_dbname    - the database that user should have access to.
#		$dbc_dbserver  - the server to connect to.
#		$dbc_dbadmin   - the administrator name.
#		$dbc_dbadmpass - the administrator password.
# Description:	drops a database.
# Sets:		$dbc_error = error message

dbc_pgsql_dropdb(){
	_dbc_sanity_check dbname dbadmin dropdb || return 1
	_dbc_pgsql_check_connect || return 1

	dbc_logpart "dropping database $dbc_dbname:"

	if _dbc_pgsql_check_database "$dbc_dbname"; then
		if _dbc_dropdb "$dbc_dbname"; then
			dbc_logline "success"
			dbc_logpart "verifying database $dbc_dbname was dropped:"
			if _dbc_pgsql_check_database "$dbc_dbname"; then
				dbc_logline "failed"
			else
				dbc_logline "success"
			fi
		else
			dbc_logline "does not exist"
		fi
	else
		dbc_logline "database does not exist"
	fi
}

# File:		pgsql-createuser.sh
# Description:	Creates or replaces a database user.
# Needs:	$dbc_dbuser    - the user name to create (or replace).
#		$dbc_dballow   - what hosts to allow. defaults to localhost/hostname
#		$dbc_dbname    - the database that user should have access to.
#		$dbc_dbpass    - the password to use.
#		$dbc_dbserver  - the server to connect to (defaults to localhost).
#		$dbc_dbadmin   - the administrator name.
#		$dbc_dbadmpass - the administrator password.
# Sets:		$dbc_error = error message

dbc_pgsql_createuser(){
	local l_dballow dbc_dbname

	dbc_dbname=template1

	_dbc_sanity_check dbuser dbadmin createuser || return 1
	_dbc_pgsql_check_connect || return 1

	if [ ! "$dbc_dballow" ]; then 
		if [ ! "$dbc_dbserver" ] || [ "$dbc_dbserver" = "localhost" ]; then
			l_dballow=localhost
		else
			l_dballow=`hostname -f`
		fi
	else
		l_dballow="$dbc_dballow" 
	fi

	dbc_logpart "creating postgres user $dbc_dbuser: "

	if dbc_pgsql_check_user; then
		dbc_logline "already exists"
		if [ "$dbc_dbpass" ]; then
			dbc_logpart "resetting password: "
			if _dbc_pgsql_exec_command "ALTER USER \"$dbc_dbuser\" WITH PASSWORD '$dbc_dbpass'"; then
				dbc_logline "success"
			else
				dbc_logline "failed"
				return 1
			fi
		fi
	elif _dbc_createuser; then
		dbc_logline "success"
		dbc_logpart "verifying creation of user:"
		if ! dbc_pgsql_check_user ; then
			dbc_logline "failed"
			return 1
		else
			dbc_logline "success"
		fi
	else
		dbc_logline "failed"
		return 1
	fi
}

# File:		pgsql-dropuser.sh
# Needs:	$dbc_dbuser    - the user name to create (or replace).
#		$dbc_dballow   - what hosts to allow (defaults to %).
#		$dbc_dbname    - the database that user should have access to.
#		$dbc_dbserver  - the server to connect to.
#		$dbc_dbadmin   - the administrator name.
#		$dbc_dbadmpass - the administrator password.
# Description:	drops a database user.
# Sets:		$dbc_error = error message

dbc_pgsql_dropuser(){
	local l_dballow

	_dbc_sanity_check dbuser dbname dbadmin dropuser || return 1
	_dbc_pgsql_check_connect || return 1

	if [ ! "$dbc_dballow" ]; then
		if [ ! "$dbc_dbserver" ] || [ "$dbc_dbserver" = "localhost" ]; then
			l_dballow=localhost
		else
			l_dballow=`hostname -f`
		fi
	else
		l_dballow="$dbc_dballow"
	fi

	dbc_logpart "revoking access to database $dbc_dbname from $dbc_dbuser@$l_dballow:"
	if ! dbc_pgsql_check_user; then
		dbc_logline "access does not exist"
	else
		if _dbc_dropuser $dbc_dbuser 2>/dev/null; then
			dbc_logline "success"
		else
			dbc_logline "failed"
		fi
	fi
}

##
## perform pg_dump
##
dbc_pgsql_dump(){
	local dumpfile
	dumpfile=$1
	_dbc_sanity_check dbuser dbname dbadmin pg_dump || return 1
	_dbc_pgsql_check_connect || return 1
	_dbc_pg_dump $dumpfile
}

##
## basic installation check
##
dbc_pgsql_db_installed(){
	test -n "`find /etc/init.d -name 'postgresql*'`"
}

##
## dbc_pgsql_escape_str: properly escape strings passed to pgsql queries
##
dbc_pgsql_escape_str(){
	sed -e 's,\\,\\&,g' -e "s,',\\\\&,g" << EOF
$1
EOF
}