#!/bin/sh

prog=genpkg

prepd=~/.genpkg/preps
modsd=~/pkg/mods
pkgd=~/pkg/dest
vard=~/.genpkg/var

mergefile()
{
	fname="$1"
	shift

	if [ -f "$fname.$$" ]
	then
		echo "$prog: error: temp file already exists: $fname.$$" 1>&2
		return 1
	fi

	while [ "$#" -gt 0 ]
	do
		sect="$1"
		shift
		getpkgtree "$fname" "$sect" >> "$fname.$$"

		case "$?" in
		0)	;;
		101)	rm "$fname.$$"
			return 101 ;;
		102)	continue ;; # empty section so don't echo a newline below
		*)	echo "$prog: unknown error from getpkgtree: $?" 1>&2
			rm "$fname.$$"
			return 1 ;;
		esac

		[ "$#" -gt 0 ] && echo >> "$fname.$$"
	done

	if du "$fname.$$" | awk '$1 == 0 { exit 1 }'
	then
		mv "$fname.$$" "$fname"
		return 0
	else
		rm "$fname.$$"
		return 1
	fi
}

scanfield()
{
	awk -v fld="$1" '
BEGIN { FS = "\n"; RS = "" }
$1 == fld { print $2; found = 1; exit }
END { exit !found }
'
	return $?
}

# Create an extra "ver" field in case the packager needs to modify the pkgver.
dupver()
{
	awk '
BEGIN { OFS = FS = "\n"; RS = ""; ORS = "\n\n" }
$1 == "pkgver" { pkgver = $2 }
1
END { if(pkgver) print "ver", pkgver }
'
}

if [ $# -lt 1 ]
then
	echo "usage: $prog [package name]" 1>&2
	exit 2
fi

if ! [ -d "$modsd" ]
then
	echo "$prog: bad package mods dir: $modsd" 1>&2
	exit 1
fi

if ! [ -d "$pkgd" ]
then
	echo "$prog: bad package dest dir: $pkgd" 1>&2
	exit 1
fi

if ! [ -d "$vard" ]
then
	echo "$prog: bad package var dir: $vard" 1>&2
	exit 1
fi

for pkg
do
	[ -d "$pkgd/$pkg" ] || mkdir "$pkgd/$pkg"
	cd "$pkgd/$pkg"

	[ -d PKGTREE ] && rm -rf PKGTREE
	mkdir PKGTREE

	trap 'rm -f PKGDATA' 1 2 15
	PREPSPATH="$prepd" PKGVAR="$vard" prepkg "$pkg" > PKGDATA
	ret=$?
	case $ret in
	0)	echo "$pkgd/$pkg"
		;;
	101)	# 101 from prepkg means cleanup
		cd
		rm -r "$pkgd/$pkg"
		exit 1
		;;
	*)	rm PKGDATA
		exit $ret
	esac
	trap '' 1 2 15

	mod="$modsd/$pkg"
	if [ -f "$mod" -a -r "$mod" ]
	then
		echo "Moding with $mod." 1>&2
		trap 'rm -f PKGDATA.new' 1 2 15

		# Duplicate the version in case modpkg modifies it.
		if cat PKGDATA | dupver | modpkg "$mod" > PKGDATA.new
		then
			mv PKGDATA.new PKGDATA
		else
			echo "$prog: modpkg failed." 1>&2
			[ "$GENPKGDBG" ] || rm PKGDATA.new
		fi

		trap '' 1 2 15
	fi

	# Insert PKGBUILD fields into prefix of PKGBUILD body.
	cat PKGDATA | injectdigs | vervar | pbfields |\
		putpkgtree PKGBUILD prefix body || exit "$?"

	# Merge split PKGTREE files into their own separate text files.
	mergefile PKGBUILD prefix build check package suffix
	case $? in
	0) ;;
	101)	echo "$PROG: error: missing PKGBUILD file in PKGTREE" 1>&2
		exit 101 ;;
	*)	exit $?
	esac

	pkgname=`scanfield pkgname < PKGDATA`
	if [ $? -ne 0 ]
	then
		echo "$PROG: pkgname missing from generated PKGDATA" 1>&2
		exit 1
	fi
	# Ignore errors when merging .install file. We don't mind missing it.
	mergefile "$pkgname.install" pre_install post_install pre_upgrade post_upgrade

	if [ -z "$GENPKGDBG" ]
	then
		rm -rf PKGTREE
		#rm PKGDATA
	fi
done