#!/usr/bin/tclsh

###
# Microversion (uvn)
# Kevin Van Vechten <kvv@apple.com>
# 9/28/2006
###

proc DEBUG {args} {
	global DEBUGGING
	global env
	if {![info exists DEBUGGING]} {
		set DEBUGGING [info exists env(UVNDEBUG)]
	}
	if {$DEBUGGING} {
		puts stderr "DEBUG: $args"
	}
}

proc PRINT {args} {
	puts stdout "$args"
}

proc ldelete {l v} {
	upvar $l ul
	while {[set i [lsearch -exact $ul $v]] != -1} {
		set ul [lreplace $ul $i $i]
	}
}

namespace eval uvn {
	variable srcroot
	variable objroot
	variable var
	variable state
	variable patchlevel 1

	proc init {} {
		global env
		variable srcroot
		variable objroot
		variable var
		variable patchlevel

		if {[info exists env(UVNPATCHLEVEL)]} {
			set patchlevel $env(UVNPATCHLEVEL)
		}

		if {[info exists env(RC_XBS)] &&
			$env(RC_XBS) == "YES" &&
			[info exists env(SRCROOT)] &&
			[file isdirectory $env(SRCROOT)] &&
			[info exists env(OBJROOT)] &&
			[file isdirectory $env(OBJROOT)]} {

			DEBUG XBS mode (using SRCROOT and OBJROOT)
			
			set srcroot $env(SRCROOT)
			set objroot $env(OBJROOT)
			
		} else {
			set dir [pwd]
			set origdir $dir

			while {![file isdirectory .uvn] && $dir != "/"} {
				set dir [file dirname $dir]
				cd $dir
			}

			### check for archive/patches/something
			if {$dir == "/"} {
				set dir $origdir
				cd $dir
			}

			set srcroot $dir
			set objroot $dir
		}
		set var $objroot/.uvn
	}
}

namespace eval uvn::util {
	proc cat {path} {
		set fd [open $path r]
		puts -nonewline [read $fd]
		close $fd
	}
}

namespace eval uvn::state {
	proc save {data} {
		if {[file isfile $uvn::var/state] || [llength $data] > 0} {
			file mkdir $uvn::var
			set fd [open $uvn::var/.tmp.state w]
			puts $fd $data
			close $fd
			file rename -force $uvn::var/.tmp.state $uvn::var/state
		}
	}

	proc load {} {
		if {[file exists $uvn::var/state]} {
			set fd [open $uvn::var/state r]
			set data [read -nonewline $fd]
			close $fd
		} else {
			set data [list]
		}
		return $data
	}
}


proc find_distfile {} {
	set sources {}
	foreach suffix {.tar .tar.Z .tar.gz .tar.bz2 .tgz .tbz2} {
		set files [glob -nocomplain -type f *$suffix]
		if {[llength $files] > 0} {
			lappend sources $files
		}
	}
	
	set c [llength $sources]
	if {$c == 0} {
		return -code error "no source archive"
	} elseif {$c > 1} {
		return -code error "too many source archives; please specify one"
	} else {
		return [file join [pwd] [lindex $sources 0]]
	}
}

proc extract_sources {path {suffix ""}} {
	set precmd {}
	set cmd {tar xf -}
	switch -glob -- $path {
		*.tar {}
		*.tar.Z { set precmd {uncompress - |} }
		*.tar.gz -
		*.tgz { set precmd {gzip -cd - |} }
		*.tar.bz2 -
		*.tbz2 { set precmd {bzip2 -cd - |} }
		default { return -code error "unsupported archive format: $path" }
	}

	### Validate temp ###

	file mkdir $uvn::var/extract
	eval DEBUG $precmd $cmd -C $uvn::var/extract < $path
	eval exec -- $precmd $cmd -C $uvn::var/extract < $path
	set files [glob $uvn::var/extract/*]
	if {[llength $files] == 0} {
		return -code error "archive is empty: $path"
	} elseif {[llength $files] > 1} {
		return -code error "archive does not have root directory: $path"
	}
	set dir [lindex $files 0]
	if {![file isdirectory $dir]} {
		return -code error "archive does not contain a directory: $path"
	}

	### Make temp visible (with optional suffix appended) ###

	set dst [file join $uvn::objroot [file tail $dir]$suffix]
	if {![file exists $dst]} {
		file rename $dir $dst
	}
	return $dst
}

##### main #####

proc extract {} {
	if {![info exists uvn::state(distfile)]} {
		set uvn::state(distfile) [find_distfile]
	}
	if {![info exists uvn::state(workdir)] ||
		![file exists $uvn::state(workdir)]} {
		PRINT Extracting: [file tail $uvn::state(distfile)]
		set uvn::state(workdir) [extract_sources $uvn::state(distfile)]
	}
}

proc clean {} {
	PRINT Cleaning
	foreach dir {workdir origdir} {
		DEBUG cleaning $dir
		if {[info exists uvn::state($dir)] &&
			[file isdirectory $uvn::state($dir)]} {
			DEBUG deleting $uvn::state($dir)
			file delete -force $uvn::state($dir)
		}
	}
	if {[file isfile $uvn::var/state]} {
		DEBUG deleting $uvn::var/state
		file delete -force $uvn::var/state
	}
	array unset uvn::state
}

proc diff {{outfile -}} {
	if {![info exists uvn::state(origdir)]} {
		PRINT Extracting orig: [file tail $uvn::state(distfile)]
		set uvn::state(origdir) [extract_sources $uvn::state(distfile) .orig]
	}

	if {[info exists uvn::state(workdir)]} {
		file mkdir $uvn::var
		cd $uvn::objroot
		### diff exits 1 if files differ ###
		DEBUG diff -r -u -N --exclude=*.orig [file tail $uvn::state(origdir)] [file tail $uvn::state(workdir)]
		catch {exec diff -r -u -N --exclude=*.orig [file tail $uvn::state(origdir)] [file tail $uvn::state(workdir)] > $uvn::var/diff}

		if {$outfile == "-" } {
			uvn::util::cat $uvn::var/diff
		} else {
			file rename -force $uvn::var/diff $outfile
		}
	}
}

namespace eval uvn::patch {

	proc create {patch {outfile patches/$patch}} {
		if {![info exists uvn::state(origdir)]} {
			set uvn::state(origdir) [extract_sources $uvn::state(distfile) .orig]
		}

		file mkdir patches
		
		set patches {}
		
		### unapply orthogonal patches ###
		if {[info exists uvn::state(patches_applied)]} {
			set patches $uvn::state(patches_applied)
			foreach p $patches {
				if {$p != $patch} {
					uvn::patch::unapply $p
				}
			}
		}
		
		### store diff in patchfile ###
		diff $outfile
		
		if {![info exists uvn::state(patches_applied)] ||
			[lsearch -exact $uvn::state(patches_applied) $patch] == -1} {
			lappend uvn::state(patches_applied) $patch
		}
		
		### reapply previously applied patches ###
		foreach p $patches {
			uvn::patch::apply $p
		}
	}

	proc apply {patch} {
		if {![info exists uvn::state(patches_applied)] ||
			[lsearch -exact $uvn::state(patches_applied) $patch] == -1} {
			PRINT Applying patch: $patch
			cd $uvn::objroot
			cd $uvn::state(workdir)
			exec patch -N -u -p$uvn::patchlevel -r $uvn::var/rejects < $uvn::srcroot/patches/$patch
			lappend uvn::state(patches_applied) $patch
		} else {
			DEBUG patch already applied: $patch
		}
	}


	proc unapply {patch} {
		if {[info exists uvn::state(patches_applied)] &&
			[lsearch -exact $uvn::state(patches_applied) $patch] != -1} {
			DEBUG unapplying patch: $patch
			cd $uvn::objroot
			cd $uvn::state(workdir)
			exec patch -R -u -p$uvn::patchlevel -r $uvn::var/rejects < $uvn::srcroot/patches/$patch
			ldelete uvn::state(patches_applied) $patch
		} else {
			DEBUG patch not applied: $patch
		}
	}

	proc all {} {
		set patches {}
		foreach p [glob -nocomplain patches/*.diff patches/*.patch] {
			lappend patches [file tail $p]
		}
		return $patches
	}

	proc list {} {
		set applied {}
		if {[info exists uvn::state(patches_applied)]} {
			set applied $uvn::state(patches_applied)
		}
		foreach p [uvn::patch::all] {
			if {[lsearch -exact $applied $p] != -1} {
				puts -nonewline "* "
			} else {
				puts -nonewline "  "
			}
			puts $p
		}
	}
	
	proc show {patch} {
		cd $uvn::srcroot
		DEBUG exec diffstat patches/$patch
		exec diffstat -o $uvn::var/diffstat patches/$patch
		PRINT
		PRINT $patch:
		uvn::util::cat $uvn::var/diffstat
	}

	proc isvalid {patch} {
		if {![regexp -- {[[:alnum:]_-]+(.diff|.patch)} $patch]} {
			return -code error "invalid patch name: $patch"
		}
		return $patch
	}
	
	proc defuzz {} {
		foreach p [uvn::patch::all] {
			uvn::patch::apply $p
			uvn::patch::create $p $uvn::srcroot/patches/.tmp.$p
			uvn::patch::unapply $p
			file rename -force $uvn::srcroot/patches/.tmp.$p $uvn::srcroot/patches/$p
		}
	}
}

proc patch {argv} {
	if {![info exists uvn::state(workdir)]} {
		extract
	}
	switch -exact -- [lindex $argv 1] {
		--apply {
			uvn::patch::apply [uvn::patch::isvalid [lindex $argv 2]]
		}
		--create {
			uvn::patch::create [uvn::patch::isvalid [lindex $argv 2]]
		}
		--defuzz {
			uvn::patch::defuzz
		}
		--list {
			uvn::patch::list
		}
		--show {
			if {[lindex $argv 2] != ""} {
			uvn::patch::show [uvn::patch::isvalid [lindex $argv 2]]
			} else {
				foreach patch [uvn::patch::all] {
					uvn::patch::show $patch
				}
			}
		}
		--unapply {
			uvn::patch::unapply [uvn::patch::isvalid [lindex $argv 2]]
		}
		{} {
			foreach p [uvn::patch::all] {
				uvn::patch::apply $p
			}
		}
		default {
			puts stderr "usage: uvn patch"
			puts stderr "       uvn patch --apply name"
			puts stderr "       uvn patch --create name"
			puts stderr {       uvn patch --defuzz [name]}
			puts stderr "       uvn patch --list"
			puts stderr {       uvn patch --show [name]}
			puts stderr "       uvn patch --unapply name"
			exit 1
		}
	}			
}

proc main {argv} {
	switch -exact -- [lindex $argv 0] {
		clean { clean }
		extract { extract }
		diff { diff }
		patch { patch $argv }
		default {
			puts stderr {usage: uvn <subcommand> [options] [args]}
			puts stderr ""
			puts stderr "Available subcommands:"
			puts stderr "   clean"
			puts stderr "   extract"
			puts stderr "   diff"
			puts stderr "   patch"
			exit 1
		}
	}
}

##### start #####

uvn::init
array set uvn::state [uvn::state::load]
DEBUG state = [array get uvn::state]
if {[catch {main $argv} res]} {
	puts stderr $res
}
uvn::state::save [array get uvn::state]