#!/usr/bin/env rake

require 'uri'
require 'tempfile'
require 'rbconfig'
require 'rake/clean'
require 'rake/extensiontask'
require 'rake/extensioncompiler'
require 'ostruct'

MISCDIR = BASEDIR + 'misc'

NUM_CPUS = if File.exist?('/proc/cpuinfo')
	File.read('/proc/cpuinfo').scan('processor').length
elsif RUBY_PLATFORM.include?( 'darwin' )
	`system_profiler SPHardwareDataType | grep 'Cores' | awk '{print $5}'`.chomp
else
	1
end

class CrossLibrary < OpenStruct
	include Rake::DSL

	def initialize(for_platform, openssl_config)
		super()

		self.for_platform               = for_platform
		self.openssl_config             = openssl_config

		# Cross-compilation constants
		self.openssl_version            = ENV['OPENSSL_VERSION'] || '1.0.1e'
		self.postgresql_version         = ENV['POSTGRESQL_VERSION'] || '9.2.3'

		self.compile_home               = Pathname( "./build" ).expand_path
		self.static_sourcesdir          = compile_home + 'sources'
		self.static_builddir            = compile_home + 'builds' + for_platform

		# Static OpenSSL build vars
		self.static_openssl_builddir    = static_builddir + "openssl-#{openssl_version}"

		self.openssl_source_uri         =
			URI( "http://www.openssl.org/source/openssl-#{openssl_version}.tar.gz" )
		self.openssl_tarball            = static_sourcesdir + File.basename( openssl_source_uri.path )
		self.openssl_makefile           = static_openssl_builddir + 'Makefile'

		self.libssleay32                = static_openssl_builddir + 'libssleay32.a'
		self.libeay32                   = static_openssl_builddir + 'libeay32.a'

		self.openssl_patches            = Rake::FileList[ (MISCDIR + "openssl-#{openssl_version}.*.patch").to_s ]

		# Static PostgreSQL build vars
		self.static_postgresql_builddir = static_builddir + "postgresql-#{postgresql_version}"
		self.postgresql_source_uri      = begin
			uristring = "http://ftp.postgresql.org/pub/source/v%s/postgresql-%s.tar.bz2" %
				[ postgresql_version, postgresql_version ]
			URI( uristring )
		end
		self.postgresql_tarball         = static_sourcesdir + File.basename( postgresql_source_uri.path )

		self.static_postgresql_srcdir   = static_postgresql_builddir + 'src'
		self.static_postgresql_libdir   = static_postgresql_srcdir + 'interfaces/libpq'
		self.static_postgresql_incdir   = static_postgresql_srcdir + 'include'

		self.postgresql_global_makefile = static_postgresql_srcdir + 'Makefile.global'
		self.postgresql_shlib_makefile  = static_postgresql_srcdir + 'Makefile.shlib'
		self.postgresql_shlib_mf_orig   = static_postgresql_srcdir + 'Makefile.shlib.orig'
		self.postgresql_lib             = static_postgresql_libdir + 'libpq.a'
		self.postgresql_patches         = Rake::FileList[ (MISCDIR + "postgresql-#{postgresql_version}.*.patch").to_s ]

		# Use rake-compilers config.yml to determine the toolchain that was used
		# to build Ruby for this platform.
		self.host_platform = begin
			config_file = YAML.load_file(File.expand_path("~/.rake-compiler/config.yml"))
			_, rbfile = config_file.find{|key, fname| key.start_with?("rbconfig-#{for_platform}-") }
			IO.read(rbfile).match(/CONFIG\["host"\] = "(.*)"/)[1]
		end


		# clean intermediate files and folders
		CLEAN.include( static_builddir.to_s )


		ENV['RUBY_CC_VERSION'] ||= '1.8.7:1.9.3:2.0.0'

		def download(url, save_to)
			part = save_to+".part"
			sh "wget #{url.to_s.inspect} -O #{part.inspect} || curl #{url.to_s.inspect} -o #{part.inspect}"
			FileUtils.mv part, save_to
		end

		def run(*args)
			sh *args
		end

		#####################################################################
		### C R O S S - C O M P I L A T I O N - T A S K S
		#####################################################################


		directory static_sourcesdir.to_s

		#
		# Static OpenSSL build tasks
		#
		directory static_openssl_builddir.to_s

		# openssl source file should be stored there
		file openssl_tarball => static_sourcesdir do |t|
			download( openssl_source_uri, t.name )
		end

		# Extract the openssl builds
		file static_openssl_builddir => openssl_tarball do |t|
			puts "extracting %s to %s" % [ openssl_tarball, static_openssl_builddir.parent ]
			static_openssl_builddir.mkpath
			run 'tar', '-xzf', openssl_tarball.to_s, '-C', static_openssl_builddir.parent.to_s
			openssl_makefile.unlink if openssl_makefile.exist?

			openssl_patches.each do |patchfile|
				puts "  applying patch #{patchfile}..."
				run 'patch', '-Np1', '-d', static_openssl_builddir.to_s,
				'-i', File.expand_path( patchfile, BASEDIR )
			end
		end

		self.cmd_prelude = [
			'env',
			"CC=#{host_platform}-gcc",
			"CFLAGS=-DDSO_WIN32",
			"AR=#{host_platform}-ar",
			"RANLIB=#{host_platform}-ranlib"
		]


		# generate the makefile in a clean build location
		file openssl_makefile => static_openssl_builddir do |t|
			Dir.chdir( static_openssl_builddir ) do
				cmd = cmd_prelude.dup
				cmd << "./Configure" << openssl_config

				run( *cmd )
			end
		end

		desc "compile static openssl libraries"
		task :openssl_libs => [ libssleay32, libeay32 ]

		task :compile_static_openssl => openssl_makefile do |t|
			Dir.chdir( static_openssl_builddir ) do
				cmd = cmd_prelude.dup
				cmd << 'make' << "-j#{NUM_CPUS}" << 'build_libs'

				run( *cmd )
			end
		end

		desc "compile static #{libeay32}"
		file libeay32 => :compile_static_openssl do |t|
			FileUtils.cp( static_openssl_builddir + 'libcrypto.a', libeay32.to_s )
		end

		desc "compile static #{libssleay32}"
		file libssleay32 => :compile_static_openssl do |t|
			FileUtils.cp( static_openssl_builddir + 'libssl.a', libssleay32.to_s )
		end



		#
		# Static PostgreSQL build tasks
		#
		directory static_postgresql_builddir.to_s


		# postgresql source file should be stored there
		file postgresql_tarball => static_sourcesdir do |t|
			download( postgresql_source_uri, t.name )
		end

		# Extract the postgresql sources
		file static_postgresql_builddir => postgresql_tarball do |t|
			puts "extracting %s to %s" % [ postgresql_tarball, static_postgresql_builddir.parent ]
			static_postgresql_builddir.mkpath
			run 'tar', '-xjf', postgresql_tarball.to_s, '-C', static_postgresql_builddir.parent.to_s
			mv postgresql_shlib_makefile, postgresql_shlib_mf_orig

			postgresql_patches.each do |patchfile|
				puts "  applying patch #{patchfile}..."
				run 'patch', '-Np1', '-d', static_postgresql_builddir.to_s,
				'-i', File.expand_path( patchfile, BASEDIR )
			end
		end

		# generate the makefile in a clean build location
		file postgresql_global_makefile => [ static_postgresql_builddir, :openssl_libs ] do |t|
			options = [
				"--target=#{host_platform}",
				"--host=#{host_platform}",
				'--with-openssl',
				'--without-zlib',
				'--disable-shared',
			]

			Dir.chdir( static_postgresql_builddir ) do
				configure_path = static_postgresql_builddir + 'configure'
				cmd = [ configure_path.to_s, *options ]
				cmd << "CFLAGS=-L#{static_openssl_builddir}"
				cmd << "LDFLAGS=-L#{static_openssl_builddir}"
				cmd << "LDFLAGS_SL=-L#{static_openssl_builddir}"
				cmd << "LIBS=-lwsock32 -lgdi32"
				cmd << "CPPFLAGS=-I#{static_openssl_builddir}/include"

				run( *cmd )
			end
		end


		# patch the Makefile.shlib -- depend on the build dir so it's only
		# rewritten if the tarball is re-extracted.
		file postgresql_shlib_makefile => postgresql_shlib_mf_orig do |t|
			tf = Tempfile.new( postgresql_shlib_makefile.basename.to_s )
			postgresql_shlib_mf_orig.open( File::RDONLY ) do |ifh|
				ifh.each_line do |line|
					tf.print( line.sub(/^(\s*haslibarule\s*=\s*yes)/, "# \\1 ") )
				end
			end
			tf.close

			FileUtils.mv( tf.path, t.name, :verbose => $puts )
		end


		# make libpq.a
		task postgresql_lib => [ postgresql_global_makefile, postgresql_shlib_makefile ] do |t|
			Dir.chdir( postgresql_lib.dirname ) do
				sh 'make', "-j#{NUM_CPUS}", postgresql_lib.basename.to_s, 'PORTNAME=win32'
			end
		end


		#desc 'compile static libpg.a'
		task :static_libpq => postgresql_lib
	end
end

if File.exist?(File.expand_path("~/.rake-compiler/config.yml"))
	CrossLibraries = [
		['i386-mingw32', 'mingw'],
		['x64-mingw32', 'mingw64'],
	].map do |platform, openssl_config|
		CrossLibrary.new platform, openssl_config
	end
else
	$stderr.puts "Cross-compilation disabled -- rake-compiler not properly installed"
	CrossLibraries = []
end

desc 'cross compile pg for win32'
task :cross do
	ENV['CROSS_COMPILING'] = 'yes'
end
task :cross => [ :mingw32, :static_libpq ]

task :mingw32 do
	# Use Rake::ExtensionCompiler helpers to find the proper host
	unless Rake::ExtensionCompiler.mingw_host then
		warn "You need to install mingw32 cross compile functionality to be able to continue."
		warn "Please refer to your distribution/package manager documentation about installation."
		fail
	end
end