require "colorize"
require "specparser"

require "./exception.cr"
require "./config.cr"
require "./backends.cr"

class Package::Context
	property working_directory = "/tmp/packaging"
	property sources_directory = Dir.current
	property packages_directory = Dir.current

	getter packaging_backends = [] of Backend::Packaging
	getter building_backends = [] of Backend::Building
	getter splitter_backends = [] of Backend::Splitter

	# Directories where ports can be found.
	getter repositories = [] of String

	# Well, this will need configuration, auto-detection and conversion,
	# but it’ll be kind of enough for now.
	property architecture = "x86_64"

	# prefixes for `packaging` running environment and child processes
	# = where to search for binaries and libraries for the build
	property prefixes = ["/usr/baguette", "/usr", "/"]

	# By default, building a package only uses one core
	property build_cores = 1

	# list of environment variables we want to have when building
	#property environment = {} of String => String

	property recipe : Recipe? = nil


	def initialize
		# Add package backends: baguette (package-tools) and apk.
		# They implement the Backend::Packaging abstract class:
		#   init (@name) + package (context, package) method
		@packaging_backends << Backend::Packaging::Baguette.new
		@packaging_backends << Backend::Packaging::APK.new
		@packaging_backends << Backend::Packaging::Pkgutils.new

		@selected_packaging_backend = @packaging_backends[0]

		# Add building backends: configuration, build and install.
		@building_backends << Backend::Configure.autotools
		@building_backends << Backend::Configure.cmake
		@building_backends << Backend::Build.make
		@building_backends << Backend::Install.make

		# Split = new package from a recipe, each one with different files being included.
		@splitter_backends << Backend::Splitter.man @prefixes
		@splitter_backends << Backend::Splitter.dev @prefixes
		@splitter_backends << Backend::Splitter.src @prefixes
	end

	def packaging_backend=(name : String)
		@selected_packaging_backend = @packaging_backends.find(&.name.==(name)).not_nil!
	end

	def packaging_backend=(backend : Backend::Packaging)
		@selected_packaging_backend = backend
	end

	def package(package : Package) : Bool
		@selected_packaging_backend.package @packages_directory, @architecture, package
	end

	def read_recipe(filename : String)
		@recipe = Recipe.new self, filename
		@recipe.not_nil!
	end

	def find_recipe(name : String) : Recipe?
		recipe_file_name = ""

		repo = @repositories.find do |repo|
			repo_dir_name = "#{repo}/#{name}"
			recipe_file_name = "#{repo_dir_name}/recipe.spec"

			if Dir.exists?(repo_dir_name) && File.exists?(recipe_file_name)
				next true
			end
		end

		read_recipe recipe_file_name if repo
	end

	def read_configuration(filename : String)
		specs = SpecParser.parse(File.read(filename))

		specs.assignments.each do |key, value|
			case key
			when "packages-directory"
				@packages_directory = value.as_s
			when "sources-directory"
				@sources_directory = value.as_s
			when "working-directory"
				@working_directory = value.as_s
			when "prefixes"
				# Prefixes during the build process.
				@prefixes = value.as_a_or_s
			when "build-cores"
				# NB of cores used to compile applications.
				@build_cores = value.as_s.to_i

			when "environment"
				# Environment variables during the build process.
				value.as_a_or_s.each do |entry|
					match = entry.split(':').map(
						&.gsub(/^[ \t]*/, "").gsub(/[ \t]*$/, ""))

					if match.size != 2
						STDERR.puts "WARNING: misformed environment definition: #{entry}"
						next
					end

					key, value = match
					Do.environment[key] = value
					if Baguette::Context.verbosity > 2
						STDOUT.puts "environment: #{key} => #{value}"
					end
				end

			when "package-manager"
				# Targeted package manager (default: package, for BaguetteOS).
				begin
					self.packaging_backend = value.as_s
				rescue e
					STDERR.puts "Error during selecting packaging backend: #{e}"
					STDERR.puts "#{value.as_s} seems not to be a valid backend"
					STDERR.puts "valid backends:"
					@packaging_backends.each do |backend|
						STDERR.puts "- #{backend.name}"
					end
					exit 1
				end
			end
		end
	end

	def install(packages : Array(String))
		@selected_packaging_backend.install packages
	end
end