service/src/service/environment.cr

require "specparser"

class Environment
	enum Type
		Prefix
		RootFileSystem
	end

	getter name : String
	getter type : Type = Type::Prefix
	getter files = Array(ServiceDefinition::FileDefinition).new

	# The place we’ll put services’ data and configuration.
	@root : String?

	def initialize()
		initialize "root"
	end

	def initialize(@name, type = "prefix")
		@type = Type.parse type

		@files = Array(ServiceDefinition::FileDefinition).new

		# FIXME: Should this *really* be here?
		# FIXME: $ENVIRONMENT_ROOT
		@files << ServiceDefinition::FileDefinition.new "/srv/${ENVIRONMENT}",
			"environment root",
			creation_command: "mkdir -p /srv/${ENVIRONMENT} && chmod a+rwt /srv/${ENVIRONMENT}",
			deletion_command: "rmdir /srv/${ENVIRONMENT}"
	end

	def initialize(@name, specs : SpecParser)
		assignments = specs.assignments

		assignments["type"].try &.as_s.tap do |type|
			@type = Type.parse type
		end

		specs.sections.select(&.name.==("check")).each do |check|
			@files << ServiceDefinition::FileDefinition.new check
		end
	end

	def root
		@root || "#{SERVED_DATA_DIRECTORY}/#{@name}"
	end

	class_getter root = Environment.new
	class_getter all = [@@root] of Environment

	def self.load(path)
		return unless Dir.exists? path

		Dir.each_child path do |child|
			unless child.match /\.spec$/
				next
			end

			file_path = "#{path}/#{child}"

			begin
				name = File.basename(child, ".spec")
				specs = SpecParser.parse File.read(file_path)

				environment = Environment.new name, specs
			rescue e
				STDERR << "error loading #{file_path}: " << e << "\n"
				# FIXME: Print stacktrace? Debug mode?
				next
			end

			@@all << environment
		end
	end

	def write(dir : String)
		File.write "#{dir}/#{@name}.spec", to_spec
	end

	def remove(dir : String)
		File.delete "#{dir}/#{@name}.spec"
	end

	def to_spec
		[
			"type: #{@type.to_s}"
		].join("\n") + "\n"
	end

	def self.get(name)
		_def = @@all.find &.name.==(name)

		if _def.nil?
			raise ::Service::Exception.new "Environment '#{name}' does not exist."
		end

		_def
	end

	def get_provider(token)
		Service.all.find do |service|
			service.environment == self && service.provides? token
		end.try &.id
	end

	def to_s
		"#{name} (#{type.to_s.downcase})"
	end
end