require 'build-tool/errors'

module BuildTool; module BuildSystem

    #
    # Base class for all build system implementations
    #
    class Base

        def initialize
            @module  = nil
            @options = Hash.new
            @out_of_source = true
        end

        #
        ### ATTRIBUTES
        #
        attr_accessor :module
        attr_accessor :out_of_source

        def build_directory
            @module.build_directory
        end

        def dup
            cp = self.clone
            cp.instance_variable_set( "@options", Marshal.load( Marshal.dump( @options ) ) )
            cp
        end

        def env
            @module.environment.values
        end

        def merge( other )
            if name == other.name
                @options.merge!( other.option_hash )
                @out_of_source = other.out_of_source
            else
                raise ConfigurationError, "Can't merge build system #{name} with #{other.name}"
            end
        end

        def option_hash
            @options
        end

        def options
            @options.keys
        end

        def install_prefix
            return @module.install_prefix_required if @module
            raise ConfigurationError, "No module set for build-system"
        end

        def source_directory
            return @module.source_directory_required if @module
            raise ConfigurationError, "No module set for build-system"
        end

        def after_rebase
        end

        #
        ### METHODS
        #
        #
        ### VIRTUAL FUNCTIONS
        #
        for method in [
            :configure,
            :configured?,
            :make,
            :name,
            :reconfigure,
            :install,
            :install_fast,
            :install_fast_supported?

        ] do
            class_eval <<-EOS
                def #{method}
                    raise NotImplementedError, "Method #{method} is not implemented for class #{self}"
                end
            EOS
        end

        def check_build_directory( create = false )
            if !out_of_source
                if File.exist? build_directory
                    if !File.symlink?( build_directory )
                       logger.warn( "Could not link build directory to source directory for inplace build of #{@module.name}." )
                    end
                elsif !$noop
                    FileUtils.mkdir_p( Pathname.new( build_directory ).parent )
                    File.symlink( source_directory, build_directory )
                end
            else
                if File.exist? build_directory
                    if File.directory? build_directory
                        return true
                    else
                        raise ConfigurationError, "Build directory #{build_directory} exists and is no directory!"
                    end
                elsif create
                    FileUtils.mkdir_p( build_directory ) if !$noop
                    return true
                else
                    return false
                end
            end
        end

        def recipe
            Application::instance.recipe
        end

        def remove_build_directory
            self.class.execute "rm -rf #{build_directory}"
        end

    end # class Base

end; end # module BuildTool::BuildSystem