require 'build-tool/vcs/base'
require 'build-tool/errors'

module BuildTool; module VCS

    class MercurialError < BuildTool::Error; end

    class MercurialConfiguration < BaseConfiguration

        def name
            "mercurial"
        end

        attr_accessor :remote

        def initialize( mod = nil )
            super( mod )
            @remote = {}
        end

        def vcs( mod )
            @module = mod
            Mercurial.new( self )
        end

        def branch
            self.module.remote_path
        end
    end

    #
    # Implementation for the hg version control system.
    #
    class Mercurial < Base

        def initialize( config )
            super( config )
            @remote = {}
            @vcs = nil
        end

        #
        ### ATTRIBUTES
        #
        def name
            "mercurial"
        end

        def fetching_supported?
            true
        end

        #
        ### METHODS
        #

        def checkedout?
            return false if !local_path_exist?
            if !Pathname.new( local_path ).join( ".hg" ).exist?
                raise Base::VcsError, "Checkout path #{local_path} is not a mercurial repo!"
            end
            return true
        end

        # Initialize the local repository
        def clone
            # Check if path exists
            if local_path_exist?
                raise MercurialError, "Failed to create repository at '#{local_path}': Path exists"
            end
            FileUtils.mkdir_p Pathname.new( local_path ).dirname if ! $noop

            # Initialize the repository
            if hg( "clone #{repository.url} #{local_path}", Pathname.new( local_path ).dirname) != 0
                raise MercurialError, "Error while initializing the repo `hg init #{local_path}'`: #{$?}"
            end

            fetch()
            rebase()
        end

        # Fetch from +repository+
        #
        # Initializes the local clone if it does not exist.
        def fetch()
            if !checkedout? and !$noop
                clone
            end
            cmd = "pull #{repository.url}"
            if ( rc = hg( cmd ) ) != 0
                raise MercurialError, "Error while fetching: #{rc}"
            end
        end

        def hg( command, wd = local_path, &block )
            rc = self.class.execute "hg #{command}", wd, &block
            if rc != 0
                raise MercurialError, "hg #{command || "" } failed with error code #{rc}";
            end
            rc
        end

        def rebase
            if 0 != ( hg "update #{config.branch}" )
                raise MercurialSvnError, "Error while rebasing the repo with `hg update: #{$?}"
            end
        end

    end # class Mercurial

end; end # module BuildTool::VCS