require 'jars/maven_exec'
require 'jars/lock'
require 'fileutils'

module Jars

  class Classpath

    # convenient method
    def self.require( scope = nil )
      new.require( scope )
    end

    # convenient method
    def self.classpath( scope = nil )
      new.classpath( scope )
    end

    # convenient method
    def self.classpath_string( scope = nil )
      new.classpath_string( scope )
    end

    def initialize( spec = nil, deps = nil )
      @spec = spec
      @deps = deps
    end

    def mvn
      @mvn ||= MavenExec.new( @spec )
    end

    def workdir( dirname )
      dir = File.join( mvn.basedir, dirname )
      dir if File.directory?( dir )
    end

    def dependencies_list
      if @deps.nil?
        deps = Jars.lock_path( mvn.basedir )
        @deps = deps if deps && File.exist?( deps )
      end
      if @deps
        @deps
      else
        resolve_dependencies
      end
    end
    private :dependencies_list
    
    DEPENDENCY_LIST = 'dependencies.list'
    def resolve_dependencies
      basedir = workdir( 'pkg' ) || workdir( 'target' ) || workdir( '' )
      deps = File.join( basedir, DEPENDENCY_LIST )
      mvn.resolve_dependencies_list( deps )
      deps
    end
    private :resolve_dependencies

    def require( scope = nil )
      process( scope ) do |jar|
        if jar.scope == :system
          Kernel.require jar.path
        else
          require_jar( *jar.gacv )
        end
      end
      if scope == nil || scope == :runtime
        process( :provided ) do |jar|
          Jars.mark_as_required( *jar.gacv )
        end
      end
    end

    def classpath( scope = nil )
      classpath = []
      process( scope ) do |jar|
        classpath << jar.file
      end
      classpath
    end

    def process( scope, &block )
      deps = dependencies_list
      Lock.new( deps ).process( scope, &block )
    ensure
      # just delete the temporary file if it exists
      FileUtils.rm_f( DEPENDENCY_LIST )
    end
    private :process

    def classpath_string( scope = nil )
      classpath( scope ).join( File::PATH_SEPARATOR )
    end
  end
end