require 'rrb/ripper'
require 'rrb/utils'
require 'rrb/node'

module RRB
      
  class Parser < Ripper

    class Scope
      def initialize
	@class_defs = []
	@method_defs = []
	@method_calls = []
	@local_vars = []
	@global_vars = []
	@instance_vars = []
	@class_vars = []
	@consts = []
	@fcalls = []
	@singleton_method_defs = []
	@class_method_defs = []
	@singleton_class_defs = []
	@assigned = []
	@attr_readers = []
	@attr_writers = []
	@attr_accessors = []
      end
      attr_reader :class_defs, :method_defs, :method_calls, :local_vars, :fcalls
      attr_reader :global_vars, :instance_vars, :class_vars, :consts
      attr_reader :singleton_method_defs, :class_method_defs
      attr_reader :singleton_class_defs
      attr_reader :assigned
      attr_reader :attr_readers, :attr_writers, :attr_accessors
    end

    # parse and return tree
    def run( file )
      @scope_stack = Array.new
      @scope_stack.push Scope.new
      self.parse( file )

      TopLevelNode.new( @scope_stack[0] )
    end

    # on constant
    def on__CONSTANT( id )
      IdInfo.new :const, lineno, pointer, id
    end

    # on normal identifier
    def on__IDENTIFIER( id )
      IdInfo.new :id, lineno, pointer, id
    end

    # on class variable 
    def on__CVAR( id )
      IdInfo.new :cvar, lineno, pointer, id
    end

    # on function identifier like "has_key?" or "map!"
    def on__FID( id )
      IdInfo.new :fid, lineno, pointer, id
    end

    # on instance varaible
    def on__IVAR( id )
      IdInfo.new :ivar, lineno, pointer, id
    end

    # on global variable
    def on__GVAR( id )
      IdInfo.new :gvar, lineno, pointer, id
    end

    def on__OP( op )
      IdInfo.new :op, lineno, pointer, op
    end

    def on__KEYWORD( keyword )
      IdInfo.new :keyword, lineno, pointer, keyword
    end
    
    def on__local_push
      @scope_stack.push( Scope.new )
    end

    def on__local_pop
      @scope_stack.pop
    end

    def on__class( kw_class, class_name, stmts, superclass, kw_end )
      @scope_stack.last.singleton_method_defs.delete_if do |sdef|
	if sdef.s_obj.name == class_name.name || sdef.s_obj.self?
	  @scope_stack.last.class_method_defs << ClassMethodNode.new( sdef )
	  @scope_stack.last.consts.delete( sdef.s_obj )
	  true
	else
	  false
	end
      end
      
      @scope_stack[-2].class_defs << ClassNode.new( class_name,
						   @scope_stack.last,
						   superclass,
						   kw_class, kw_end )
    end

    def on__module( kw_module, module_name, stmts, kw_end )
      @scope_stack[-2].class_defs << ModuleNode.new( module_name,
						    @scope_stack.last,
						    kw_module, kw_end )
    end

    def on__sclass( kw_class, s_obj, stmts, kw_end )
      @scope_stack[-2].singleton_class_defs <<
	SingletonClassNode.new( IdInfo.new( :nil, 0, 0, "[sclass]" ),
			       @scope_stack.last, kw_class, kw_end )
    end
    
    def on__def( kw_def, name, arglist, stmts, rescue_clause, kw_end )
      @scope_stack[-2].method_defs <<
	MethodNode.new( name, @scope_stack.last, arglist, kw_def, kw_end )
    end

    def on__sdef( kw_def, s_obj, method_name, arglist, stmts, kw_end )
      s_obj = IdInfo.new( :nil, 0, 0, "" ) if s_obj == nil
      @scope_stack[-2].singleton_method_defs <<
	SingletonMethodNode.new( s_obj, method_name, @scope_stack.last,
				arglist, kw_def, kw_end )
    end
    
    def on__call( receiver, method, args )
      @scope_stack.last.method_calls << MethodCall.new(method, args || []) 
    end

    def add_attr( function, args )
      return unless args.kind_of?(Array) 
      case function.name
      when 'attr_reader'
	@scope_stack.last.attr_readers.concat args
      when 'attr_writer'
	@scope_stack.last.attr_writers.concat args	  
      when 'attr_accessor'
	@scope_stack.last.attr_accessors.concat args
      end
    end
    
    def on__fcall( function, args )
      @scope_stack.last.fcalls << MethodCall.new(function, args || [])
      add_attr( function, args )
    end

    def on__varcall( method, args )
      @scope_stack.last.fcalls << MethodCall.new(method, args || [])
    end

    def add_var( var )
      case var.type
      when :id
	@scope_stack.last.local_vars << var
        return var
      when :gvar
	@scope_stack.last.global_vars << var
        return var
      when :ivar
	@scope_stack.last.instance_vars << var
        return var
      when :cvar
	@scope_stack.last.class_vars << var
        return var
      when :const
	const = ConstInfo.new_normal( var )
	@scope_stack.last.consts << const
	return const
      when :keyword
        return var
      end      
    end

    def on__assignable( var, arg )
      return unless var.kind_of?( IdInfo )
      @scope_stack.last.assigned << var if var.type == :id
      add_var( var )
    end

    def on__local_count(  arg )
      return if arg == '~'.intern
      @scope_stack.last.local_vars << arg
    end
    
    def on__varref( var )
      return unless var.kind_of?( IdInfo )
      if @scope_stack.last.local_vars.find{|i| i.name == var.name } then
	@scope_stack.last.local_vars << var
        return var
      elsif var.type == :id
        method_call = MethodCall.new(var, [])
	@scope_stack.last.fcalls << method_call
        return method_call
      else
	return add_var( var )
      end
    end

    def on__toplevel_const_get( const_id )
      const = ConstInfo.new_toplevel( const_id )
      @scope_stack.last.consts << const
      return const
    end

    def on__const_get( lconst, const_id )
      return nil unless lconst.kind_of?( ConstInfo )
      const = ConstInfo.new_colon2( const_id, lconst )
      @scope_stack.last.consts << const
      return const
    end

    def on__symbol( id )
      IdInfo.new( :symbol, id.lineno, id.pointer, id.name )
    end
    
    def on__argstart
      Array.new
    end

    def on__argadd (args, arg )
      return nil unless args.kind_of?( Array )
      return nil unless arg.kind_of?( IdInfo )
      args << arg
    end

    def on__argadd_args( args, arg )
      on__argadd( args, arg )
    end

    def on__argadd_value( args, arg )
      on__argadd( args, arg )
    end

    def on__argadd_assocs( args, arg)
      args
    end

    def on__argadd_block( args, arg )
      args
    end

    def on__argadd_opt( args, arg )
      args 
    end

    def on__argadd_rest( args, arg )
      args
    end

    def on__argadd_star( args, arg)
      args
    end

    def on__add_eval_string( context, str )
      @eval_str = str
    end

    def on__eval_string_end( context, str )
      if str == "}"
	mcalls, fcalls, lvars, gvars, ivars, cvars, consts =
	  EvalStringParser.new.run( @eval_str, @scope_stack.last, lineno,
				   pointer - @eval_str.size - 1  )
      else
	mcalls, fcalls, lvars, gvars, ivars, cvars, consts =
	  EvalStringParser.new.run( @eval_str, @scope_stack.last, lineno,
				   pointer - @eval_str.size )
      end
      @scope_stack.last.method_calls.concat mcalls
      @scope_stack.last.fcalls.concat fcalls
      @scope_stack.last.local_vars.concat lvars
      @scope_stack.last.global_vars.concat gvars
      @scope_stack.last.instance_vars.concat ivars
      @scope_stack.last.class_vars.concat cvars
      @scope_stack.last.consts.concat consts
    end
    
  end
  
  class EvalStringParser < Parser
    
    def run( input, scope, lineno, pointer )
      @scope_stack = Array.new
      # push current scope to distinguish local variable from function call
      new_scope = Scope.new
      new_scope.local_vars.concat( scope.local_vars )
      @scope_stack.push new_scope
      
      self.parse( input )

      method_calls = @scope_stack.first.method_calls
      fcalls = @scope_stack.first.fcalls
      local_vars = @scope_stack.first.local_vars[scope.local_vars.size..-1]
      global_vars = @scope_stack.first.global_vars
      instance_vars = @scope_stack.first.instance_vars
      class_vars = @scope_stack.first.class_vars
      consts = @scope_stack.first.consts
      
      method_calls.each{|id| id.adjust_id!( lineno, pointer )}
      fcalls.each{|fcall| fcall.body.adjust_id!( lineno, pointer )}
      local_vars.each{|id| id.adjust_id!( lineno, pointer )}
      global_vars.each{|id| id.adjust_id!( lineno, pointer )}
      instance_vars.each{|id| id.adjust_id!( lineno, pointer )}
      class_vars.each{|id| id.adjust_id!( lineno, pointer )}
      consts.each{|const| const.adjust_id!( lineno, pointer )}
      
      return method_calls, fcalls, local_vars, global_vars, instance_vars,
	class_vars, consts
    end
    
  end
  
end