# frozen_string_literal: true
#
# ronin-code-sql - A Ruby DSL for crafting SQL Injections.
#
# Copyright (c) 2007-2022 Hal Brodigan (postmodern.mod3 at gmail.com)
#
# ronin-code-sql is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# ronin-code-sql is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with ronin-code-sql.  If not, see <https://www.gnu.org/licenses/>.
#

require 'ronin/code/sql/binary_expr'
require 'ronin/code/sql/literals'
require 'ronin/code/sql/fields'
require 'ronin/code/sql/functions'
require 'ronin/code/sql/statements'
require 'ronin/code/sql/emittable'

module Ronin
  module Code
    module SQL
      #
      # @api private
      #
      # @since 1.1.0
      #
      class InjectionExpr

        include Literals
        include Fields
        include Functions
        include Statements
        include Emittable

        # The expression that will be injected
        attr_reader :expression

        #
        # Initializes the new expression to inject.
        #
        # @param [String, Integer, Float, Array, Symbol] initial_value
        #   The initial value for the expression.
        #
        def initialize(initial_value)
          @expression = initial_value
        end

        #
        # Appends an `AND` expression to the injection.
        #
        # @yield [(self)]
        #   The return value of the block will be used as the right-hand side
        #   operand.  If the block accepts an argument, it will be called with
        #   the injection expression.
        #
        # @return [self]
        #
        def and(&block)
          value = case block.arity
                  when 0 then instance_eval(&block)
                  else        block.call(self)
                  end

          @expression = BinaryExpr.new(@expression,:AND,value)
          return self
        end

        #
        # Appends an `OR` expression to the injection.
        #
        # @yield [(self)]
        #   The return value of the block will be used as the right-hand side
        #   operand. If the block accepts an argument, it will be called with
        #   the injection expression.
        #
        # @return [self]
        #
        def or(&block)
          value = case block.arity
                  when 0 then instance_eval(&block)
                  else        block.call(self)
                  end

          @expression = BinaryExpr.new(@expression,:OR,value)
          return self
        end

        #
        # Emits the injection expression.
        #
        # @param [Hash{Symbol => Object}] kwargs
        #   Additional keyword arguments for {Emitter#initialize}.
        #
        # @return [String]
        #   The raw SQL.
        #
        def to_sql(**kwargs)
          emitter(**kwargs).emit(@expression)
        end

      end
    end
  end
end