require "search_cop/version"
require "search_cop/arel"
require "search_cop/search_scope"
require "search_cop/query_info"
require "search_cop/query_builder"
require "search_cop/grammar_parser"
require "search_cop/hash_parser"

module SearchCop
  class SpecificationError < StandardError; end
  class UnknownAttribute < SpecificationError; end

  class RuntimeError < StandardError; end
  class UnknownColumn < RuntimeError; end
  class NoSearchableAttributes < RuntimeError; end
  class IncompatibleDatatype < RuntimeError; end
  class ParseError < RuntimeError; end

  module Parser
    def self.parse(query, query_info)
      if query.is_a?(Hash)
        SearchCop::HashParser.new(query_info).parse(query)
      else
        SearchCop::GrammarParser.new(query_info).parse(query)
      end
    end
  end

  def self.included(base)
    base.extend ClassMethods

    base.class_attribute :search_scopes
    base.search_scopes = {}

    base.search_scopes[:search] = SearchScope.new(:search, base)
  end

  module ClassMethods
    def search_scope(name, &block)
      search_scope = search_scopes[name] || SearchScope.new(name, self)
      search_scope.instance_exec(&block)

      search_scopes[name] = search_scope

      self.class.send(:define_method, name) { |query| search_cop query, name }
      self.class.send(:define_method, "unsafe_#{name}") { |query| unsafe_search_cop query, name }
    end

    def search_reflection(scope_name)
      search_scopes[scope_name].reflection
    end

    def search_cop(query, scope_name)
      unsafe_search_cop query, scope_name
    rescue SearchCop::RuntimeError
      respond_to?(:none) ? none : where("1 = 0")
    end

    def unsafe_search_cop(query, scope_name)
      return respond_to?(:scoped) ? scoped : all if query.blank?

      query_builder = QueryBuilder.new(self, query, search_scopes[scope_name])

      scope = search_scopes[scope_name].reflection.scope ? instance_exec(&search_scopes[scope_name].reflection.scope) : eager_load(query_builder.associations)

      scope.where query_builder.sql
    end
  end
end