module Isomorfeus
  module Props
    class Validator
      def initialize(source_class, prop, value, options)
        @c = source_class
        @p = prop
        @v = value
        @o = options
      end

      def validate!
        ensured = ensure!
        unless ensured
          set_default_value
          cast!
          type!
        end
        run_checks!
        true
      end

      def validated_value
        validate!
        @v
      end

      private

      # basic tests

      def set_default_value
        return unless @v.nil?
        @v = @o[:default] if @o.key?(:default)
      end

      def cast!
        if @o.key?(:cast)
          begin
            return if @o[:is_a] && @v.is_a?(@o[:is_a])
            return if @o[:class] && @v.class == @o[:class]
            if @o[:type] == :boolean
              @v = !!@v
              return
            end
            cl = @o[:is_a] || @o[:class]
            @v = case cl.name
                 when 'Integer' then @v.to_i
                 when 'String' then @v.to_s
                 when 'Float' then @v.to_f
                 when 'Array' then @v.to_a
                 when 'Hash' then @v.to_h
                 else
                  Isomorfeus.raise_error(message: "#{@c}: Dont know how to cast #{@p} to #{cl}!")
                 end
          rescue
            Isomorfeus.raise_error(message: "#{@c}: #{@p} cast to #{cl} failed!")
          end
        end
      end

      def ensure!
        if @o.key?(:ensure)
          proc_or_val = @o[:ensure]
          if proc_or_val.class == Proc
            @v = proc_or_val.call(@v)
          else
            @v = proc_or_val
          end
          true
        else
          false
        end
      end

      def type!
        return if @o[:allow_nil] && @v.nil?
        if @o.key?(:class)
          Isomorfeus.raise_error(message: "#{@c}: #{@p} class is not #{@o[:class]}") unless @v.class == @o[:class]
        elsif @o.key?(:is_a)
          Isomorfeus.raise_error(message: "#{@c}: #{@p} is not a #{@o[:is_a]}") unless @v.is_a?(@o[:is_a])
        elsif @o.key?(:type)
          case @o[:type]
          when :boolean
            Isomorfeus.raise_error(message: "#{@c}: #{@p} is not a boolean") unless @v.class == TrueClass || @v.class == FalseClass
          else
            c_string_sub_types
          end
        end
      end

      # all other checks

      def run_checks!
        if @o.key?(:validate)
          @o[:validate].each do |m, l|
            send('c_' + m, l)
          end
        end
        @o[:validate_block].call(@v) if @o.key?(:validate_block)
      end

      # specific validations
      def c_gt(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} not greater than #{v}!") unless @v > v
      end

      def c_lt(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} not less than #{v}!") unless @v < v
      end

      def c_keys(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} keys dont fit!") unless @v.keys.sort == v.sort
      end

      def c_size(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} length/size is not #{v}") unless @v.length == v
      end

      def c_matches(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} does not match #{v}") unless v.match?(@v)
      end

      def c_max(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is larger than #{v}") unless @v <= v
      end

      def c_min(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is smaller than #{v}") unless @v >= v
      end

      def c_max_size(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is larger than #{v}") unless @v.length <= v
      end

      def c_min_size(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is smaller than #{v}") unless @v.length >= v
      end

      def c_direction(v)
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is positive") if v == :negative && @v >= 0
        Isomorfeus.raise_error(message: "#{@c}: #{@p} is negative") if v == :positive && @v < 0
      end

      def c_test
        Isomorfeus.raise_error(message: "#{@c}: #{@p} test condition check failed") unless @o[:test].call(@v)
      end

      def c_string_sub_types
        Isomorfeus.raise_error(message: "#{@c}: #{@p} must be a String") unless @v.class == String
        case @o[:type]
        when :email
          Isomorfeus.raise_error(message: "#{@c}: #{@p} is not a valid email address") unless @v.match?(/\A[^@\s]+@([^@\s]+\.)+[^@\s]+\z/)
        when :uri
          if RUBY_ENGINE == 'opal'
            %x{
              try {
                new URL(#@v);
              } catch {
                #{Isomorfeus.raise_error(message: "#{@c}: #{@p} is not a valid uri")}
              }
            }
          else
            Isomorfeus.raise_error(message: "#{@c}: #{@p} is not a valid uri") unless @v.match?(/\A#{URI.regexp}\z/)
          end
        end
      end
    end
  end
end