module RequestLogAnalyzer::RSpec::Matchers
  class HasLineDefinition
    def initialize(line_type)
      @line_type = line_type.to_sym
      @captures  = []
    end

    def and_capture(*captures)
      @captures += captures
      self
    end

    alias_method :capturing, :and_capture

    def description
      description = "have a #{@line_type.inspect} line definition"
      description << " that captures #{@captures.join(', ')}" unless @captures.empty?
      description
    end

    def matches?(file_format)
      file_format = file_format.create if file_format.is_a?(Class)
      if ld = file_format.line_definitions[@line_type]
        @captures.all? { |c| ld.all_captured_variables.include?(c) }
      else
        false
      end
    end
  end

  class ParseLine
    def initialize(line, line_description = nil)
      @line      = line
      @captures  = {}
      @line_type = nil
      @line_description = line_description
    end

    def line_description
      @full_line_description ||= if @line_description
                                   if @line_type && @line_description =~ /^(?:with|without|having|using) /
                                     "a #{@line_type.inspect} line #{@line_description}"
                                   else
                                     @line_description
                                   end
      elsif @line_type
                                   "a #{@line_type.inspect} line"
      else
        "line #{@line.inspect}"
      end
    end

    attr_reader :failure_message

    def as(line_type)
      @line_type = line_type
      self
    end

    def and_capture(captures)
      @captures = captures
      self
    end

    alias_method :capturing, :and_capture

    def fail(message)
      @failure_message = message
      false
    end

    def description
      description = "parse #{line_description}"
      description << " as line type #{@line_type.inspect}" if @line_type
      description << " and capture #{@captures.keys.join(', ')} correctly" unless @captures.empty?
      description
    end

    def matches?(file_format)
      if @line_hash = file_format.parse_line(@line)
        if @line_type.nil? || @line_hash[:line_definition].name == @line_type
          @request   = file_format.request(@line_hash)
          @captures.each do |key, value|
            return fail("Expected line #{@line.inspect}\n    to capture #{key.inspect} as #{value.inspect} but was #{@request[key].inspect}.") if @request[key] != value
          end
          return true
        else
          return fail("The line should match the #{@line_type.inspect} line definition, but matched #{@line_hash[:line_definition].name.inspect} instead.")
        end
      else
        return fail('The line did not match any line definition.')
      end
    end
  end

  def have_line_definition(line_type)
    HasLineDefinition.new(line_type)
  end

  def parse_line(line, line_description = nil)
    ParseLine.new(line, line_description)
  end
end