module Pluginscan
  class ErrorListPrinter < Printer
    def initialize(hide_ignores = false, output = $stdout)
      @hide_ignores = hide_ignores
      @output = output
      @line_printer = ErrorLinePrinter.new
    end

    def print(data)
      issues = data[:issues]
      @output.puts error_lines(issues)
    end

    # TODO: this should be the print method; return an array of lines, and let the caller be responsible for outputting it
    def error_lines(issues)
      issues.inject([]) do |output, (file, file_findings)|
        output + file_error_lines(file, file_findings)
      end
    end

    private def file_error_lines(file, file_findings)
      file_findings.inject([]) do |checks_output, check_findings|
        checks_output + check_output(file, check_findings.check, check_findings.findings)
      end
    end

    private def check_output(file, check, findings)
      findings.reject!(&:ignored) if @hide_ignores
      findings.map do |finding|
        error_line = ErrorLineFactory.build(file, check.name, finding)
        @line_printer.print(error_line)
      end
    end
  end

  class ErrorLinePrinter
    def print(el)
      "\"#{el.file}\", line #{el.line_number}, col #{el.column_number}: #{el.message}"
    end
  end

  # This is almost like a view model: exposes methods for use in a template
  class ErrorLine
    attr_reader :file

    def initialize(file, check_name, finding)
      @file         = file
      @check_name   = check_name
      @finding      = PrintableFinding.new(finding)
    end

    def line_number
      # TODO: why is the original called lineno?? That's a rubbish name!
      @finding.lineno
    end

    def column_number
      @finding.col_number
    end

    def message
      "[#{@check_name}] #{@finding.line}"
    end
  end

  class IgnoredErrorLine < ErrorLine
    # TODO: would decoration be better here?
    def message
      super.sub("]", "][IGNORE]")
    end
  end

  class ErrorLineFactory
    def self.build(file, check_name, finding)
      klass(finding.ignored).new(file, check_name, finding)
    end

    def self.klass(ignored)
      ignored ? IgnoredErrorLine : ErrorLine
    end
  end

  class PrintableFinding < SimpleDelegator
    def col_number
      # Seems like vim treats tabs as single spaces for the purposes of calculating columns - at least on my setup
      # so we don't need to expand the tabs
      __getobj__.line.index(match) + 1
    end

    def line
      escape_special_chars(__getobj__.line.strip)
    end

    private def escape_special_chars(string)
      # Vim interprets `:` as a delimiter
      string.gsub(":", '\:')
    end
  end
end