require 'optparse'

require_relative 'bigfiles/source_code_finder'
require_relative 'bigfiles/file_with_lines'

# Simple tool to find the largest source files in your project.
module BigFiles
  # Simple tool to find the largest source files in your project.
  class BigFiles
    def initialize(args,
                   io: Kernel,
                   exiter: Kernel,
                   file_with_lines: FileWithLines,
                   source_file_finder: SourceCodeFinder.new,
                   option_parser: OptionParser)
      @io, @exiter, @file_with_lines = io, exiter, file_with_lines
      @source_file_finder = source_file_finder
      @option_parser = option_parser
      @options = parse_options(args)
    end

    def parse_options(args)
      options = nil
      @option_parser.new do |opts|
        options = setup_options(opts)
      end.parse!(args)
      options
    end

    DEFAULT_GLOB =
      '{app,lib,test,spec,feature}/**/*.{rb,swift,cpp,c,java,py}'

    def glob
      @options[:glob] || DEFAULT_GLOB
    end

    def setup_options(opts)
      options = {}
      opts.banner = 'Usage: bigfiles [options]'
      opts.on('-g glob here', '--glob',
              "Which files to parse - default is #{DEFAULT_GLOB}") do |v|
        options[:glob] = v
      end
      opts.on('-h', '--help', 'This message') do |_|
        options[:help] = true
      end
      options
    end

    def usage
      @io.puts "USAGE: bigfiles [-n <top n files>]\n"
      @exiter.exit 1
    end

    def find_analyze_and_report_on_files
      file_list = @source_file_finder.find(glob)
      files_with_lines = file_list.map do |filename|
        @file_with_lines.new(filename)
      end
      files_with_lines.sort.reverse[0..2].each do |file|
        @io.puts "#{file.num_lines}: #{file.filename}"
      end
    end

    def run
      if @options[:help]
        usage
      else
        find_analyze_and_report_on_files
      end
    end
  end
end