#!/usr/bin/env ruby

class Chunk
  attr_accessor :char_1
  attr_accessor :char_2
  attr_accessor :index_1
  attr_accessor :index_2

  def initialize(c1, c2, i1, i2)
    @char_1 = c1
    @char_2 = c2
    @index_1 = i1
    @index_2 = i2
  end

  def to_s
    "#{char_1} #{char_2} #{index_1} #{index_2}"
  end
end

class Similarity
  CHAR_REGEX = /./

  attr_accessor :string_1
  attr_accessor :string_2

  def initialize(string_1, string_2)
    @string_1 = string_1
    @string_2 = string_2
  end

  def tokens
    chunks = []
    string_1.scan(CHAR_REGEX).each_with_index do |char_1, index_1|
      string_2.scan(CHAR_REGEX).each_with_index do |char_2, index_2|
        next if char_1 != char_2
        chunks.push(Chunk.new(char_1, char_2, index_1, index_2))
      end
    end
    chunks
  end

  def count
    counter = 0
    prev = false
    tokens.each_with_index do |chunk, index|

      unless prev
        prev = chunk.index_1
        next
      end

      if prev == (chunk.index_1 - 1)
        counter += 1
      end

      prev = chunk.index_1
    end

    counter
  end

  def score
    desired = (string_1.size + string_2.size) / 2
    size_thresh = ([string_1.size, string_2.size].sort.first.to_f / desired)
    compatibility_thresh = (count.to_f + 1) / string_1.size
    (size_thresh + compatibility_thresh).to_f / 2
  end
end

require 'optparse'

options = {}
options[:threshold] = 0.8

OptionParser.new do |opts|

  opts.banner = "Usage: #{$0} [OPTIONS]"

  opts.on('-t', '--threshold [NUMBER]', 'Threshold default value is 0.8.') do |value|
    options[:threshold] = value.to_f
  end

end.parse!

required_options = [:threshold]
required_options.each do |option|
  unless options[option]
    $stderr.puts "Can not run #{option.to_s} was not given."
    exit 1
  end
end

# hash = {
#   'line' => [
#     { :line => 'line', :score => 1 },
#   ]
# }

hash = {}
lines = 0

STDIN.each_line do |line|
  line.chomp!
  next if line == ''
  lines += 1
  resolved = false
  hash.keys.each do |registered_line|
    score = Similarity.new(line, registered_line).score
    if score > options[:threshold]
      hash[registered_line].push({
        :line => line,
        :score => score
      })
      resolved = true
    end
  end
  next if resolved
  hash[line] ||= []
end

module Template

  class Banner < Struct.new(:lines, :groups, :threshold, :datetime)
    def to_s
      format(template, to_h)
    end
    def template
      '
Total Lines Parsed: %<lines>s
Total Groups Generated: %<groups>s
Similarity Theshold at: %<threshold>s
Generated on: %<datetime>s
      '
    end
  end

  class Group < Struct.new(:number, :percent, :items, :line)
    def to_s
      format(template, to_h)
    end
    def template
      'Group %<number>s represents %<percent>s and has %<items>s items similar to: %<line>s'
    end
  end

  class Item < Struct.new(:count, :total, :score, :line)
    def to_s
      format(template, to_h)
    end
    def template
      '  %<count>s/%<total>s %<score>s  %<line>s'
    end
  end

end

require 'isna'

banner = Template::Banner.new
banner.lines = lines.to_s.to_ansi.yellow.to_s
banner.groups = hash.keys.size.to_s.to_ansi.yellow.to_s
banner.threshold = options[:threshold].to_s.to_ansi.yellow.to_s
banner.datetime = Time.now.to_s.to_ansi.yellow.to_s
puts banner.to_s

groups = []

hash.each do |category_name, records|
  groups.push([category_name, records.size])
end

sorted_groups_by_n_records_asc = groups.sort do |array_a, array_b|
  number_of_records_in_a = array_a[1]
  number_of_records_in_b = array_b[1]
  number_of_records_in_a <=> number_of_records_in_b
end

sorted_groups_by_n_records_asc.reverse.each_with_index do |key, index|
  line, records = key[0], hash[key[0]]

  puts ''

  group = Template::Group.new
  group.percent = ('%2.2f%%' % ((records.size.to_f / lines) * 100)).to_s.to_ansi.red.to_s
  group.number = (index + 1).to_s.to_ansi.red.to_s
  group.items = records.size.to_s.to_ansi.cyan.to_s
  group.line = line.chomp.to_ansi.green.to_s
  puts group.to_s

  sorted_items_in_group = records.sort do |a, b|
    a[:score] <=> b[:score]
  end

  sorted_items_in_group.reverse.each_with_index do |record, index|
    item = Template::Item.new
    item.count = (index + 1).to_s.rjust(4, ' ').to_ansi.cyan.to_s
    item.total = records.size.to_s.ljust(4, ' ').to_ansi.cyan.to_s
    item.score = ('%4.2f%%' % (record[:score] * 100)).rjust(7, ' ').to_ansi.green.to_s
    item.line = record[:line]
    puts item.to_s
  end

end