#!/usr/bin/env ruby
require 'benchmark'

class Finder
  MAX = {
        money: 1_000_000,
        index: 1_000_000,
        high: 300,
        age: 100,
        gender: 2
      }
  def initialize(arr)
    @arr = arr
    @default = {
        money: 1_000_000,
        index: 1_000_000,
        high: 300,
        age: 100,
        gender: 2
      }
  end

  def search(params = {})
    return @arr if params.empty?
    sorted_params(params).inject(@arr) {|arr, h| arr.select{|p| filter(p,h[0],h[1])}}
  end

  ### Only for becnhmark
  def find(params = {})
    return @arr if params.empty?
    params.to_a.inject(@arr) {|arr, h| arr.select{|p| filter(p,h[0],h[1])}}
  end

  def filter(obj, key, val)
    val.is_a?(Range) ? val.cover?(obj[key]) : val == obj[key]
  end

  def sorted_params(params)
    args = params.to_a
    return args if params.length < 2
    args.sort_by! do |x|
      -MAX[x[0]] / (x[1].is_a?(Range) ? x[1].count : 1)
    end
  end
end

Person = Struct.new(:money, :index, :high, :age, :gender)
arr = [Person.new(400, 1000, 200, 30, 1)]
1000000.times do
  arr << Person.new(
      rand(Finder::MAX[:money]),
      rand(Finder::MAX[:index]),
      rand(Finder::MAX[:high]),
      rand(Finder::MAX[:age]),
      rand(Finder::MAX[:gender])
    )
end

Benchmark.bm do |x|
  x.report('find') do
    10.times do
      Finder.new(arr).find(gender: 1, age: 30, money: (100..500), index: (900..2000))
    end
  end
  x.report('search') do
    10.times do
      Finder.new(arr).search(gender: 1, age: 30, money: (100..500), index: (900..2000))
    end
  end
  x.report('find_small') do
    10.times do
      Finder.new(arr).find(gender: 1, index: (900..2000))
    end
  end
  x.report('search_small') do
    10.times do
      Finder.new(arr).search(gender: 1, index: (900..2000))
    end
  end
  x.report('find_empty') do
    10.times do
      Finder.new(arr).find(gender: 1, index: 1_000_001)
    end
  end
  x.report('search_empty') do
    10.times do
      Finder.new(arr).search(gender: 1, index: 1_000_001)
    end
  end
end