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#!/usr/bin/env ruby -w

require "yaml"

# An address book

def prompt(addresses)
  menu = "
  1. Look for someone
  2. Enter some data
  3. Show all entries
  4. Getouttahere (quit)
  "
  
  loop do
    puts menu
    
    # Chomp is used all over the place in order to get rid of newline characters (\n)
    input = gets.chomp
    
    next if input == nil
    
    case input
    when '1'
      look_for_someone(addresses)
    when '2'
      enter_data(addresses)
    when '3'
      show_all(addresses)
    when '4'
      puts "Writing stuff down..."
      begin
        File.open("addresses.yaml", "w") { |f| YAML.dump(addresses, f) }
        puts "Done! See you later!"
      rescue
        puts "Uh oh... there's been a problem, so you might have lost some data."
      end
      
      exit
    else
      puts "Please select a command from the menu"
    end
  end
end

def look_for_someone(addresses)
  puts "Who or what would you like to look for?"
  query = gets.chomp
  
  # Look for it directly (fastest, constant time lookup)
  
  if addresses.has_key?(query)
    result = addresses[query]
  else
    
    # We couldn't find a direct lookup, so just hunt through everything else
    found_entries = addresses.select do |key, value|
      key.downcase.include?(query.downcase) || value.downcase.include?(query.downcase)
    end
    
    if found_entries.empty?
      puts "Sorry, I couldn't find anything that matches your request."
    else
      # We got something.
      result = ""
      found_entries.each do |key, value|
        result << "#{key}\t#{value}\n"
      end
      puts result
    end
    
  end
end

def enter_data(addresses)
  puts "I'm gonna need a name, and some other address-like stuff, ok? 
It'll happen in two steps. Be cool."
  
  puts "\nPlease enter a name (and hit  when you're done.)"
  name = gets.chomp
  
  puts "\nGreat. Now enter some address-data all on one line. (Hit  when you're done.)"
  address = gets.chomp
  
  if addresses.has_key?(name)
    puts "\nWhoa whoa whoa... We've already got that guy in here. Are you sure you want to overwrite that entry?
Enter 'yes' or  'no':"
    if gets.include?('y')
      puts "Alright, I wrote over the entry."
      addresses[name] = address
    else
      puts "Ok, I didn't do anything."
    end
    
  else
    # A fresh new entry
    puts "Entry added:"
    puts "#{name}\t#{address}"
    addresses[name] = address
  end  
end

def show_all(addresses)
  addresses.each do |key, value|
    puts "#{key}\t#{value}"
  end
end

begin
  addresses = YAML.load_file("addresses.yaml")
rescue
  puts "No address file found. This must be your first time."
  addresses = {}
end

puts "Hi, this is an address book. What would you like to do?"

prompt(addresses)