require 'subdomain_fu/routing_extensions'
require 'subdomain_fu/url_rewriter'

module SubdomainFu
  # The length of the period-split top-level domain for each environment.
  # For example, "localhost" has a tld_size of zero, and "something.co.uk"
  # has a tld_size of two.
  #
  # To set a tld size for a given environment, just call SubdomainFu.tld_sizes[:environment] = value
  DEFAULT_TLD_SIZES = {:development => 0, :test => 0, :production => 1}
  mattr_accessor :tld_sizes
  @@tld_sizes = DEFAULT_TLD_SIZES.dup
  
  # Subdomains that are equivalent to going to the website with no subdomain at all.
  # Defaults to "www" as the only member.
  DEFAULT_MIRRORS = %w(www)
  mattr_accessor :mirrors
  @@mirrors = DEFAULT_MIRRORS.dup
  
  mattr_accessor :preferred_mirror
  @@preferred_mirror = nil

  mattr_accessor :override_only_path
  @@override_only_path = false
  
  # Returns the TLD Size of the current environment.
  def self.tld_size
    tld_sizes[RAILS_ENV.to_sym]
  end
  
  # Sets the TLD Size of the current environment
  def self.tld_size=(value)
    tld_sizes[RAILS_ENV.to_sym] = value
  end
  
  # Is the current subdomain either nil or a mirror?
  def self.has_subdomain?(subdomain)
    subdomain != false && !subdomain.blank? && !SubdomainFu.mirrors.include?(subdomain)
  end

  # Is the subdomain a preferred mirror
  def self.preferred_mirror?(subdomain)
    subdomain == SubdomainFu.preferred_mirror || SubdomainFu.preferred_mirror.nil?
  end
  
  # Gets the subdomain from the host based on the TLD size
  def self.subdomain_from(host)
    return nil if host.nil? || /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.match(host)
    parts = host.split('.')
    sub = parts[0..-(SubdomainFu.tld_size+2)].join(".")
    sub.blank? ? nil : sub
  end
  
  # Gets only non-mirror subdomains from the host based on the TLD size
  def self.non_mirror_subdomain_from(host)
    sub = subdomain_from(host) 
    has_subdomain?(sub) ? sub : nil 
  end

  def self.host_without_subdomain(host)
    parts = host.split('.')
    parts[-(SubdomainFu.tld_size+1)..-1].join(".")
  end
  
  # Rewrites the subdomain of the host unless they are equivalent (i.e. mirrors of each other)
  def self.rewrite_host_for_subdomains(subdomain, host)
    if needs_rewrite?(subdomain, host)
      change_subdomain_of_host(subdomain || SubdomainFu.preferred_mirror, host)
    else
      if has_subdomain?(subdomain) || preferred_mirror?(subdomain_from(host)) ||
          (subdomain.nil? && has_subdomain?(subdomain_from(host)))
        host
      else
        change_subdomain_of_host(SubdomainFu.preferred_mirror, host)
      end
    end
  end
  
  # Changes the subdomain of the host to whatever is passed in.
  def self.change_subdomain_of_host(subdomain, host)
    host = SubdomainFu.host_without_subdomain(host)
    host = "#{subdomain}.#{host}" if subdomain
    host
  end
  
  # Is this subdomain equivalent to the subdomain found in this host string?
  def self.same_subdomain?(subdomain, host)
    subdomain = nil unless subdomain
    (subdomain == subdomain_from(host)) ||
      (!has_subdomain?(subdomain) && !has_subdomain?(subdomain_from(host)))
  end
  
  def self.needs_rewrite?(subdomain, host)
    return false if subdomain.nil?

    (!has_subdomain?(subdomain) && preferred_mirror?(subdomain) && !preferred_mirror?(subdomain_from(host))) || 
      !same_subdomain?(subdomain, host)
  end
  
  def self.current_subdomain(request)
    subdomain = request.subdomains(SubdomainFu.tld_size).join(".")
    if has_subdomain?(subdomain)
      subdomain
    else
      nil
    end
  end
  
  module Controller
    def self.included(controller)
      controller.helper_method(:current_subdomain)
    end
    
    protected
    def current_subdomain
      SubdomainFu.current_subdomain(request)
    end
  end
end