module Likeable

# File lib/likeable/module_methods.rb, line 75
def adapter=(adapter)
  self.find_one  = adapter.find_one
  self.find_many = adapter.find_many
  @adapter = adapter
end

# File lib/likeable/module_methods.rb, line 63
def after_like(&block)
  @after_like = block if block.present?
  @after_like ||= lambda {|like|}
  @after_like
end

# File lib/likeable/module_methods.rb, line 69
def after_unlike(&block)
  @after_unlike = block if block.present?
  @after_unlike ||= lambda {|like|}
  @after_unlike
end

# File lib/likeable/module_methods.rb, line 81
def cast_id(id)
  @cast_id ||= if @adapter && @adapter.respond_to?(:cast_id)
    @adapter.cast_id
  else
    DefaultAdapter.cast_id
  end
  @cast_id.call(id)
end

# File lib/likeable/module_methods.rb, line 13
def classes
  (@classes||[]).flatten
end

# File lib/likeable/module_methods.rb, line 17
def classes=(*args)
  @classes = args
end

# File lib/likeable/module_methods.rb, line 35
def find_by_resource_id(resource_name, target_id)
  target = Likeable.get_class_for_resource_name(resource_name)
  if target.present?
    Likeable.find_one(target, target_id)
  else
    false
  end
end

# File lib/likeable/module_methods.rb, line 90
def find_many(klass, ids)
  @find_many ||= DefaultAdapter.find_many
  @find_many.call(klass, ids)
end

# File lib/likeable/module_methods.rb, line 95
def find_one(klass, id)
  @find_one ||= DefaultAdapter.find_one
  @find_one.call(klass, id)
end

# File lib/likeable/module_methods.rb, line 47
def get_class_for_resource_name(resource_name)
  self.model(resource_name)
end

# File lib/likeable/module_methods.rb, line 51
def get_resource_name_for_class(klass)
  klass
end

# File lib/likeable/module_methods.rb, line 25
def model(target_model)
  target_model.camelcase.constantize
rescue NameError => ex
  return false
end

# File lib/likeable/module_methods.rb, line 55
def redis
  @redis ||= Redis.new
end

# File lib/likeable/module_methods.rb, line 59
def redis=(redis)
  @redis = redis
end

# File lib/likeable/module_methods.rb, line 118
def setup(&block)
  yield self unless block.blank?
  true
end

# File lib/likeable/module_methods.rb, line 100
def user_class
  begin
    @user_class ||= ::User
  rescue NameError
    nil
  end
end

# File lib/likeable/module_methods.rb, line 108
def user_class=(klass)
  raise ArgumentError, "Argument must be a class" unless klass.is_a?(Class)
  @user_class = klass
end

# File lib/likeable.rb, line 25
def add_like_from(user, time = Time.now.to_f)
  Likeable.redis.hset(like_key, user.id, time)
  Likeable.redis.hset(user.like_key(self.class.to_s.downcase), self.id, time)
  like = Like.new(:target => self, :user => user, :time => time)
  after_like(like)
  clear_memoized_methods(:like_count, :like_user_ids, :liked_user_ids, :liked_users, :likes)
  like
end

# File lib/likeable.rb, line 40
def after_like(like)
  Likeable.after_like.call(like)
end

# File lib/likeable.rb, line 54
def after_unlike(user)
  Likeable.after_unlike.call(user)
end

# File lib/likeable.rb, line 34
def clear_memoized_methods(*methods)
  methods.each do |method|
    eval("@#{method} = nil")
  end
end

# File lib/likeable.rb, line 19
def destroy_all_likes
  liked_users.each {|user| self.remove_like_from(user) }
end

# File lib/likeable.rb, line 58
def like_count
  @like_count ||= @like_user_ids.try(:count) || @likes.try(:count) || Likeable.redis.hlen(like_key)
end

# File lib/likeable.rb, line 63
def like_user_ids
  @like_user_ids ||= (Likeable.redis.hkeys(like_key)||[]).map {|id| Likeable.cast_id(id)}
end

# File lib/likeable.rb, line 87
def likeable_resource_name
  Likeable.get_resource_name_for_class(self.class)
end

# File lib/likeable.rb, line 80
def liked_by?(user)
  return false unless user
  liked_by =    @like_user_ids.include?(Likeable.cast_id(user.id)) if @like_user_ids
  liked_by ||=  true & Likeable.redis.hexists(like_key, user.id)
end

# File lib/likeable.rb, line 67
def liked_users(limit = nil)
  @liked_users ||= Likeable.find_many(Likeable.user_class, like_user_ids)
end

# File lib/likeable.rb, line 71
def likes
  @likes ||= begin
    Likeable.redis.hgetall(like_key).collect do |user_id, time|
      Like.new(:user_id => user_id, :time => time, :target => self)
    end
  end
end

# File lib/likeable.rb, line 45
def remove_like_from(user)
  if Likeable.redis.hexists(like_key, user.id)
    Likeable.redis.hdel(like_key, user.id)
    Likeable.redis.hdel(user.like_key(self.class.to_s.downcase), self.id)
    after_unlike(user)
    clear_memoized_methods(:like_count, :like_user_ids, :liked_user_ids, :liked_users)
  end
end