class Typhoeus::Hydra

def self.hydra
  @hydra ||= new
end

def self.hydra=(val)
  @hydra = val
end

def assign_to_stub(request)
  m = @stubs.detect {|stub| stub.matches? request}
  m && m.add_request(request)
end

def cache_getter(&block)
  @cache_getter = block
end

def cache_setter(&block)
  @cache_setter = block
end

def clear_stubs
  @stubs = []
end

def disable_memoization
  @memoize_requests = false
end

def fire_and_forget
  @queued_requests.each {|r| queue(r, false)}
  @multi.fire_and_forget
end

def get_easy_object(request)
  @running_requests += 1
  easy = @easy_pool.pop || Easy.new
  easy.url          = request.url
  easy.method       = request.method
  easy.params       = request.params  if request.method == :post && !request.params.nil?
  easy.headers      = request.headers if request.headers
  easy.request_body = request.body    if request.body
  easy.timeout      = request.timeout if request.timeout
  easy.on_success do |easy|
    queue_next
    handle_request(request, response_from_easy(easy, request))
    release_easy_object(easy)
  end
  easy.on_failure do |easy|
    queue_next
    handle_request(request, response_from_easy(easy, request))
    release_easy_object(easy)
  end
  easy.set_headers
  easy
end

def get_from_cache_or_queue(request)
  if @cache_getter
    val = @cache_getter.call(request)
    if val
      @retrieved_from_cache[request.url] = val
      handle_request(request, val, false)
    else
      @multi.add(get_easy_object(request))
    end
  else
    @multi.add(get_easy_object(request))
  end
end

def handle_request(request, response, live_request = true)
  request.response = response
  if live_request && request.cache_timeout && @cache_setter
    @cache_setter.call(request)
  end
  @on_complete.call(response) if @on_complete
  request.call_handlers
  if requests = @memoized_requests[request.url]
    requests.each do |r|
      r.response = response
      r.call_handlers
    end
  end
end

def initialize(options = {})
  @memoize_requests = true
  @multi       = Multi.new
  @easy_pool   = []
  initial_pool_size = options[:initial_pool_size] || 10
  @max_concurrency = options[:max_concurrency] || 200
  initial_pool_size.times { @easy_pool << Easy.new }
  @stubs       = []
  @memoized_requests = {}
  @retrieved_from_cache = {}
  @queued_requests = []
  @running_requests = 0
end

def on_complete(&block)
  @on_complete = block
end

def on_complete=(proc)
  @on_complete = proc
end

def queue(request, obey_concurrency_limit = true)
  return if assign_to_stub(request)
  if @running_requests >= @max_concurrency && obey_concurrency_limit
    @queued_requests << request
  else
    if request.method == :get
      if @memoize_requests && @memoized_requests.has_key?(request.url)
        if response = @retrieved_from_cache[request.url]
          request.response = response
          request.call_handlers
        else
          @memoized_requests[request.url] << request
        end
      else
        @memoized_requests[request.url] = [] if @memoize_requests
        get_from_cache_or_queue(request)
      end
    else
      get_from_cache_or_queue(request)
    end
  end
end

def queue_next
  @running_requests -= 1
  queue(@queued_requests.pop) unless @queued_requests.empty?
end

def release_easy_object(easy)
  easy.reset
  @easy_pool.push easy
end

def response_from_easy(easy, request)
  Response.new(:code    => easy.response_code,
               :headers => easy.response_header,
               :body    => easy.response_body,
               :time    => easy.total_time_taken,
               :request => request)
end

def run
  @stubs.each do |m|
    m.requests.each do |request|
      m.response.request = request
      handle_request(request, m.response)
    end
  end
  @multi.perform
  @memoized_requests = {}
  @retrieved_from_cache = {}
end

def stub(method, url)
  @stubs << HydraMock.new(url, method)
  @stubs.last
end