# encoding: utf-8
require 'sidekiq'

module Sidekiq
  class Stats
    def processed
      Sidekiq.redis { |conn| conn.get("stat:processed") }.to_i
    end

    def failed
      Sidekiq.redis { |conn| conn.get("stat:failed") }.to_i
    end

    def reset(*stats)
      all   = %w(failed processed)
      stats = stats.empty? ? all : all & stats.flatten.compact.map(&:to_s)

      mset_args = []
      stats.each do |stat|
        mset_args << "stat:#{stat}"
        mset_args << 0
      end
      Sidekiq.redis do |conn|
        conn.mset(*mset_args)
      end
    end

    def queues
      Sidekiq.redis do |conn|
        queues = conn.smembers('queues')

        lengths = conn.pipelined do
          queues.each do |queue|
            conn.llen("queue:#{queue}")
          end
        end

        i = 0
        array_of_arrays = queues.inject({}) do |memo, queue|
          memo[queue] = lengths[i]
          i += 1
          memo
        end.sort_by { |_, size| size }

        Hash[array_of_arrays.reverse]
      end
    end

    def enqueued
      queues.values.inject(&:+) || 0
    end

    def scheduled_size
      Sidekiq.redis {|c| c.zcard('schedule') }
    end

    def retry_size
      Sidekiq.redis {|c| c.zcard('retry') }
    end

    def dead_size
      Sidekiq.redis {|c| c.zcard('dead') }
    end

    class History
      def initialize(days_previous, start_date = nil)
        @days_previous = days_previous
        @start_date = start_date || Time.now.utc.to_date
      end

      def processed
        date_stat_hash("processed")
      end

      def failed
        date_stat_hash("failed")
      end

      private

      def date_stat_hash(stat)
        i = 0
        stat_hash = {}
        keys = []
        dates = []

        while i < @days_previous
          date = @start_date - i
          keys << "stat:#{stat}:#{date}"
          dates << date
          i += 1
        end

        Sidekiq.redis do |conn|
          conn.mget(keys).each_with_index do |value, i|
            stat_hash[dates[i].to_s] = value ? value.to_i : 0
          end
        end

        stat_hash
      end
    end
  end

  ##
  # Encapsulates a queue within Sidekiq.
  # Allows enumeration of all jobs within the queue
  # and deletion of jobs.
  #
  #   queue = Sidekiq::Queue.new("mailer")
  #   queue.each do |job|
  #     job.klass # => 'MyWorker'
  #     job.args # => [1, 2, 3]
  #     job.delete if job.jid == 'abcdef1234567890'
  #   end
  #
  class Queue
    include Enumerable

    def self.all
      Sidekiq.redis {|c| c.smembers('queues') }.map {|q| Sidekiq::Queue.new(q) }
    end

    attr_reader :name

    def initialize(name="default")
      @name = name
      @rname = "queue:#{name}"
    end

    def size
      Sidekiq.redis { |con| con.llen(@rname) }
    end

    # Sidekiq Pro overrides this
    def paused?
      false
    end

    def latency
      entry = Sidekiq.redis do |conn|
        conn.lrange(@rname, -1, -1)
      end.first
      return 0 unless entry
      Time.now.to_f - Sidekiq.load_json(entry)['enqueued_at']
    end

    def each(&block)
      initial_size = size
      deleted_size = 0
      page = 0
      page_size = 50

      loop do
        range_start = page * page_size - deleted_size
        range_end   = page * page_size - deleted_size + (page_size - 1)
        entries = Sidekiq.redis do |conn|
          conn.lrange @rname, range_start, range_end
        end
        break if entries.empty?
        page += 1
        entries.each do |entry|
          block.call Job.new(entry, @name)
        end
        deleted_size = initial_size - size
      end
    end

    def find_job(jid)
      self.detect { |j| j.jid == jid }
    end

    def clear
      Sidekiq.redis do |conn|
        conn.multi do
          conn.del(@rname)
          conn.srem("queues", name)
        end
      end
    end
    alias_method :💣, :clear
  end

  ##
  # Encapsulates a pending job within a Sidekiq queue or
  # sorted set.
  #
  # The job should be considered immutable but may be
  # removed from the queue via Job#delete.
  #
  class Job
    attr_reader :item

    def initialize(item, queue_name=nil)
      @value = item
      @item = Sidekiq.load_json(item)
      @queue = queue_name || @item['queue']
    end

    def klass
      @item['class']
    end

    def args
      @item['args']
    end

    def jid
      @item['jid']
    end

    def enqueued_at
      Time.at(@item['enqueued_at'] || 0).utc
    end

    def queue
      @queue
    end

    def latency
      Time.now.to_f - @item['enqueued_at']
    end

    ##
    # Remove this job from the queue.
    def delete
      count = Sidekiq.redis do |conn|
        conn.lrem("queue:#{@queue}", 1, @value)
      end
      count != 0
    end

    def [](name)
      @item.__send__(:[], name)
    end
  end

  class SortedEntry < Job
    attr_reader :score
    attr_reader :parent

    def initialize(parent, score, item)
      super(item)
      @score = score
      @parent = parent
    end

    def at
      Time.at(score).utc
    end

    def delete
      @parent.delete(score, jid)
    end

    def reschedule(at)
      @parent.delete(score, jid)
      @parent.schedule(at, item)
    end

    def add_to_queue
      Sidekiq.redis do |conn|
        results = conn.multi do
          conn.zrangebyscore('schedule', score, score)
          conn.zremrangebyscore('schedule', score, score)
        end.first
        results.map do |message|
          msg = Sidekiq.load_json(message)
          Sidekiq::Client.push(msg)
        end
      end
    end

    def retry
      raise "Retry not available on jobs which have not failed" unless item["failed_at"]
      Sidekiq.redis do |conn|
        results = conn.multi do
          conn.zrangebyscore(parent.name, score, score)
          conn.zremrangebyscore(parent.name, score, score)
        end.first
        results.map do |message|
          msg = Sidekiq.load_json(message)
          msg['retry_count'] = msg['retry_count'] - 1
          Sidekiq::Client.push(msg)
        end
      end
    end
  end

  class SortedSet
    include Enumerable

    attr_reader :name

    def initialize(name)
      @name = name
      @_size = size
    end

    def size
      Sidekiq.redis {|c| c.zcard(name) }
    end

    def clear
      Sidekiq.redis do |conn|
        conn.del(name)
      end
    end
    alias_method :💣, :clear
  end

  class JobSet < SortedSet

    def schedule(timestamp, message)
      Sidekiq.redis do |conn|
        conn.zadd(name, timestamp.to_f.to_s, Sidekiq.dump_json(message))
      end
    end

    def each(&block)
      initial_size = @_size
      offset_size = 0
      page = -1
      page_size = 50

      loop do
        range_start = page * page_size + offset_size
        range_end   = page * page_size + offset_size + (page_size - 1)
        elements = Sidekiq.redis do |conn|
          conn.zrange name, range_start, range_end, :with_scores => true
        end
        break if elements.empty?
        page -= 1
        elements.each do |element, score|
          block.call SortedEntry.new(self, score, element)
        end
        offset_size = initial_size - @_size
      end
    end

    def fetch(score, jid = nil)
      elements = Sidekiq.redis do |conn|
        conn.zrangebyscore(name, score, score)
      end

      elements.inject([]) do |result, element|
        entry = SortedEntry.new(self, score, element)
        if jid
          result << entry if entry.jid == jid
        else
          result << entry
        end
        result
      end
    end

    def find_job(jid)
      self.detect { |j| j.jid == jid }
    end

    def delete(score, jid = nil)
      if jid
        elements = Sidekiq.redis do |conn|
          conn.zrangebyscore(name, score, score)
        end

        elements_with_jid = elements.map do |element|
          message = Sidekiq.load_json(element)

          if message["jid"] == jid
            _, @_size = Sidekiq.redis do |conn|
              conn.multi do
                conn.zrem(name, element)
                conn.zcard name
              end
            end
          end
        end
        elements_with_jid.count != 0
      else
        count, @_size = Sidekiq.redis do |conn|
          conn.multi do
            conn.zremrangebyscore(name, score, score)
            conn.zcard name
          end
        end
        count != 0
      end
    end

  end

  ##
  # Allows enumeration of scheduled jobs within Sidekiq.
  # Based on this, you can search/filter for jobs.  Here's an
  # example where I'm selecting all jobs of a certain type
  # and deleting them from the retry queue.
  #
  #   r = Sidekiq::ScheduledSet.new
  #   r.select do |retri|
  #     retri.klass == 'Sidekiq::Extensions::DelayedClass' &&
  #     retri.args[0] == 'User' &&
  #     retri.args[1] == 'setup_new_subscriber'
  #   end.map(&:delete)
  class ScheduledSet < JobSet
    def initialize
      super 'schedule'
    end
  end

  ##
  # Allows enumeration of retries within Sidekiq.
  # Based on this, you can search/filter for jobs.  Here's an
  # example where I'm selecting all jobs of a certain type
  # and deleting them from the retry queue.
  #
  #   r = Sidekiq::RetrySet.new
  #   r.select do |retri|
  #     retri.klass == 'Sidekiq::Extensions::DelayedClass' &&
  #     retri.args[0] == 'User' &&
  #     retri.args[1] == 'setup_new_subscriber'
  #   end.map(&:delete)
  class RetrySet < JobSet
    def initialize
      super 'retry'
    end

    def retry_all
      while size > 0
        each(&:retry)
      end
    end
  end

  class DeadSet < JobSet
    def initialize
      super 'dead'
    end

    def retry_all
      while size > 0
        each(&:retry)
      end
    end
  end

  ##
  # Enumerates the set of Sidekiq processes which are actively working
  # right now.  Each process send a heartbeat to Redis every 5 seconds
  # so this set should be relatively accurate, barring network partitions.
  #
  # Yields a Sidekiq::Process.
  #

  class ProcessSet
    include Enumerable

    def each(&block)
      procs = Sidekiq.redis { |conn| conn.smembers('processes') }

      to_prune = []
      sorted = procs.sort
      Sidekiq.redis do |conn|
        # We're making a tradeoff here between consuming more memory instead of
        # making more roundtrips to Redis, but if you have hundreds or thousands of workers,
        # you'll be happier this way
        result = conn.pipelined do
          sorted.each do |key|
            conn.hmget(key, 'info', 'busy', 'beat')
          end
        end

        result.each_with_index do |(info, busy, at_s), i|
          # the hash named key has an expiry of 60 seconds.
          # if it's not found, that means the process has not reported
          # in to Redis and probably died.
          (to_prune << sorted[i]; next) if info.nil?
          hash = Sidekiq.load_json(info)
          yield Process.new(hash.merge('busy' => busy.to_i, 'beat' => at_s.to_f))
        end
      end

      Sidekiq.redis {|conn| conn.srem('processes', to_prune) } unless to_prune.empty?
      nil
    end

    # This method is not guaranteed accurate since it does not prune the set
    # based on current heartbeat.  #each does that and ensures the set only
    # contains Sidekiq processes which have sent a heartbeat within the last
    # 60 seconds.
    def size
      Sidekiq.redis { |conn| conn.scard('processes') }
    end
  end

  #
  # Sidekiq::Process has a set of attributes which look like this:
  #
  # {
  #   'hostname' => 'app-1.example.com',
  #   'started_at' => <process start time>,
  #   'pid' => 12345,
  #   'tag' => 'myapp'
  #   'concurrency' => 25,
  #   'queues' => ['default', 'low'],
  #   'busy' => 10,
  #   'beat' => <last heartbeat>,
  # }
  class Process
    def initialize(hash)
      @attribs = hash
    end

    def [](key)
      @attribs[key]
    end
  end

  ##
  # Programmatic access to the current active worker set.
  #
  # WARNING WARNING WARNING
  #
  # This is live data that can change every millisecond.
  # If you call #size => 5 and then expect #each to be
  # called 5 times, you're going to have a bad time.
  #
  #    workers = Sidekiq::Workers.new
  #    workers.size => 2
  #    workers.each do |process_id, thread_id, work|
  #      # process_id is a unique identifier per Sidekiq process
  #      # thread_id is a unique identifier per thread
  #      # work is a Hash which looks like:
  #      # { 'queue' => name, 'run_at' => timestamp, 'payload' => msg }
  #      # run_at is an epoch Integer.
  #    end
  #
  class Workers
    include Enumerable

    def each(&block)
      Sidekiq.redis do |conn|
        procs = conn.smembers('processes')
        procs.sort.each do |key|
          valid, workers = conn.pipelined do
            conn.exists(key)
            conn.hgetall("#{key}:workers")
          end
          next unless valid
          workers.each_pair do |tid, json|
            yield key, tid, Sidekiq.load_json(json)
          end
        end
      end
    end

    # Note that #size is only as accurate as Sidekiq's heartbeat,
    # which happens every 5 seconds.  It is NOT real-time.
    #
    # Not very efficient if you have lots of Sidekiq
    # processes but the alternative is a global counter
    # which can easily get out of sync with crashy processes.
    def size
      Sidekiq.redis do |conn|
        procs = conn.smembers('processes')
        return 0 if procs.empty?

        conn.pipelined do
          procs.each do |key|
            conn.hget(key, 'busy')
          end
        end.map(&:to_i).inject(:+)
      end
    end
  end

end