# encoding: utf-8
require 'rails_helper'
require 'scheduler/scheduler'

describe Scheduler::Manager do

  module Testing
    class RandomJob
      extend ::Scheduler::Schedule

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

      def self.runs
        @runs ||= 0
      end

      every 5.minutes

      def perform
        self.class.runs += 1
        sleep 0.001
      end
    end

    class SuperLongJob
      extend ::Scheduler::Schedule

      every 10.minutes

      def perform
        sleep 1000
      end
    end

    class PerHostJob
      extend ::Scheduler::Schedule

      per_host
      every 10.minutes

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

      def self.runs
        @runs ||= 0
      end

      def perform
        self.class.runs += 1
      end
    end
  end

  let(:manager) {
    Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
  }

  before do
    expect(ActiveRecord::Base.connection_pool.connections.length).to eq(1)
    @thread_count = Thread.list.count

    @backtraces = {}
    Thread.list.each do |t|
      @backtraces[t.object_id] = t.backtrace
    end
  end

  after do
    manager.stop!
    manager.remove(Testing::RandomJob)
    manager.remove(Testing::SuperLongJob)
    manager.remove(Testing::PerHostJob)
    $redis.flushall

    # connections that are not in use must be removed
    # otherwise active record gets super confused
    ActiveRecord::Base.connection_pool.connections.reject { |c| c.in_use? }.each do |c|
      ActiveRecord::Base.connection_pool.remove(c)
    end
    expect(ActiveRecord::Base.connection_pool.connections.length).to (be <= 1)

    on_thread_mismatch = lambda do
      current = Thread.list.map { |t| t.object_id }

      old_threads = @backtraces.keys
      extra = current - old_threads

      missing = old_threads - current

      if missing.length > 0
        STDERR.puts "\nMissing Threads #{missing.length} thread/s"
        missing.each do |id|
          STDERR.puts @backtraces[id]
          STDERR.puts
        end
      end

      if extra.length > 0
        Thread.list.each do |thread|
          if extra.include?(thread.object_id)
            STDERR.puts "\nExtra Thread Backtrace:"
            STDERR.puts thread.backtrace
            STDERR.puts
          end
        end
      end
    end

    wait_for(on_fail: on_thread_mismatch) do
      @thread_count == Thread.list.count
    end
  end

  it 'can disable stats' do
    manager = Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
    expect(manager.enable_stats).to eq(false)
    manager.stop!

    manager = Scheduler::Manager.new(DiscourseRedis.new)
    expect(manager.enable_stats).to eq(true)
    manager.stop!
  end

  describe 'per host jobs' do
    it "correctly schedules on multiple hosts" do

      freeze_time

      Testing::PerHostJob.runs = 0

      hosts = ['a', 'b', 'c']

      hosts.map do |host|

        manager = Scheduler::Manager.new(DiscourseRedis.new, hostname: host, enable_stats: false)
        manager.ensure_schedule!(Testing::PerHostJob)

        info = manager.schedule_info(Testing::PerHostJob)
        info.next_run = Time.now.to_i - 10
        info.write!

        manager

      end.each do |manager|

        manager.blocking_tick
        manager.stop!

      end

      expect(Testing::PerHostJob.runs).to eq(3)
    end
  end

  describe '#sync' do

    it 'increases' do
      expect(Scheduler::Manager.seq).to eq(Scheduler::Manager.seq - 1)
    end
  end

  describe '#tick' do

    it 'should nuke missing jobs' do
      $redis.zadd Scheduler::Manager.queue_key, Time.now.to_i - 1000, "BLABLA"
      manager.tick
      expect($redis.zcard(Scheduler::Manager.queue_key)).to eq(0)
    end

    it 'should recover from crashed manager' do

      info = manager.schedule_info(Testing::SuperLongJob)
      info.next_run = Time.now.to_i - 1
      info.write!

      manager.tick
      manager.stop!

      $redis.del manager.identity_key

      manager = Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
      manager.reschedule_orphans!

      info = manager.schedule_info(Testing::SuperLongJob)
      expect(info.next_run).to be <= Time.now.to_i

      manager.stop!
    end

    it 'should log when job finishes running' do

      Testing::RandomJob.runs = 0

      info = manager.schedule_info(Testing::RandomJob)
      info.next_run = Time.now.to_i - 1
      info.write!

      # with stats so we must be careful to cleanup
      manager = Scheduler::Manager.new(DiscourseRedis.new)
      manager.blocking_tick
      manager.stop!

      stat = SchedulerStat.first
      expect(stat).to be_present
      expect(stat.duration_ms).to be > 0
      expect(stat.success).to be true
      SchedulerStat.destroy_all
    end

    it 'should only run pending job once' do

      Testing::RandomJob.runs = 0

      info = manager.schedule_info(Testing::RandomJob)
      info.next_run = Time.now.to_i - 1
      info.write!

      (0..5).map do
        Thread.new do
          manager = Scheduler::Manager.new(DiscourseRedis.new, enable_stats: false)
          manager.blocking_tick
          manager.stop!
        end
      end.map(&:join)

      expect(Testing::RandomJob.runs).to eq(1)

      info = manager.schedule_info(Testing::RandomJob)
      expect(info.prev_run).to be <= Time.now.to_i
      expect(info.prev_duration).to be > 0
      expect(info.prev_result).to eq("OK")
    end

  end

  describe '#discover_schedules' do
    it 'Discovers Testing::RandomJob' do
      expect(Scheduler::Manager.discover_schedules).to include(Testing::RandomJob)
    end
  end

  describe '#next_run' do
    it 'should be within the next 5 mins if it never ran' do

      manager.remove(Testing::RandomJob)
      manager.ensure_schedule!(Testing::RandomJob)

      expect(manager.next_run(Testing::RandomJob))
        .to be_within(5.minutes.to_i).of(Time.now.to_i + 5.minutes)
    end
  end
end