class CfnStatus

# File lib/cfn_status.rb, line 11
def initialize(stack_name, options={})
  @stack_name = stack_name
  @options = options
  @cfn = options[:cfn] # allow use of different cfn client. can be useful multiple cfn clients and with different regions
  resp = cfn.describe_stacks(stack_name: @stack_name)
  @stack = resp.stacks.first
  reset
end

# File lib/cfn_status.rb, line 178
def add_events_pages(resp, index_method)
  found = !!send(index_method)
  until found
    resp = cfn.describe_stack_events(stack_name: @stack_name, next_token: resp["next_token"])
    @events += resp["stack_events"]
    found = !!send(index_method)
  end
end

# File lib/cfn_status.rb, line 90
def completed
  last_event_status =~ /(_COMPLETE|_FAILED)$/ &&
  @events[0]["logical_resource_id"] == @stack_name &&
  @events[0]["resource_type"] == "AWS::CloudFormation::Stack"
end

# File lib/cfn_status.rb, line 138
def event_time(timestamp)
  Time.parse(timestamp.to_s).localtime.strftime("%I:%M:%S%p")
end

# File lib/cfn_status.rb, line 210
def find_update_failed_event
  i = @events.find_index do |event|
    event["resource_type"] == "AWS::CloudFormation::Stack" &&
    event["resource_status_reason"] == "User Initiated"
  end

  @events[0..i].reverse.find do |e|
    e["resource_status"] == "UPDATE_FAILED"
  end
end

# File lib/cfn_status.rb, line 256
def handle_rollback!
  CfnStatus::RollbackStack.handle!(@stack_name, cfn: cfn)
end

# File lib/cfn_status.rb, line 41
def in_progress?
  in_progress = stack.stack_status =~ /_IN_PROGRESS$/
  !!in_progress
end

# File lib/cfn_status.rb, line 96
def last_event_status
  @events.dig(0, "resource_status")
end

# File lib/cfn_status.rb, line 195
def last_shown_index
  @events.find_index do |event|
    event["event_id"] == @last_shown_event_id
  end
end

# File lib/cfn_status.rb, line 237
def messages_map
  {
    /CloudFormation cannot update a stack when a custom-named resource requires replacing/ => "A workaround is to run ufo again with STATIC_NAME=0 and to switch to dynamic names for resources. Then run ufo again with STATIC_NAME=1 to get back to statically name resources. Note, there are caveats with the workaround.",
    /cannot be associated with more than one load balancer/ => "There's was an issue updating the stack. Target groups can only be associated with one load balancer at a time. The workaround for this is to use UFO_FORCE_TARGET_GROUP=1 and run the command again. This will force the recreation of the target group resource.",
    /SetSubnets is not supported for load balancers of type/ => "Changing subnets for Network Load Balancers is currently not supported. You can try workarouding this with UFO_FORCE_ELB=1 and run the command again. This will force the recreation of the elb resource."
  }
end

# File lib/cfn_status.rb, line 246
def pretty_time(total_seconds)
  minutes = (total_seconds / 60) % 60
  seconds = total_seconds % 60
  if total_seconds < 60
    "#{seconds.to_i}s"
  else
    "#{minutes.to_i}m #{seconds.to_i}s"
  end
end

# File lib/cfn_status.rb, line 125
def print_event(e)
  message = [
    event_time(e["timestamp"]),
    e["resource_status"],
    e["resource_type"],
    e["logical_resource_id"],
    e["resource_status_reason"]
  ].join(" ")
  message = message.color(:red) if e["resource_status"] =~ /_FAILED/
  puts message
end

# File lib/cfn_status.rb, line 116
def print_events(i)
  @events[0..i].reverse.each do |e|
    print_event(e)
  end

  @last_shown_event_id = @events[0]["event_id"]
  # puts "@last_shown_event_id #{@last_shown_event_id.inspect}"
end

# File lib/cfn_status.rb, line 144
def refresh_events
  resp = cfn.describe_stack_events(stack_name: @stack_name)
  @events = resp["stack_events"]

  # refresh_events uses add_events_pages and resp["next_token"] to load all events until:
  #
  #     1. @last_shown_event_id found - if @last_shown_event_id is set
  #     2. User Initiated Event found - fallback when @last_shown_event_id is not set
  #
  if @last_shown_event_id
    add_events_pages(resp, :last_shown_index)
  else
    add_events_pages(resp, :start_index)
  end

rescue Aws::CloudFormation::Errors::ValidationError => e
  if e.message =~ /Stack .* does not exis/
    @stack_deletion_completed = true
  else
    raise
  end
end

# File lib/cfn_status.rb, line 46
def reset
  @events = [] # constantly replaced with recent events
  @last_shown_event_id = nil
  @stack_deletion_completed = nil
end

# File lib/cfn_status.rb, line 221
def rollback_error_message
  return unless update_rollback?

  event = find_update_failed_event
  return unless event

  reason = event["resource_status_reason"]
  messages_map.each do |pattern, message|
    if reason =~ pattern
      return message
    end
  end

  reason # default message is original reason if not found in messages map
end

# File lib/cfn_status.rb, line 20
def run
  unless stack_exists?(@stack_name)
    puts "The stack #{@stack_name.color(:green)} does not exist."
    return true
  end

  puts "The current status for the stack #{@stack_name.color(:green)} is #{stack.stack_status.color(:green)}"
  if in_progress?
    puts "Stack events (tailing):"
    # tail all events until done
    @hide_time_took = true
    wait
  else
    puts "Stack events:"
    # show the last events that was user initiated
    refresh_events
    show_events(final: true)
  end
  success?
end

# File lib/cfn_status.rb, line 101
def show_events(final: false)
  if @last_shown_event_id.nil?
    i = start_index
    print_events(i)
  else
    i = last_shown_index
    # puts "last_shown index #{i}"
    print_events(i-1) unless i == 0
  end

  return if final
  sleep 5 unless ENV['TEST']
  refresh_events
end

# File lib/cfn_status.rb, line 188
def start_index
  @events.find_index do |event|
    event["resource_type"] == "AWS::CloudFormation::Stack" &&
    event["resource_status_reason"] == "User Initiated"
  end
end

# File lib/cfn_status.rb, line 201
def success?
  resource_status = @events[0]["resource_status"]
  %w[CREATE_COMPLETE UPDATE_COMPLETE].include?(resource_status)
end

# File lib/cfn_status.rb, line 206
def update_rollback?
  @events[0]["resource_status"] == "UPDATE_ROLLBACK_COMPLETE"
end

# File lib/cfn_status.rb, line 53
def wait
  # Check for in progress again in case .wait is called from other libraries like s3-antivirus
  # Showing the event messages when will show old messages which can be confusing.
  return unless in_progress?

  puts "Waiting for stack to complete"
  start_time = Time.now

  refresh_events
  until completed || @stack_deletion_completed
    show_events(final: false)
  end
  show_events(final: true) # show the final event

  if @stack_deletion_completed
    puts "Stack #{@stack_name} deleted."
    return
  end

  # Never gets beyond here when deleting a stack because the describe stack returns nothing
  # once the stack is deleted. Gets here for stack create and update though.

  if last_event_status =~ /_FAILED/
    puts "Stack failed: #{last_event_status}".color(:red)
    puts "Stack reason #{@events[0]["resource_status_reason"]}".color(:red)
  elsif last_event_status =~ /_ROLLBACK_/
    puts "Stack rolled back: #{last_event_status}".color(:red)
  else # success
    puts "Stack success status: #{last_event_status}".color(:green)
  end

  return if @hide_time_took # set in run
  took = Time.now - start_time
  puts "Time took for stack deployment: #{pretty_time(took).color(:green)}."
  success?
end