class Krane::Kubectl

def allowlist_flag
  if client_version >= Gem::Version.new(ALLOW_LIST_MIN_VERSION)
    "--prune-allowlist"
  else
    "--prune-whitelist"
  end
end

def build_command_from_options(args, use_namespace, use_context, output)
  cmd = ["kubectl"] + args
  cmd.push("--namespace=#{namespace}")              if use_namespace
  cmd.push("--context=#{context}")                  if use_context
  cmd.push("--output=#{output}")                     if output
  cmd.push("--request-timeout=#{@default_timeout}")  if @default_timeout
  cmd
end

def client_version
  version_info[:client]
end

def dry_run_flag
  "--dry-run=server"
end

def initialize(task_config:, log_failure_by_default:, default_timeout: DEFAULT_TIMEOUT,
  output_is_sensitive_default: false)
  @task_config = task_config
  @log_failure_by_default = log_failure_by_default
  @default_timeout = default_timeout
  @output_is_sensitive_default = output_is_sensitive_default
end

def platform_agnostic_version(version_string)
  if match = version_string.match(/v(?<version>\d+\.\d+\.\d+)/)
    Gem::Version.new(match[:version])
  end
end

def retriable_err?(err, retry_whitelist)
  return !err.match(ERROR_MATCHERS[:not_found]) if retry_whitelist.nil?
  retry_whitelist.any? do |retriable|
    raise NotImplementedError, "No matcher defined for #{retriable.inspect}" unless ERROR_MATCHERS.key?(retriable)
    err.match(ERROR_MATCHERS[retriable])
  end
end

def retry_delay(attempt)
  # exponential backoff starting at 1s with cap at 16s, offset by up to 0.5s
  [2**(attempt - 1), MAX_RETRY_DELAY].min - Random.rand(0.5).round(1)
end

def run(*args, log_failure: nil, use_context: true, use_namespace: true, output: nil,
  raise_if_not_found: false, attempts: 1, output_is_sensitive: nil, retry_whitelist: nil)
  raise ArgumentError, "namespace is required" if namespace.blank? && use_namespace
  log_failure = @log_failure_by_default if log_failure.nil?
  output_is_sensitive = @output_is_sensitive_default if output_is_sensitive.nil?
  cmd = build_command_from_options(args, use_namespace, use_context, output)
  out, err, st = nil
  (1..attempts).to_a.each do |current_attempt|
    logger.debug("Running command (attempt #{current_attempt}): #{cmd.join(' ')}")
    env = { 'KUBECONFIG' => kubeconfig }
    out, err, st = Open3.capture3(env, *cmd)
    # https://github.com/Shopify/krane/issues/395
    unless out.valid_encoding?
      out = out.dup.force_encoding(Encoding::UTF_8)
    end
    if logger.debug? && !output_is_sensitive
      # don't do the gsub unless we're going to print this
      logger.debug("Kubectl out: " + out.gsub(/\s+/, ' '))
    end
    break if st.success?
    raise(ResourceNotFoundError, err) if err.match(ERROR_MATCHERS[:not_found]) && raise_if_not_found
    if log_failure
      warning = if current_attempt == attempts
        "The following command failed (attempt #{current_attempt}/#{attempts})"
      elsif retriable_err?(err, retry_whitelist)
        "The following command failed and will be retried (attempt #{current_attempt}/#{attempts})"
      else
        "The following command failed and cannot be retried"
      end
      logger.warn("#{warning}: #{Shellwords.join(cmd)}")
      logger.warn(err) unless output_is_sensitive
    else
      logger.debug("Kubectl err: #{output_is_sensitive ? '<suppressed sensitive output>' : err}")
    end
    StatsD.client.increment('kubectl.error', 1, tags: { context: context, namespace: namespace, cmd: cmd[1],
                                                        max_attempt: attempts, current_attempt: current_attempt })
    break unless retriable_err?(err, retry_whitelist) && current_attempt < attempts
    sleep(retry_delay(current_attempt))
  end
  [out.chomp, err.chomp, st]
end

def server_dry_run_enabled?
  server_version >= Gem::Version.new(SERVER_DRY_RUN_MIN_VERSION)
end

def server_version
  version_info[:server]
end

def version_info
  @version_info ||=
    begin
      response, _, status = run("version", output: "json", use_namespace: false, log_failure: true, attempts: 2)
      raise KubectlError, "Could not retrieve kubectl version info" unless status.success?
      version_data = MultiJson.load(response)
      client_version = platform_agnostic_version(version_data.dig("clientVersion", "gitVersion").to_s)
      server_version = platform_agnostic_version(version_data.dig("serverVersion", "gitVersion").to_s)
      unless client_version && server_version
        raise KubectlError, "Received invalid kubectl version data: #{version_data}"
      end
      { client: client_version, server: server_version }
    end
end