// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import Foundation
#if SWIFT_PACKAGE
  import GoogleUtilities_Logger
#else
  import GoogleUtilities
#endif

/// Enum of debug messages.
// TODO: Create list of all possible messages with code - according to format.
enum LoggerMessageCode: Int {
  case modelDownloaded = 1
  case downloadedModelFileSaved
  case downloadedModelInfoSaved
  case downloaderInstanceCreated
  case downloaderInstanceRetrieved
  case downloaderInstanceDeleted
  case localModelFound
  case backgroundModelDownloaded
  case modelNameParseError
  case noLocalModelInfo
  case outdatedModelPathError
  case allLocalModelsFound
  case listModelsError
  case modelNotFound
  case modelDeleted
  case invalidOptions
  case retryDownload
  case anotherDownloadInProgressError
  case invalidModelName
  case permissionDenied
  case notEnoughSpace
  case validHTTPResponse
  case invalidModelInfoFetchURL
  case modelInfoRetrievalError
  case validAuthToken
  case hostnameError
  case invalidDownloadSessionError
  case invalidHTTPResponse
  case missingModelHash
  case invalidModelInfoJSON
  case modelInfoDeleted
  case modelInfoDownloaded
  case modelInfoUnmodified
  case mergeRequests
  case authTokenError
  case expiredModelInfo
  case modelDownloadError
  case downloadedModelSaveError
  case modelHashMismatchError
  case noModelHash
  case analyticsEventEncodeError
  case telemetryInitError
  case backgroundDownloadError
  case testError
}

/// On-device logger.
class DeviceLogger {
  static let service = "[Firebase/MLModelDownloader]"
  static func logEvent(level: GoogleLoggerLevel, message: String, messageCode: LoggerMessageCode) {
    let code = String(format: "I-MLM%06d", messageCode.rawValue)
    let args: [CVarArg] = []
    GULLoggerWrapper.log(
      with: level,
      withService: DeviceLogger.service,
      withCode: code,
      withMessage: message,
      withArgs: getVaList(args)
    )
  }
}