omnivore/apple/OmnivoreKit/Sources/Services/DataService/Mutations/SavePDF.swift

import Combine
import Foundation
import Models
import SwiftGraphQL

public struct UploadFileRequestPayload {
  public let uploadID: String?
  public let uploadFileID: String?
  public let urlString: String?
}

public extension DataService {
  func uploadFileRequest(id: String, url: String) async throws -> UploadFileRequestPayload {
    enum MutationResult {
      case success(payload: UploadFileRequestPayload)
      case error(errorCode: Enums.UploadFileRequestErrorCode?)
    }

    let input = InputObjects.UploadFileRequestInput(
      clientRequestId: OptionalArgument(id),
      contentType: "application/pdf",
      createPageEntry: OptionalArgument(false),
      url: url
    )

    let selection = Selection<MutationResult, Unions.UploadFileRequestResult> {
      try $0.on(
        uploadFileRequestError: .init { .error(errorCode: try? $0.errorCodes().first) },
        uploadFileRequestSuccess: .init {
          .success(
            payload: UploadFileRequestPayload(
              uploadID: try $0.id(),
              uploadFileID: try $0.uploadFileId(),
              urlString: try $0.uploadSignedUrl()
            )
          )
        }
      )
    }

    let mutation = Selection.Mutation {
      try $0.uploadFileRequest(input: input, selection: selection)
    }

    let path = appEnvironment.graphqlPath
    let headers = networker.defaultHeaders

    return try await withCheckedThrowingContinuation { continuation in
      send(mutation, to: path, headers: headers) { result in
        switch result {
        case let .success(payload):
          if let graphqlError = payload.errors {
            continuation.resume(
              throwing: SaveArticleError.unknown(description: graphqlError.first.debugDescription)
            )
            return
          }

          switch payload.data {
          case let .success(payload):
            if let urlString = payload.urlString, let url = URL(string: urlString) {
              continuation.resume(returning: payload)
            } else {
              continuation.resume(throwing: SaveArticleError.unknown(description: "No upload URL"))
            }
          case let .error(errorCode: errorCode):
            switch errorCode {
            case .unauthorized:
              continuation.resume(throwing: SaveArticleError.unauthorized)
            default:
              continuation.resume(throwing: SaveArticleError.unknown(description: errorCode?.rawValue ?? "unknown"))
            }
          }
        case let .failure(error):
          continuation.resume(throwing: SaveArticleError.make(from: error))
        }
      }
    }
  }

  func uploadFile(id _: String, localPdfURL: URL, url: URL) async throws {
    var request = URLRequest(url: url)
    request.httpMethod = "PUT"
    request.addValue("application/pdf", forHTTPHeaderField: "content-type")

    return try await withCheckedThrowingContinuation { continuation in
      let task = networker.urlSession.uploadTask(with: request, fromFile: localPdfURL) { _, response, _ in
        if let httpResponse = response as? HTTPURLResponse, 200 ... 299 ~= httpResponse.statusCode {
          continuation.resume()
        } else {
          continuation.resume(throwing: SaveArticleError.unknown(description: "Invalid response"))
        }
      }
      task.resume()
    }
  }

  func uploadFileInBackground(id: String, localPdfURL: String?, url: URL, usingSession session: URLSession) -> URLSessionTask? {
    if let localPdfURL = localPdfURL, let localUrl = URL(string: localPdfURL) {
      var request = URLRequest(url: url)
      request.httpMethod = "PUT"
      request.setValue("application/pdf", forHTTPHeaderField: "content-type")
      request.setValue(id, forHTTPHeaderField: "clientRequestId")

      let task = session.uploadTask(with: request, fromFile: localUrl)
      return task
    } else {
      // TODO: How should we handle this scenario?
      return nil
    }
  }

  // swiftlint:disable:next line_length
  func saveFilePublisher(requestId: String, uploadFileId: String, url: String) async throws {
    enum MutationResult {
      case saved(requestId: String, url: String)
      case error(errorCode: Enums.SaveErrorCode)
    }

    let input = InputObjects.SaveFileInput(
      clientRequestId: requestId,
      source: "ios-file",
      uploadFileId: uploadFileId,
      url: url
    )

    let selection = Selection<MutationResult, Unions.SaveResult> {
      try $0.on(
        saveError: .init { .error(errorCode: (try? $0.errorCodes().first) ?? .unknown) },
        saveSuccess: .init { .saved(requestId: requestId, url: (try? $0.url()) ?? "") }
      )
    }

    let mutation = Selection.Mutation {
      try $0.saveFile(input: input, selection: selection)
    }

    let path = appEnvironment.graphqlPath
    let headers = networker.defaultHeaders

    return try await withCheckedThrowingContinuation { continuation in
      send(mutation, to: path, headers: headers) { result in
        switch result {
        case let .success(payload):
          if let graphqlError = payload.errors {
            continuation.resume(throwing: SaveArticleError.unknown(description: graphqlError.first.debugDescription))
            return
          }

          switch payload.data {
          case .saved:
            continuation.resume()
          case let .error(errorCode: errorCode):
            switch errorCode {
            case .unauthorized:
              continuation.resume(throwing: SaveArticleError.unauthorized)
            default:
              continuation.resume(throwing: SaveArticleError.unknown(description: errorCode.rawValue))
            }
          }
        case let .failure(error):
          continuation.resume(throwing: SaveArticleError.make(from: error))
        }
      }
    }
  }
}

private extension SaveError {
  static func make(from httpError: HttpError) -> SaveArticleError {
    switch httpError {
    case .network, .timeout:
      return .network
    case .badpayload, .badURL, .badstatus, .cancelled:
      return .unknown(description: httpError.localizedDescription)
    }
  }
}