/*
 * Copyright 2019, gRPC Authors All rights reserved.
 *
 * 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
@testable import GRPC
import EchoModel
import NIO
import NIOHPACK
import NIOHTTP1
import NIOHTTP2
import XCTest
import Logging

class GRPCStatusCodeTests: GRPCTestCase {
  var channel: EmbeddedChannel!

  override func setUp() {
    super.setUp()

    let handler = _GRPCClientChannelHandler<Echo_EchoRequest, Echo_EchoResponse>(
      streamID: .init(1),
      callType: .unary,
      logger: self.logger
    )

    self.channel = EmbeddedChannel(handler: handler)
  }

  func headersFrame(status: HTTPResponseStatus) -> HTTP2Frame {
    let headers: HPACKHeaders = [":status": "\(status.code)"]
    return .init(streamID: .init(1), payload: .headers(.init(headers: headers)))
  }

  func sendRequestHead() {
    let requestHead = _GRPCRequestHead(
      method: "POST",
      scheme: "http",
      path: "/foo/bar",
      host: "localhost",
      deadline: .distantFuture,
      customMetadata: [:],
      encoding: .disabled
    )
    let clientRequestHead: _GRPCClientRequestPart<Echo_EchoRequest> = .head(requestHead)
    XCTAssertNoThrow(try self.channel.writeOutbound(clientRequestHead))
  }

  func doTestResponseStatus(_ status: HTTPResponseStatus, expected: GRPCStatus.Code) throws {
    // Send the request head so we're in a valid state to receive headers.
    self.sendRequestHead()
    XCTAssertThrowsError(try self.channel.writeInbound(self.headersFrame(status: status))) { error in
      guard let withContext = error as? GRPCError.WithContext,
            let invalidHTTPStatus = withContext.error as? GRPCError.InvalidHTTPStatus  else {
        XCTFail("Unexpected error: \(error)")
        return
      }

      XCTAssertEqual(invalidHTTPStatus.makeGRPCStatus().code, expected)
    }
  }

  func testTooManyRequests() throws {
    try self.doTestResponseStatus(.tooManyRequests, expected: .unavailable)
  }

  func testBadGateway() throws {
    try self.doTestResponseStatus(.badGateway, expected: .unavailable)
  }

  func testServiceUnavailable() throws {
    try self.doTestResponseStatus(.serviceUnavailable, expected: .unavailable)
  }

  func testGatewayTimeout() throws {
    try self.doTestResponseStatus(.gatewayTimeout, expected: .unavailable)
  }

  func testBadRequest() throws {
    try self.doTestResponseStatus(.badRequest, expected: .internalError)
  }

  func testUnauthorized() throws {
    try self.doTestResponseStatus(.unauthorized, expected: .unauthenticated)
  }

  func testForbidden() throws {
    try self.doTestResponseStatus(.forbidden, expected: .permissionDenied)
  }

  func testNotFound() throws {
    try self.doTestResponseStatus(.notFound, expected: .unimplemented)
  }

  func testStatusCodeAndMessageAreRespectedForNon200Responses() throws {
    let status = GRPCStatus(code: .doNotUse, message: "Not the HTTP error phrase")

    let headers: HPACKHeaders = [
      ":status": "\(HTTPResponseStatus.imATeapot.code)",
      GRPCHeaderName.statusCode: "\(status.code.rawValue)",
      GRPCHeaderName.statusMessage: status.message!
    ]

    self.sendRequestHead()
    let headerFrame = HTTP2Frame(streamID: .init(1), payload: .headers(.init(headers: headers)))
    XCTAssertThrowsError(try self.channel.writeInbound(headerFrame)) { error in
      guard let withContext = error as? GRPCError.WithContext,
            let invalidHTTPStatus = withContext.error as? GRPCError.InvalidHTTPStatusWithGRPCStatus  else {
        XCTFail("Unexpected error: \(error)")
        return
      }
      XCTAssertEqual(invalidHTTPStatus.makeGRPCStatus(), status)
    }
  }
}