//
//  Copyright (c) 2016 Google Inc.
//
//  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 UIKit

import FirebaseAuth

@objc(EmailViewController)
class EmailViewController: UIViewController {
  @IBOutlet var emailField: UITextField!
  @IBOutlet var passwordField: UITextField!

  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    view.endEditing(true)
  }

  @IBAction func didTapEmailLogin(_ sender: AnyObject) {
    guard let email = emailField.text, let password = passwordField.text else {
      showMessagePrompt("email/password can't be empty")
      return
    }
    showSpinner {
      // [START headless_email_auth]
      Auth.auth().signIn(withEmail: email, password: password) { [weak self] authResult, error in
        guard let strongSelf = self else { return }
        // [START_EXCLUDE]
        strongSelf.hideSpinner {
          if let error = error {
            let authError = error as NSError
            if authError.code == AuthErrorCode.secondFactorRequired.rawValue {
              // The user is a multi-factor user. Second factor challenge is required.
              let resolver = authError
                .userInfo[AuthErrorUserInfoMultiFactorResolverKey] as! MultiFactorResolver
              var displayNameString = ""
              for tmpFactorInfo in resolver.hints {
                displayNameString += tmpFactorInfo.displayName ?? ""
                displayNameString += " "
              }
              self!.showTextInputPrompt(
                withMessage: "Select factor to sign in\n\(displayNameString)",
                completionBlock: { userPressedOK, displayName in
                  var selectedHint: PhoneMultiFactorInfo?
                  for tmpFactorInfo in resolver.hints {
                    if displayName == tmpFactorInfo.displayName {
                      selectedHint = tmpFactorInfo as? PhoneMultiFactorInfo
                    }
                  }
                  PhoneAuthProvider.provider()
                    .verifyPhoneNumber(with: selectedHint!, uiDelegate: nil,
                                       multiFactorSession: resolver
                                         .session) { verificationID, error in
                      if error != nil {
                        print("Multi factor start sign in failed. Error: \(error.debugDescription)")
                      } else {
                        self!.showTextInputPrompt(
                          withMessage: "Verification code for \(selectedHint?.displayName ?? "")",
                          completionBlock: { userPressedOK, verificationCode in
                            let credential: PhoneAuthCredential? = PhoneAuthProvider.provider()
                              .credential(withVerificationID: verificationID!,
                                          verificationCode: verificationCode!)
                            let assertion: MultiFactorAssertion? = PhoneMultiFactorGenerator
                              .assertion(with: credential!)
                            resolver.resolveSignIn(with: assertion!) { authResult, error in
                              if error != nil {
                                print(
                                  "Multi factor finanlize sign in failed. Error: \(error.debugDescription)"
                                )
                              } else {
                                strongSelf.navigationController?.popViewController(animated: true)
                              }
                            }
                          }
                        )
                      }
                    }
                }
              )
            } else {
              strongSelf.showMessagePrompt(error.localizedDescription)
              return
            }
          }
          strongSelf.navigationController?.popViewController(animated: true)
        }
        // [END_EXCLUDE]
      }
      // [END headless_email_auth]
    }
  }

  /** @fn requestPasswordReset
   @brief Requests a "password reset" email be sent.
   */
  @IBAction func didRequestPasswordReset(_ sender: AnyObject) {
    showTextInputPrompt(withMessage: "Email:") { [weak self] userPressedOK, email in
      guard let strongSelf = self, let email = email else {
        return
      }
      strongSelf.showSpinner {
        // [START password_reset]
        Auth.auth().sendPasswordReset(withEmail: email) { error in
          // [START_EXCLUDE]
          strongSelf.hideSpinner {
            if let error = error {
              strongSelf.showMessagePrompt(error.localizedDescription)
              return
            }
            strongSelf.showMessagePrompt("Sent")
          }
          // [END_EXCLUDE]
        }
        // [END password_reset]
      }
    }
  }

  /** @fn getProvidersForEmail
   @brief Prompts the user for an email address, calls @c FIRAuth.getProvidersForEmail:callback:
   and displays the result.
   */
  @IBAction func didGetProvidersForEmail(_ sender: AnyObject) {
    showTextInputPrompt(withMessage: "Email:") { [weak self] userPressedOK, email in
      guard let strongSelf = self else { return }
      guard let email = email else {
        strongSelf.showMessagePrompt("email can't be empty")
        return
      }
      strongSelf.showSpinner {
        // [START get_methods]
        Auth.auth().fetchSignInMethods(forEmail: email) { methods, error in
          // [START_EXCLUDE]
          strongSelf.hideSpinner {
            if let error = error {
              strongSelf.showMessagePrompt(error.localizedDescription)
              return
            }
            strongSelf.showMessagePrompt(methods!.joined(separator: ", "))
          }
          // [END_EXCLUDE]
        }
        // [END get_methods]
      }
    }
  }

  @IBAction func didCreateAccount(_ sender: AnyObject) {
    showTextInputPrompt(withMessage: "Email:") { [weak self] userPressedOK, email in
      guard let strongSelf = self else { return }
      guard let email = email else {
        strongSelf.showMessagePrompt("email can't be empty")
        return
      }
      strongSelf.showTextInputPrompt(withMessage: "Password:") { userPressedOK, password in
        guard let password = password else {
          strongSelf.showMessagePrompt("password can't be empty")
          return
        }
        strongSelf.showSpinner {
          // [START create_user]
          Auth.auth().createUser(withEmail: email, password: password) { authResult, error in
            // [START_EXCLUDE]
            strongSelf.hideSpinner {
              guard let user = authResult?.user, error == nil else {
                strongSelf.showMessagePrompt(error!.localizedDescription)
                return
              }
              print("\(user.email!) created")
              strongSelf.navigationController?.popViewController(animated: true)
            }
            // [END_EXCLUDE]
          }
          // [END create_user]
        }
      }
    }
  }
}