Goodle/Comedores Sociales/LoginView.swift

//
//  LogIn.swift
//  Comedores Sociales
//
//  Created by Hector Carrion on 10/24/20.
//

import SwiftUI

class LoginViewModel: ObservableObject {
    @Published var response: Bool?
    
    func changeResponse(response: Bool) {
        self.response = response
    }
    
    func login(data: Authentication) {
        
        let service = "login.php"
        guard let encodedData = try? JSONEncoder().encode(data)
        else {
            print("Failed to encode login request")
            return
        }
        
        //print("JSON to send:", String(data: encodedData, encoding: .utf8)!)
        
        let url = URL(string: serverAddress + service)!
        var request = URLRequest(url: url)
        request.setValue("applogin/json", forHTTPHeaderField: "Content-Type")
        request.httpMethod = "POST"
        request.httpBody = encodedData
        
        URLSession.shared.dataTask(with: request) {data, response, error in
            
            //handle result here
            guard let data = data
            else {
                print("No data in response: \(error?.localizedDescription ?? "Unknown error").")
                return
            }
            print(response ?? "No response")
            print("Recieved data:", data)
            print(error ?? "No error")
            
            if let httpResponse = response as? HTTPURLResponse {
                DispatchQueue.main.async {
                    if httpResponse.statusCode == 200 {
                        self.changeResponse(response: true)
                    } else {
                        self.changeResponse(response: false)
                    }
                    
                }
            }
            
        }.resume()
    }
}

struct LoginView: View {
    @State var email: String = ""
    @State var password: String = ""
    @State var showingRegister: Bool = false
    
    @ObservedObject var loginVM = LoginViewModel()
    @State private var showingAlert = false
    
    var body: some View {
        VStack {
            WelcomeImage()
            WelcomeText()
            EmailField(email: $email)
            PasswordField(password: $password)
            
            if self.loginVM.response == false {
                Text("Information incorrect, please try again")
                    .offset(y: -10)
                    .foregroundColor(.red)
            } else if self.loginVM.response == true {
                Text("Login successful 🎉")
                    .offset(y: -10)
                    .foregroundColor(.green)
            }
            
            Button(action: {
                let authData = Authentication(email: email, password: password)
                if authData.isComplete() {
                    self.loginVM.login(data: authData)
                } else {
                    // alert
                    self.showingAlert = true
                }
                
            }) {
                LoginText()
            }
            
            Button(action: {self.showingRegister.toggle()}) {
                RegisterText()
            }
            .sheet(isPresented: $showingRegister, content: {RegisterView()})
            .alert(isPresented: $showingAlert) {
                Alert(title: Text("Fields incomplete"), message: Text("Please enter a valid email and password"), dismissButton: .default(Text("OK")))
                
            }
        }
        .padding()
    }
}

struct LogInView_Previews: PreviewProvider {
    static var previews: some View {
        LoginView()
    }
}

struct WelcomeText: View {
    var body: some View {
        Text("Comedores Sociales")
            .font(.largeTitle)
            .fontWeight(.semibold)
            .padding(.bottom, 20)
    }
}

struct WelcomeImage: View {
    var body: some View {
        Image("logInImage")
            .resizable()
            .aspectRatio(contentMode: .fill)
            .frame(width: 150, height: 150)
            .clipped()
            //.cornerRadius(150)
            //.padding(.bottom, 75)
    }
}

struct LoginText: View {
    var body: some View {
        Text("Login")
            .font(.headline)
            .foregroundColor(.white)
            .padding()
            .frame(width: 220, height: 50)
            .background(Color.blue)
            .cornerRadius(5)
            .padding(.bottom, 5)
    }
}

struct RegisterText: View {
    var body: some View {
        Text("Don't have an account? Register")
            .font(.headline)
            .foregroundColor(.gray)
            .padding()
            .frame(width: 350, height: 50)
            .background(Color.clear)
            .cornerRadius(5)
    }
}

struct EmailField: View {
    @Binding var email: String
    @Environment(\.colorScheme) var colorScheme
    var body: some View {
        TextField("Email", text: $email)
            .autocapitalization(.none)
            .padding()
            .background(colorScheme == .dark ? darkGreyColor : lightGreyColor)
            .cornerRadius(5.0)
            .padding(.bottom, 5)
    }
}

struct PasswordField: View {
    @Binding var password: String
    @Environment(\.colorScheme) var colorScheme
    var body: some View {
        SecureField("Password", text: $password)
            .autocapitalization(.none)
            .padding()
            .background(colorScheme == .dark ? darkGreyColor : lightGreyColor)
            .cornerRadius(5.0)
            .padding(.bottom, 20)
    }
}