Untitled

import SwiftUI

enum Operation {
    case none, addition, subtraction, multiplication, division
}

struct ContentView: View {
    @State private var input: String = ""
    @State private var result: Double = 0
    @State private var currentOperation: Operation = .none

    var formattedResult: String {
        let formatter = NumberFormatter()
        formatter.maximumFractionDigits = result.truncatingRemainder(dividingBy: 1) == 0 ? 0 : 2
        return formatter.string(from: NSNumber(value: result)) ?? ""
    }

    var body: some View {
        VStack {
            Text("Calculator")
                .font(.title)
                .padding()

            TextField("Enter a number", text: $input)
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .padding()

            HStack {
                Button(action: {
                    appendInput("7")
                }, label: {
                    Text("7")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("8")
                }, label: {
                    Text("8")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("9")
                }, label: {
                    Text("9")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("+")
                }, label: {
                    Text("+")
                        .font(.title)
                        .padding()
                        .background(Color.orange)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })
            }
            .padding()

            HStack {
                Button(action: {
                    appendInput("4")
                }, label: {
                    Text("4")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("5")
                }, label: {
                    Text("5")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("6")
                }, label: {
                    Text("6")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("-")
                }, label: {
                    Text("-")
                        .font(.title)
                        .padding()
                        .background(Color.orange)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })
            }
            .padding()

            HStack {
                Button(action: {
                    appendInput("1")
                }, label: {
                    Text("1")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("2")
                }, label: {
                    Text("2")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("3")
                }, label: {
                    Text("3")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("*")
                }, label: {
                    Text("*")
                        .font(.title)
                        .padding()
                        .background(Color.orange)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })
            }
            .padding()

            HStack {
                Button(action: {
                    appendInput("0")
                }, label: {
                    Text("0")
                        .font(.title)
                        .padding()
                        .background(Color.gray)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    calculateResult()
                }, label: {
                    Text("=")
                        .font(.title)
                        .padding()
                        .background(Color.blue)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })

                Button(action: {
                    appendInput("/")
                }, label: {
                    Text("/")
                        .font(.title)
                        .padding()
                        .background(Color.orange)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                })
            }
            .padding()

            Button(action: {
                clearInput()
            }, label: {
                Text("Clear")
                    .font(.title)
                    .padding()
                    .background(Color.red)
                    .foregroundColor(.white)
                    .cornerRadius(10)
            })
            .padding()

            Text("Result: \(formattedResult)")
                .font(.title)
                .padding()
        }
        .padding()
    }

    func appendInput(_ character: String) {
        input += character
    }

    func performOperation(_ operation: Operation) {
        if let number = Double(input) {
            switch currentOperation {
            case .none:
                result = number
            case .addition:
                result += number
            case .subtraction:
                result -= number
            case .multiplication:
                result *= number
            case .division:
                result /= number
            }
        } else {
            result = 0
        }

        currentOperation = operation
        input = ""
    }

    func calculateResult() {
        if let number = Double(input) {
            switch currentOperation {
            case .none:
                result = number
            case .addition:
                result += number
            case .subtraction:
                result -= number
            case .multiplication:
                result *= number
            case .division:
                result /= number
            }
            input = String(result) // Die berechnete Zahl wird wieder in das Eingabefeld gesetzt
        } else {
            result = 0
        }

        currentOperation = .none
    }

    func clearInput() {
        input = ""
        result = 0
        currentOperation = .none
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}