//
//  CBManagerState.swift
//  USB Meter
//
//  Created by Bogdan Timofte on 02/03/2020.
//  Copyright © 2020 Bogdan Timofte. All rights reserved.
//

//import Foundation

import CoreBluetooth
import SwiftUI

//Manager States
//.poweredOff   A state that indicates Bluetooth is currently powered off.
//.poweredOn    A state that indicates Bluetooth is currently powered on and available to use.
//.resetting    A state that indicates the connection with the system service was momentarily lost.
//.unauthorized A state that indicates the application isn’t authorized to use the Bluetooth low energy role.
//.unknown      The manager’s state is unknown.
//.unsupported  A state that indicates this device doesn’t support the Bluetooth low energy central or client role.

extension CBManagerState {
    var description: String  {
        switch self {
        case .poweredOff:
            return "CBManagerState.poweredOff"
        case .poweredOn:
            return "CBManagerState.poweredOn"
        case .resetting:
            return "CBManagerState.resetting"
        case .unauthorized:
            return "CBManagerState.unauthorized"
        case .unknown:
            return "CBManagerState.unknown"
        case .unsupported:
            return "CBManagerState.unsupported"
        default:
            return "CBManagerState.other"
        }
    }
    
    var color: Color  {
        switch self {
        case .poweredOff:
            return Color.red
        case .poweredOn:
            return Color.blue
        case .resetting:
            return Color.green
        case .unauthorized:
            return Color.orange
        case .unknown:
            return Color.secondary
        case .unsupported:
            return Color.gray
        default:
            return Color.yellow
        }
    }
    
    var helpView: AnyView  {
        switch self {
        case .poweredOff:
            return AnyView(poweredOffHelperView())
        case .poweredOn:
            return AnyView(poweredOnHelperView())
        case .resetting:
            return AnyView(resettingHelperView())
        case .unauthorized:
            return AnyView(unauthorizedHelperView())
        case .unknown:
            return AnyView(unknownHelperView())
        case .unsupported:
            return AnyView(unsupportedHelperView())
        default:
            return AnyView(defaultHelperView())
        }
    }
    
    private struct poweredOffHelperView: View {
        var body: some View {
            Text("Bluetooth is turned off on this device. Tou can turn it on in Settings->Bluetooth")
        }
    }
    private struct poweredOnHelperView: View {
        var body: some View {
            Text("Bluetooth is up an running")
        }
    }
    
    private struct resettingHelperView: View {
        var body: some View {
            VStack {
                Text("Bluetooth is resetting")
                Text("Maybe wait for a while...")
            }
        }
    }
    
    private struct unauthorizedHelperView: View {
        var body: some View {
            HStack {
                Text("This application does not have permission to access Bluetooth. You can give it in ")
                Button(action: { UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!, options: [:], completionHandler: nil) }) {
                    Text("Settings")
                }
            }
        }
    }
    
    private struct unknownHelperView: View {
        var body: some View {
            VStack {
            Text("Bluetooth state is unknown!")
            Text("There is no help available for this situation.")
            }
        }
    }
    
    private struct unsupportedHelperView: View {
        var body: some View {
            VStack {
            Text("Your device does not have required capabilities to establish Bluetooth connections with USB Meters")
            Text("There is no help available for this situation.")
            }
        }
    }
    
    private struct defaultHelperView: View {
        var body: some View {
            VStack {
                Text("Unknown Bluetooth state.")
                Text("You may contact develloper.")
            }
        }
    }
}