//
//  SettingsView.swift
//  USB Meter
//
//  Created by Bogdan Timofte on 14/03/2020.
//  Copyright © 2020 Bogdan Timofte. All rights reserved.
//

import SwiftUI

struct MeterSettingsView: View {
    
    @EnvironmentObject private var meter: Meter
    
    @State private var editingName = false
    @State private var editingScreenTimeout = false
    @State private var editingScreenBrightness = false

    var body: some View {
        ScrollView {
            VStack (spacing: 14) {
                settingsCard(title: "Name", tint: meter.color) {
                    HStack {
                        Spacer()
                        if !editingName {
                            Text(meter.name)
                                .foregroundColor(.secondary)
                        }
                        ChevronView(rotate: $editingName)
                    }
                    if editingName {
                        EditNameView(editingName: $editingName, newName: meter.name)
                    }
                }

                if meter.operationalState == .dataIsAvailable && meter.supportsManualTemperatureUnitSelection {
                    settingsCard(title: "Meter Temperature Unit", tint: .orange) {
                        Text("TC66 temperature is shown as degrees without assuming Celsius or Fahrenheit. Keep this matched to the unit configured on the device so you can interpret the reading correctly.")
                            .font(.footnote)
                            .foregroundColor(.secondary)
                        Picker("", selection: $meter.tc66TemperatureUnitPreference) {
                            ForEach(TemperatureUnitPreference.allCases) { unit in
                                Text(unit.title).tag(unit)
                            }
                        }
                        .pickerStyle(SegmentedPickerStyle())
                    }
                }

                if meter.operationalState == .dataIsAvailable && meter.supportsUMSettings {
                    settingsCard(title: "Screen Timeout", tint: .purple) {
                        HStack {
                            Spacer()
                            if !editingScreenTimeout {
                                Text(meter.screenTimeout != 0 ? "\(meter.screenTimeout) Minutes" : "Off")
                                    .foregroundColor(.secondary)
                            }
                            ChevronView(rotate: $editingScreenTimeout)
                        }
                        if editingScreenTimeout {
                            EditScreenTimeoutView()
                        }
                    }

                    settingsCard(title: "Screen Brightness", tint: .yellow) {
                        HStack {
                            Spacer()
                            if !editingScreenBrightness {
                                Text("\(meter.screenBrightness)")
                                    .foregroundColor(.secondary)
                            }
                            ChevronView(rotate: $editingScreenBrightness)
                        }
                        if editingScreenBrightness {
                            EditScreenBrightnessView()
                        }
                    }
                }
            }
            .padding()
        }
        .background(
            LinearGradient(
                colors: [meter.color.opacity(0.14), Color.clear],
                startPoint: .topLeading,
                endPoint: .bottomTrailing
            )
            .ignoresSafeArea()
        )
        .navigationBarTitle("Meter Settings")
        .navigationBarItems( trailing: RSSIView( RSSI: meter.btSerial.RSSI ).frame( width: 18, height: 18 ) )
    }

    private func settingsCard<Content: View>(
        title: String,
        tint: Color,
        @ViewBuilder content: () -> Content
    ) -> some View {
        VStack(alignment: .leading, spacing: 12) {
            Text(title)
                .font(.headline)
            content()
        }
        .padding(18)
        .meterCard(tint: tint, fillOpacity: 0.18, strokeOpacity: 0.24)
    }
}

struct EditNameView: View {
    
    @EnvironmentObject private var meter: Meter
    
    @Binding var editingName: Bool
    @State var newName: String
    
    var body: some View {
        TextField("Name", text: self.$newName, onCommit: {
            self.meter.name = self.newName
            self.editingName = false
        })
            .textFieldStyle(RoundedBorderTextFieldStyle())
            .lineLimit(1)
            .disableAutocorrection(true)
            .multilineTextAlignment(.center)
    }
}

struct EditScreenTimeoutView: View {
    
    @EnvironmentObject private var meter: Meter
    
    var body: some View {
        Picker("", selection: self.$meter.screenTimeout ) {
            Text("1").tag(1)
            Text("2").tag(2)
            Text("3").tag(3)
            Text("4").tag(4)
            Text("5").tag(5)
            Text("6").tag(6)
            Text("7").tag(7)
            Text("8").tag(8)
            Text("9").tag(9)
            Text("Off").tag(0)
        }
        .pickerStyle( SegmentedPickerStyle() )
    }
}

struct EditScreenBrightnessView: View {
    
    @EnvironmentObject private var meter: Meter
    
    var body: some View {
        Picker("", selection: self.$meter.screenBrightness ) {
            Text("0").tag(0)
            Text("1").tag(1)
            Text("2").tag(2)
            Text("3").tag(3)
            Text("4").tag(4)
            Text("5").tag(5)
        }
        .pickerStyle( SegmentedPickerStyle() )
    }
}
