import SwiftUI
import SFSafeSymbols

private let df: DateFormatter = {
    let df = DateFormatter()
    df.locale = .current
    df.dateStyle = .short
    df.timeStyle = .short
    return df
}()

struct DeviceInfoView: View {

    private let storageWarnBytes = 500
    
    let info: DeviceInfo

    @Binding
    var isPresented: Bool

    private var runTimeString: String {
        let number = info.time.secondsSincePowerOn
        guard number >= 60 else {
            return "\(number) s"
        }
        let minutes = number / 60
        guard minutes > 1 else {
            return "1 min"
        }
        guard minutes >= 60 else {
            return "\(minutes) min"
        }
        let hours = minutes / 60
        guard hours > 1 else {
            return "1 hour"
        }
        guard hours >= 60 else {
            return "\(hours) hours"
        }
        let days = hours / 24
        guard days > 1 else {
            return "1 day"
        }
        return "\(days) days"
    }
    
    private var nextUpdateText: String {
        let secs = info.time.nextMeasurement.secondsToNow
        guard secs > 1 else {
            return "Now"
        }
        return "In \(secs) s"
    }
    
    private var storageIcon: SFSymbol {
        if info.storageSize - info.numberOfRecordedBytes < storageWarnBytes {
            return .externaldriveTrianglebadgeExclamationmark
        }
        return .externaldrive
    }
    
    private var storageText: String {
        if info.storageSize <= 0 {
            return "\(info.numberOfRecordedBytes)"
        }
        return "\(info.numberOfRecordedBytes) / \(info.storageSize) Bytes (\(info.storageFillPercentage) %)"
    }
    
    func sensorView(_ sensor: TemperatureSensor?, id: Int) -> some View {
            VStack(alignment: .leading, spacing: 5) {
                Text("Sensor \(id)")
                    .font(.headline)
                if let sensor {
                    IconAndTextView(
                        icon: sensor.temperatureIcon,
                        text: "\(sensor.temperatureText) (\(sensor.updateText))")
                    IconAndTextView(
                        icon: .tag,
                        text: sensor.hexAddress)
                } else {
                    IconAndTextView(
                        icon: .thermometerMediumSlash,
                        text: "Not connected")
                }
            }
    }
    
    var updateText: String {
        guard info.time.date.secondsToNow > 3 else {
            return "Updated Now"
        }
        return "Updated \(info.time.date.timePassedText)"
    }
    
    var body: some View {
        NavigationView {
            VStack(alignment: .leading, spacing: 5) {
                VStack(alignment: .leading, spacing: 5) {
                    Text("System")
                        .font(.headline)
                    IconAndTextView(
                        icon: .power,
                        text: "\(df.string(from: info.time.deviceStartTime)) (\(runTimeString))")
                    IconAndTextView(
                        icon: .autostartstop,
                        text: "Wakeup: \(info.wakeupReason.text)")
                }
                VStack(alignment: .leading, spacing: 5) {
                    Text("Recording")
                        .font(.headline)
                    IconAndTextView(
                        icon: .stopwatch,
                        text: "\(nextUpdateText) (Every \(info.measurementInterval) s)")
                }
                VStack(alignment: .leading, spacing: 5) {
                    Text("Storage")
                        .font(.headline)
                    IconAndTextView(
                        icon: .speedometer,
                        text: "\(info.numberOfStoredMeasurements) Measurements (\(info.time.totalNumberOfMeasurements) total)")
                    IconAndTextView(
                        icon: storageIcon,
                        text: storageText)
                    IconAndTextView(
                        icon: .iphoneAndArrowForward,
                        text: "\(info.transferBlockSize) Byte Block Size")
                }
                sensorView(info.sensor0, id: 0)
                sensorView(info.sensor1, id: 1)
                Spacer()
                HStack {
                    Spacer()
                    TimelineView(.periodic(from: Date(), by: 1)) { context in
                        Text(updateText)
                            .font(.footnote)
                            .textCase(.uppercase)
                    }
                    Spacer()
                }
            }
            .padding()
            .navigationTitle("Device Info")
            .navigationBarTitleDisplayMode(.large)
        }
    }
}

struct DeviceInfoView_Previews: PreviewProvider {
    static var previews: some View {
        DeviceInfoView(info: .mock, isPresented: .constant(true))
    }
}