import EnergyKit

import EnergyKit

func observeGuidance(venueID: UUID) async throws {
    let query = ElectricityGuidance.Query(suggestedAction: .shift)
    let service = ElectricityGuidance.sharedService  // Verify access pattern against Xcode 26 SDK

    let guidanceStream = service.guidance(using: query, at: venueID)

    for try await guidance in guidanceStream {
        print("Guidance token: \(guidance.guidanceToken)")
        print("Interval: \(guidance.interval)")
        print("Venue: \(guidance.energyVenueID)")

        // Check if rate plan information is available
        if guidance.options.contains(.guidanceIncorporatesRatePlan) {
            print("Rate plan data incorporated")
        }
        if guidance.options.contains(.locationHasRatePlan) {
            print("Location has a rate plan")
        }

        processGuidanceValues(guidance.values)
    }
}

func processGuidanceValues(_ values: [ElectricityGuidance.Value]) {
    for value in values {
        let interval = value.interval
        let rating = value.rating  // 0.0 (best) to 1.0 (worst)

        print("From \(interval.start) to \(interval.end): rating \(rating)")
    }
}

// Find the best time to charge
func bestChargingWindow(
    in values: [ElectricityGuidance.Value]
) -> ElectricityGuidance.Value? {
    values.min(by: { $0.rating < $1.rating })
}

// Find all "good" windows below a threshold
func goodWindows(
    in values: [ElectricityGuidance.Value],
    threshold: Double = 0.3
) -> [ElectricityGuidance.Value] {
    values.filter { $0.rating <= threshold }
}

import SwiftUI
import EnergyKit

struct GuidanceTimelineView: View {
    let values: [ElectricityGuidance.Value]

    var body: some View {
        List(values, id: \.interval.start) { value in
            HStack {
                VStack(alignment: .leading) {
                    Text(value.interval.start, style: .time)
                    Text(value.interval.end, style: .time)
                        .foregroundStyle(.secondary)
                }
                Spacer()
                RatingIndicator(rating: value.rating)
            }
        }
    }
}

struct RatingIndicator: View {
    let rating: Double

    var color: Color {
        if rating <= 0.3 { return .green }
        if rating <= 0.6 { return .yellow }
        return .red
    }

    var label: String {
        if rating <= 0.3 { return "Good" }
        if rating <= 0.6 { return "Fair" }
        return "Avoid"
    }

    var body: some View {
        Text(label)
            .padding(.horizontal, 8)
            .padding(.vertical, 4)
            .background(color.opacity(0.2))
            .foregroundStyle(color)
            .clipShape(Capsule())
    }
}

// List all venues
func listVenues() async throws -> [EnergyVenue] {
    try await EnergyVenue.venues()
}

// Get a specific venue by ID
func getVenue(id: UUID) async throws -> EnergyVenue {
    try await EnergyVenue.venue(for: id)
}

// Get a venue matching a HomeKit home
func getVenueForHome(homeID: UUID) async throws -> EnergyVenue {
    try await EnergyVenue.venue(matchingHomeUniqueIdentifier: homeID)
}

let venue = try await EnergyVenue.venue(for: venueID)
print("Venue ID: \(venue.id)")
print("Venue name: \(venue.name)")

func submitEVChargingEvent(
    at venue: EnergyVenue,
    guidanceToken: UUID,
    deviceID: String
) async throws {
    let session = ElectricVehicleLoadEvent.Session(
        id: UUID(),
        state: .begin,
        guidanceState: ElectricVehicleLoadEvent.Session.GuidanceState(
            wasFollowingGuidance: true,
            guidanceToken: guidanceToken
        )
    )

    let measurement = ElectricVehicleLoadEvent.ElectricalMeasurement(
        stateOfCharge: 45,
        direction: .imported,
        power: Measurement(value: 7.2, unit: .kilowatts),
        energy: Measurement(value: 0, unit: .kilowattHours)
    )

    let event = ElectricVehicleLoadEvent(
        timestamp: Date(),
        measurement: measurement,
        session: session,
        deviceID: deviceID
    )

    try await venue.submitEvents([event])
}

func submitHVACEvent(
    at venue: EnergyVenue,
    guidanceToken: UUID,
    stage: Int,
    deviceID: String
) async throws {
    let session = ElectricHVACLoadEvent.Session(
        id: UUID(),
        state: .active,
        guidanceState: ElectricHVACLoadEvent.Session.GuidanceState(
            wasFollowingGuidance: true,
            guidanceToken: guidanceToken
        )
    )

    let measurement = ElectricHVACLoadEvent.ElectricalMeasurement(stage: stage)

    let event = ElectricHVACLoadEvent(
        timestamp: Date(),
        measurement: measurement,
        session: session,
        deviceID: deviceID
    )

    try await venue.submitEvents([event])
}

func queryEnergyInsights(deviceID: String, venueID: UUID) async throws {
    let query = ElectricityInsightQuery(
        options: [.cleanliness, .tariff],
        range: DateInterval(
            start: Calendar.current.date(byAdding: .day, value: -7, to: Date())!,
            end: Date()
        ),
        granularity: .daily,
        flowDirection: .imported
    )

    let service = ElectricityInsightService.shared
    let stream = try await service.energyInsights(
        forDeviceID: deviceID, using: query, atVenue: venueID
    )

    for await record in stream {
        if let total = record.totalEnergy { print("Total: \(total)") }
        if let cleaner = record.dataByGridCleanliness?.cleaner {
            print("Cleaner: \(cleaner)")
        }
    }
}

// WRONG: No entitlement configured
let service = ElectricityGuidance.sharedService  // Will fail

// CORRECT: Add com.apple.developer.energykit to entitlements
// Then use the service
let service = ElectricityGuidance.sharedService

// WRONG: Assume guidance is always available
for try await guidance in service.guidance(using: query, at: venueID) {
    updateUI(guidance)
}

// CORRECT: Handle region-specific errors
do {
    for try await guidance in service.guidance(using: query, at: venueID) {
        updateUI(guidance)
    }
} catch let error as EnergyKitError {
    switch error {
    case .unsupportedRegion:
        showUnsupportedRegionMessage()
    case .guidanceUnavailable:
        showGuidanceUnavailableMessage()
    case .venueUnavailable:
        showNoVenueMessage()
    case .permissionDenied:
        showPermissionDeniedMessage()
    case .serviceUnavailable:
        retryLater()
    case .rateLimitExceeded:
        backOff()
    default:
        break
    }
}

// WRONG: Ignore the guidance token
for try await guidance in guidanceStream {
    startCharging()
}

// CORRECT: Store the token for load events
for try await guidance in guidanceStream {
    let token = guidance.guidanceToken
    startCharging(followingGuidanceToken: token)
}

// WRONG: Only submit one event
let event = ElectricVehicleLoadEvent(/* state: .active */)
try await venue.submitEvents([event])

// CORRECT: Full session lifecycle
try await venue.submitEvents([beginEvent])
// ... periodic active events ...
try await venue.submitEvents([activeEvent])
// ... when done ...
try await venue.submitEvents([endEvent])

// WRONG: Use a hardcoded UUID
let fakeID = UUID()
service.guidance(using: query, at: fakeID)  // Will fail

// CORRECT: Discover venues first
let venues = try await EnergyVenue.venues()
guard let venue = venues.first else {
    showNoVenueSetup()
    return
}
let guidanceStream = service.guidance(using: query, at: venue.id)