//
//  CandidatesViewModel.swift
//  iris
//
//  Created by Codex.
//

import CoreLocation
import Foundation
import os

@MainActor
final class CandidatesViewModel: ObservableObject {
    @Published private(set) var candidates: [Candidate] = []
    @Published private(set) var lastUpdatedAt: Date? = nil
    @Published private(set) var isLoading = false
    @Published private(set) var lastError: String? = nil
    @Published private(set) var diagnostics: [String: String] = [:]

    var demoLatitude: Double = 51.5074
    var demoLongitude: Double = -0.1278
    private let logger = Logger(subsystem: Bundle.main.bundleIdentifier ?? "iris", category: "CandidatesViewModel")

    func refresh() {
        guard !isLoading else { return }
        isLoading = true
        lastError = nil
        diagnostics = [:]

        let location = CLLocation(latitude: demoLatitude, longitude: demoLongitude)
        let now = Int(Date().timeIntervalSince1970)
        logger.info("Refresh start lat=\(self.demoLatitude, format: .fixed(precision: 4)) lon=\(self.demoLongitude, format: .fixed(precision: 4)) now=\(now)")

        Task {
            defer {
                Task { @MainActor in
                    self.isLoading = false
                    self.lastUpdatedAt = Date()
                }
            }

            if #available(iOS 16.0, *) {
                let ds = WeatherDataSource()
                let result = await ds.candidatesWithDiagnostics(for: location, now: now)
                await MainActor.run {
                    self.candidates = result.candidates.sorted { $0.confidence > $1.confidence }
                    self.diagnostics = result.diagnostics
                    if let error = result.weatherKitError {
                        self.lastError = "WeatherKit error: \(error)"
                    }
                }

                if let error = result.weatherKitError {
                    self.logger.error("WeatherKit error: \(error)")
                }
                self.logger.info("Produced candidates count=\(result.candidates.count)")
                for c in result.candidates {
                    self.logger.info("Candidate id=\(c.id, privacy: .public) type=\(c.type.rawValue, privacy: .public) conf=\(c.confidence, format: .fixed(precision: 2)) ttl=\(c.ttlSec) title=\(c.title, privacy: .public)")
                }
                if result.candidates.isEmpty {
                    self.logger.info("Diagnostics: \(String(describing: result.diagnostics), privacy: .public)")
                }
            } else {
                await MainActor.run {
                    self.candidates = []
                    self.lastError = "WeatherKit requires iOS 16+."
                }
            }
        }
    }
}