import Foundation
#if canImport(UIKit)
import UIKit
#endif

/// Swissapp Pushs — client iOS
/// CDN: https://sdk.pushs.swissapp.net/native/ios/SwissappPushs.swift
public final class SwissappPushs {
    public static let version = "1.0.0"
    public let apiKey: String
    public let apiURL: URL
    public var externalUserId: String?

    public init(
        apiKey: String,
        apiURL: URL = URL(string: "https://api.pushs.swissapp.net")!,
        externalUserId: String? = nil
    ) {
        self.apiKey = apiKey
        self.apiURL = apiURL
        self.externalUserId = externalUserId
    }

    public static func tokenHex(from deviceToken: Data) -> String {
        deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
    }

    @discardableResult
    public func register(deviceToken: Data, deviceName: String? = nil) async throws -> [String: Any] {
        #if canImport(UIKit)
        let name = deviceName ?? UIDevice.current.name
        let model = UIDevice.current.model
        #else
        let name = deviceName
        let model: String? = nil
        #endif
        let appVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String
        return try await register(
            pushToken: Self.tokenHex(from: deviceToken),
            platform: "ios",
            deviceName: name,
            deviceModel: model,
            appVersion: appVersion
        )
    }

    @discardableResult
    public func register(
        pushToken: String,
        platform: String = "ios",
        deviceName: String? = nil,
        deviceModel: String? = nil,
        appVersion: String? = nil,
        externalUserId: String? = nil
    ) async throws -> [String: Any] {
        var body: [String: Any] = [
            "push_token": pushToken,
            "platform": platform,
            "locale": Locale.current.identifier,
            "timezone": TimeZone.current.identifier
        ]
        if let ext = externalUserId ?? self.externalUserId { body["external_user_id"] = ext }
        if let deviceName { body["device_name"] = deviceName }
        if let deviceModel { body["device_model"] = deviceModel }
        if let appVersion { body["app_version"] = appVersion }
        return try await post(path: "/api/devices/register", body: body)
    }

    @discardableResult
    public func send(
        title: String? = nil,
        message: String,
        externalUserId: String? = nil,
        data: [String: Any]? = nil
    ) async throws -> [String: Any] {
        var body: [String: Any] = ["message": message]
        if let title { body["title"] = title }
        if let data { body["data"] = data }
        if let ext = externalUserId ?? self.externalUserId { body["external_user_id"] = ext }
        return try await post(path: "/api/send", body: body)
    }

    private func post(path: String, body: [String: Any]) async throws -> [String: Any] {
        let base = apiURL.absoluteString.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
        var req = URLRequest(url: URL(string: base + path)!)
        req.httpMethod = "POST"
        req.setValue("application/json", forHTTPHeaderField: "Content-Type")
        req.setValue("Bearer \(apiKey)", forHTTPHeaderField: "Authorization")
        req.setValue("ios/\(Self.version)", forHTTPHeaderField: "X-Swissapp-SDK")
        req.httpBody = try JSONSerialization.data(withJSONObject: body)

        let (data, response) = try await URLSession.shared.data(for: req)
        let http = response as? HTTPURLResponse
        let json = (try? JSONSerialization.jsonObject(with: data)) as? [String: Any] ?? [:]
        if let http, !(200...299).contains(http.statusCode) {
            let msg = json["error"] as? String ?? "HTTP \(http.statusCode)"
            throw NSError(domain: "SwissappPushs", code: http.statusCode, userInfo: [NSLocalizedDescriptionKey: msg])
        }
        if let ok = json["success"] as? Bool, ok == false {
            throw NSError(domain: "SwissappPushs", code: 400, userInfo: [NSLocalizedDescriptionKey: json["error"] as? String ?? "Erreur"])
        }
        return json
    }
}

/*
 // AppDelegate
 UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { _, _ in
   DispatchQueue.main.async { UIApplication.shared.registerForRemoteNotifications() }
 }

 func application(_ application: UIApplication,
                  didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
   Task {
     let push = SwissappPushs(apiKey: "pushs_…", externalUserId: "user_123")
     _ = try? await push.register(deviceToken: deviceToken)
   }
 }
*/