//
//  WebSocketClient.swift
//
//  Copyright 2026 Brendan Szymanski <hello@bscubed.dev>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
//
//  SPDX-License-Identifier: GPL-3.0-or-later
//

import Foundation

#if canImport(FoundationNetworking)
    import FoundationNetworking
#endif

public actor WebSocketClient {
    private var task: URLSessionWebSocketTask?
    private let session: URLSession
    private let serverURL: URL
    private let token: String
    private var isConnected = false

    public init(serverURL: URL, token: String) {
        self.serverURL = serverURL
        self.token = token
        self.session = URLSession(configuration: .default)
    }

    public func connect() {
        var components = URLComponents(url: serverURL, resolvingAgainstBaseURL: false)!
        components.scheme = serverURL.scheme == "https" ? "wss" : "ws"
        components.path = "/socket"
        components.queryItems = [.init(name: "api_key", value: token)]
        guard let url = components.url else { return }
        task = session.webSocketTask(with: url)
        task?.resume()
        isConnected = true
        receiveMessage()
    }

    public func disconnect() {
        task?.cancel(with: .goingAway, reason: nil)
        isConnected = false
    }

    private func receiveMessage() {
        task?.receive { [weak self] result in
            Task { [weak self] in
                switch result {
                case .success(let message):
                    await self?.handleMessage(message)
                    await self?.receiveMessage()
                case .failure:
                    await self?.reconnect()
                }
            }
        }
    }

    private func handleMessage(_ message: URLSessionWebSocketTask.Message) {
        switch message {
        case .string(let text):
            guard let data = text.data(using: .utf8),
                let event = try? JSONDecoder().decode(WebSocketEvent.self, from: data)
            else { return }
            Task { @MainActor in
                NotificationCenter.default.post(
                    name: .init(event.messageType),
                    object: event
                )
            }
        case .data:
            break
        @unknown default:
            break
        }
    }

    private func reconnect() async {
        guard isConnected else { return }
        try? await Task.sleep(nanoseconds: 5_000_000_000)
        connect()
    }
}

public struct WebSocketEvent: Decodable {
    public let messageType: String
    public let data: [String: AnyDecodable]?
}

public struct AnyDecodable: Decodable {
    public var value: Any

    public init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        if let intVal = try? container.decode(Int.self) {
            value = intVal
        } else if let doubleVal = try? container.decode(Double.self) {
            value = doubleVal
        } else if let boolVal = try? container.decode(Bool.self) {
            value = boolVal
        } else if let stringVal = try? container.decode(String.self) {
            value = stringVal
        } else if let arrayVal = try? container.decode([AnyDecodable].self) {
            value = arrayVal.map(\.value)
        } else if let dictVal = try? container.decode([String: AnyDecodable].self) {
            value = dictVal.mapValues(\.value)
        } else {
            throw DecodingError.dataCorrupted(
                .init(codingPath: container.codingPath, debugDescription: "AnyDecodable error"))
        }
    }
}