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

/// https://discord.com/developers/docs/topics/gateway#gateway-intents
public struct Intents: OptionSet, Sendable {
    public var rawValue: UInt32

    public static let guilds = Intents(rawValue: 1 << 0)
    public static let guildMembers = Intents(rawValue: 1 << 1)
    public static let guildModeration = Intents(rawValue: 1 << 2)
    public static let guildEmojisAndStickers = Intents(rawValue: 1 << 3)
    public static let guildIntegrations = Intents(rawValue: 1 << 4)
    public static let guildWebhooks = Intents(rawValue: 1 << 5)
    public static let guildInvites = Intents(rawValue: 1 << 6)
    public static let guildVoiceStates = Intents(rawValue: 1 << 7)
    public static let guildPresences = Intents(rawValue: 1 << 8)
    public static let guildMessages = Intents(rawValue: 1 << 9)
    public static let guildMessageReactions = Intents(rawValue: 1 << 10)
    public static let guildMessageTyping = Intents(rawValue: 1 << 11)
    public static let directMessages = Intents(rawValue: 1 << 12)
    public static let directMessageReactions = Intents(rawValue: 1 << 13)
    public static let directMessageTyping = Intents(rawValue: 1 << 14)
    public static let messageContent = Intents(rawValue: 1 << 15)
    public static let guildScheduledEvents = Intents(rawValue: 1 << 16)
    public static let autoModerationConfiguration = Intents(rawValue: 1 << 20)
    public static let autoModerationExecution = Intents(rawValue: 1 << 21)
    public static let guildMessagePolls = Intents(rawValue: 1 << 24)
    public static let directMessagePolls = Intents(rawValue: 1 << 25)

    public init(rawValue: UInt32) {
        self.rawValue = rawValue
    }
}

public struct GetGatewayResponse: Codable, Sendable {
    let url: URL
    let shards: Int
    let session_start_limit: SessionStartLimit
}

public struct SessionStartLimit: Codable, Sendable {
    let total: Int
    let remaining: Int
    let reset_after: Int
    let max_concurrency: Int
}

public enum GatewayPayload: Decodable, Sendable {
    case hello(HelloPayload)
}

public struct GatewayMessage: Decodable, Sendable {
    let op: Int
    let d: GatewayPayload?
    let s: Int?
    let t: String?

    enum CodingKeys: String, CodingKey {
        case t
        case s
        case op
        case d
    }

    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        op = try container.decode(Int.self, forKey: .op)
        s = try container.decode(Int?.self, forKey: .s)
        t = try container.decode(String?.self, forKey: .t)
        switch op {
            case 10:
                let hello = try container.decode(HelloPayload.self, forKey: .d)
                d = .hello(hello)
            default:
                d = nil
                break
        }
    }

    public init(op: Int, d: GatewayPayload?, s: Int?, t: String?) {
        self.op = op
        self.d = d
        self.s = s
        self.t = t
    }
}

public struct HelloPayload: Codable, Sendable {
    let heartbeat_interval: Int
}