//! Platform abstraction layer
//!
//! This module defines traits that each platform (web, desktop, mobile) must implement.
//! The traits make the platform boundary explicit and provide compile-time verification.
#![allow(async_fn_in_trait)]

use crate::{app::Command, effects::AudioProcessor};
use color_eyre::eyre::Error;
use dioxus::hooks::UnboundedReceiver;
use mumble_web2_common::{ProxyOverrides, ServerStatus};
use std::collections::HashMap;
use std::future::Future;
use std::time::Duration;

// ============================================================================
// Trait Definitions
// ============================================================================

/// Platform-specific audio subsystem for capturing microphone input and creating playback streams.
///
/// The audio system handles Opus encoding internally - callers receive encoded frames
/// ready for network transmission.
pub trait AudioSystemInterface: Sized {
    /// The player type returned by [`create_player`](Self::create_player).
    type AudioPlayer: AudioPlayerInterface;

    /// Initialize the audio system.
    async fn new() -> Result<Self, Error>;

    /// Set the processor for the microphone input, mainly noise cancellation settings.
    fn set_processor(&self, processor: AudioProcessor);

    /// Begin listening to microphone input, calling the `each` function with
    /// encoded opus frames.
    fn start_recording(
        &mut self,
        each: impl FnMut(Vec<u8>, bool) + Send + 'static,
    ) -> Result<(), Error>;

    /// Begin playback of an audio stream, returning an object that can be passed  opus frames.
    fn create_player(&mut self) -> Result<Self::AudioPlayer, Error>;
}

/// A handle to an active audio playback stream for a single remote user.
///
/// Each connected user gets their own `AudioPlayer` instance, which decodes
/// incoming Opus frames and outputs PCM audio to the platform's audio device.
/// The player manages its own decoder state and output buffer.
pub trait AudioPlayerInterface {
    /// Decode and play an Opus-encoded audio frame.
    fn play_opus(&mut self, payload: &[u8]);
}

pub trait ConfigSystemInterface: Sized {
    fn new() -> Result<Self, Error>;

    fn config_get<T>(&self, key: &str) -> Option<T>
    where
        T: serde::de::DeserializeOwned;

    fn config_set<T>(&self, key: &str, value: &T)
    where
        T: serde::Serialize;
}

/// This is the main trait that each platform must implement. It combines all
/// platform-specific functionality into a single interface, providing compile-time
/// verification that all platforms implement the required functionality.
pub trait PlatformInterface {
    type AudioSystem: AudioSystemInterface;
    type ConfigSystem: ConfigSystemInterface;

    /// Initialize logging for the platform.
    fn init_logging();

    /// Request runtime permissions (Android audio recording, etc.).
    fn request_permissions();

    /// Establish a connection to the Mumble server and run the network loop.
    fn network_connect(
        address: String,
        username: String,
        event_rx: &mut UnboundedReceiver<Command>,
        proxy_overrides: &ProxyOverrides,
    ) -> impl Future<Output = Result<(), Error>>;

    /// Get server status (user count, version, etc.).
    fn get_status(
        client: &reqwest::Client,
    ) -> impl Future<Output = color_eyre::Result<ServerStatus>>;

    /// Load the proxy overrides (proxy URL, cert hash, etc.).
    fn load_proxy_overrides() -> impl Future<Output = color_eyre::Result<ProxyOverrides>>;

    /// Async sleep for the given duration.
    fn sleep(duration: Duration) -> impl Future<Output = ()>;
}

// ============================================================================
// Platform Modules
// ============================================================================

mod stub;

#[cfg(any(feature = "desktop", feature = "mobile"))]
mod connect;
#[cfg(any(feature = "desktop", feature = "mobile"))]
mod native_audio;
#[cfg(any(feature = "desktop", feature = "mobile"))]
mod native_config;

#[cfg(feature = "desktop")]
mod desktop;

#[cfg(feature = "mobile")]
mod mobile;

#[cfg(feature = "web")]
mod web;

// ============================================================================
// Platform Type Alias
// ============================================================================

#[cfg(feature = "web")]
pub type Platform = web::WebPlatform;

#[cfg(all(feature = "desktop", not(feature = "web")))]
pub type Platform = desktop::DesktopPlatform;

#[cfg(all(feature = "mobile", not(feature = "web"), not(feature = "desktop")))]
pub type Platform = mobile::MobilePlatform;

#[cfg(all(
    not(feature = "mobile"),
    not(feature = "web"),
    not(feature = "desktop")
))]
pub type Platform = stub::StubPlatform;

pub type AudioSystem = <Platform as PlatformInterface>::AudioSystem;
pub type AudioPlayer = <AudioSystem as AudioSystemInterface>::AudioPlayer;

pub type ConfigSystem = <Platform as PlatformInterface>::ConfigSystem;

// ========================
// Platform Async Runtime
// ========================

// Note: these can not be part of the Platform because they differ in Send requiremets
#[cfg(all(any(feature = "desktop", feature = "mobile"), not(feature = "web")))]
pub use connect::{spawn, SpawnHandle};
#[cfg(all(
    not(feature = "desktop"),
    not(feature = "mobile"),
    not(feature = "web")
))]
pub use stub::{spawn, SpawnHandle};
#[cfg(feature = "web")]
pub use web::{spawn, SpawnHandle};

// =======================
// Compile-time Assertions
// =======================
const _: () = {
    fn assert_platform<T: PlatformInterface>() {}

    // Check each implementation, and prevent warnings that the implementations are unused.
    #[cfg(feature = "web")]
    let _ = assert_platform::<web::WebPlatform>;
    #[cfg(feature = "desktop")]
    let _ = assert_platform::<desktop::DesktopPlatform>;
    #[cfg(feature = "mobile")]
    let _ = assert_platform::<mobile::MobilePlatform>;
    let _ = assert_platform::<stub::StubPlatform>;
};

fn global_default_config() -> HashMap<String, serde_json::Value> {
    serde_json::json!({})
        .as_object()
        .unwrap()
        .clone()
        .into_iter()
        .collect()
}