extern crate crossbeam_channel;
extern crate ferretro_components;
#[cfg(feature = "ffmpeg_comp")]
extern crate ffmpeg_next as ffmpeg;
extern crate sdl2;

use std::path::PathBuf;
use sdl2::video::FullscreenType;
use structopt::StructOpt;

use ferretro_components::base::ControlFlow;
use ferretro_components::prelude::*;
use ferretro_components::provided::{
    sdl2::*,
    stdlib::*,
};
#[cfg(feature = "ffmpeg_comp")]
use ferretro_components::provided::ffmpeg::FfmpegComponent;

#[derive(StructOpt)]
struct Opt {
    /// Core module to use.
    #[structopt(short, long, parse(from_os_str))]
    core: PathBuf,
    /// ROM to load using the core.
    #[structopt(parse(from_os_str))]
    rom: PathBuf,
    /// Save state to load at startup.
    #[structopt(long, parse(from_os_str))]
    state: Option<PathBuf>,
    /// System directory, often containing BIOS files
    #[structopt(short, long, parse(from_os_str))]
    system: Option<PathBuf>,
    /// Recorded video to write.
    #[cfg(feature = "ffmpeg_comp")]
    #[structopt(long, parse(from_os_str))]
    record_video: Option<PathBuf>,
    /// Disable OpenGL context creation.
    #[structopt(long)]
    no_opengl: bool,
    /// Fullscreen (borderless).
    #[structopt(short, long)]
    fullscreen: bool,
    /// Print core-provided system information to stderr.
    #[structopt(long)]
    sys_info: bool,
    /// Trace all API calls to stderr.
    #[structopt(long)]
    trace_api: bool,
}

pub fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let opt: Opt = Opt::from_args();

    let mut emu = RetroComponentBase::new(&opt.core);

    let mut sdl_context = sdl2::init()?;

    let mut stderr_log = StderrLogComponent::default();
    stderr_log.prefix = "{log} ".to_string();
    emu.register_component(stderr_log)?;

    let mut stderr_msg = StderrMessageComponent::default();
    stderr_msg.prefix = "{message} ".to_string();
    emu.register_component(stderr_msg)?;

    if opt.trace_api {
        emu.register_component(StderrCallTraceComponent { prefix: "{trace} ".to_string() })?;
    }

    // must register before opengl so it can have priority in queries about what N64 plugin to use
    // (only supports software-rendered 2D frames currently)
    #[cfg(feature = "ffmpeg_comp")]
    if let Some(video_path) = opt.record_video {
        ffmpeg::log::set_level(ffmpeg::log::Level::Info);
        ffmpeg::init()?;
        let ffmpeg_comp = FfmpegComponent::new(emu.libretro_core(), video_path);
        emu.register_component(ffmpeg_comp)?;
    }

    let ft = if opt.fullscreen {
        FullscreenType::Desktop
    } else {
        FullscreenType::Off
    };

    let sdl2_ogl_res = if opt.no_opengl {
        Err("OpenGL disabled".into())
    } else {
        SimpleSdl2OpenglComponent::new(&mut sdl_context, ft)
    };

    if let Ok(sdl2_ogl) = sdl2_ogl_res {
        emu.register_component(sdl2_ogl)?;
    } else {
        match SimpleSdl2CanvasComponent::new(&mut sdl_context, ft) {
            Ok(sdl2_canvas) => emu.register_component(sdl2_canvas)?,
            Err(e) => eprintln!("Couldn't initialize SDL2 video component: {:?}", e),
        }
    }

    emu.register_component(Sdl2RateControlledAudioComponent::new(&mut sdl_context)?)?;

    emu.register_component(SimpleSdl2KeyboardComponent::new(&mut sdl_context)?)?;
    emu.register_component(SimpleSdl2GamepadComponent::new(&mut sdl_context))?;

    emu.register_component(SleepFramerateLimitComponent::default())?;

    emu.register_component(PathBufComponent {
        sys_path: opt.system.clone(),
        libretro_path: Some(opt.core.to_path_buf()),
        core_assets_path: None,
        save_path: Some(std::env::temp_dir()),
    })?;

    emu.register_component(LocalFileSaveComponent::default())?;

    if opt.sys_info {
        emu.register_component(StderrSysInfoLogComponent::default())?;
    }

    emu.register_component(EnvironmentVariableComponent::default())?;

    let mut var_store = VariableStoreComponent::default();
    // TODO: load a config file specified on the CLI
    var_store.insert("mgba_skip_bios", "ON");
    var_store.insert("gpsp_drc", "enabled");
    var_store.insert("gpsp_frame_mixing", "enabled");
    var_store.insert("gpsp_save_method", "libretro");
    emu.register_component(var_store)?;

    emu.init()?;
    emu.load_game(&opt.rom)?;
    if let Some(state) = opt.state {
        emu.unserialize_path(state)?;
    }

    let mut frame = 0u64;
    while let ControlFlow::Continue = emu.run() {
        frame = frame.wrapping_add(1);
    }

    eprintln!("Ran for {} frames.", frame);
    Ok(())
}