/*
    wearechat - generic multiplayer game with voip
    Copyright (C) 2025 metamuffin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
#![feature(iter_array_chunks)]
#![allow(clippy::too_many_arguments, clippy::type_complexity)]
pub mod mesh;
pub mod physics;

use anyhow::{Result, anyhow};
use clap::Parser;
use gltf::{Gltf, Node, image::Source, import_buffers, scene::Transform};
use humansize::BINARY;
use image::{ImageReader, codecs::webp::WebPEncoder};
use log::{debug, info};
use mesh::import_mesh;
use physics::import_physics;
use rand::random;
use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
use std::{
    borrow::Cow,
    collections::HashMap,
    fs::File,
    io::{Cursor, Read, Write},
    marker::PhantomData,
    net::{SocketAddr, TcpStream},
    path::{Path, PathBuf},
    sync::{Arc, Mutex},
    thread::{self, sleep},
    time::Duration,
};
use weareshared::{
    Affine3A, Vec3A,
    helper::ReadWrite,
    packets::{Data, Object, Packet, Resource},
    resources::{Armature, EnvironmentPart, Image, LightPart, Prefab},
    store::ResourceStore,
    vec3a,
};

#[derive(Parser)]
pub struct Args {
    address: SocketAddr,
    /// Path(s) to a glTF file, binary or json format
    scene: Vec<PathBuf>,
    /// Send all resources to the server then quit
    #[arg(short, long)]
    push: bool,
    /// Spin the object
    #[arg(long)]
    spin: bool,
    /// Remove all other object from the world
    #[arg(short, long)]
    clear: bool,
    /// Add the object to the world
    #[arg(short, long)]
    add: bool,
    /// Transcode all textures to WebP
    #[arg(short, long)]
    webp: bool,
    /// Add skybox
    #[arg(long)]
    skybox: Option<PathBuf>,
    /// Override prefab name
    #[arg(short, long)]
    name: Option<String>,
    #[arg(short, long)]
    scale: Option<f32>,
    #[arg(short, long)]
    dry_run: bool,

    #[arg(long)]
    put_cache: bool,

    #[arg(long)]
    debug_light: bool,
}

fn main() -> Result<()> {
    env_logger::init_from_env("LOG");
    let args = Args::parse();

    let store = if args.put_cache {
        ResourceStore::new_env()?
    } else {
        ResourceStore::new_memory()
    };

    let mut prefabs = Vec::new();
    let texture_cache = Arc::new(Mutex::new(HashMap::new()));

    let mut root_affine = Affine3A::IDENTITY;
    root_affine.matrix3 *= args.scale.unwrap_or(1.);
    root_affine.translation *= args.scale.unwrap_or(1.);

    for scenepath in &args.scene {
        let path_base = scenepath.parent().unwrap();
        let mut gltf = Gltf::from_reader_without_validation(File::open(scenepath)?)?;
        let blob = gltf.blob.take();
        let buffers = import_buffers(&gltf, Some(path_base), blob)?;

        let root = gltf.default_scene().ok_or(anyhow!("no default scene"))?;

        let mut nodes = Vec::new();
        fn traverse<'a>(out: &mut Vec<(Affine3A, Node<'a>)>, node: Node<'a>, trans: Affine3A) {
            let trans = trans * transform_to_affine(node.transform());
            for c in node.children() {
                traverse(out, c, trans);
            }
            out.push((trans, node));
        }

        for node in root.nodes() {
            traverse(&mut nodes, node, root_affine);
        }

        let armatures = gltf
            .skins()
            .map(|skin| {
                if let Some(root) = skin.skeleton() {
                    fn traverse(
                        ars: &mut (&mut Vec<String>, &mut Vec<Affine3A>, &mut Vec<u16>),
                        trans: Affine3A,
                        parent: Option<u16>,
                        node: &Node,
                    ) {
                        let trans = trans * transform_to_affine(node.transform());
                        let ind = ars.0.len() as u16;
                        ars.0.push(node.name().unwrap_or("").to_owned());
                        ars.1.push(trans);
                        ars.2.push(parent.unwrap_or(ind));
                        for c in node.children() {
                            traverse(ars, trans, Some(ind), &c);
                        }
                    }
                    let mut name = Vec::new();
                    let mut transform = Vec::new();
                    let mut parent = Vec::new();
                    traverse(
                        &mut (&mut name, &mut transform, &mut parent),
                        Affine3A::IDENTITY,
                        None,
                        &root,
                    );
                    let armature = Armature {
                        name: Some(name),
                        parent: Some(parent),
                        transform: Some(transform),
                    };
                    // let armature = store.set(&armature)?;
                    // eprintln!("{armature:?}")
                    Ok::<_, anyhow::Error>(Some(armature))
                } else {
                    Ok::<_, anyhow::Error>(None)
                }
            })
            .collect::<Result<Vec<_>>>()?;

        eprintln!("{armatures:?}");

        let mut prefab = nodes
            .par_iter()
            .map(|(trans, node)| {
                let mut prefab = Prefab::default();

                if let Some(mesh) = node.mesh() {
                    import_mesh(
                        mesh,
                        *trans,
                        &buffers,
                        &store,
                        path_base,
                        node,
                        &mut prefab,
                        &args,
                        &texture_cache,
                        &armatures,
                    )?;
                }
                let (position, _, _) = node.transform().decomposed();
                if let Some(light) = node.light() {
                    let name = node.name().map(|e| e.to_owned());
                    if let Some(name) = &name {
                        info!("adding light {name:?}");
                    } else {
                        info!("adding light");
                    }
                    let emission = Some(Vec3A::from_array(light.color()) * light.intensity());
                    if let Some(e) = emission {
                        debug!("emission is {e}");
                    }
                    prefab.light.push((
                        Vec3A::from_array(position),
                        store.set(&LightPart {
                            emission,
                            name,
                            radius: None,
                        })?,
                    ));
                }
                import_physics(&gltf, *trans, node, &mut prefab, &store, &buffers)?;
                Ok::<_, anyhow::Error>(prefab)
            })
            .reduce(
                || Ok(Prefab::default()),
                |a, b| {
                    let mut a = a?;
                    let b = b?;
                    a.collision.extend(b.collision);
                    a.mesh.extend(b.mesh);
                    a.light.extend(b.light);
                    a.environment = a.environment.or(b.environment);
                    a.name = a.name.or(b.name);
                    Ok(a)
                },
            )?;

        if let Some(skybox) = &args.skybox {
            let mut buf = Vec::new();
            File::open(skybox)?.read_to_end(&mut buf)?;
            prefab.environment = Some(store.set(&EnvironmentPart {
                skybox: Some(store.set(&Image(Cow::Owned(buf)))?),
                ..Default::default()
            })?);
        }

        prefab.name = args.name.clone().or(gltf
            .default_scene()
            .and_then(|n| n.name())
            .map(|n| n.to_owned()));

        if args.debug_light {
            prefab.light.push((
                vec3a(5., 5., 5.),
                store.set(&LightPart {
                    name: Some("debug light".to_owned()),
                    emission: Some(vec3a(10., 5., 15.)),
                    radius: Some(0.3),
                })?,
            ));
        }

        prefabs.push(store.set(&prefab)?);
    }

    let mut size = 0;
    store.iter(|_k, len| size += len).unwrap();
    info!(
        "prefab has network size of {}",
        humansize::format_size(size, BINARY)
    );

    if args.dry_run {
        return Ok(());
    }

    let mut sock = TcpStream::connect(args.address)?;
    Packet::Connect(random()).write(&mut sock)?;
    for p in &prefabs {
        Packet::AnnouncePrefab(p.clone()).write(&mut sock)?;
    }
    sock.flush()?;

    let mut obs = Vec::new();
    if args.add {
        for p in &prefabs {
            let ob = Object::new();
            info!("adding object {ob}");
            Packet::Add(ob, p.clone()).write(&mut sock)?;
            obs.push(ob);
        }
        sock.flush()?;
    }

    if args.spin {
        let ob = obs[0];
        let mut sock2 = sock.try_clone().unwrap();
        thread::spawn(move || {
            let mut x = 0.;
            loop {
                Packet::Position(ob, Vec3A::ZERO, vec3a(0., x * 0.1, 0.))
                    .write(&mut sock2)
                    .unwrap();
                sock2.flush().unwrap();
                x += 0.1;
                sleep(Duration::from_millis(50));
            }
        });
    }

    if args.put_cache {
        return Ok(());
    }
    if args.push {
        store.iter(|k, _| {
            Packet::RespondResource(k, Data(store.get_raw(k).unwrap().unwrap()))
                .write(&mut sock)
                .unwrap();
        })?;
        sock.flush()?;
    } else {
        loop {
            let packet = Packet::read(&mut sock)?;
            match packet {
                Packet::RequestResource(hash) => {
                    if let Some(d) = store.get_raw(hash)? {
                        Packet::RespondResource(hash, Data(d)).write(&mut sock)?;
                        sock.flush()?;
                    }
                }
                Packet::Add(ob_a, _) => {
                    if args.clear && !obs.contains(&ob_a) {
                        info!("removing object {ob_a}");
                        Packet::Remove(ob_a).write(&mut sock)?;
                        sock.flush()?;
                    }
                }
                _ => (),
            }
        }
    }
    Ok(())
}

pub type TextureCache = Arc<Mutex<HashMap<String, Resource<Image<'static>>>>>;
fn load_texture(
    name: &str,
    store: &ResourceStore,
    path: &Path,
    buffers: &[gltf::buffer::Data],
    source: &Source,
    webp: bool,
    texture_cache: &TextureCache,
) -> Result<Resource<Image<'static>>> {
    let (mut image, uri) = match source {
        gltf::image::Source::View { view, mime_type } => {
            debug!("{name} texture is embedded and of type {mime_type:?}");
            let buf =
                &buffers[view.buffer().index()].0[view.offset()..view.offset() + view.length()];
            (Image(Cow::Borrowed(buf)), None)
        }
        gltf::image::Source::Uri {
            uri,
            mime_type: Some(mime_type),
        } => {
            debug!("{name} texture is {uri:?} and of type {mime_type:?}");
            if let Some(res) = texture_cache.lock().unwrap().get(*uri) {
                return Ok(res.to_owned());
            }
            let path = path.join(uri);
            let mut buf = Vec::new();
            File::open(path)?.read_to_end(&mut buf)?;
            (Image(buf.into()), Some(uri.to_string()))
        }
        gltf::image::Source::Uri {
            uri,
            mime_type: None,
        } => {
            debug!("{name} texture is {uri:?} and has no type");
            if let Some(res) = texture_cache.lock().unwrap().get(*uri) {
                return Ok(res.to_owned());
            }
            let path = path.join(uri);
            let mut buf = Vec::new();
            File::open(path)?.read_to_end(&mut buf)?;
            (Image(buf.into()), Some(uri.to_string()))
        }
    };

    if webp {
        let mut image_out = Vec::new();

        let len = image.0.len();
        ImageReader::new(Cursor::new(image.0))
            .with_guessed_format()?
            .decode()?
            .write_with_encoder(WebPEncoder::new_lossless(&mut image_out))?;
        debug!("webp encode: {len} -> {}", image_out.len());
        image = Image(Cow::Owned(image_out));
    }
    let res = Resource(store.set(&image)?.0, PhantomData);
    if let Some(uri) = uri {
        texture_cache.lock().unwrap().insert(uri, res.clone());
    }
    Ok(res)
}

pub fn transform_to_affine(trans: Transform) -> Affine3A {
    let mat = trans.matrix();
    Affine3A::from_cols_array_2d(&[
        [mat[0][0], mat[0][1], mat[0][2]],
        [mat[1][0], mat[1][1], mat[1][2]],
        [mat[2][0], mat[2][1], mat[2][2]],
        [mat[3][0], mat[3][1], mat[3][2]],
    ])
}