use std::io::{Write, Read};

use uuid::Uuid;

use crate::{ser::{Serializable, Deserializable}, varint::VarInt};

use super::{ServerPacket, ClientPacket, Protocol, ProtocolState, common::COMMON};

pub const VERSION: i32 = 763;

pub const PROTOCOL: Protocol = Protocol {
    name: "1.20.1",
    version: VERSION,
    encode,
    decode,
};

fn encode(mut w: Box<&mut dyn Write>, state: ProtocolState, ev: ServerPacket) -> anyhow::Result<()> {
    match ev {
        ServerPacket::LoginSuccess { name, uuid } => {
            VarInt(0x02).serialize(&mut w)?;
            uuid.serialize(&mut w)?;
            name.serialize(&mut w)?;
            // number of properties (0)
            VarInt(0x00).serialize(&mut w)?;
        },
        ServerPacket::JoinGame { eid, gamemode, hardcode } => {
            VarInt(0x28).serialize(&mut w)?;
            eid.serialize(&mut w)?;
            hardcode.serialize(&mut w)?;
            gamemode.serialize(&mut w)?;
            (-1i8).serialize(&mut w)?; // prev gamemode undefined
            VarInt(1).serialize(&mut w)?; // dimension count
            "qc:world".serialize(&mut w)?; // register one dimension
            include_bytes!("registry.nbt").serialize(&mut w)?; // registry codec
            "minecraft:the_end".serialize(&mut w)?; // dimension type
            "qc:world".serialize(&mut w)?; // dimension name
            0i64.serialize(&mut w)?; // seed
            VarInt(65535).serialize(&mut w)?; // max players
            VarInt(8).serialize(&mut w)?; // view dist
            VarInt(0).serialize(&mut w)?; // sim dist
            false.serialize(&mut w)?; // reduce debug info
            false.serialize(&mut w)?; // respawn screen
            false.serialize(&mut w)?; // is debug
            false.serialize(&mut w)?; // is flat
            false.serialize(&mut w)?; // has death location
            VarInt(1).serialize(&mut w)?; // portal cooldown
        },
        ServerPacket::KeepAlive(data) => {
            VarInt(0x23).serialize(&mut w)?;
            data.serialize(&mut w)?;
        },
        ServerPacket::PlayDisconnect(msg) => {
            VarInt(0x1A).serialize(&mut w)?;
            msg.serialize(&mut w)?;
        },
        ServerPacket::PluginMessage { channel, mut data } => {
            VarInt(0x17).serialize(&mut w)?;
            channel.serialize(&mut w)?;
            w.write_all(&mut data)?;
        },
        ServerPacket::ChunkData { x, z } => {
            VarInt(0x24).serialize(&mut w)?;
            // chunk x
            x.serialize(&mut w)?;
            // chunk z
            z.serialize(&mut w)?;
            // heightmap
            let hmdata = [0i64; 37];
            let mut heightmap = nbt::Blob::new();
            heightmap.insert("MOTION_BLOCKING", hmdata.as_ref()).unwrap();
            heightmap.serialize(&mut w)?;
            // chunk data
            let mut chunk_data: Vec<u8> = Vec::new();
            for _ in 0..(384 / 16) {
                // number of non-air blocks
                (0i16).serialize(&mut chunk_data)?;
                // block states
                (0u8).serialize(&mut chunk_data)?;
                VarInt(0).serialize(&mut chunk_data)?;
                VarInt(0).serialize(&mut chunk_data)?;
                // biomes
                (0u8).serialize(&mut chunk_data)?;
                VarInt(0).serialize(&mut chunk_data)?;
                VarInt(0).serialize(&mut chunk_data)?;
            }
            VarInt(chunk_data.len() as i32).serialize(&mut w)?;
            w.write_all(&chunk_data)?;
            // block entities
            VarInt(0).serialize(&mut w)?;
            // light masks
            VarInt(0).serialize(&mut w)?;
            VarInt(0).serialize(&mut w)?;
            VarInt(0).serialize(&mut w)?;
            VarInt(0).serialize(&mut w)?;
            // sky light array len
            VarInt(0).serialize(&mut w)?;
            // block light array len
            VarInt(0).serialize(&mut w)?;
        },
        ServerPacket::SetDefaultSpawn { pos, angle } => {
            VarInt(0x50).serialize(&mut w)?;
            pos.serialize(&mut w)?;
            angle.serialize(&mut w)?;
        },
        _ => { (COMMON.encode)(w, state, ev)?; }
    }
    Ok(())
}

fn decode(mut r: Box<&mut dyn Read>, state: ProtocolState, len: i32, id: i32) -> anyhow::Result<Option<ClientPacket>> {
    type Ps = ProtocolState;
    match (state, id) {
        (Ps::Login, 0x00) => {
            let name = String::deserialize(&mut r)?;
            let has_uuid = bool::deserialize(&mut r)?;
            let uuid = if has_uuid {
                Some(Uuid::deserialize(&mut r)?)
            } else { None };
            Ok(Some(ClientPacket::LoginStart { name, uuid }))
        }
        (Ps::Login, 0x01 | 0x02) => Ok(None), // unsupported
        (Ps::Play, 0x0D) => {
            let channel = String::deserialize(&mut r)?;
            let mut data = Vec::new();
            r.read_to_end(&mut data)?;
            Ok(Some(ClientPacket::PluginMessage { channel, data }))
        }
        (Ps::Play, 0x12) => {
            let data = i64::deserialize(&mut r)?;
            Ok(Some(ClientPacket::KeepAlive(data)))
        }
        (Ps::Play, 0x14 | 0x15 | 0x16) => Ok(None), // position & rotation
        _ => (COMMON.decode)(r, state, len, id)
    }
}