package basic

import (
	"unsafe"

	"github.com/Tnze/go-mc/data/packetid"
	pk "github.com/Tnze/go-mc/net/packet"
)

// WorldInfo content player info in server.
type WorldInfo struct {
	DimensionCodec struct {
		DimensionType interface{} `nbt:"minecraft:dimension_type"`
		WorldgenBiome interface{} `nbt:"minecraft:worldgen/biome"`
	}
	Dimension           interface{}
	WorldNames          []string // Identifiers for all worlds on the server.
	WorldName           string   // Name of the world being spawned into.
	HashedSeed          int64    // First 8 bytes of the SHA-256 hash of the world's seed. Used client side for biome noise
	MaxPlayers          int32    // Was once used by the client to draw the player list, but now is ignored.
	ViewDistance        int32    // Render distance (2-32).
	ReducedDebugInfo    bool     // If true, a Notchian client shows reduced information on the debug screen. For servers in development, this should almost always be false.
	EnableRespawnScreen bool     // Set to false when the doImmediateRespawn gamerule is true.
	IsDebug             bool     // True if the world is a debug mode world; debug mode worlds cannot be modified and have predefined blocks.
	IsFlat              bool     // True if the world is a superflat world; flat worlds have different void fog and a horizon at y=0 instead of y=63.
}

type PlayerInfo struct {
	EID          int32 // The player's Entity ID (EID).
	Hardcore     bool  // Is hardcore
	Gamemode     byte  // Gamemode. 0: Survival, 1: Creative, 2: Adventure, 3: Spectator.
	PrevGamemode int8  // Previous Gamemode
}

// ServInfo contains information about the server implementation.
type ServInfo struct {
	Brand string
}

func (p *Player) handleJoinGamePacket(packet pk.Packet) error {
	var WorldCount pk.VarInt
	var WorldNames = make([]pk.Identifier, 0)
	err := packet.Scan(
		(*pk.Int)(&p.EID),
		(*pk.Boolean)(&p.Hardcore),
		(*pk.UnsignedByte)(&p.Gamemode),
		(*pk.Byte)(&p.PrevGamemode),
		&WorldCount,
		pk.Ary{Len: &WorldCount, Ary: &WorldNames},
		pk.NBT(new(interface{})),
		pk.NBT(new(interface{})),
		(*pk.Identifier)(&p.WorldName),
		(*pk.Long)(&p.HashedSeed),
		(*pk.VarInt)(&p.MaxPlayers),
		(*pk.VarInt)(&p.ViewDistance),
		(*pk.Boolean)(&p.ReducedDebugInfo),
		(*pk.Boolean)(&p.EnableRespawnScreen),
		(*pk.Boolean)(&p.IsDebug),
		(*pk.Boolean)(&p.IsFlat),
	)
	if err != nil {
		return Error{err}
	}

	// This line should work "like" the following code but without copy things
	//	p.WorldNames = make([]string, len(WorldNames))
	//	for i, v := range WorldNames {
	//		p.WorldNames[i] = string(v)
	//	}
	p.WorldNames = *(*[]string)(unsafe.Pointer(&WorldNames))

	err = p.c.Conn.WritePacket(pk.Marshal( //PluginMessage packet
		packetid.CustomPayloadServerbound,
		pk.Identifier("minecraft:brand"),
		pk.String(p.Settings.Brand),
	))
	if err != nil {
		return Error{err}
	}

	err = p.c.Conn.WritePacket(pk.Marshal(
		packetid.Settings, // Client settings
		pk.String(p.Settings.Locale),
		pk.Byte(p.Settings.ViewDistance),
		pk.VarInt(p.Settings.ChatMode),
		pk.Boolean(p.Settings.ChatColors),
		pk.UnsignedByte(p.Settings.DisplayedSkinParts),
		pk.VarInt(p.Settings.MainHand),
	))
	if err != nil {
		return Error{err}
	}
	return nil
}