// messages sent between the client and the server, as json over a websocket
import type { Faces } from "./constants.ts";
import type { ItemData } from "./inventory.ts";
import type { AtlasListing, ModListing } from "./mod_loader.ts";

export const AIR_ID = "bworld:air";

// bump when a client and server of different versions can't play together.
// the server rejects a different version before the client downloads anything
export const PROTOCOL_VERSION = 2;

export interface PlayerInfo {
	id: string;
	name: string;
	x: number;
	y: number;
	z: number;
	yaw: number;
	pitch: number;
}

// an entity that isn't a player, as the server first sends it. players have their own messages
export interface EntityInfo {
	kind: "item";
	id: string;
	x: number;
	y: number;
	z: number;
	item: ItemData;
}

// x, y, z, block id, and its state bits when they aren't 0
export type BlockChange = [number, number, number, string, number?];

// the containers a client can see and click. "screen" is whatever the open server screen shows
export type ContainerKey = "inventory" | "crafting" | "screen";

export const CRAFTING_RESULT_SLOT = 9;

// a screen the server opens, drawn below the player's inventory and hotbar
export interface ScreenLayout {
	// height of the screen's own area, in slots
	rows: number;
	// x and y in slots, can be fractional
	// output slots can only be taken from, like the furnace result
	slots: { index: number; x: number; y: number; output?: boolean }[];
	// progress bars filled from properties[value] / properties[max]
	bars: {
		x: number;
		y: number;
		value: string;
		max: string;
		direction: "up" | "right";
		empty_texture: string;
		full_texture: string;
	}[];
}

// clients send what the player is trying to do, the server decides what happens
export type ClientMessage =
	| { type: "hello"; name: string; protocol: number }
	// sent once the client has downloaded, checked and loaded everything in welcome
	| { type: "ready" }
	| { type: "move"; x: number; y: number; z: number; yaw: number; pitch: number }
	| { type: "break_block"; x: number; y: number; z: number }
	// the player started hitting a block, for on_click
	| { type: "hit_block"; x: number; y: number; z: number }
	// right click without looking at a block, for items' on_use
	| { type: "use_item" }
	// right click on a block: interact with it, or place the held block against `face`
	| { type: "use_block"; x: number; y: number; z: number; face: Faces }
	| { type: "select_slot"; slot: number }
	| { type: "click"; container: ContainerKey; index: number; button: number }
	// q on a slot (the held one when no screen is open) throws one item, or the whole stack with ctrl
	| { type: "drop_item"; container: ContainerKey; index: number; all: boolean }
	// closes the open screen, including the player's own inventory screen
	| { type: "close_screen" }
	| { type: "chat"; text: string };

export type ServerMessage =
	// what to download before joining, see "Delivery to clients" in MODS.md
	| {
		type: "welcome";
		protocol: number;
		seed: string;
		atlas: AtlasListing;
		// in load order, the client loads them before joining the world
		mods: ModListing[];
	}
	// the connection is closed right after
	| { type: "rejected"; reason: string }
	// answers ready, the player is in the world from here
	| {
		type: "join";
		id: string;
		// the server may change the name asked for, like alice to alice2
		name: string;
		players: PlayerInfo[];
		// items on the ground
		entities: EntityInfo[];
		changes: BlockChange[];
		spawn: { x: number; y: number; z: number; yaw: number; pitch: number };
		selected_slot: number;
	}
	| { type: "player_join"; player: PlayerInfo }
	| { type: "player_leave"; id: string }
	| { type: "player_move"; id: string; x: number; y: number; z: number; yaw: number; pitch: number }
	| { type: "add_entity"; entity: EntityInfo }
	| { type: "move_entity"; id: string; x: number; y: number; z: number }
	// a dropped item's stack changed, like when two stacks merge
	| { type: "set_entity_item"; id: string; item: ItemData }
	| { type: "remove_entity"; id: string }
	// a player picked up an item, it flies to them and goes away
	| { type: "take_entity"; id: string; player: string }
	// also sent to the player who caused it, which corrects anything their client predicted wrong
	| { type: "set_block"; x: number; y: number; z: number; id: string; state?: number }
	| { type: "chat"; from?: string; text: string }
	| { type: "teleport"; x: number; y: number; z: number }
	| { type: "container"; container: ContainerKey; items: (ItemData | null)[] }
	| { type: "cursor"; item: ItemData | null }
	| { type: "open_screen"; layout: ScreenLayout; properties: Record<string, number> }
	| { type: "screen_properties"; properties: Record<string, number> }
	| { type: "close_screen" };

export const MAX_NAME_LENGTH = 16;
export const MAX_CHAT_LENGTH = 256;