import { System } from "$/common/ecs/mod.ts";
import { Velocity } from "$/common/components/velocity.ts";
import { InputManager } from "../input_manager.ts";
import { ClientWorld } from "../client_world.ts";
import { PlayerControls } from "../components/player_controls.ts";
import { Camera } from "../components/camera.ts";
import { Position } from "../../common/components/position.ts";
import { PlayerComponent } from "../player.ts";
import { GuiPlayerInventory } from "../gui/gui_player_inventory.ts";
import { CollisionCuboid } from "../components/collision.ts";
import { BlockRegistry, EverythingRegistry, ItemRegistry } from "$/common/everything_registry.ts";
import { AIR, FACE_OFFSETS } from "$/common/constants.ts";
import { ClientMessage } from "$/common/protocol.ts";
import { GuiChat } from "../gui/gui_chat.ts";
import { GuiInventoryScreen } from "../gui/gui_screen.ts";

export class PlayerControlsSystem extends System {
	constructor() {
		super();
	}

	update(world: ClientWorld, delta: number): void {
		const [player] = world.get_tag("player")!;
		const velocity = player.get(Velocity)!;
		const controls = player.get(PlayerControls)!;
		const player_component = player.get(PlayerComponent)!;
		const position = player.get(Position)!;
		const camera = player.get(Camera)!;
		const send = (message: ClientMessage) => world.connection.send(message);

		if (player_component.screens.length === 0) {
			let input_x = 0;
			let input_z = 0;

			if (InputManager.is_key_down(controls.move_left)) {
				input_x -= 1;
			}
			if (InputManager.is_key_down(controls.move_right)) {
				input_x += 1;
			}
			if (InputManager.is_key_down(controls.move_forward)) {
				input_z -= 1;
			}
			if (InputManager.is_key_down(controls.move_backwards)) {
				input_z += 1;
			}

			const size = Math.hypot(input_x, input_z);
			if (size > 0) {
				input_x /= size;
				input_z /= size;
			}

			const sin = Math.sin(camera.yaw);
			const cos = Math.cos(camera.yaw);

			const forwardX = sin;
			const forwardZ = cos;

			const rightX = cos;
			const rightZ = -sin;

			const speed_modifier = InputManager.is_key_down(controls.sprint_key) ? 1.75 : 1;

			velocity.vx = (forwardX * input_z + rightX * input_x) * controls.move_speed * speed_modifier;
			velocity.vz = (forwardZ * input_z + rightZ * input_x) * controls.move_speed * speed_modifier;

			const cuboid = player.get(CollisionCuboid);

			if (InputManager.is_key_down("Space") && cuboid?.colliding_y === 1) {
				velocity.vy += controls.jump_force;
			}
		}

		if (InputManager.is_key_pressed(controls.open_inventory)) {
			if (player_component.screens.length === 0) {
				player_component.screens.push(new GuiPlayerInventory(player_component.inventories, send));
			} else if (player_component.screens.at(-1) instanceof GuiInventoryScreen) {
				player_component.pop_screen();
			}
		}

		if (InputManager.is_key_pressed(controls.open_chat)) {
			if (player_component.screens.length === 0) {
				player_component.screens.push(new GuiChat(world));
			}
		}

		if (InputManager.is_key_pressed("Escape")) {
			player_component.pop_screen();
		}

		if (InputManager.is_key_pressed(controls.open_debug)) {
			world.debugging = !world.debugging;
		}

		if (InputManager.is_key_pressed("F11")) {
			InputManager.toggle_fullscreen();
		}

		camera.x = position.x;
		camera.y = position.y + 1.69;
		camera.z = position.z;

		if (InputManager.is_mouse_grabbed()) {
			const mouse_delta = InputManager.get_mouse_delta();
			camera.yaw += -mouse_delta.x * 0.001;
			camera.pitch += -mouse_delta.y * 0.001;

			const limit = Math.PI / 2 - 0.01;
			camera.pitch = Math.max(-limit, Math.min(limit, camera.pitch));
		}

		InputManager.set_mouse_grabbed(player_component.screens.length === 0);

		if (InputManager.is_mouse_down(0) && player_component.screens.length === 0) {
			player_component.breaking_block = { x: 0, y: 9999, z: 0 };
		} else {
			player_component.breaking_block = undefined;
			player_component.break_progress_max = 0;
			player_component.break_progress = 0;
		}

		const block = world.dimension.get_looked_block(world.dimension, camera);
		const inventories = player_component.inventories;
		const hotbar_slot = inventories.inventory.get_slot(inventories.hotbar_selected);
		const holding_item_info = EverythingRegistry.get<ItemRegistry>("items", hotbar_slot.type_id ?? "");

		if (block && player_component.screens.length === 0) {
			const block_info = EverythingRegistry.get_by_id<BlockRegistry>("blocks", block.block)!;
			if (InputManager.is_mouse_pressed(0)) {
				// for mods' on_click, breaking itself is timed here and sent when done
				send({ type: "hit_block", x: block.x, y: block.y, z: block.z });
			}
			if (player_component.breaking_block) {
				player_component.breaking_block = { x: block.x, y: block.y, z: block.z };
				player_component.break_progress_max = block_info.toughness ?? 9999;
				let multiplier = 1;
				if (holding_item_info?.tool_type === block_info.tool_to_break) {
					multiplier *= 2;
				}
				player_component.break_progress += delta * multiplier;
				if (player_component.break_progress >= player_component.break_progress_max) {
					// show it right away, the server decides drops and corrects us if it disagrees
					world.dimension.break_block(block.x, block.y, block.z);
					send({ type: "break_block", x: block.x, y: block.y, z: block.z });
					player_component.break_progress_max = 0;
					player_component.break_progress = 0;
				}
			} else if (InputManager.is_mouse_pressed(2)) {
				send({ type: "use_block", x: block.x, y: block.y, z: block.z, face: block.face });

				// guess that it places the held block, unless the block does something when used
				const offset = FACE_OFFSETS[block.face];
				const target = { x: block.x + offset.x, y: block.y + offset.y, z: block.z + offset.z };
				const target_id = world.dimension.get_block(target.x, target.y, target.z);
				const replaceable = target_id === AIR ||
					EverythingRegistry.get_by_id<BlockRegistry>("blocks", target_id)?.replaceable;
				// items with components might do something else on the server, like on_use
				const place_id = holding_item_info?.components ? undefined : holding_item_info?.block_id;
				if (!block_info.interactive && place_id && replaceable) {
					world.dimension.add_block({ ...target, id: place_id });
					hotbar_slot.amount = hotbar_slot.amount! - 1;
				}
			}
		} else {
			player_component.breaking_block = undefined;
			player_component.break_progress_max = 0;
			player_component.break_progress = 0;
			if (!block && player_component.screens.length === 0 && InputManager.is_mouse_pressed(2)) {
				send({ type: "use_item" });
			}
		}

		if (player_component.screens.length === 0) {
			const previous = inventories.hotbar_selected;
			const scroll = InputManager.get_wheel_delta();
			if (scroll > 0) {
				inventories.hotbar_selected = Math.min(8, inventories.hotbar_selected + 1);
			} else if (scroll < 0) {
				inventories.hotbar_selected = Math.max(0, inventories.hotbar_selected - 1);
			}

			const hotbar_keys = [
				controls.hotbar_1,
				controls.hotbar_2,
				controls.hotbar_3,
				controls.hotbar_4,
				controls.hotbar_5,
				controls.hotbar_6,
				controls.hotbar_7,
				controls.hotbar_8,
				controls.hotbar_9,
			];
			const pressed = hotbar_keys.findIndex((key) => InputManager.is_key_pressed(key));
			if (pressed !== -1) {
				inventories.hotbar_selected = pressed;
			}

			if (inventories.hotbar_selected !== previous) {
				send({ type: "select_slot", slot: inventories.hotbar_selected });
			}
		}
	}
}