import { assert, assertEquals } from "@std/assert";
import { bake_model, block_variant, BUILTIN_MODELS, type ModelJson, resolve_texture } from "$/common/block_models.ts";
import { block_from_json } from "$/common/mod_data.ts";
import { set_state_value } from "$/common/utils.ts";

const cube = BUILTIN_MODELS["engine:cube"];

Deno.test("cubes resolve the old texture shapes", () => {
	assertEquals(resolve_texture("#top", "a:all", cube), "a:all");
	const pillar = { top: "a:top", bottom: "a:bottom", side: "a:side" };
	assertEquals(["#top", "#bottom", "#front", "#side"].map((t) => resolve_texture(t, pillar, cube)), [
		"a:top",
		"a:bottom",
		"a:side",
		"a:side",
	]);
	const furnace = { front: "a:front", side: "a:side" };
	assertEquals(["#top", "#bottom", "#front"].map((t) => resolve_texture(t, furnace, cube)), [
		"a:side",
		"a:side",
		"a:front",
	]);
	assertEquals(resolve_texture("#nothing", { crop: "a:crop" }), "engine:missing");
});

Deno.test("a cube bakes into six full faces that cull against their neighbors", () => {
	const quads = bake_model(cube, "a:all");
	assertEquals(quads.length, 6);
	assert(quads.every((q) => q.flush && q.cull === q.face && q.texture === "a:all"));
	// the top face, corners and uvs like the mesher always had
	assertEquals(quads[0].positions, [0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0]);
	assertEquals(quads[0].uvs, [0, 16, 16, 16, 16, 0, 0, 0]);
});

Deno.test("crop and cross models are planes inside the block, seen from both sides", () => {
	const crop = bake_model(BUILTIN_MODELS["engine:crop"], { crop: "a:wheat" });
	assertEquals(crop.length, 8);
	assert(crop.every((q) => !q.flush && q.cull === -1 && !q.shade && q.texture === "a:wheat"));
	assertEquals(crop[0].positions.filter((_, i) => i % 3 === 0), [0.25, 0.25, 0.25, 0.25]);

	const cross = bake_model(BUILTIN_MODELS["engine:cross"], { cross: "a:flower" });
	assertEquals(cross.length, 4);
	// rescaled so the diagonal planes stay as wide as the block, like minecraft's (0.8 to 15.2 pixels)
	for (const quad of cross) {
		for (const v of quad.positions) assert(v > -1e-6 && v < 1 + 1e-6, `${v} is outside the block`);
	}
	const xs = cross[0].positions.filter((_, i) => i % 3 === 0).map((v) => Math.round(v * 1000) / 1000);
	assertEquals(new Set(xs), new Set([0.05, 0.95]));
});

Deno.test("turning a model moves its faces and cullfaces", () => {
	const model: ModelJson = {
		id: "a:half",
		elements: [{
			from: [0, 0, 0],
			to: [16, 16, 8],
			faces: { north: { texture: "a:x", cullface: "north" } },
		}],
	};
	const [north] = bake_model(model, undefined, 0);
	const [east] = bake_model(model, undefined, 90);
	assertEquals([north.face, north.cull], [3, 3]);
	assertEquals([east.face, east.cull], [5, 5]);
	assert(east.flush);
});

Deno.test("variants pick textures by state", () => {
	const { block } = block_from_json(JSON.parse(Deno.readTextFileSync("mods/bworld/blocks/wheat.json")).block);
	assertEquals(block_variant(block, { age: 5 }).textures, { crop: "bworld:wheat_stage_5" });
	assertEquals(block_variant(block, { age: 5 }).model, "engine:crop");
	assertEquals(block_variant(block).textures, { crop: "bworld:wheat_stage_0" });
	// states live above the numeric id
	assertEquals(set_state_value(7, block, "age", 3), (3 << 16) | 7);
});