//  core/grid.js; the ONE rotation convention + facing tables + ground/water probes.

import { safeGetBlock } from "./mc.js";

export const RIGHT = { south: [1, 0, 0], north: [-1, 0, 0], east: [0, 0, -1], west: [0, 0, 1] };
export const FWD = { south: [0, 0, 1], north: [0, 0, -1], east: [1, 0, 0], west: [-1, 0, 0] };

// world position of a south-frame offset g given the anchor + facing. rotating=false -> raw offset (symmetric canopies um/bu/bt).
export function cellWorld(g, ax, ay, az, dir, rotating = true) {
	if (!rotating) return { x: ax + g[0], y: ay + g[1], z: az + g[2] };
	const R = RIGHT[dir] || RIGHT.south, F = FWD[dir] || FWD.south;
	return { x: ax + g[0] * R[0] + g[2] * F[0], y: ay + g[1], z: az + g[0] * R[2] + g[2] * F[2] };
}
// inverse of cellWorld: back compute the anchor from a cell's world position + facing.
export function anchorFrom(g, x, y, z, dir, rotating = true) {
	if (!rotating) return { x: x - g[0], y: y - g[1], z: z - g[2] };
	const R = RIGHT[dir] || RIGHT.south, F = FWD[dir] || FWD.south;
	return { x: x - g[0] * R[0] - g[2] * F[0], y: y - g[1], z: z - g[0] * R[2] - g[2] * F[2] };
}
// Bundle a cell map into ready-to-use cellWorld/anchorFrom closures (used by every multiblock family).
export function grid(cells, rotating = true) {
	return {
		cells,
		cellWorld: (cell, ax, ay, az, dir) => cellWorld(cells[cell], ax, ay, az, dir, rotating),
		anchorFrom: (cell, x, y, z, dir) => anchorFrom(cells[cell], x, y, z, dir, rotating),
	};
}

// Facing / yaw tables
export const DIR_YAW = { north: 0, south: 180, east: 90, west: 270 };   // seat: player faces OUT of the seat
export const DIR_TROT = { south: 0, north: 180, east: 90, west: -90 };  // seat: block geometry transformation angle
export const DISPLAY_DIR_YAW = { north: 0, east: 90, south: 180, west: -90 }; // DecoCraft display-entity summon yaw
export const TUBE_DIR_YAW = { south: 0, west: 90, north: 180, east: -90 };    // rideable block-facing -> entity body yaw
export const displayYawToDir = (yaw) => { const y = ((yaw % 360) + 360) % 360; if (y < 45 || y >= 315) return "north"; if (y < 135) return "east"; if (y < 225) return "south"; return "west"; };
export const tubeYawToDir = (yaw) => { const y = ((yaw % 360) + 360) % 360; if (y < 45 || y >= 315) return "south"; if (y < 135) return "west"; if (y < 225) return "north"; return "east"; };

export function fcCanReplace(nb) {
	if (!nb) return false;
	if (nb.isAir) return true;
	const t = nb.typeId || "";
	if (/grass_block|dirt|podzol|mycelium|mud|farmland|clay|gravel|sand|stone|terracotta|concrete|planks|log|wool/.test(t)) return false;
	return /short_grass|tall_grass|tallgrass|fern|flower|sapling|snow_layer|dead_bush|azalea|deadbush|seagrass|\bvine|leaf_litter/.test(t);
}

export function tubeWaterTop(dim, x, z, nearY) {
	const isW = (b) => { try { return b.typeId.endsWith("water"); } catch { return false; } };
	for (let y = Math.floor(nearY) + 3; y >= Math.floor(nearY) - 6; y--) { const b = safeGetBlock(dim, { x, y, z }); if (isW(b)) return y; }
	return null;
}

export function tubeOverWater(block) {
	try { if (block.isWaterlogged) return true; } catch {}
	const dim = block.dimension;
	for (const [dx, dy, dz] of [[0, -1, 0], [1, 0, 0], [-1, 0, 0], [0, 0, 1], [0, 0, -1]]) {
		const b = safeGetBlock(dim, { x: block.x + dx, y: block.y + dy, z: block.z + dz });
		try { if (b && (b.typeId.endsWith("water") || b.isWaterlogged)) return true; } catch {}
	}
	return false;
}

export function loungerSupportY(dim, x, z, fromY, noFloat, float = 0) {
	for (let y = Math.floor(fromY) + 1; y >= Math.floor(fromY) - 48; y--) {
		const b = safeGetBlock(dim, { x, y, z });
		if (!b) continue;
		const id = b.typeId || "";
		if (id.endsWith("water")) { if (noFloat) continue; return y + 1 + float; }
		let air = id === "minecraft:air"; try { air = b.isAir; } catch {}
		if (!air && !/water|lava/.test(id)) return y + 1;
	}
	return null;
}