// Case id -> GLB node binding. Pure functions shared by the manager dialog and
// the runtime view. Motion values always come from LinuxCNC WASM joints; this
// module only says which scene node receives which joint slot.
import bindings from "./machine-visual-bindings.json" with { type: "json" };
import { MACHINE_DEFINITIONS } from "./machine-definitions.mjs";

export const VISUAL_BINDINGS_SCHEMA = "linuxcnc.machine-visual-bindings/1";
const SLOT_KINDS = new Set(["prismatic", "revolute", "strut"]);
const SLOT_SOURCES = new Set(["kinematics", "extra", "duplicate", "passive"]);
const AXIS_LETTER = /^[XYZABCUVW]$/;

const fail = (message) => { throw new Error(`视觉绑定配置无效：${message}`); };

if (bindings.schema !== VISUAL_BINDINGS_SCHEMA) fail("schema");
if (typeof bindings.glbRoot !== "string" || !bindings.glbRoot) fail("glbRoot");
if (!Array.isArray(bindings.cases) || !bindings.cases.length) fail("cases");

const catalog = new Map(MACHINE_DEFINITIONS.map((machine) => [machine.id, machine]));
const byId = new Map();
const byEntrypoint = new Map();

for (const item of bindings.cases) {
  if (!item.machineId || byId.has(item.machineId)) fail(`machineId 缺失或重复：${item.machineId}`);
  const machine = catalog.get(item.machineId);
  if (!machine) fail(`案例目录中没有 ${item.machineId}`);
  if (item.entrypoint !== machine.entrypoint) fail(`${item.machineId} entrypoint 与运行目录不一致`);
  if (item.coordinates !== machine.coordinates) fail(`${item.machineId} coordinates 与运行目录不一致`);
  if (!Array.isArray(item.jointOrder) || item.jointOrder.length !== machine.joint_count) fail(`${item.machineId} 槽位数 ${item.jointOrder?.length} 与 joint_count ${machine.joint_count} 不符`);
  if (!Array.isArray(item.bindings) || item.bindings.length !== item.jointOrder.length) fail(`${item.machineId} 绑定数量与槽位数不符`);
  const keys = new Set(), bound = new Set();
  for (const [position, slot] of item.jointOrder.entries()) {
    if (slot.index !== position) fail(`${item.machineId} 槽位索引不连续`);
    if (typeof slot.key !== "string" || !slot.key || keys.has(slot.key)) fail(`${item.machineId} 槽位 key 缺失或重复`);
    keys.add(slot.key);
    if (!SLOT_KINDS.has(slot.kind)) fail(`${item.machineId}/${slot.key} 类型`);
    if (slot.unit !== (slot.kind === "revolute" ? "deg" : "mm")) fail(`${item.machineId}/${slot.key} 单位`);
    if (slot.axis !== null && !AXIS_LETTER.test(slot.axis)) fail(`${item.machineId}/${slot.key} 轴字母`);
    if (!SLOT_SOURCES.has(slot.source)) fail(`${item.machineId}/${slot.key} 来源`);
  }
  for (const binding of item.bindings) {
    if (!Number.isInteger(binding.slot) || binding.slot < 0 || binding.slot >= item.jointOrder.length) fail(`${item.machineId} 绑定槽位越界`);
    if (bound.has(binding.slot)) fail(`${item.machineId} 槽位 ${binding.slot} 重复绑定`);
    bound.add(binding.slot);
    if (typeof binding.node !== "string" || !binding.node) fail(`${item.machineId} 槽位 ${binding.slot} 缺少节点名`);
    if (!["x", "y", "z"].includes(binding.direction)) fail(`${item.machineId} 槽位 ${binding.slot} 方向`);
    if (![1, -1].includes(binding.sign)) fail(`${item.machineId} 槽位 ${binding.slot} 正负向`);
  }
  for (const slot of item.jointOrder) if (slot.source !== "passive" && !bound.has(slot.index)) fail(`${item.machineId} 槽位 ${slot.key} 未绑定节点`);
  const zeros = item.calibration?.physicalZero;
  if (!Array.isArray(zeros) || zeros.length !== item.jointOrder.length || !zeros.every(Number.isFinite)) fail(`${item.machineId} 物理零点`);
  byId.set(item.machineId, Object.freeze(item));
  byEntrypoint.set(item.entrypoint, byId.get(item.machineId));
}

export const VISUAL_BINDINGS = Object.freeze({ schema: VISUAL_BINDINGS_SCHEMA, glbRoot: bindings.glbRoot, cases: Object.freeze([...byId.values()]) });
export const glbPath = (binding) => binding ? `${bindings.glbRoot}${binding.glb.default}` : null;
export const visualBinding = (value) => byId.get(String(value ?? "")) ?? byEntrypoint.get(String(value ?? "")) ?? null;
export const hasVisualBinding = (value) => Boolean(visualBinding(value));
export const bindingGlbPath = (value) => glbPath(visualBinding(value));

// Build a v2 joint model from a binding plus the GLB node ids that carry
// userData.linuxcncNodeId. Fails per slot instead of guessing a node.
export function bindingJointModel(binding, nodeIds) {
  if (!binding) fail("缺少绑定");
  const ids = new Set(nodeIds);
  const slotMap = binding.jointOrder.map((slot) => {
    const row = binding.bindings.find((item) => item.slot === slot.index);
    // Node identity is userData.linuxcncNodeId, not the display name: two
    // machines may both call their node "x".
    const id = row?.nodeId ?? row?.node ?? null;
    return id && ids.has(id) ? id : null;
  });
  const missing = binding.jointOrder.filter((slot, index) => slotMap[index] === null && slot.source !== "passive").map((slot) => slot.key);
  return {
    schema: "linuxcnc.joint-model/2",
    machineId: binding.machineId,
    coordinates: binding.coordinates,
    units: { length: "mm", angle: "deg", gltfLength: "m" },
    controller: { source: "linuxcnc-wasm.visual.joints", jointOrder: binding.jointOrder.map((slot) => ({ ...slot })) },
    calibration: { cOriginMm: [...binding.calibration.cOriginMm], tiltOffsetMm: [...binding.calibration.tiltOffsetMm], physicalZero: [...binding.calibration.physicalZero] },
    slotMap,
    missing,
  };
}