/* groups.js — busbar (parallel cell group) CRUD.
 *
 * A Busbar is { id, name, color, cells: [cellId, …] }.
 * Cell `assigned` lookup is maintained so the canvas can render colors.
 */

const Groups = (() => {
  // Friendly hue palette — rotates as new busbars are added.
  const COLORS = [
    "#f08a24", "#4fa3ff", "#3ecf8e", "#e85aad",
    "#a78bfa", "#f5d142", "#52d6c6", "#ff6b6b",
    "#7cb342", "#ba68c8", "#26c6da", "#ffa726",
  ];

  let nextId = 1;
  let nextNameIdx = 1;

  function create(state, cellIds) {
    if (!cellIds || cellIds.length === 0) return null;
    const id = nextId++;
    const bb = {
      id,
      name: `P${nextNameIdx++}`,
      color: COLORS[(id - 1) % COLORS.length],
      shape: "panel",          // "panel" (default, production plate) | "wire"
      cells: [...cellIds],
    };
    state.busbars.push(bb);
    _reassign(state);
    return bb;
  }

  function remove(state, busbarId) {
    state.busbars = state.busbars.filter((b) => b.id !== busbarId);
    _reassign(state);
  }

  function rename(state, busbarId, name) {
    const bb = state.busbars.find((b) => b.id === busbarId);
    if (bb) bb.name = name;
  }

  function recolor(state, busbarId, color) {
    const bb = state.busbars.find((b) => b.id === busbarId);
    if (bb) bb.color = color;
  }

  function addCells(state, busbarId, cellIds) {
    const bb = state.busbars.find((b) => b.id === busbarId);
    if (!bb) return;
    const set = new Set(bb.cells);
    for (const id of cellIds) {
      if (!set.has(id)) { bb.cells.push(id); set.add(id); }
    }
    _reassign(state);
  }

  function removeCells(state, busbarId, cellIds) {
    const bb = state.busbars.find((b) => b.id === busbarId);
    if (!bb) return;
    const rm = new Set(cellIds);
    bb.cells = bb.cells.filter((id) => !rm.has(id));
    _reassign(state);
  }

  function _reassign(state) {
    state.cellToBusbar = new Map();
    for (const bb of state.busbars) {
      for (const cid of bb.cells) state.cellToBusbar.set(cid, bb.id);
    }
  }

  function findByCell(state, cellId) {
    return state.cellToBusbar.get(cellId);
  }

  function reset() {
    nextId = 1;
    nextNameIdx = 1;
  }

  return { create, remove, rename, recolor, addCells, removeCells, findByCell, reset };
})();