// Various helper function for working with tables

import { PluginKey } from 'prosemirror-state';

import { TableMap } from './tablemap';
import { tableNodeTypes } from './schema';

export const key = new PluginKey('selectingCells');

export function cellAround($pos) {
  for (let d = $pos.depth - 1; d > 0; d--)
    if ($pos.node(d).type.spec.tableRole == 'row')
      return $pos.node(0).resolve($pos.before(d + 1));
  return null;
}

export function cellWrapping($pos) {
  for (let d = $pos.depth; d > 0; d--) {
    // Sometimes the cell can be in the same depth.
    const role = $pos.node(d).type.spec.tableRole;
    if (role === 'cell' || role === 'header_cell') return $pos.node(d);
  }
  return null;
}

export function isInTable(state) {
  let $head = state.selection.$head;
  for (let d = $head.depth; d > 0; d--)
    if ($head.node(d).type.spec.tableRole == 'row') return true;
  return false;
}

export function selectionCell(state) {
  let sel = state.selection;
  if (sel.$anchorCell) {
    return sel.$anchorCell.pos > sel.$headCell.pos
      ? sel.$anchorCell
      : sel.$headCell;
  } else if (sel.node && sel.node.type.spec.tableRole == 'cell') {
    return sel.$anchor;
  }
  return cellAround(sel.$head) || cellNear(sel.$head);
}

function cellNear($pos) {
  for (
    let after = $pos.nodeAfter, pos = $pos.pos;
    after;
    after = after.firstChild, pos++
  ) {
    let role = after.type.spec.tableRole;
    if (role == 'cell' || role == 'header_cell') return $pos.doc.resolve(pos);
  }
  for (
    let before = $pos.nodeBefore, pos = $pos.pos;
    before;
    before = before.lastChild, pos--
  ) {
    let role = before.type.spec.tableRole;
    if (role == 'cell' || role == 'header_cell')
      return $pos.doc.resolve(pos - before.nodeSize);
  }
}

export function pointsAtCell($pos) {
  return $pos.parent.type.spec.tableRole == 'row' && $pos.nodeAfter;
}

export function moveCellForward($pos) {
  return $pos.node(0).resolve($pos.pos + $pos.nodeAfter.nodeSize);
}

export function inSameTable($a, $b) {
  return $a.depth == $b.depth && $a.pos >= $b.start(-1) && $a.pos <= $b.end(-1);
}

export function findCell($pos) {
  return TableMap.get($pos.node(-1)).findCell($pos.pos - $pos.start(-1));
}

export function colCount($pos) {
  return TableMap.get($pos.node(-1)).colCount($pos.pos - $pos.start(-1));
}

export function nextCell($pos, axis, dir) {
  let start = $pos.start(-1),
    map = TableMap.get($pos.node(-1));
  let moved = map.nextCell($pos.pos - start, axis, dir);
  return moved == null ? null : $pos.node(0).resolve(start + moved);
}

export function setAttr(attrs, name, value) {
  let result = {};
  for (let prop in attrs) result[prop] = attrs[prop];
  result[name] = value;
  return result;
}

export function removeColSpan(attrs, pos, n = 1) {
  let result = setAttr(attrs, 'colspan', attrs.colspan - n);
  if (result.colwidth) {
    result.colwidth = result.colwidth.slice();
    result.colwidth.splice(pos, n);
    if (!result.colwidth.some((w) => w > 0)) result.colwidth = null;
  }
  return result;
}

export function addColSpan(attrs, pos, n = 1) {
  let result = setAttr(attrs, 'colspan', attrs.colspan + n);
  if (result.colwidth) {
    result.colwidth = result.colwidth.slice();
    for (let i = 0; i < n; i++) result.colwidth.splice(pos, 0, 0);
  }
  return result;
}

export function columnIsHeader(map, table, col) {
  let headerCell = tableNodeTypes(table.type.schema).header_cell;
  for (let row = 0; row < map.height; row++)
    if (table.nodeAt(map.map[col + row * map.width]).type != headerCell)
      return false;
  return true;
}