import { EditorState, Transaction } from "prosemirror-state";
import { HighlightRange, RangeType } from "../range/types";
import { RangeCreateStep } from "../range/RangeCreateStep";
import { getPluginStateOrThrow as getRangePluginStateOrThrow } from "../range/RangePlugin";
import uuidv1 from "uuid/v1";
import { RangeSetAttrsStep } from "../range/RangeSetAttrsStep";
import { RangeDeleteStep } from "../range/RangeDeleteStep";

export function upsertTagToHighlight(
  editorState: EditorState,
  highlight: { from: number; to: number },
  tagId: string,
  tr = editorState.tr
): Transaction {
  const rangePluginState = getRangePluginStateOrThrow(editorState);
  const existingRange = rangePluginState.sortedRanges.find<HighlightRange>(
    (range): range is HighlightRange =>
      range.from === highlight.from && range.to === highlight.to && range.type === RangeType.HIGHLIGHT
  );
  if (existingRange !== undefined) {
    const tagIds = new Set(existingRange.attrs.tagIds);
    tagIds.add(tagId);

    return tr.step(
      new RangeSetAttrsStep(existingRange.id, existingRange.type, existingRange.attrs, {
        tagIds: [...tagIds]
      })
    );
  } else {
    return tr.step(new RangeCreateStep({ id: uuidv1(), type: RangeType.HIGHLIGHT, ...highlight, attrs: { tagIds: [tagId] } }));
  }
}

export function removeTagFromHighlight(
  editorState: EditorState,
  highlight: { from: number; to: number },
  tagId: string,
  tr = editorState.tr
): Transaction {
  const rangePluginState = getRangePluginStateOrThrow(editorState);
  const existingRange = rangePluginState.sortedRanges.find<HighlightRange>(
    (range): range is HighlightRange =>
      range.from === highlight.from && range.to === highlight.to && range.type === RangeType.HIGHLIGHT
  );
  if (existingRange === undefined) {
    throw new Error(`Unable to delete range with id=${existingRange}, as it was not found.`);
  }
  const tagIds = new Set(existingRange.attrs.tagIds);
  tagIds.delete(tagId);

  if (tagIds.size > 0) {
    return tr.step(
      new RangeSetAttrsStep(existingRange.id, existingRange.type, existingRange.attrs, {
        tagIds: [...tagIds]
      })
    );
  } else {
    return tr.step(new RangeDeleteStep(existingRange));
  }
}