/*
Helpers for schema management
*/
import _ from "lodash";

import fromEntries from "../fromEntries";
import catLabelSort from "../catLabelSort";

/*
System wide schema assumptions:
  - schema and data wil be consistent (eg, for user-created annotations)
  - schema will be internally self-consistent (eg, index matches columns)
  - world & universe schema are same - only data is subset
*/

export function indexEntireSchema(schema) {
  /* Index schema for ease of use */
  schema.annotations.obsByName = fromEntries(
    schema.annotations.obs.columns.map(v => [v.name, v])
  );
  schema.annotations.varByName = fromEntries(
    schema.annotations.var.columns.map(v => [v.name, v])
  );
  schema.layout.obsByName = fromEntries(
    schema.layout.obs.map(v => [v.name, v])
  );
  schema.layout.varByName = fromEntries(
    schema.layout.var.map(v => [v.name, v])
  );

  return schema;
}

export function sortAllCategorical(schema) {
  /* UI relies on OBS annotation categories being in presentation sort order */
  schema.annotations.obs.columns.forEach(c => {
    if (c.categories) {
      c.categories = catLabelSort(c.writable, c.categories);
    }
  });
}

function _copy(schema) {
  /* redux copy conventions - WARNING, only for modifyign obs annotations */
  return {
    ...schema,
    annotations: {
      ...schema.annotations,
      obs: _.cloneDeep(schema.annotations.obs)
    }
  };
}

function _reindex(schema) {
  /* reindex obs annotations ONLY */
  schema.annotations.obsByName = fromEntries(
    schema.annotations.obs.columns.map(v => [v.name, v])
  );
  return schema;
}

export function removeObsAnnoColumn(schema, name) {
  const newSchema = _copy(schema);
  newSchema.annotations.obs.columns = schema.annotations.obs.columns.filter(
    v => v.name !== name
  );
  return _reindex(newSchema);
}

export function addObsAnnoColumn(schema, name, defn) {
  const newSchema = _copy(schema);
  newSchema.annotations.obs.columns.push(defn);
  return _reindex(newSchema);
}

export function removeObsAnnoCategory(schema, name, category) {
  /* remove a category from a categorical annotation */
  const categories = schema.annotations.obsByName[name]?.categories;
  if (!categories)
    throw new Error("column does not exist or is not categorical");

  const idx = categories.indexOf(category);
  if (idx === -1) throw new Error("category does not exist");

  const newSchema = _reindex(_copy(schema));

  /* remove category.  Do not need to resort as this can't change presentation order */
  newSchema.annotations.obsByName[name].categories.splice(idx, 1);
  return newSchema;
}

export function addObsAnnoCategory(schema, name, category) {
  /* add a category to a categorical annotation */
  const categories = schema.annotations.obsByName[name]?.categories;
  if (!categories)
    throw new Error("column does not exist or is not categorical");

  const idx = categories.indexOf(category);
  if (idx !== -1) throw new Error("category already exists");

  const newSchema = _reindex(_copy(schema));

  /* add category, retaining presentation sort order */
  const catAnno = newSchema.annotations.obsByName[name];
  catAnno.categories = catLabelSort(catAnno.writable, [
    ...catAnno.categories,
    category
  ]);
  return newSchema;
}