////////////////////////////////////////////////////////////////////////////
//
// Copyright 2024 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////

import { createUseObject } from "./useObject";
import { createUseQuery } from "./useQuery";
import { createUseRealm } from "./useRealm";
import {
  DynamicRealmProvider,
  RealmProviderFromConfiguration,
  RealmProviderFromRealm,
  createRealmProvider,
} from "./RealmProvider";
import { createContext } from "react";
import Realm from "realm";

export type RealmContext<RealmProvider = DynamicRealmProvider> = {
  /**
   * The Provider component that is required to wrap any component using
   * the Realm hooks.
   * @example
   * ```
   * const AppRoot = () => {
   *   const syncConfig = {
   *     flexible: true,
   *     user: currentUser
   *   };
   *
   *   return (
   *     <RealmProvider schema={[Task, User]} path={"data.realm"} sync={syncConfig}>
   *       <App/>
   *     </RealmProvider>
   *   )
   * }
   * ```
   * @param props - The {@link Realm.Configuration} or {@link Realm} of the provider
   * are set based on the options passed to `createRealmProvider`. When using a
   * {@link Realm.Configuration}, individual config keys can be overridden when
   * creating a `<RealmProvider>` by passing them as props. For example, to override
   * the `path` config value, use a prop named `path` e.g., `path="newPath.realm"` an
   * attribute of the same key.
   */
  RealmProvider: RealmProvider;
  /**
   * Returns the instance of the {@link Realm} opened by the `RealmProvider`.
   * @example
   * ```
   * const realm = useRealm();
   * ```
   * @returns a realm instance
   */
  useRealm: ReturnType<typeof createUseRealm>;

  /**
   * Returns a {@link Realm.Collection} of {@link Realm.Object}s from a given type.
   * The hook will update on any changes to any object in the collection.
   *
   * The result of this can be consumed directly by the `data` argument of any React Native
   * VirtualizedList or FlatList.  If the component used for the list's `renderItem` prop is {@link React.Memo}ized,
   * then only the modified object will re-render.
   * @example
   * ```tsx
   * // Return all collection items
   * const collection = useQuery({ type: Object });
   *
   * // Return all collection items sorted by name and filtered by category
   * const filteredAndSorted = useQuery({
   *   type: Object,
   *   query: (collection) => collection.filtered('category == $0',category).sorted('name'),
   * }, [category]);
   *
   * // Return all collection items sorted by name and filtered by category, triggering re-renders only if "name" changes
   * const filteredAndSorted = useQuery({
   *   type: Object,
   *   query: (collection) => collection.filtered('category == $0',category).sorted('name'),
   *   keyPaths: ["name"]
   * }, [category]);
   * ```
   * @param options
   * @param options.type - The object type, depicted by a string or a class extending Realm.Object
   * @param options.query - A function that takes a {@link Realm.Collection} and returns a {@link Realm.Collection} of the same type. This allows for filtering and sorting of the collection, before it is returned.
   * @param options.keyPaths - Indicates a lower bound on the changes relevant for the hook. This is a lower bound, since if multiple hooks add listeners (each with their own `keyPaths`) the union of these key-paths will determine the changes that are considered relevant for all listeners registered on the collection. In other words: A listener might fire and cause a re-render more than the key-paths specify, if other listeners with different key-paths are present.
   * @param deps - An array of dependencies that will be passed to {@link React.useMemo}
   * @returns a collection of realm objects or an empty array
   */
  useQuery: ReturnType<typeof createUseQuery>;
  /**
   * Returns a {@link Realm.Object} from a given type and value of primary key.
   * The hook will update on any changes to the properties on the returned object
   * and return null if it either doesn't exists or has been deleted.
   * @example
   * ```
   * const object = useObject(ObjectClass, objectId);
   * ```
   * @param type - The object type, depicted by a string or a class extending {@link Realm.Object}
   * @param primaryKey - The primary key of the desired object which will be retrieved using {@link Realm.objectForPrimaryKey}
   * @param keyPaths - Indicates a lower bound on the changes relevant for the hook. This is a lower bound, since if multiple hooks add listeners (each with their own `keyPaths`) the union of these key-paths will determine the changes that are considered relevant for all listeners registered on the object. In other words: A listener might fire and cause a re-render more than the key-paths specify, if other listeners with different key-paths are present.
   * @returns either the desired {@link Realm.Object} or `null` in the case of it being deleted or not existing.
   */
  useObject: ReturnType<typeof createUseObject>;
};

/**
 * Creates Realm React hooks and Provider component for a given Realm configuration
 * @example
 * ```
 *class Task extends Realm.Object {
 *  ...
 *
 *  static schema: ObjectSchema = {
 *    name: 'Task',
 *    primaryKey: '_id',
 *    properties: {
 *      ...
 *    },
 *  };
 *}
 *
 *const {useRealm, useQuery, useObject, RealmProvider} = createRealmContext({schema: [Task]});
 * ```
 * @param realmConfig - {@link Realm.Configuration} used to open the Realm
 * @returns An object containing a `RealmProvider` component, and `useRealm`, `useQuery` and `useObject` hooks
 */
export function createRealmContext(realmConfig: Realm.Configuration): RealmContext<RealmProviderFromConfiguration>;
/**
 * Creates Realm React hooks and Provider component for a given Realm instance.
 *
 * **Note:** the hooks returned from `createRealmContext` using an existing Realm can be used outside of the scope of the provider.
 * @example
 * ```
 * const realm = new Realm({ schema: [...] });
 * const {useRealm, useQuery, useObject, RealmProvider} = createRealmContext(realm);
 * ```
 * @param realm - {@link Realm} instance
 * @returns An object containing a `RealmProvider` component, and `useRealm`, `useQuery` and `useObject` hooks
 */
export function createRealmContext(realm: Realm): RealmContext<RealmProviderFromRealm>;
/**
 * Creates Realm React hooks and Provider component.
 * @example
 * ```
 * class Task extends Realm.Object {
 *  ...
 *  static schema: ObjectSchema = {
 *    name: 'Task',
 *    primaryKey: '_id',
 *    properties: {
 *      ...
 *    },
 *  };
 * }
 * const {useRealm, useQuery, useObject, RealmProvider} = createRealmContext();
 * ...
 * <RealmProvider schema={[Task]}></RealmProvider>
 * ```
 * @example
 * ```
 * const realm = await Realm.open({ path: "example.realm", schema: [Task] });
 * const {RealmProvider} = createRealmContext();
 * ...
 * <RealmProvider realm={realm}></RealmProvider>
 * ```
 * @returns An object containing a `RealmProvider` component, and `useRealm`, `useQuery` and `useObject` hooks
 */
export function createRealmContext(): RealmContext<DynamicRealmProvider>;
export function createRealmContext(
  realmOrConfig?: Realm | Realm.Configuration,
): RealmContext<RealmProviderFromConfiguration | RealmProviderFromRealm | DynamicRealmProvider> {
  const RealmContext = createContext<Realm | null>(realmOrConfig instanceof Realm ? realmOrConfig : null);
  const RealmProvider = createRealmProvider(realmOrConfig, RealmContext);

  const useRealm = createUseRealm(RealmContext);
  const useQuery = createUseQuery(useRealm);
  const useObject = createUseObject(useRealm);

  return {
    RealmProvider,
    useRealm,
    useQuery,
    useObject,
  };
}