import { useCallback } from "react";
import { validateBeforeTransaction } from "./Utils";
import { ObjectStoreMeta, ObjectStoreSchema } from "./indexed-hooks";
import { createReadwriteTransaction } from "./createReadwriteTransaction";
import { createReadonlyTransaction } from "./createReadonlyTransaction";

export type Key =
  | string
  | number
  | Date
  | ArrayBufferView
  | ArrayBuffer
  | IDBKeyRange; // IDBArrayKey
export interface IndexDetails {
  indexName: string;
  order: string;
}
const indexedDB: IDBFactory =
  window.indexedDB ||
  (<any>window).mozIndexedDB ||
  (<any>window).webkitIndexedDB ||
  (<any>window).msIndexedDB;

export function openDatabase(
  dbName: string,
  version: number,
  upgradeCallback?: (e: Event, db: IDBDatabase) => void,
) {
  return new Promise<IDBDatabase>((resolve, reject) => {
    const request = indexedDB.open(dbName, version);
    let db: IDBDatabase;
    request.onsuccess = () => {
      db = request.result;
      resolve(db);
    };
    request.onerror = () => {
      reject(`IndexedDB error: ${request.error}`);
    };
    if (typeof upgradeCallback === "function") {
      request.onupgradeneeded = (event: Event) => {
        upgradeCallback(event, db);
      };
    }
  });
}

export function CreateObjectStore(
  dbName: string,
  version: number,
  storeSchemas: ObjectStoreMeta[],
) {
  const request: IDBOpenDBRequest = indexedDB.open(dbName, version);

  request.onupgradeneeded = function (event: IDBVersionChangeEvent) {
    const database: IDBDatabase = (event.target as any).result;
    storeSchemas.forEach((storeSchema: ObjectStoreMeta) => {
      if (!database.objectStoreNames.contains(storeSchema.store)) {
        const objectStore = database.createObjectStore(
          storeSchema.store,
          storeSchema.storeConfig,
        );
        storeSchema.storeSchema.forEach((schema: ObjectStoreSchema) => {
          objectStore.createIndex(schema.name, schema.keypath, schema.options);
        });
      }
    });
    database.close();
  };
  request.onsuccess = function (e: any) {
    e.target.result.close();
  };
}

export function DBOperations(
  dbName: string,
  version: number,
  currentStore: string,
) {
  // Readonly operations
  const getAll = <T>() =>
    new Promise<T[]>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store } = createReadonlyTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const request = store.getAll();

        request.onerror = (error) => reject(error);

        request.onsuccess = function ({ target: { result } }: any) {
          resolve(result as T[]);
        };
      });
    });

  const getByID = <T>(id: string | number) =>
    new Promise<T>((resolve, reject) => {
      openDatabase(dbName, version).then((db: IDBDatabase) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store } = createReadonlyTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const request = store.get(id);

        request.onsuccess = function (event: Event) {
          resolve((event.target as any).result as T);
        };
      });
    });

  const openCursor = (
    cursorCallback: (event: Event) => void,
    keyRange?: IDBKeyRange,
  ) => {
    return new Promise<void>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store } = createReadonlyTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const request = store.openCursor(keyRange);

        request.onsuccess = (event: Event) => {
          cursorCallback(event);
          resolve();
        };
      });
    });
  };

  const getByIndex = (indexName: string, key: any) =>
    new Promise<any>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store } = createReadonlyTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const index = store.index(indexName);
        const request = index.get(key);

        request.onsuccess = (event: Event) => {
          resolve((<IDBOpenDBRequest>event.target).result);
        };
      });
    });

  // Readwrite operations
  const add = <T>(value: T, key?: any) =>
    new Promise<number>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        const { store } = createReadwriteTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const request = store.add(value, key);

        request.onsuccess = (evt: any) => {
          key = evt.target.result;
          resolve(key);
        };

        request.onerror = (error) => reject(error);
      });
    });

  const update = <T>(value: T, key?: any) =>
    new Promise<any>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { transaction, store } = createReadwriteTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );

        transaction.oncomplete = (event) => resolve(event);

        store.put(value, key);
      });
    });

  const deleteRecord = (key: Key) =>
    new Promise<any>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store } = createReadwriteTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );
        const request = store.delete(key);

        request.onsuccess = (event) => resolve(event);
      });
    });

  const clear = () =>
    new Promise<void>((resolve, reject) => {
      openDatabase(dbName, version).then((db) => {
        validateBeforeTransaction(db, currentStore, reject);
        const { store, transaction } = createReadwriteTransaction(
          db,
          currentStore,
          resolve,
          reject,
        );

        transaction.oncomplete = () => resolve();

        store.clear();
      });
    });

  return {
    add,
    getByID,
    getAll,
    update,
    deleteRecord,
    clear,
    openCursor,
    getByIndex,
  };
}

export enum DBMode {
  readonly = "readonly",
  readwrite = "readwrite",
}