/*
 * Copyright (c) 2016-present Invertase Limited & Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this library 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 { isNull, isObject, isString, isUndefined } from '@react-native-firebase/app/lib/common';
import NativeError from '@react-native-firebase/app/lib/internal/NativeFirebaseError';
import FirestoreDocumentSnapshot from './FirestoreDocumentSnapshot';
import FirestoreFieldPath, { fromDotSeparatedString } from './FirestoreFieldPath';
import FirestoreQuerySnapshot from './FirestoreQuerySnapshot';
import { parseSnapshotArgs } from './utils';

let _id = 0;

export default class FirestoreQuery {
  constructor(firestore, collectionPath, modifiers) {
    this._firestore = firestore;
    this._collectionPath = collectionPath;
    this._modifiers = modifiers;
  }

  get firestore() {
    return this._firestore;
  }

  _handleQueryCursor(cursor, docOrField, fields) {
    if (isUndefined(docOrField)) {
      throw new Error(
        `firebase.firestore().collection().${cursor}(*) Expected a DocumentSnapshot or list of field values but got undefined.`,
      );
    }

    // Handles cases where the first arg is a DocumentSnapshot
    if (docOrField instanceof FirestoreDocumentSnapshot) {
      if (fields.length > 0) {
        throw new Error(
          `firebase.firestore().collection().${cursor}(*) Too many arguments provided. Expected DocumentSnapshot or list of field values.`,
        );
      }

      const documentSnapshot = docOrField;

      if (!documentSnapshot.exists) {
        throw new Error(
          `firebase.firestore().collection().${cursor}(*) Can't use a DocumentSnapshot that doesn't exist.`,
        );
      }

      const currentOrders = this._modifiers.orders;

      const values = [];

      for (let i = 0; i < currentOrders.length; i++) {
        const order = currentOrders[i];
        const value = documentSnapshot.get(order.fieldPath);

        if (value === undefined) {
          throw new Error(
            `firebase.firestore().collection().${cursor}(*) You are trying to start or end a query using a document for which the field '${
              order.fieldPath
            }' (used as the orderBy) does not exist.`,
          );
        }

        values.push(value);
      }

      this._modifiers._orders.push({
        fieldPath: '__name__',
        direction: 'ASCENDING',
      });

      values.push(documentSnapshot.id);

      return this._modifiers.setFieldsCursor(cursor, values);
    }

    /**
     * Assumes list of field values to query by. Orders must be of equal length.
     */

    const allFields = [docOrField].concat(fields);

    if (allFields.length > this._modifiers.orders.length) {
      throw new Error(
        `firebase.firestore().collection().${cursor}(*) Too many arguments provided. The number of arguments must be less than or equal to the number of orderBy() clauses.`,
      );
    }

    return this._modifiers.setFieldsCursor(cursor, allFields);
  }

  endAt(docOrField, ...fields) {
    return new FirestoreQuery(
      this._firestore,
      this._collectionPath,
      this._handleQueryCursor('endAt', docOrField, fields),
    );
  }

  endBefore(docOrField, ...fields) {
    return new FirestoreQuery(
      this._firestore,
      this._collectionPath,
      this._handleQueryCursor('endBefore', docOrField, fields),
    );
  }

  get(options) {
    if (!isUndefined(options) && !isObject(options)) {
      throw new Error(
        "firebase.firestore().collection().get(*) 'options' must be an object is provided.",
      );
    }

    if (
      options &&
      options.source &&
      options.source !== 'default' &&
      options.source !== 'server' &&
      options.source !== 'cache'
    ) {
      throw new Error(
        "firebase.firestore().collection().get(*) 'options' GetOptions.source must be one of 'default', 'server' or 'cache'.",
      );
    }

    return this._firestore.native
      .collectionGet(
        this._collectionPath.relativeName,
        this._modifiers.type,
        this._modifiers.filters,
        this._modifiers.orders,
        this._modifiers.options,
        options,
      )
      .then(data => new FirestoreQuerySnapshot(this._firestore, this, data));
  }

  isEqual(other) {
    if (!(other instanceof FirestoreQuery)) {
      throw new Error(
        "firebase.firestore().collection().isEqual(*) 'other' expected a Query instance.",
      );
    }

    // Carry out lightweight checks first
    if (
      this.firestore.app.name !== other.firestore.app.name ||
      this._modifiers.type !== other._modifiers.type ||
      this._modifiers.filters.length !== other._modifiers.filters.length ||
      this._modifiers.orders.length !== other._modifiers.orders.length ||
      Object.keys(this._modifiers.options).length !== Object.keys(other._modifiers.options).length
    ) {
      return false;
    }

    // Carry out potentially expensive checks
    // noinspection RedundantIfStatementJS
    if (
      JSON.stringify(this._modifiers.filters) !== JSON.stringify(other._modifiers.filters) ||
      JSON.stringify(this._modifiers.orders) !== JSON.stringify(other._modifiers.orders) ||
      JSON.stringify(this._modifiers.options) !== JSON.stringify(other._modifiers.options)
    ) {
      return false;
    }

    return true;
  }

  limit(limit) {
    if (this._modifiers.isValidLimit(limit)) {
      throw new Error(
        "firebase.firestore().collection().limit(*) 'limit' must be a positive integer value.",
      );
    }

    const modifiers = this._modifiers.limit(limit);

    return new FirestoreQuery(this._firestore, this._collectionPath, modifiers);
  }

  onSnapshot(...args) {
    let snapshotListenOptions;
    let callback;
    let onNext;
    let onError;

    try {
      const options = parseSnapshotArgs(args);
      snapshotListenOptions = options.snapshotListenOptions;
      callback = options.callback;
      onNext = options.onNext;
      onError = options.onError;
    } catch (e) {
      throw new Error(`firebase.firestore().collection().onSnapshot(*) ${e.message}`);
    }

    function handleSuccess(querySnapshot) {
      callback(querySnapshot, null);
      onNext(querySnapshot);
    }

    function handleError(error) {
      callback(null, error);
      onError(error);
    }

    const listenerId = _id++;

    const onSnapshotSubscription = this._firestore.emitter.addListener(
      this._firestore.eventNameForApp(`firestore_collection_sync_event:${listenerId}`),
      event => {
        if (event.body.error) {
          handleError(NativeError.fromEvent(event.body.error, 'firestore'));
        } else {
          const querySnapshot = new FirestoreQuerySnapshot(
            this._firestore,
            this,
            event.body.snapshot,
          );
          handleSuccess(querySnapshot);
        }
      },
    );

    const unsubscribe = () => {
      onSnapshotSubscription.remove();
      this._firestore.native.collectionOffSnapshot(listenerId);
    };

    this._firestore.native.collectionOnSnapshot(
      this._collectionPath.relativeName,
      this._modifiers.type,
      this._modifiers.filters,
      this._modifiers.orders,
      this._modifiers.options,
      listenerId,
      snapshotListenOptions,
    );

    return unsubscribe;
  }

  orderBy(fieldPath, directionStr) {
    if (!isString(fieldPath) && !(fieldPath instanceof FirestoreFieldPath)) {
      throw new Error(
        "firebase.firestore().collection().orderBy(*) 'fieldPath' must be a string or instance of FieldPath.",
      );
    }

    let path;

    if (isString(fieldPath)) {
      try {
        path = fromDotSeparatedString(fieldPath);
      } catch (e) {
        throw new Error(`firebase.firestore().collection().orderBy(*) 'fieldPath' ${e.message}.`);
      }
    } else {
      path = fieldPath;
    }

    if (!isUndefined(directionStr) && !this._modifiers.isValidDirection(directionStr)) {
      throw new Error(
        "firebase.firestore().collection().orderBy(_, *) 'directionStr' must be one of 'asc' or 'desc'.",
      );
    }

    if (this._modifiers.hasStart()) {
      throw new Error(
        'firebase.firestore().collection().orderBy() Invalid query. You must not call startAt() or startAfter() before calling orderBy().',
      );
    }

    if (this._modifiers.hasEnd()) {
      throw new Error(
        'firebase.firestore().collection().orderBy() Invalid query. You must not call endAt() or endBefore() before calling orderBy().',
      );
    }

    const modifiers = this._modifiers.orderBy(path, directionStr);

    try {
      modifiers.validateOrderBy();
    } catch (e) {
      throw new Error(`firebase.firestore().collection().orderBy() ${e.message}`);
    }

    return new FirestoreQuery(this._firestore, this._collectionPath, modifiers);
  }

  startAfter(docOrField, ...fields) {
    return new FirestoreQuery(
      this._firestore,
      this._collectionPath,
      this._handleQueryCursor('startAfter', docOrField, fields),
    );
  }

  startAt(docOrField, ...fields) {
    return new FirestoreQuery(
      this._firestore,
      this._collectionPath,
      this._handleQueryCursor('startAt', docOrField, fields),
    );
  }

  where(fieldPath, opStr, value) {
    if (!isString(fieldPath) && !(fieldPath instanceof FirestoreFieldPath)) {
      throw new Error(
        "firebase.firestore().collection().where(*) 'fieldPath' must be a string or instance of FieldPath.",
      );
    }

    let path;

    if (isString(fieldPath)) {
      try {
        path = fromDotSeparatedString(fieldPath);
      } catch (e) {
        throw new Error(`firebase.firestore().collection().where(*) 'fieldPath' ${e.message}.`);
      }
    } else {
      path = fieldPath;
    }

    if (!this._modifiers.isValidOperator(opStr)) {
      throw new Error(
        "firebase.firestore().collection().where(_, *) 'opStr' is invalid. Expected one of '==', '>', '>=', '<', '<=' or 'array-contains'.",
      );
    }

    if (isUndefined(value)) {
      throw new Error(
        "firebase.firestore().collection().where(_, _, *) 'value' argument expected.",
      );
    }

    if (isNull(value) && !this._modifiers.isEqualOperator(opStr)) {
      throw new Error(
        "firebase.firestore().collection().where(_, _, *) 'value' is invalid. You can only perform equals comparisons on null",
      );
    }

    const modifiers = this._modifiers.where(path, opStr, value);

    try {
      modifiers.validateWhere();
    } catch (e) {
      throw new Error(`firebase.firestore().collection().where() ${e.message}`);
    }

    modifiers.validateWhere();

    return new FirestoreQuery(this._firestore, this._collectionPath, modifiers);
  }
}