/**
 * @module @ember-data/record-data
 */
import { assert } from '@ember/debug';
import { schedule } from '@ember/runloop';
import { isEqual } from '@ember/utils';

import { LOG_MUTATIONS, LOG_OPERATIONS } from '@ember-data/private-build-infra/debugging';
import type {
  CollectionResourceRelationship,
  SingleResourceRelationship,
} from '@ember-data/types/q/ember-data-json-api';
import type { StableRecordIdentifier } from '@ember-data/types/q/identifier';
import type { ChangedAttributesHash, MergeOperation, RecordData } from '@ember-data/types/q/record-data';
import type { AttributesHash, JsonApiResource, JsonApiValidationError } from '@ember-data/types/q/record-data-json-api';
import { AttributeSchema, RelationshipSchema } from '@ember-data/types/q/record-data-schemas';
import { RecordDataStoreWrapper, V2RecordDataStoreWrapper } from '@ember-data/types/q/record-data-store-wrapper';
import { Dict } from '@ember-data/types/q/utils';

import { LocalRelationshipOperation } from './graph/-operations';
import { isImplicit } from './graph/-utils';
import { graphFor, peekGraph } from './graph/index';
import type BelongsToRelationship from './relationships/state/belongs-to';
import type ManyRelationship from './relationships/state/has-many';

const EMPTY_ITERATOR = {
  iterator() {
    return {
      next() {
        return { done: true, value: undefined };
      },
    };
  },
};

/**
  The default cache implementation used by ember-data. The cache
  is configurable and using a different implementation can be
  achieved by implementing the store's createRecordDataFor hook.

  @class RecordDataDefault
  @public
 */

interface CachedResource {
  remoteAttrs: Dict<unknown> | null;
  localAttrs: Dict<unknown> | null;
  inflightAttrs: Dict<unknown> | null;
  changes: Dict<unknown[]> | null;
  errors: JsonApiValidationError[] | null;
  isNew: boolean;
  isDeleted: boolean;
  isDeletionCommitted: boolean;
}

function makeCache(): CachedResource {
  return {
    remoteAttrs: null,
    localAttrs: null,
    inflightAttrs: null,
    changes: null,
    errors: null,
    isNew: false,
    isDeleted: false,
    isDeletionCommitted: false,
  };
}

export default class SingletonRecordData implements RecordData {
  version: '2' = '2';

  __storeWrapper: V2RecordDataStoreWrapper;
  __cache: Map<StableRecordIdentifier, CachedResource> = new Map();
  __destroyedCache: Map<StableRecordIdentifier, CachedResource> = new Map();

  constructor(storeWrapper: V2RecordDataStoreWrapper) {
    this.__storeWrapper = storeWrapper;
  }

  /**
   * Private method used when the store's `createRecordDataFor` hook is called
   * to populate an entry for the identifier into the singleton.
   *
   * @method createCache
   * @private
   * @param identifier
   */
  createCache(identifier: StableRecordIdentifier): void {
    this.__cache.set(identifier, makeCache());
  }

  __peek(identifier: StableRecordIdentifier, allowDestroyed = false): CachedResource {
    let resource = this.__cache.get(identifier);
    if (!resource && allowDestroyed) {
      resource = this.__destroyedCache.get(identifier);
    }
    assert(
      `Expected RecordData Cache to have a resource cache for the identifier ${String(identifier)} but none was found`,
      resource
    );
    return resource;
  }

  pushData(
    identifier: StableRecordIdentifier,
    data: JsonApiResource,
    calculateChanges?: boolean | undefined
  ): void | string[] {
    let changedKeys: string[] | undefined;
    const cached = this.__peek(identifier);

    if (LOG_OPERATIONS) {
      try {
        let _data = JSON.parse(JSON.stringify(data));
        // eslint-disable-next-line no-console
        console.log('EmberData | Operation - pushData (upsert)', _data);
      } catch (e) {
        // eslint-disable-next-line no-console
        console.log('EmberData | Operation - pushData (upsert)', data);
      }
    }

    if (cached.isNew) {
      cached.isNew = false;
      this.__storeWrapper.notifyChange(identifier, 'state');
    }

    if (calculateChanges) {
      changedKeys = calculateChangedKeys(cached, data.attributes);
    }

    cached.remoteAttrs = Object.assign(cached.remoteAttrs || Object.create(null), data.attributes);
    if (cached.localAttrs) {
      if (patchLocalAttributes(cached)) {
        this.__storeWrapper.notifyChange(identifier, 'state');
      }
    }

    if (data.relationships) {
      setupRelationships(this.__storeWrapper, identifier, data);
    }

    if (changedKeys && changedKeys.length) {
      notifyAttributes(this.__storeWrapper, identifier, changedKeys);
    }

    return changedKeys;
  }

  sync(op: MergeOperation): void {
    if (LOG_OPERATIONS) {
      try {
        let _data = JSON.parse(JSON.stringify(op));
        // eslint-disable-next-line no-console
        console.log(`EmberData | Operation - sync ${op.op}`, _data);
      } catch (e) {
        // eslint-disable-next-line no-console
        console.log(`EmberData | Operation - sync ${op.op}`, op);
      }
    }
    if (op.op === 'mergeIdentifiers') {
      const cache = this.__cache.get(op.record);
      if (cache) {
        this.__cache.set(op.value, cache);
        this.__cache.delete(op.record);
      }
      graphFor(this.__storeWrapper).update(op, true);
    }
  }

  update(op: LocalRelationshipOperation): void {
    if (LOG_MUTATIONS) {
      try {
        let _data = JSON.parse(JSON.stringify(op));
        // eslint-disable-next-line no-console
        console.log(`EmberData | Mutation - update ${op.op}`, _data);
      } catch (e) {
        // eslint-disable-next-line no-console
        console.log(`EmberData | Mutation - update ${op.op}`, op);
      }
    }
    graphFor(this.__storeWrapper).update(op, false);
  }

  clientDidCreate(identifier: StableRecordIdentifier, options?: Dict<unknown> | undefined): Dict<unknown> {
    if (LOG_MUTATIONS) {
      try {
        let _data = options ? JSON.parse(JSON.stringify(options)) : options;
        // eslint-disable-next-line no-console
        console.log(`EmberData | Mutation - clientDidCreate ${identifier.lid}`, _data);
      } catch (e) {
        // eslint-disable-next-line no-console
        console.log(`EmberData | Mutation - clientDidCreate ${identifier.lid}`, options);
      }
    }
    const cached = this.__peek(identifier);
    cached.isNew = true;
    let createOptions = {};

    if (options !== undefined) {
      const storeWrapper = this.__storeWrapper;
      let attributeDefs = storeWrapper.getSchemaDefinitionService().attributesDefinitionFor(identifier);
      let relationshipDefs = storeWrapper.getSchemaDefinitionService().relationshipsDefinitionFor(identifier);
      const graph = graphFor(storeWrapper);
      let propertyNames = Object.keys(options);

      for (let i = 0; i < propertyNames.length; i++) {
        let name = propertyNames[i];
        let propertyValue = options[name];

        if (name === 'id') {
          continue;
        }

        const fieldType: AttributeSchema | RelationshipSchema | undefined =
          relationshipDefs[name] || attributeDefs[name];
        let kind = fieldType !== undefined ? ('kind' in fieldType ? fieldType.kind : 'attribute') : null;
        let relationship;

        switch (kind) {
          case 'attribute':
            this.setAttr(identifier, name, propertyValue);
            break;
          case 'belongsTo':
            this.update({
              op: 'replaceRelatedRecord',
              field: name,
              record: identifier,
              value: propertyValue as StableRecordIdentifier | null,
            });
            relationship = graph.get(identifier, name);
            relationship.state.hasReceivedData = true;
            relationship.state.isEmpty = false;
            break;
          case 'hasMany':
            this.update({
              op: 'replaceRelatedRecords',
              field: name,
              record: identifier,
              value: propertyValue as StableRecordIdentifier[],
            });
            relationship = graph.get(identifier, name);
            relationship.state.hasReceivedData = true;
            relationship.state.isEmpty = false;
            break;
          default:
            // reflect back (pass-thru) unknown properties
            createOptions[name] = propertyValue;
        }
      }
    }

    return createOptions;
  }
  willCommit(identifier: StableRecordIdentifier): void {
    const cached = this.__peek(identifier);
    cached.inflightAttrs = cached.localAttrs;
    cached.localAttrs = null;
  }
  didCommit(identifier: StableRecordIdentifier, data: JsonApiResource | null): void {
    const cached = this.__peek(identifier);
    if (cached.isDeleted) {
      graphFor(this.__storeWrapper).push({
        op: 'deleteRecord',
        record: identifier,
        isNew: false,
      });
      cached.isDeletionCommitted = true;
    }

    cached.isNew = false;
    let newCanonicalAttributes: AttributesHash | undefined;
    if (data) {
      if (data.id) {
        // didCommit provided an ID, notify the store of it
        this.__storeWrapper.setRecordId(identifier, data.id);
      }
      if (data.relationships) {
        setupRelationships(this.__storeWrapper, identifier, data);
      }
      newCanonicalAttributes = data.attributes;
    }
    let changedKeys = calculateChangedKeys(cached, newCanonicalAttributes);

    cached.remoteAttrs = Object.assign(
      cached.remoteAttrs || Object.create(null),
      cached.inflightAttrs,
      newCanonicalAttributes
    );
    cached.inflightAttrs = null;
    patchLocalAttributes(cached);

    if (cached.errors) {
      cached.errors = null;
      this.__storeWrapper.notifyChange(identifier, 'errors');
    }

    notifyAttributes(this.__storeWrapper, identifier, changedKeys);
    this.__storeWrapper.notifyChange(identifier, 'state');
  }

  commitWasRejected(identifier: StableRecordIdentifier, errors?: JsonApiValidationError[] | undefined): void {
    const cached = this.__peek(identifier);
    if (cached.inflightAttrs) {
      let keys = Object.keys(cached.inflightAttrs);
      if (keys.length > 0) {
        let attrs = (cached.localAttrs = cached.localAttrs || Object.create(null));
        for (let i = 0; i < keys.length; i++) {
          if (attrs[keys[i]] === undefined) {
            attrs[keys[i]] = cached.inflightAttrs[keys[i]];
          }
        }
      }
      cached.inflightAttrs = null;
    }
    if (errors) {
      cached.errors = errors;
    }
    this.__storeWrapper.notifyChange(identifier, 'errors');
  }

  unloadRecord(identifier: StableRecordIdentifier): void {
    const cached = this.__peek(identifier);
    const storeWrapper = this.__storeWrapper;
    peekGraph(storeWrapper)?.unload(identifier);

    // effectively clearing these is ensuring that
    // we report as `isEmpty` during teardown.
    cached.localAttrs = null;
    cached.remoteAttrs = null;
    cached.inflightAttrs = null;

    let relatedIdentifiers = _allRelatedRecordDatas(storeWrapper, identifier);
    if (areAllModelsUnloaded(storeWrapper, relatedIdentifiers)) {
      for (let i = 0; i < relatedIdentifiers.length; ++i) {
        let identifier = relatedIdentifiers[i];
        storeWrapper.disconnectRecord(identifier);
      }
    }

    this.__cache.delete(identifier);
    this.__destroyedCache.set(identifier, cached);

    /*
     * The destroy cache is a hack to prevent applications
     * from blowing up during teardown. Accessing state
     * on a destroyed record is not safe, but historically
     * was possible due to a combination of teardown timing
     * and retention of a RecordData instance directly on the
     * record itself.
     *
     * Once we have deprecated accessing state on a destroyed
     * instance we may remove this. The timing isn't a huge deal
     * as momentarily retaining the objects outside the bounds
     * of a test won't cause issues.
     */
    if (this.__destroyedCache.size === 1) {
      schedule('destroy', () => {
        setTimeout(() => {
          this.__destroyedCache.clear();
        }, 100);
      });
    }
  }

  getAttr(identifier: StableRecordIdentifier, attr: string): unknown {
    const cached = this.__peek(identifier, true);
    if (cached.localAttrs && attr in cached.localAttrs) {
      return cached.localAttrs[attr];
    } else if (cached.inflightAttrs && attr in cached.inflightAttrs) {
      return cached.inflightAttrs[attr];
    } else if (cached.remoteAttrs && attr in cached.remoteAttrs) {
      return cached.remoteAttrs[attr];
    } else {
      const attrSchema = this.__storeWrapper.getSchemaDefinitionService().attributesDefinitionFor(identifier)[attr];
      return getDefaultValue(attrSchema?.options);
    }
  }
  setAttr(identifier: StableRecordIdentifier, attr: string, value: unknown): void {
    const cached = this.__peek(identifier);
    const existing =
      cached.inflightAttrs && attr in cached.inflightAttrs
        ? cached.inflightAttrs[attr]
        : cached.remoteAttrs && attr in cached.remoteAttrs
        ? cached.remoteAttrs[attr]
        : undefined;
    if (existing !== value) {
      cached.localAttrs = cached.localAttrs || Object.create(null);
      cached.localAttrs![attr] = value;
      cached.changes = cached.changes || Object.create(null);
      cached.changes![attr] = [existing, value];
    } else if (cached.localAttrs) {
      delete cached.localAttrs[attr];
      delete cached.changes![attr];
    }

    this.__storeWrapper.notifyChange(identifier, 'attributes', attr);
  }
  changedAttrs(identifier: StableRecordIdentifier): ChangedAttributesHash {
    // TODO freeze in dev
    return this.__peek(identifier).changes || Object.create(null);
  }
  hasChangedAttrs(identifier: StableRecordIdentifier): boolean {
    const cached = this.__peek(identifier, true);
    return cached.localAttrs !== null && Object.keys(cached.localAttrs).length > 0;
  }
  rollbackAttrs(identifier: StableRecordIdentifier): string[] {
    const cached = this.__peek(identifier);
    let dirtyKeys: string[] | undefined;
    cached.isDeleted = false;

    if (cached.localAttrs !== null) {
      dirtyKeys = Object.keys(cached.localAttrs);
      cached.localAttrs = null;
      cached.changes = null;
    }

    if (cached.isNew) {
      graphFor(this.__storeWrapper).push({
        op: 'deleteRecord',
        record: identifier,
        isNew: true,
      });
      cached.isDeleted = true;
      cached.isNew = false;
    }

    cached.inflightAttrs = null;

    if (cached.errors) {
      cached.errors = null;
      this.__storeWrapper.notifyChange(identifier, 'errors');
    }

    this.__storeWrapper.notifyChange(identifier, 'state');

    if (dirtyKeys && dirtyKeys.length) {
      notifyAttributes(this.__storeWrapper, identifier, dirtyKeys);
    }

    return dirtyKeys || [];
  }

  getRelationship(
    identifier: StableRecordIdentifier,
    field: string
  ): SingleResourceRelationship | CollectionResourceRelationship {
    return (graphFor(this.__storeWrapper).get(identifier, field) as BelongsToRelationship | ManyRelationship).getData();
  }

  setIsDeleted(identifier: StableRecordIdentifier, isDeleted: boolean): void {
    const cached = this.__peek(identifier);
    cached.isDeleted = isDeleted;
    if (cached.isNew) {
      // TODO can we delete this since we will do this in unload?
      graphFor(this.__storeWrapper).push({
        op: 'deleteRecord',
        record: identifier,
        isNew: true,
      });
    }
    this.__storeWrapper.notifyChange(identifier, 'state');
  }
  getErrors(identifier: StableRecordIdentifier): JsonApiValidationError[] {
    return this.__peek(identifier, true).errors || [];
  }
  isEmpty(identifier: StableRecordIdentifier): boolean {
    const cached = this.__peek(identifier, true);
    return cached.remoteAttrs === null && cached.inflightAttrs === null && cached.localAttrs === null;
  }
  isNew(identifier: StableRecordIdentifier): boolean {
    return this.__peek(identifier, true).isNew;
  }
  isDeleted(identifier: StableRecordIdentifier): boolean {
    return this.__peek(identifier, true).isDeleted;
  }
  isDeletionCommitted(identifier: StableRecordIdentifier): boolean {
    return this.__peek(identifier, true).isDeletionCommitted;
  }
}

function areAllModelsUnloaded(wrapper: V2RecordDataStoreWrapper, identifiers: StableRecordIdentifier[]): boolean {
  for (let i = 0; i < identifiers.length; ++i) {
    let identifier = identifiers[i];
    if (wrapper.hasRecord(identifier)) {
      return false;
    }
  }
  return true;
}

function getLocalState(rel) {
  if (rel.definition.kind === 'belongsTo') {
    return rel.localState ? [rel.localState] : [];
  }
  return rel.localState;
}
function getRemoteState(rel) {
  if (rel.definition.kind === 'belongsTo') {
    return rel.remoteState ? [rel.remoteState] : [];
  }
  return rel.remoteState;
}

function getDefaultValue(options: { defaultValue?: unknown } | undefined) {
  if (!options) {
    return;
  }
  if (typeof options.defaultValue === 'function') {
    // If anyone opens an issue for args not working right, we'll restore + deprecate it via a Proxy
    // that lazily instantiates the record. We don't want to provide any args here
    // because in a non @ember-data/model world they don't make sense.
    return options.defaultValue();
  } else {
    let defaultValue = options.defaultValue;
    assert(
      `Non primitive defaultValues are not supported because they are shared between all instances. If you would like to use a complex object as a default value please provide a function that returns the complex object.`,
      typeof defaultValue !== 'object' || defaultValue === null
    );
    return defaultValue;
  }
}

function notifyAttributes(storeWrapper: RecordDataStoreWrapper, identifier: StableRecordIdentifier, keys?: string[]) {
  if (!keys) {
    storeWrapper.notifyChange(identifier, 'attributes');
    return;
  }

  for (let i = 0; i < keys.length; i++) {
    storeWrapper.notifyChange(identifier, 'attributes', keys[i]);
  }
}

/*
      TODO @deprecate IGOR DAVID
      There seems to be a potential bug here, where we will return keys that are not
      in the schema
  */
function calculateChangedKeys(cached: CachedResource, updates?: AttributesHash) {
  let changedKeys: string[] = [];

  if (updates) {
    const keys = Object.keys(updates);
    const length = keys.length;
    const localAttrs = cached.localAttrs;

    const original = Object.assign(Object.create(null), cached.remoteAttrs, cached.inflightAttrs);

    for (let i = 0; i < length; i++) {
      let key = keys[i];
      let value = updates[key];

      // A value in localAttrs means the user has a local change to
      // this attribute. We never override this value when merging
      // updates from the backend so we should not sent a change
      // notification if the server value differs from the original.
      if (localAttrs && localAttrs[key] !== undefined) {
        continue;
      }

      if (!isEqual(original[key], value)) {
        changedKeys.push(key);
      }
    }
  }

  return changedKeys;
}

function setupRelationships(
  storeWrapper: RecordDataStoreWrapper,
  identifier: StableRecordIdentifier,
  data: JsonApiResource
) {
  // TODO @runspired iterating by definitions instead of by payload keys
  // allows relationship payloads to be ignored silently if no relationship
  // definition exists. Ensure there's a test for this and then consider
  // moving this to an assertion. This check should possibly live in the graph.
  const relationships = storeWrapper.getSchemaDefinitionService().relationshipsDefinitionFor(identifier);
  const keys = Object.keys(relationships);
  for (let i = 0; i < keys.length; i++) {
    const relationshipName = keys[i];
    const relationshipData = data.relationships![relationshipName];

    if (!relationshipData) {
      continue;
    }

    graphFor(storeWrapper).push({
      op: 'updateRelationship',
      record: identifier,
      field: relationshipName,
      value: relationshipData,
    });
  }
}

function patchLocalAttributes(cached: CachedResource): boolean {
  const { localAttrs, remoteAttrs, inflightAttrs, changes } = cached;
  if (!localAttrs) {
    return false;
  }
  let hasAppliedPatch = false;
  let mutatedKeys = Object.keys(localAttrs);

  for (let i = 0, length = mutatedKeys.length; i < length; i++) {
    let attr = mutatedKeys[i];
    const existing =
      inflightAttrs && attr in inflightAttrs
        ? inflightAttrs[attr]
        : remoteAttrs && attr in remoteAttrs
        ? remoteAttrs[attr]
        : undefined;

    if (existing === localAttrs[attr]) {
      hasAppliedPatch = true;
      delete localAttrs[attr];
      delete changes![attr];
    }
  }
  return hasAppliedPatch;
}

/*
    Iterates over the set of internal models reachable from `this` across exactly one
    relationship.
  */
function _directlyRelatedRecordDatasIterable(
  storeWrapper: RecordDataStoreWrapper,
  originating: StableRecordIdentifier
) {
  const graph = peekGraph(storeWrapper);
  const initializedRelationships = graph?.identifiers.get(originating);

  if (!initializedRelationships) {
    return EMPTY_ITERATOR;
  }

  const initializedRelationshipsArr: Array<ManyRelationship | BelongsToRelationship> = [];
  Object.keys(initializedRelationships).forEach((key) => {
    const rel = initializedRelationships[key];
    if (rel && !isImplicit(rel)) {
      initializedRelationshipsArr.push(rel);
    }
  });

  let i = 0;
  let j = 0;
  let k = 0;

  const findNext = () => {
    while (i < initializedRelationshipsArr.length) {
      while (j < 2) {
        let relatedIdentifiers =
          j === 0 ? getLocalState(initializedRelationshipsArr[i]) : getRemoteState(initializedRelationshipsArr[i]);
        while (k < relatedIdentifiers.length) {
          let relatedIdentifier = relatedIdentifiers[k++];
          if (relatedIdentifier !== null) {
            return relatedIdentifier;
          }
        }
        k = 0;
        j++;
      }
      j = 0;
      i++;
    }
    return undefined;
  };

  return {
    iterator() {
      return {
        next: () => {
          const value = findNext();
          return { value, done: value === undefined };
        },
      };
    },
  };
}

/*
      Computes the set of Identifiers reachable from this Identifier.

      Reachability is determined over the relationship graph (ie a graph where
      nodes are identifiers and edges are belongs to or has many
      relationships).

      Returns an array including `this` and all identifiers reachable
      from `this.identifier`.
    */
function _allRelatedRecordDatas(
  storeWrapper: RecordDataStoreWrapper,
  originating: StableRecordIdentifier
): StableRecordIdentifier[] {
  let array: StableRecordIdentifier[] = [];
  let queue: StableRecordIdentifier[] = [];
  let seen = new Set();
  queue.push(originating);
  while (queue.length > 0) {
    let identifier = queue.shift()!;
    array.push(identifier);
    seen.add(identifier);

    const iterator = _directlyRelatedRecordDatasIterable(storeWrapper, originating).iterator();
    for (let obj = iterator.next(); !obj.done; obj = iterator.next()) {
      const identifier = obj.value;
      if (identifier && !seen.has(identifier)) {
        seen.add(identifier);
        queue.push(identifier);
      }
    }
  }

  return array;
}