datum-focus/src/generation/context.ts

Data shape, model, metadata, JSON, JSON Schema, GraphQL, MongoDB query and aggregations, iterator generators

import { Model } from '../model';
import { KnownRecord } from '../record';

export class GenerationContext<T extends {} = KnownRecord> {
  private readonly generators: Record<string, () => number | string> = {};
  private readonly indexes: Record<
    string,
    Record<number | string, number>
  > = {};

  constructor(
    public readonly collection: T[],
    public readonly target: Model<T>,
    public readonly sources: Record<string, Model>
  ) {
    this.claim = this.claim.bind(this);
    this.find = this.find.bind(this);
  }

  public claim(key: string, val: number | string, index: number): boolean {
    let map = this.indexes[key];
    if (!map) {
      this.indexes[key] = map = {};
    } else if (map[val]) {
      return false;
    }
    map[val] = index;
    return true;
  }

  public find(key: string, val: number | string): number | undefined {
    const map = this.indexes[key];
    return map && map[val];
  }

  public init() {
    Object.entries(this.target.fields).reduce((acc, [key, val]) => {
      return acc;
    }, {});
  }

  public make(): T {
    throw "";
  }

  public push(item: T): number {
    return this.collection.push(item) - 1;
  }
}