api.service.ts

import { Injectable } from '@angular/core';

export interface RawData {
  index: string[][];
  values: number[][];
}

export interface LshData {
  candidates: number[][][];
  distances: number[][][];
  average_candidates: number[];
  average_distances: number[];
  tables: {[bucket: string]: number[]}[];
  average_table: {[bucket: string]: number[]};
  samples: number[];
  hash_functions: number[][];
  parameters?: number[];
}

export interface TableInfoData {
  prototypes: {
    average: number[][];
    min: number[][];
    max: number[][];
  }[];
  distances: number[][];
}

export interface Parameters {
  windowsize: number;
  hashsize: number;
  tablesize: number;
  stepsize: number;
}

@Injectable({
  providedIn: 'root'
})
/**
 * This service acts as the interface between the client and server side.
 */
export class ApiService {

  constructor() { }

  /**
   * Read input data. The format is a list of channels, where each channel is an object of type RawData
   */
  async readFile(): Promise<RawData[]> {
    const response = await fetch('http://127.0.0.1:5000/read-data');
    return await response.json();
  }

  /**
   * Split the data into windows (server side)
   */
  async createWindows(parameters: Parameters): Promise<any> {
    const postData = {parameters};
    await fetch('http://127.0.0.1:5000/create-windows', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(postData)
    });
  }

  /**
   * Get weights which will be applied to the LSH hash functions
   */
  async getWeights(query: number[][], labels: {[index: number]: boolean}, weights: number[], hash_functions: number[][]): Promise<number[]> {
    const response = await fetch('http://127.0.0.1:5000/weights', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: new Blob( [ JSON.stringify({query, labels, weights, hash_functions}) ], { type: 'text/plain' } )
    });
    return await response.json();
  }

  /**
   * Do the first iteration of LSH and return important information
   */
  async lshInitial(query: number[][]): Promise<LshData> {
    const response = await fetch('http://127.0.0.1:5000/initialize', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: new Blob( [ JSON.stringify({query}) ], { type: 'text/plain' } )
    });
    return await response.json();
  }

  /**
   * Do another iteration of LSH, with weights, and return important information
   */
  async lshUpdate(query, weights, parameters): Promise<LshData> {
    const response = await fetch('http://127.0.0.1:5000/update', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: new Blob( [ JSON.stringify({query, weights, parameters}) ], { type: 'text/plain' } )
    });
    return await response.json();
  }

  /**
   * Get query window based on windows labeled correct
   */
  async getQueryWindow(indices: number | {[index: number]: boolean}): Promise<number[][]> {
    const response = await fetch('http://127.0.0.1:5000/query', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({indices})
    });
    return await response.json();
  }

  /**
   * Get data of a window by indices
   */
  async getWindowByIndices(indices: number[]): Promise<number[][][]> {
    const response = await fetch('http://127.0.0.1:5000/window', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({indices})
    });
    return await response.json();
  }

  /**
   * Get additional information for a given table
   */
  async getTableInfo(table: number[][]): Promise<TableInfoData> {
    const response = await fetch('http://127.0.0.1:5000/table-info', {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({table})
    });
    return await response.json();
  }
}