export default class WordMatrix {
  public matrix: number[][]
  private scores: { [key: string]: number } = {}
  private size: number
  private index: { [key: string]: number } = {}

  constructor(private keys: string[]) {
    this.size = keys.length
    this.createIndex()
    this.createZeroMatrix()
  }

  public incField(row: number, col: number) {
    this.matrix[row][col] += 1
  }

  public getRow(row: number): number[] {
    return this.matrix[row]
  }

  public process(values: string[]) {
    const indexes = values.map(key => this.index[key])
    for (const row of indexes) {
      for (const col of indexes) {
        this.matrix[row][col] += 1
      }
    }
  }

  public calculateScores() {
    for (const key of this.keys) {
      const row = this.getRow(this.index[key])
      let deg = 0.0
      let freq = 0.0
      for (const col of row) {
        if (col !== 0) {
          deg += col
          freq += 1
        }
      }
      this.scores[key] = deg / freq
    }
    return this.scores
  }

  private createIndex() {
    const index = {}
    this.keys.forEach((key, i) => (index[key] = i))
    this.index = index
  }

  private createZeroMatrix() {
    const matrix = []
    for (let i = 0; i < this.size; i++) {
      matrix.push(Array(this.size).fill(0))
    }
    this.matrix = matrix
  }
}