import {
  FormattableData,
  InputOutputValue,
  INumberArray,
  INumberHash,
  ITrainingDatum,
  lookup,
} from '../lookup';
import { ArrayLookupTable } from '../utilities/array-lookup-table';
import {
  arraysToFloat32Arrays,
  arrayToFloat32Arrays,
  inputOutputArraysToFloat32Arrays,
  inputOutputArrayToFloat32Arrays,
  inputOutputObjectsToFloat32Arrays,
  inputOutputObjectToFloat32Arrays,
  objectToFloat32Array,
  objectToFloat32Arrays,
} from '../utilities/cast';
import { LookupTable } from '../utilities/lookup-table';
import { randomFloat } from '../utilities/random';
import { IMatrixJSON, Matrix } from './matrix';
import { Equation } from './matrix/equation';
import { maxI } from './matrix/max-i';
import { RandomMatrix } from './matrix/random-matrix';
import { sampleI } from './matrix/sample-i';
import { softmax } from './matrix/softmax';
import {
  defaults as rnnDefaults,
  IRNNHiddenLayer,
  IRNNHiddenLayerModel,
  IRNNOptions,
  IRNNStatus,
  IRNNTrainingOptions,
  last,
  RNN,
  trainDefaults as rnnTrainDefaults,
} from './rnn';

export type ValuesOf<
  T extends InputOutputValue | InputOutputValue[]
> = T[number];

export interface IRNNTimeStepOptions extends IRNNTimeStepJSONOptions {
  inputSize: number;
  inputRange: number;
  hiddenLayers: number[];
  outputSize: number;
  decayRate: number;
  smoothEps: number;
  regc: number;
  clipval: number;
  maxPredictionLength: number;
  json?: IRNNTimeStepJSON;
}

export interface IRNNTimeStepJSONOptions {
  inputSize: number;
  inputRange: number;
  hiddenLayers: number[];
  outputSize: number;
  decayRate: number;
  smoothEps: number;
  regc: number;
  clipval: number;
  maxPredictionLength: number;
}

export interface IRNNTimeStepJSON {
  type: string;
  options: IRNNTimeStepJSONOptions;
  hiddenLayers: Array<{ [index: string]: IMatrixJSON }>;
  outputConnector: IMatrixJSON;
  output: IMatrixJSON;
  inputLookup: INumberHash | null;
  inputLookupLength: number;
  outputLookup: INumberHash | null;
  outputLookupLength: number;
}

export interface IMisclass {
  value: FormattableData;
  actual: FormattableData;
}

export interface ITestResults {
  misclasses: IMisclass[];
  error: number;
  total: number;
}

export interface IRNNTimeStepModel {
  isInitialized: boolean;
  hiddenLayers: IRNNHiddenLayer[];
  output: Matrix;
  equations: Equation[];
  allMatrices: Matrix[];
  equationConnections: Matrix[][];
  outputConnector: RandomMatrix | Matrix;
}

export const defaults = (): IRNNOptions => {
  return {
    ...rnnDefaults(),
    inputSize: 1,
    hiddenLayers: [20],
    outputSize: 1,
    inputRange: 0,
  };
};

export class RNNTimeStep extends RNN {
  inputLookupLength = 0;
  inputLookup: INumberHash | null = null;
  outputLookup: INumberHash | null = null;
  outputLookupLength = 0;

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  model: IRNNTimeStepModel = Object.seal({
    isInitialized: false,
    hiddenLayers: [],
    output: new Matrix(0, 0),
    equations: [],
    allMatrices: [],
    equationConnections: [],
    outputConnector: new RandomMatrix(0, 0, 0.08),
  });

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  options: IRNNTimeStepOptions = defaults();
  constructor(
    options: Partial<IRNNTimeStepOptions & IRNNTrainingOptions> = {}
  ) {
    super();
    this.options = { ...this.options, ...options };
    this.updateTrainingOptions({
      ...trainDefaults,
      ...options,
    });

    if (options.json) {
      this.fromJSON(options.json);
    }
  }

  createInputMatrix(): RandomMatrix {
    throw new Error('Input Matrices do not exist on RNNTimeStep');
  }

  createOutputMatrices(): { outputConnector: RandomMatrix; output: Matrix } {
    const { outputSize } = this.options;
    const lastHiddenSize = last(this.options.hiddenLayers);

    // whd
    const outputConnector = new RandomMatrix(outputSize, lastHiddenSize, 0.08);
    // bd
    const output = new RandomMatrix(outputSize, 1, 0.08);
    return { output, outputConnector };
  }

  bindEquation(): void {
    const { model, options } = this;
    const { hiddenLayers, inputSize } = options;
    const layers = model.hiddenLayers;
    const equation = new Equation();
    const outputs = [];
    const equationConnection =
      model.equationConnections.length > 0
        ? model.equationConnections[model.equationConnections.length - 1]
        : this.initialLayerInputs;
    // 0 index
    let output = this.getEquation(
      equation,
      equation.input(new Matrix(inputSize, 1)),
      equationConnection[0],
      layers[0]
    );
    outputs.push(output);
    // 1+ indices
    for (let i = 1, max = hiddenLayers.length; i < max; i++) {
      output = this.getEquation(
        equation,
        output,
        equationConnection[i],
        layers[i]
      );
      outputs.push(output);
    }

    model.equationConnections.push(outputs);
    equation.add(
      equation.multiply(model.outputConnector, output),
      model.output
    );
    model.equations.push(equation);
  }

  initialize(): void {
    this.model = this.mapModel();
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  mapModel(): IRNNTimeStepModel {
    const allMatrices: Matrix[] = [];
    this.initialLayerInputs = this.options.hiddenLayers.map(
      (size) => new Matrix(size, 1)
    );

    const hiddenLayers = this.createHiddenLayers();
    for (let i = 0, max = hiddenLayers.length; i < max; i++) {
      const hiddenMatrix = hiddenLayers[i];
      for (const property in hiddenMatrix) {
        if (!hiddenMatrix.hasOwnProperty(property)) continue;
        allMatrices.push(hiddenMatrix[property]);
      }
    }

    const { outputConnector, output } = this.createOutputMatrices();

    allMatrices.push(outputConnector);
    allMatrices.push(output);
    return Object.seal({
      isInitialized: true,
      hiddenLayers,
      output,
      equations: [],
      allMatrices,
      equationConnections: [],
      outputConnector,
    });
  }

  backpropagate(): void {
    for (let i = this.model.equations.length - 1; i > -1; i--) {
      this.model.equations[i].backpropagate();
    }
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  run<InputType extends InputOutputValue | InputOutputValue[]>(
    rawInput: InputType
  ): ValuesOf<InputType> {
    const shape = lookup.dataShape(rawInput).join(',');
    switch (shape) {
      case 'array,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.runArray(rawInput as Float32Array);
      case 'array,array,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.runArrayOfArray(rawInput as Float32Array[]);
      case 'object,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.runObject(rawInput as INumberHash); // Backward compatibility, will be result of `unknown` and need casting.  Better to just use net.runObject() directly
      case 'array,object,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.runArrayOfObject(rawInput as INumberHash[]);
      default:
        throw new Error(`Unrecognized data shape ${shape}`);
    }
  }

  forecast<InputType extends InputOutputValue | InputOutputValue[]>(
    rawInput: InputType,
    count = 1
  ): InputType {
    const shape = lookup.dataShape(rawInput).join(',');
    switch (shape) {
      case 'array,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.forecastArray(rawInput as Float32Array, count);
      case 'array,array,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.forecastArrayOfArray(rawInput as Float32Array[], count);
      case 'object,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.runObject(rawInput as INumberHash);
      case 'array,object,number':
        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
        // @ts-expect-error
        return this.forecastArrayOfObject(rawInput as INumberHash[], count);
      default:
        throw new Error(`Unrecognized data shape ${shape}`);
    }
  }

  forecastArray(input: Float32Array, count = 1): Float32Array {
    this.checkRunnable();
    const { model } = this;
    const { equations } = model;
    const length = input.length + count;
    while (equations.length <= length) {
      this.bindEquation();
    }
    let lastOutput;
    let equationIndex = 0;
    if (this.options.inputSize === 1) {
      for (let i = 0; i < input.length; i++) {
        lastOutput = equations[equationIndex++].runInput(
          Float32Array.from([input[i]])
        );
      }
    } else {
      for (let i = 0; i < input.length; i++) {
        lastOutput = equations[equationIndex++].runInput(Float32Array.from([]));
      }
    }
    if (!lastOutput) {
      throw new Error('lastOutput not set');
    }
    const result = [lastOutput.weights[0]];
    for (let i = 0, max = count - 1; i < max; i++) {
      lastOutput = equations[equationIndex++].runInput(lastOutput.weights);
      result.push(lastOutput.weights[0]);
    }
    this.end();
    return Float32Array.from(result);
  }

  forecastArrayOfArray(input: Float32Array[], count = 1): Float32Array[] {
    this.checkRunnable();
    const { model } = this;
    const { equations } = model;
    const length = input.length + count;
    while (equations.length <= length) {
      this.bindEquation();
    }
    let lastOutput;
    let equationIndex = 0;
    for (let i = 0; i < input.length; i++) {
      lastOutput = equations[equationIndex++].runInput(input[i]);
    }
    if (!lastOutput) {
      throw new Error('lastOutput not set');
    }
    const result = [Float32Array.from(lastOutput.weights)];
    for (let i = 0, max = count - 1; i < max; i++) {
      lastOutput = equations[equationIndex++].runInput(lastOutput.weights);
      result.push(Float32Array.from(lastOutput.weights.slice(0)));
    }
    this.end();
    return result;
  }

  forecastArrayOfObject(input: INumberHash[], count = 1): INumberHash[] {
    if (!this.inputLookup) {
      throw new Error('this.inputLookup not set');
    }
    if (!this.outputLookup) {
      throw new Error('this.outputLookup not set');
    }
    const formattedData = input.map((value) =>
      lookup.toArray(
        this.inputLookup as INumberHash,
        value,
        this.inputLookupLength
      )
    );
    return this.forecastArrayOfArray(formattedData, count).map((value) =>
      lookup.toObject(this.outputLookup as INumberHash, value)
    );
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  train(
    data: FormattableData[],
    trainOpts: Partial<IRNNTrainingOptions> = {}
  ): IRNNStatus {
    this.trainOpts = trainOpts = {
      ...rnnTrainDefaults,
      ...trainOpts,
    };
    // Don't destructure here because this.setSize() can reset this.options.
    if (this.options.inputSize === 1 && this.options.outputSize === 1) {
      this.setSize(data);
    }
    this.verifySize();

    const formattedData = this.formatData(data);
    let error = Infinity;
    let i;

    this.verifyIsInitialized();
    const {
      iterations,
      errorThresh,
      logPeriod,
      callback,
      callbackPeriod,
    } = this.trainOpts;
    const log = trainOpts.log === true ? console.log : trainOpts.log;
    for (i = 0; i < iterations && error > errorThresh; i++) {
      let sum = 0;
      for (let j = 0; j < formattedData.length; j++) {
        const err = this.trainPattern(formattedData[j], true);
        sum += err;
      }
      error = sum / formattedData.length;

      if (isNaN(error))
        throw new Error(
          'Network error rate is unexpected NaN, check network configurations and try again. Most probably input format is not correct or training data is not enough. '
        );
      if (log && i % logPeriod === 0) {
        log(`iterations: ${i}, training error: ${error}`);
      }
      if (callback && i % callbackPeriod === 0) {
        callback({ error, iterations: i });
      }
    }

    return {
      error,
      iterations: i,
    };
  }

  trainArrayOfArray(input: Float32Array[]): number {
    if (input.length < 2) {
      throw new Error('input must be an array of 2 or more');
    }
    const { equations } = this.model;
    while (equations.length < input.length) {
      this.bindEquation();
    }
    let errorSum = 0;
    for (let i = 0, max = input.length - 1; i < max; i++) {
      errorSum += equations[i].predictTarget(input[i], input[i + 1]);
    }
    this.end();
    return errorSum / input.length;
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  trainPattern(input: Float32Array[], logErrorRate?: boolean): number {
    const error = this.trainArrayOfArray(input);
    this.backpropagate();
    this.adjustWeights();

    if (logErrorRate) {
      return error;
    }
    return 0;
  }

  setSize(data: FormattableData[]): void {
    let size = 0;
    const dataShape = lookup.dataShape(data).join(',');
    switch (dataShape) {
      case 'array,array,number':
      case 'array,object,number':
      case 'array,datum,array,number':
      case 'array,datum,object,number':
        size = 1;
        // probably 1
        break;
      case 'array,array,array,number':
        size = (data as number[][][])[0][0].length;
        break;
      case 'array,array,object,number':
        // inputs and outputs should match
        size = Object.keys(lookup.toTable2D(data as INumberHash[][])).length;
        break;
      case 'array,datum,array,array,number':
        size = ((data as unknown) as Array<{
          [key: string]: number[][];
        }>)[0].input[0].length;
        break;
      case 'array,datum,array,object,number':
        size = Object.keys(
          lookup.toInputTable2D(
            data as Array<{ input: Array<{ [key: string]: number }> }>
          )
        ).length;
        break;
      default:
        throw new Error('unknown data shape or configuration');
    }
    this.options = Object.seal({
      ...this.options,
      inputSize: size,
      outputSize: size,
    });
  }

  verifySize(): void {
    if (this.options.inputSize || this.options.outputSize) {
      if (this.options.inputSize !== this.options.outputSize) {
        throw new Error('manually set inputSize and outputSize mismatch');
      }
    }
  }

  runArray(input: Float32Array): number {
    this.checkRunnable();
    const { equations } = this.model;
    while (equations.length <= input.length) {
      this.bindEquation();
    }
    let lastOutput;
    for (let i = 0; i < input.length; i++) {
      lastOutput = equations[i].runInput(new Float32Array([input[i]]));
    }
    this.end();
    return (lastOutput as Matrix).weights[0];
  }

  runArrayOfArray(input: Float32Array[]): Float32Array {
    this.checkRunnable();
    const { model } = this;
    const { equations } = model;
    while (equations.length <= input.length) {
      this.bindEquation();
    }
    let lastOutput;
    for (let i = 0; i < input.length; i++) {
      const outputMatrix = equations[i].runInput(input[i]);
      lastOutput = outputMatrix.weights;
    }
    this.end();
    return lastOutput ?? Float32Array.from([]);
  }

  runObject(input: INumberHash): INumberHash {
    if (!this.inputLookup) {
      throw new Error('this.inputLookup not set');
    }
    if (!this.outputLookup) {
      throw new Error('this.outputLookup not set');
    }
    if (!this.outputLookupLength) {
      throw new Error('this.outputLookupLength not set');
    }
    if (this.inputLookup === this.outputLookup) {
      const inputArray = lookup.toArrayShort(this.inputLookup, input);
      return lookup.toObjectPartial(
        this.outputLookup,
        this.forecastArray(
          inputArray,
          this.outputLookupLength - inputArray.length
        ),
        inputArray.length
      );
    }
    return lookup.toObject(
      this.outputLookup,
      this.forecastArray(
        lookup.toArray(this.inputLookup, input, this.inputLookupLength),
        this.outputLookupLength
      )
    );
  }

  runArrayOfObject(input: INumberHash[]): INumberHash {
    if (this.inputLookup === null) {
      throw new Error('this.inputLookup not set');
    }
    if (this.outputLookup === null) {
      throw new Error('this.outputLookup not set');
    }
    const formattedInput = input.map((value) =>
      lookup.toArray(
        this.inputLookup as INumberHash,
        value,
        this.inputLookupLength
      )
    );
    return this.forecastArrayOfArray(formattedInput, 1).map((value) =>
      lookup.toObject(this.outputLookup as INumberHash, value)
    )[0];
  }

  runArrayOfObjectOfArray(input: INumberHash[]): INumberHash {
    if (!this.inputLookup) {
      throw new Error('this.inputLookup not set');
    }
    if (!this.outputLookup) {
      throw new Error('this.outputLookup not set');
    }
    return lookup.toObject(
      this.outputLookup,
      this.runArrayOfArray(
        lookup.toArrays(this.inputLookup, input, this.inputLookupLength)
      )
    );
  }

  end(): void {
    this.model.equations[this.model.equations.length - 1].runInput(
      new Float32Array(this.options.outputSize)
    );
  }

  requireInputOutputOfOne(): void {
    if (this.options.inputSize !== 1) {
      throw new Error('inputSize must be 1 for this data size');
    }
    if (this.options.outputSize !== 1) {
      throw new Error('outputSize must be 1 for this data size');
    }
  }

  // Handles data shape of 'array,number'
  formatArray(data: number[]): Float32Array[][] {
    const result = [];
    this.requireInputOutputOfOne();
    for (let i = 0; i < data.length; i++) {
      result.push(Float32Array.from([data[i]]));
    }
    return [result];
  }

  // Handles data shape of 'array,array,number'
  formatArrayOfArray(data: number[][]): Float32Array[][] {
    const result = [];
    const { inputSize, outputSize } = this.options;
    if (inputSize === 1 && outputSize === 1) {
      for (let i = 0; i < data.length; i++) {
        result.push(arrayToFloat32Arrays(data[i]));
      }
      return result;
    }
    if (inputSize !== data[0].length) {
      throw new Error('inputSize must match data input size');
    }
    if (outputSize !== data[0].length) {
      throw new Error('outputSize must match data output size');
    }
    for (let i = 0; i < data.length; i++) {
      result.push(Float32Array.from(data[i]));
    }
    return [result];
  }

  // Handles data shape of 'array,object,number'
  formatArrayOfObject(data: INumberHash[]): Float32Array[][] {
    this.requireInputOutputOfOne();
    if (!this.inputLookup) {
      const lookupTable = new LookupTable(data);
      this.inputLookup = this.outputLookup = lookupTable.table;
      this.inputLookupLength = this.outputLookupLength = lookupTable.length;
    }
    const result = [];
    for (let i = 0; i < data.length; i++) {
      result.push(objectToFloat32Arrays(data[i]));
    }
    return result;
  }

  // Handles data shape of 'array,object,number' when this.options.inputSize > 1
  formatArrayOfObjectMulti(data: INumberHash[]): Float32Array[][] {
    if (!this.inputLookup) {
      const lookupTable = new LookupTable(data);
      this.inputLookup = this.outputLookup = lookupTable.table;
      this.inputLookupLength = this.outputLookupLength = lookupTable.length;
    }
    const result = [];
    for (let i = 0; i < data.length; i++) {
      result.push([
        objectToFloat32Array(data[i], this.inputLookup, this.inputLookupLength),
      ]);
    }
    return result;
  }

  // Handles data shape of 'array,datum,array,number'
  formatArrayOfDatumOfArray(data: ITrainingDatum[]): Float32Array[][] {
    const result = [];
    this.requireInputOutputOfOne();
    for (let i = 0; i < data.length; i++) {
      const datum = data[i];
      result.push(
        inputOutputArrayToFloat32Arrays(
          datum.input as number[],
          datum.output as number[]
        )
      );
    }
    return result;
  }

  // Handles data shape of 'array,datum,object,number'
  formatArrayOfDatumOfObject(data: ITrainingDatum[]): Float32Array[][] {
    this.requireInputOutputOfOne();
    if (!this.inputLookup) {
      const inputLookup = new LookupTable(data, 'input');
      this.inputLookup = inputLookup.table;
      this.inputLookupLength = inputLookup.length;
    }
    if (!this.outputLookup) {
      const outputLookup = new LookupTable(data, 'output');
      this.outputLookup = outputLookup.table;
      this.outputLookupLength = outputLookup.length;
    }
    const result = [];
    for (let i = 0; i < data.length; i++) {
      const datum = data[i];
      result.push(
        inputOutputObjectToFloat32Arrays(
          datum.input as INumberHash,
          datum.output as INumberHash
        )
      );
    }
    return result;
  }

  // Handles data shape of 'array,array,array,number'
  formatArrayOfArrayOfArray(data: number[][][]): Float32Array[][] {
    const result = [];
    for (let i = 0; i < data.length; i++) {
      result.push(arraysToFloat32Arrays(data[i]));
    }
    return result;
  }

  // Handles data shape of 'array,array,object,number'
  formatArrayOfArrayOfObject(data: INumberHash[][]): Float32Array[][] {
    if (!this.inputLookup) {
      const lookupTable = new LookupTable(data);
      this.inputLookup = this.outputLookup = lookupTable.table;
      this.inputLookupLength = this.outputLookupLength = lookupTable.length;
    }
    const result = [];
    for (let i = 0; i < data.length; i++) {
      const array = [];
      for (let j = 0; j < data[i].length; j++) {
        array.push(
          objectToFloat32Array(
            data[i][j],
            this.inputLookup,
            this.inputLookupLength
          )
        );
      }
      result.push(array);
    }
    return result;
  }

  // Handles data shape of 'array,datum,array,array,number'
  formatArrayOfDatumOfArrayOfArray(data: ITrainingDatum[]): Float32Array[][] {
    const result = [];
    const { inputSize, outputSize } = this.options;
    if (inputSize !== (data[0].input as INumberArray[][])[0].length) {
      throw new Error('inputSize must match data input size');
    }
    if (outputSize !== (data[0].output as INumberArray[][])[0].length) {
      throw new Error('outputSize must match data output size');
    }
    for (let i = 0; i < data.length; i++) {
      const datum = data[i];
      result.push(
        inputOutputArraysToFloat32Arrays(
          datum.input as number[][],
          datum.output as number[][]
        )
      );
    }
    return result;
  }

  // 'Handles data shape of array,datum,array,object,number'
  formatArrayOfDatumOfArrayOfObject(
    data: Array<{
      input: Array<Record<string, number>>;
      output: Array<Record<string, number>>;
    }>
  ): Float32Array[][] {
    if (!this.inputLookup) {
      const inputLookup = new ArrayLookupTable(data, 'input');
      this.inputLookup = inputLookup.table;
      this.inputLookupLength = inputLookup.length;
    }
    if (!this.outputLookup) {
      const outputLookup = new ArrayLookupTable(data, 'output');
      this.outputLookup = outputLookup.table;
      this.outputLookupLength = outputLookup.length;
    }
    if (!this.outputLookupLength) {
      throw new Error('this.outputLookupLength not set to usable number');
    }
    const result = [];
    for (let i = 0; i < data.length; i++) {
      const datum = data[i];
      result.push(
        inputOutputObjectsToFloat32Arrays(
          datum.input,
          datum.output,
          this.inputLookup,
          this.outputLookup,
          this.inputLookupLength,
          this.outputLookupLength
        )
      );
    }
    return result;
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  formatData(data: FormattableData[]): Float32Array[][] {
    const dataShape = lookup.dataShape(data).join(',');
    switch (dataShape) {
      case 'array,number':
        return this.formatArray(data as number[]);
      case 'array,array,number':
        return this.formatArrayOfArray(data as number[][]);
      case 'array,object,number':
        if (this.options.inputSize === 1) {
          return this.formatArrayOfObject(data as INumberHash[]);
        } else {
          return this.formatArrayOfObjectMulti(data as INumberHash[]);
        }
      case 'array,datum,array,number':
        return this.formatArrayOfDatumOfArray(data as ITrainingDatum[]);
      case 'array,datum,object,number':
        return this.formatArrayOfDatumOfObject(data as ITrainingDatum[]);
      case 'array,array,array,number':
        return this.formatArrayOfArrayOfArray(data as number[][][]);
      case 'array,array,object,number':
        return this.formatArrayOfArrayOfObject(data as INumberHash[][]);
      case 'array,datum,array,array,number':
        return this.formatArrayOfDatumOfArrayOfArray(data as ITrainingDatum[]);
      case 'array,datum,array,object,number':
        return this.formatArrayOfDatumOfArrayOfObject(
          data as Array<{
            input: Array<Record<string, number>>;
            output: Array<Record<string, number>>;
          }>
        );
      default:
        throw new Error('unknown data shape or configuration');
    }
  }

  test(data: FormattableData[]): ITestResults {
    // for classification problems
    const misclasses = [];
    // run each pattern through the trained network and collect
    // error and misclassification statistics
    let errorSum = 0;
    const formattedData = this.formatData(data);
    for (let i = 0; i < formattedData.length; i++) {
      const input = formattedData[i];
      const output = this.run(input.splice(0, input.length - 1));
      const target = input[input.length - 1];
      let errors = 0;
      let errorCount = 0;
      for (let j = 0; j < output.length; j++) {
        errorCount++;
        const error = target[j] - output[j];
        // mse
        errors += error * error;
      }
      errorSum += errors / errorCount;
      const errorsAbs = Math.abs(errors);
      if (errorsAbs > this.trainOpts.errorThresh) {
        const misclass = (data as number[][][])[i];
        misclasses.push({
          value: misclass,
          actual: output,
        });
      }
    }
    return {
      error: errorSum / formattedData.length,
      misclasses,
      total: formattedData.length,
    };
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  addFormat(value: FormattableData): void {
    const dataShape = lookup.dataShape(value).join(',');
    switch (dataShape) {
      case 'array,array,number':
      case 'datum,array,array,number':
      case 'array,number':
      case 'datum,array,number':
        return;
      case 'datum,object,number': {
        this.inputLookup = lookup.addKeys(
          (value as ITrainingDatum).input as INumberHash,
          this.inputLookup ?? {}
        );
        if (this.inputLookup) {
          this.inputLookupLength = Object.keys(this.inputLookup).length;
        }
        this.outputLookup = lookup.addKeys(
          (value as ITrainingDatum).output as INumberHash,
          this.outputLookup ?? {}
        );
        if (this.outputLookup) {
          this.outputLookupLength = Object.keys(this.outputLookup).length;
        }
        break;
      }
      case 'object,number': {
        this.inputLookup = this.outputLookup = lookup.addKeys(
          value as INumberHash,
          this.inputLookup ?? {}
        );
        if (this.inputLookup) {
          this.inputLookupLength = this.outputLookupLength = Object.keys(
            this.inputLookup
          ).length;
        }
        break;
      }
      case 'array,object,number': {
        const typedValue = value as INumberHash[];
        for (let i = 0; i < typedValue.length; i++) {
          this.inputLookup = this.outputLookup = lookup.addKeys(
            typedValue[i],
            this.inputLookup ?? {}
          );
          if (this.inputLookup) {
            this.inputLookupLength = this.outputLookupLength = Object.keys(
              this.inputLookup
            ).length;
          }
        }
        break;
      }
      case 'datum,array,object,number': {
        const typedValue = value as ITrainingDatum;
        const typedInput = typedValue.input as INumberHash[];
        for (let i = 0; i < typedInput.length; i++) {
          this.inputLookup = lookup.addKeys(
            typedInput[i],
            this.inputLookup ?? {}
          );
          if (this.inputLookup) {
            this.inputLookupLength = Object.keys(this.inputLookup).length;
          }
        }
        const typedOutput = typedValue.output as INumberHash[];
        for (let i = 0; i < typedOutput.length; i++) {
          this.outputLookup = lookup.addKeys(
            typedOutput[i],
            this.outputLookup ?? {}
          );
          if (this.outputLookup) {
            this.outputLookupLength = Object.keys(this.outputLookup).length;
          }
        }
        break;
      }

      default:
        throw new Error('unknown data shape or configuration');
    }
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  toJSON(): IRNNTimeStepJSON {
    if (!this.model) {
      this.initialize();
    }
    const { model } = this;
    const options = { ...this.options, ...rnnDefaults };

    return {
      type: this.constructor.name,
      options,
      hiddenLayers: model.hiddenLayers.map((hiddenLayer) => {
        const layers: { [index: string]: IMatrixJSON } = {};
        for (const p in hiddenLayer) {
          if (!hiddenLayer.hasOwnProperty(p)) continue;
          layers[p] = hiddenLayer[p].toJSON();
        }
        return layers;
      }),
      outputConnector: model.outputConnector.toJSON(),
      output: model.output.toJSON(),
      inputLookup: this.inputLookup,
      inputLookupLength: this.inputLookupLength,
      outputLookup: this.outputLookup,
      outputLookupLength: this.outputLookupLength,
    };
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  fromJSON(json: IRNNTimeStepJSON): this {
    const { options } = json;
    const allMatrices = [];
    const hiddenLayers: IRNNHiddenLayerModel[] = [];

    // backward compatibility for hiddenSizes
    json.hiddenLayers.forEach((hiddenLayer) => {
      const layers: { [index: string]: Matrix } = {};
      for (const p in hiddenLayer) {
        layers[p] = Matrix.fromJSON(hiddenLayer[p]);
        allMatrices.push(layers[p]);
      }
      hiddenLayers.push(layers as IRNNHiddenLayerModel);
    });

    const outputConnector = Matrix.fromJSON(json.outputConnector);
    allMatrices.push(outputConnector);
    const output = Matrix.fromJSON(json.output);
    allMatrices.push(output);

    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
    // @ts-expect-error
    this.options = { ...defaults(), ...options };
    this.inputLookup = json.inputLookup;
    this.inputLookupLength = json.inputLookupLength;
    this.outputLookup = json.outputLookup;
    this.outputLookupLength = json.outputLookupLength;

    this.model = Object.seal({
      isInitialized: true,
      hiddenLayers,
      output,
      allMatrices,
      outputConnector,
      equations: [],
      equationConnections: [],
    });
    this.initialLayerInputs = options.hiddenLayers.map(
      (size) => new Matrix(size, 1)
    );
    this.bindEquation();
    return this;
  }

  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-expect-error
  toFunction(cb?: (src: string) => string): RNNTimeStepFunction {
    const {
      model,
      inputLookup,
      inputLookupLength,
      outputLookup,
      outputLookupLength,
    } = this;
    const { inputSize } = this.options;
    const { equations } = model;
    const equation = equations[1];
    const { states } = equation;
    const jsonString = JSON.stringify(this.toJSON());

    function previousConnectionIndex(m: Matrix) {
      const connection = model.equationConnections[0];
      const { states } = equations[0];
      for (let i = 0, max = states.length; i < max; i++) {
        if (states[i].product === m) {
          return i;
        }
      }
      return connection.indexOf(m);
    }

    function matrixOrigin(m: Matrix, stateIndex: number): string {
      for (let i = 0, max = states.length; i < max; i++) {
        const state = states[i];

        if (i === stateIndex) {
          const j = previousConnectionIndex(m);
          switch (m) {
            case state.left:
              if (j > -1) {
                return `typeof prevStates[${j}] === 'object' ? prevStates[${j}].product : new Matrix(${m.rows}, ${m.columns})`;
              }
            // eslint-disable-next-line no-fallthrough
            case state.right:
              if (j > -1) {
                return `typeof prevStates[${j}] === 'object' ? prevStates[${j}].product : new Matrix(${m.rows}, ${m.columns})`;
              }
            // eslint-disable-next-line no-fallthrough
            case state.product:
              return `new Matrix(${m.rows}, ${m.columns})`;
            default:
              throw Error('unknown state');
          }
        }

        if (m === state.product) return `states[${i}].product`;
        if (m === state.right) return `states[${i}].right`;
        if (m === state.left) return `states[${i}].left`;
      }
      return '';
    }

    function matrixToString(m: Matrix, stateIndex: number): string {
      if (!m || !m.rows || !m.columns) return 'null';
      if (m === model.outputConnector) return `json.outputConnector`;
      if (m === model.output) return `json.output`;

      for (let i = 0, max = model.hiddenLayers.length; i < max; i++) {
        const hiddenLayer = model.hiddenLayers[i];
        for (const p in hiddenLayer) {
          if (!hiddenLayer.hasOwnProperty(p)) continue;
          if (hiddenLayer[p] !== m) continue;
          return `json.hiddenLayers[${i}].${p}`;
        }
      }

      return matrixOrigin(m, stateIndex);
    }

    function formatInputData() {
      if (!inputLookup) return '';
      if (inputSize === 1) {
        if (inputLookup === outputLookup) {
          return `function lookupInput(input) {
            var table = ${JSON.stringify(inputLookup)};
            var result = [];
            for (var p in table) {
              if (!input.hasOwnProperty(p)) break;
              result.push(Float32Array.from([input[p]]));
            }
            return result;
          }`;
        }
        return `function lookupInput(input) {
          var table = ${JSON.stringify(inputLookup)};
          var result = [];
          for (var p in table) {
            result.push(Float32Array.from([input[p]]));
          }
          return result;
        }`;
      }
      return `function lookupInput(rawInputs) {
        var table = ${JSON.stringify(inputLookup)};
        var result = [];
        for (var i = 0; i < rawInputs.length; i++) {
          var rawInput = rawInputs[i];
          var input = new Float32Array(${inputLookupLength});
          for (var p in table) {
            input[table[p]] = rawInput.hasOwnProperty(p) ? rawInput[p] : 0;
          }
          result.push(input);
        }
        return result;
      }`;
    }

    function formatOutputData() {
      if (!outputLookup) return '';
      if (inputSize === 1) {
        if (inputLookup === outputLookup) {
          return `function lookupOutputPartial(output, input) {
            var table = ${JSON.stringify(outputLookup)};
            var offset = input.length;
            var result = {};
            var i = 0;
            for (var p in table) {
              if (i++ < offset) continue;
              result[p] = output[table[p] - offset][0];
            }
            return result;
          }`;
        }
        return `function lookupOutput(output) {
          var table = ${JSON.stringify(outputLookup)};
          var result = {};
          for (var p in table) {
            result[p] = output[table[p]][0];
          }
          return result;
        }`;
      }
      return `function lookupOutput(output) {
        var table = ${JSON.stringify(outputLookup)};
        var result = {};
        for (var p in table) {
          result[p] = output[table[p]];
        }
        return result;
      }`;
    }

    function toInner(fnString: string) {
      // crude, but should be sufficient for now
      // function() { body }
      // crude, but should be sufficient for now
      // function() { body }
      const fnParts = fnString.toString().split('{');
      fnParts.shift();
      // body }
      const fnBodyString = fnParts.join('{');
      const fnBodyParts = fnBodyString.split('}');
      fnBodyParts.pop();
      // body
      return fnBodyParts
        .join('}')
        .split('\n')
        .join('\n        ')
        .replace('product.deltas[i] = 0;', '')
        .replace('product.deltas[column] = 0;', '')
        .replace('left.deltas[leftIndex] = 0;', '')
        .replace('right.deltas[rightIndex] = 0;', '')
        .replace('product.deltas = left.deltas.slice(0);', '');
    }

    function fileName(fnName: string) {
      return `src/recurrent/matrix/${fnName.replace(/[A-Z]/g, function (value) {
        return `-${value.toLowerCase()}`;
      })}.js`;
    }

    const statesRaw = [];
    const usedFunctionNames: { [methodName: string]: boolean } = {};
    const innerFunctionsSwitch = [];
    for (let i = 0, max = states.length; i < max; i++) {
      const state = states[i];
      statesRaw.push(`states[${i}] = {
      name: '${state.forwardFn.name}',
      left: ${state.left ? matrixToString(state.left, i) : 'undefined'},
      right: ${state.right ? matrixToString(state.right, i) : 'undefined'},
      product: ${matrixToString(state.product, i)}
    }`);

      const fnName = state.forwardFn.name;
      if (!usedFunctionNames[fnName]) {
        usedFunctionNames[fnName] = true;
        if (state.name === 'input') {
          innerFunctionsSwitch.push(`case '${fnName}':`);
          innerFunctionsSwitch.push(
            inputLookup && inputSize === 1
              ? 'product.weights = _i < input.length ? input[_i]: prevStates[prevStates.length - 1].product.weights;'
              : inputSize === 1
              ? 'product.weights = [input[_i]];'
              : 'product.weights = input[_i];'
          );
          innerFunctionsSwitch.push('break;');
        } else {
          innerFunctionsSwitch.push(
            `        case '${fnName}':${
              fnName !== 'forwardFn'
                ? ` //compiled from ${fileName(fnName)}`
                : ''
            }
          ${toInner(state.forwardFn.toString())}
          break;`
          );
        }
      }
    }

    const forceForecast = inputSize === 1 && this.outputLookup;
    const src = `
  var input = ${this.inputLookup ? 'lookupInput(rawInput)' : 'rawInput'};
  var json = ${jsonString};
  var output = [];
  var states = [];
  var prevStates;
  var state;
  var max = ${
    forceForecast
      ? inputLookup === outputLookup
        ? inputLookupLength
        : `input.length + ${outputLookupLength - 1}`
      : 'input.length'
  };
  for (var _i = 0; _i < max; _i++) {
    prevStates = states;
    states = [];
    ${statesRaw.join(';\n    ')};
    for (var stateIndex = 0, stateMax = ${
      statesRaw.length
    }; stateIndex < stateMax; stateIndex++) {
      state = states[stateIndex];
      var product = state.product;
      var left = state.left;
      var right = state.right;

      switch (state.name) {
${innerFunctionsSwitch.join('\n')}
      }
    }
    ${
      inputSize === 1 && inputLookup
        ? 'if (_i >= input.length - 1) { output.push(state.product.weights); }'
        : 'output = state.product.weights;'
    }
  }
  ${
    outputLookup
      ? outputLookup === inputLookup
        ? 'return lookupOutputPartial(output, input)'
        : 'return lookupOutput(output)'
      : inputSize === 1
      ? 'return output[0]'
      : 'return output'
  };
  ${formatInputData()}
  ${formatOutputData()}

  function Matrix(rows, columns) {
    this.rows = rows;
    this.columns = columns;
    this.weights = new Float32Array(rows * columns);
  }
  ${softmax.toString().replace('_2.default', 'Matrix')}
  ${randomFloat.toString()}
  ${sampleI.toString()}
  ${maxI.toString()}`;
    // eslint-disable-next-line
    return new Function('rawInput', cb ? cb(src) : src) as RNNTimeStepFunction;
  }
}

export type RNNTimeStepFunction = <
  InputType extends InputOutputValue | InputOutputValue[]
>(
  rawInput?: InputType,
  isSampleI?: boolean,
  temperature?: number
) => ValuesOf<InputType>;

export const trainDefaults = { ...rnnTrainDefaults };