import { default as M, Cloud } from "./m.ts";
export type N = Array<Array<Array<number>>>

const Forward = (inData:Cloud.M, inLayers:N):N =>
{
    let i:number;
    let stages:N = [inData];
    let process = (index:number):Cloud.M => M.Batch.Sig(M.Batch.Affine(stages[index], inLayers[index]));

    for(i=0; i<inLayers.length-1; i++){ stages[i+1] = M.Mutate.Pad(process(i)); }
    stages[i+1] = process(i);
    return stages;
};
const Backward = (inStages:N, inLayers:N, inGoals:Cloud.M, inRate:number):N =>
{
    let i:number;
    let errorBack:Cloud.M = M.Batch.Subtract(inStages[inStages.length-1], inGoals);

    for(i=inLayers.length-1; i>=0; i--)
    {
        let errorScaled:Cloud.M = M.Batch.Multiply(errorBack, M.Batch.SigDeriv(inStages[i+1]));
        errorBack = M.Batch.Affine(errorScaled, M.Create.Transpose(inLayers[i]));
        errorScaled.forEach((inScaledError:Cloud.V, inIndex:number)=>
        {
            inLayers[i] = M.Batch.Subtract(
                inLayers[i],
                M.Batch.Scale(M.Create.Outer(inStages[i][inIndex], inScaledError), inRate)
            );
        });
    }
    return inLayers;
};
const Split = (inTrainingSet:Cloud.M, inHeaderLabel:Cloud.V, inHeaderKeep:Cloud.V = []):N =>
{
    let data:Cloud.M = [];
    let label:Cloud.M = [];
    if(!inHeaderKeep.length)
    {
        inTrainingSet[0].forEach( (item:number, index:number)=> inHeaderLabel.includes(index) ? false : inHeaderKeep.push(index) );
    }
    inTrainingSet.forEach((row:Cloud.V):void =>
    {
         data.push(  inHeaderKeep.map((i:number)=>row[i]) );
        label.push( inHeaderLabel.map((i:number)=>row[i]) );
    });
    return [ data, label ];
};
const Build = (...inLayers:Array<number>):N =>
{
    let i:number;
    let output:N = [];
    let rand = (inDimensions:number, inCount:number):Cloud.M => M.Create.Box( new Array(inDimensions).fill(-1), new Array(inDimensions).fill(1), inCount);
    for(i=0; i<inLayers.length-1; i++)
    {
        output.push(rand( inLayers[i]+1, inLayers[i+1]));
    }
    return output;
};
const Label = (inData:Cloud.M, inLayers:N):Cloud.M =>
{
    let stages:N = Forward(M.Create.Padded(inData), inLayers);
    return stages[stages.length-1];
};
const Learn = (inData:Cloud.M, inLayers:N, inLabels:Cloud.M, inIterations:number, inRate:number):Cloud.M =>
{
    let stages:N = [];
    for(let i=0; i<inIterations; i++)
    {
        stages = Forward(M.Create.Padded(inData), inLayers);
        Backward(stages, inLayers, inLabels, inRate);
    }
    return M.Batch.Subtract(stages[stages.length-1], inLabels);
};
const Check = (inData:Cloud.M, inLayers:N, inLabels:Cloud.M):Cloud.M => Learn(inData, inLayers, inLabels, 1, 0);

export { Split, Build, Label, Learn, Check, Forward, Backward };