// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.search.ranking;

import ai.vespa.models.evaluation.FunctionEvaluator;
import com.yahoo.search.result.FeatureData;
import com.yahoo.search.result.Hit;
import com.yahoo.tensor.Tensor;

import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.function.Supplier;

class SimpleEvaluator implements Evaluator {

    private final FunctionEvaluator evaluator;

    static Supplier<Evaluator> wrap(Supplier<FunctionEvaluator> supplier) {
        return () -> new SimpleEvaluator(supplier.get());
    }

    SimpleEvaluator(FunctionEvaluator prototype) {
        this.evaluator = prototype;
    }

    @Override
    public Evaluator bind(String name, Tensor value) {
        evaluator.bind(name, value);
        return this;
    }

    @Override
    public double evaluateScore() {
        return evaluator.evaluate().asDouble();
    }

    @Override
    public String toString() {
        var buf = new StringBuilder();
        buf.append("SimpleEvaluator(");
        buf.append(evaluator.function().toString());
        buf.append(")[");
        for (String arg : evaluator.function().arguments()) {
            buf.append("{").append(arg).append("}");
        }
        buf.append("]");
        return buf.toString();
    }
}