/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.painless.action;

import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.painless.lookup.PainlessClassBinding;
import org.elasticsearch.painless.lookup.PainlessInstanceBinding;
import org.elasticsearch.painless.lookup.PainlessLookup;
import org.elasticsearch.painless.lookup.PainlessMethod;
import org.elasticsearch.script.ScriptContext;
import org.elasticsearch.xcontent.ConstructingObjectParser;
import org.elasticsearch.xcontent.ParseField;
import org.elasticsearch.xcontent.ToXContentObject;
import org.elasticsearch.xcontent.XContentBuilder;
import org.elasticsearch.xcontent.XContentParser;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

public class PainlessContextInfo implements Writeable, ToXContentObject {

    public static final ParseField NAME = new ParseField("name");
    public static final ParseField CLASSES = new ParseField("classes");
    public static final ParseField IMPORTED_METHODS = new ParseField("imported_methods");
    public static final ParseField CLASS_BINDINGS = new ParseField("class_bindings");
    public static final ParseField INSTANCE_BINDINGS = new ParseField("instance_bindings");

    @SuppressWarnings("unchecked")
    private static final ConstructingObjectParser<PainlessContextInfo, Void> PARSER = new ConstructingObjectParser<>(
        PainlessContextInfo.class.getCanonicalName(),
        (v) -> new PainlessContextInfo(
            (String) v[0],
            (List<PainlessContextClassInfo>) v[1],
            (List<PainlessContextMethodInfo>) v[2],
            (List<PainlessContextClassBindingInfo>) v[3],
            (List<PainlessContextInstanceBindingInfo>) v[4]
        )
    );

    static {
        PARSER.declareString(ConstructingObjectParser.constructorArg(), NAME);
        PARSER.declareObjectArray(ConstructingObjectParser.constructorArg(), (p, c) -> PainlessContextClassInfo.fromXContent(p), CLASSES);
        PARSER.declareObjectArray(
            ConstructingObjectParser.constructorArg(),
            (p, c) -> PainlessContextMethodInfo.fromXContent(p),
            IMPORTED_METHODS
        );
        PARSER.declareObjectArray(
            ConstructingObjectParser.constructorArg(),
            (p, c) -> PainlessContextClassBindingInfo.fromXContent(p),
            CLASS_BINDINGS
        );
        PARSER.declareObjectArray(
            ConstructingObjectParser.constructorArg(),
            (p, c) -> PainlessContextInstanceBindingInfo.fromXContent(p),
            INSTANCE_BINDINGS
        );
    }

    private final String name;
    private final List<PainlessContextClassInfo> classes;
    private final List<PainlessContextMethodInfo> importedMethods;
    private final List<PainlessContextClassBindingInfo> classBindings;
    private final List<PainlessContextInstanceBindingInfo> instanceBindings;

    public PainlessContextInfo(ScriptContext<?> scriptContext, PainlessLookup painlessLookup) {
        this(
            scriptContext.name,
            painlessLookup.getClasses()
                .stream()
                .map(
                    javaClass -> new PainlessContextClassInfo(
                        javaClass,
                        javaClass == painlessLookup.canonicalTypeNameToType(
                            javaClass.getName().substring(javaClass.getName().lastIndexOf('.') + 1).replace('$', '.')
                        ),
                        painlessLookup.lookupPainlessClass(javaClass)
                    )
                )
                .collect(Collectors.toList()),
            painlessLookup.getImportedPainlessMethodsKeys().stream().map(importedPainlessMethodKey -> {
                String[] split = importedPainlessMethodKey.split("/");
                String importedPainlessMethodName = split[0];
                int importedPainlessMethodArity = Integer.parseInt(split[1]);
                PainlessMethod importedPainlessMethod = painlessLookup.lookupImportedPainlessMethod(
                    importedPainlessMethodName,
                    importedPainlessMethodArity
                );
                return new PainlessContextMethodInfo(importedPainlessMethod);
            }).collect(Collectors.toList()),
            painlessLookup.getPainlessClassBindingsKeys().stream().map(painlessClassBindingKey -> {
                String[] split = painlessClassBindingKey.split("/");
                String painlessClassBindingName = split[0];
                int painlessClassBindingArity = Integer.parseInt(split[1]);
                PainlessClassBinding painlessClassBinding = painlessLookup.lookupPainlessClassBinding(
                    painlessClassBindingName,
                    painlessClassBindingArity
                );
                return new PainlessContextClassBindingInfo(painlessClassBinding);
            }).collect(Collectors.toList()),
            painlessLookup.getPainlessInstanceBindingsKeys().stream().map(painlessInstanceBindingKey -> {
                String[] split = painlessInstanceBindingKey.split("/");
                String painlessInstanceBindingName = split[0];
                int painlessInstanceBindingArity = Integer.parseInt(split[1]);
                PainlessInstanceBinding painlessInstanceBinding = painlessLookup.lookupPainlessInstanceBinding(
                    painlessInstanceBindingName,
                    painlessInstanceBindingArity
                );
                return new PainlessContextInstanceBindingInfo(painlessInstanceBinding);
            }).collect(Collectors.toList())
        );
    }

    public PainlessContextInfo(
        String name,
        List<PainlessContextClassInfo> classes,
        List<PainlessContextMethodInfo> importedMethods,
        List<PainlessContextClassBindingInfo> classBindings,
        List<PainlessContextInstanceBindingInfo> instanceBindings
    ) {
        this.name = Objects.requireNonNull(name);
        classes = new ArrayList<>(Objects.requireNonNull(classes));
        classes.sort(Comparator.comparing(PainlessContextClassInfo::getSortValue));
        this.classes = Collections.unmodifiableList(classes);
        importedMethods = new ArrayList<>(Objects.requireNonNull(importedMethods));
        importedMethods.sort(Comparator.comparing(PainlessContextMethodInfo::getSortValue));
        this.importedMethods = Collections.unmodifiableList(importedMethods);
        classBindings = new ArrayList<>(Objects.requireNonNull(classBindings));
        classBindings.sort(Comparator.comparing(PainlessContextClassBindingInfo::getSortValue));
        this.classBindings = Collections.unmodifiableList(classBindings);
        instanceBindings = new ArrayList<>(Objects.requireNonNull(instanceBindings));
        instanceBindings.sort(Comparator.comparing(PainlessContextInstanceBindingInfo::getSortValue));
        this.instanceBindings = Collections.unmodifiableList(instanceBindings);
    }

    public PainlessContextInfo(StreamInput in) throws IOException {
        name = in.readString();
        classes = in.readImmutableList(PainlessContextClassInfo::new);
        importedMethods = in.readImmutableList(PainlessContextMethodInfo::new);
        classBindings = in.readImmutableList(PainlessContextClassBindingInfo::new);
        instanceBindings = in.readImmutableList(PainlessContextInstanceBindingInfo::new);
    }

    @Override
    public void writeTo(StreamOutput out) throws IOException {
        out.writeString(name);
        out.writeList(classes);
        out.writeList(importedMethods);
        out.writeList(classBindings);
        out.writeList(instanceBindings);
    }

    public static PainlessContextInfo fromXContent(XContentParser parser) {
        return PARSER.apply(parser, null);
    }

    @Override
    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
        builder.startObject();
        builder.field(NAME.getPreferredName(), name);
        builder.field(CLASSES.getPreferredName(), classes);
        builder.field(IMPORTED_METHODS.getPreferredName(), importedMethods);
        builder.field(CLASS_BINDINGS.getPreferredName(), classBindings);
        builder.field(INSTANCE_BINDINGS.getPreferredName(), instanceBindings);
        builder.endObject();

        return builder;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        PainlessContextInfo that = (PainlessContextInfo) o;
        return Objects.equals(name, that.name)
            && Objects.equals(classes, that.classes)
            && Objects.equals(importedMethods, that.importedMethods)
            && Objects.equals(classBindings, that.classBindings)
            && Objects.equals(instanceBindings, that.instanceBindings);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, classes, importedMethods, classBindings, instanceBindings);
    }

    @Override
    public String toString() {
        return "PainlessContextInfo{"
            + "name='"
            + name
            + '\''
            + ", classes="
            + classes
            + ", importedMethods="
            + importedMethods
            + ", classBindings="
            + classBindings
            + ", instanceBindings="
            + instanceBindings
            + '}';
    }

    public String getName() {
        return name;
    }

    public List<PainlessContextClassInfo> getClasses() {
        return classes;
    }

    public List<PainlessContextMethodInfo> getImportedMethods() {
        return importedMethods;
    }

    public List<PainlessContextClassBindingInfo> getClassBindings() {
        return classBindings;
    }

    public List<PainlessContextInstanceBindingInfo> getInstanceBindings() {
        return instanceBindings;
    }
}
