/*
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.gradle.api.internal.artifacts.dsl;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import groovy.lang.Closure;
import org.gradle.api.Action;
import org.gradle.api.InvalidUserCodeException;
import org.gradle.api.artifacts.ComponentMetadataDetails;
import org.gradle.api.artifacts.ModuleIdentifier;
import org.gradle.api.artifacts.dsl.ComponentMetadataHandler;
import org.gradle.api.artifacts.ivy.IvyModuleDescriptor;
import org.gradle.api.internal.artifacts.ComponentMetadataProcessor;
import org.gradle.api.internal.artifacts.ivyservice.DefaultIvyModuleDescriptor;
import org.gradle.api.internal.artifacts.repositories.resolver.ComponentMetadataDetailsAdapter;
import org.gradle.api.internal.notations.ModuleIdentifierNotationConverter;
import org.gradle.api.specs.Spec;
import org.gradle.api.specs.Specs;
import org.gradle.internal.component.external.model.IvyModuleResolveMetadata;
import org.gradle.internal.component.external.model.ModuleComponentResolveMetadata;
import org.gradle.internal.component.external.model.MutableModuleComponentResolveMetadata;
import org.gradle.internal.reflect.Instantiator;
import org.gradle.internal.resolve.ModuleVersionResolveException;
import org.gradle.internal.rules.*;
import org.gradle.internal.typeconversion.NotationParser;
import org.gradle.internal.typeconversion.NotationParserBuilder;
import org.gradle.internal.typeconversion.UnsupportedNotationException;

import java.util.Collections;
import java.util.List;
import java.util.Set;

public class DefaultComponentMetadataHandler implements ComponentMetadataHandler, ComponentMetadataProcessor {
    private static final String ADAPTER_NAME = ComponentMetadataHandler.class.getSimpleName();
    private static final List<Class<?>> VALIDATOR_PARAM_LIST = Collections.<Class<?>>singletonList(IvyModuleDescriptor.class);

    private static final NotationParser<Object, ModuleIdentifier> MODULE_IDENTIFIER_NOTATION_PARSER = NotationParserBuilder
        .toType(ModuleIdentifier.class)
        .converter(new ModuleIdentifierNotationConverter())
        .toComposite();
    private static final String INVALID_SPEC_ERROR = "Could not add a component metadata rule for module '%s'.";

    private final Instantiator instantiator;
    private final Set<SpecRuleAction<? super ComponentMetadataDetails>> rules = Sets.newLinkedHashSet();
    private final RuleActionAdapter<ComponentMetadataDetails> ruleActionAdapter;
    private final NotationParser<Object, ModuleIdentifier> moduleIdentifierNotationParser;

    public DefaultComponentMetadataHandler(Instantiator instantiator, RuleActionAdapter<ComponentMetadataDetails> ruleActionAdapter, NotationParser<Object, ModuleIdentifier> moduleIdentifierNotationParser) {
        this.instantiator = instantiator;
        this.ruleActionAdapter = ruleActionAdapter;
        this.moduleIdentifierNotationParser = moduleIdentifierNotationParser;
    }

    public DefaultComponentMetadataHandler(Instantiator instantiator) {
        this(instantiator, createAdapter(), createModuleIdentifierNotationParser());
    }

    private static RuleActionAdapter<ComponentMetadataDetails> createAdapter() {
        RuleActionValidator<ComponentMetadataDetails> ruleActionValidator = new DefaultRuleActionValidator<ComponentMetadataDetails>(VALIDATOR_PARAM_LIST);
        return new DefaultRuleActionAdapter<ComponentMetadataDetails>(ruleActionValidator, ADAPTER_NAME);
    }

    private static NotationParser<Object, ModuleIdentifier> createModuleIdentifierNotationParser() {
        return MODULE_IDENTIFIER_NOTATION_PARSER;
    }

    private ComponentMetadataHandler addRule(SpecRuleAction<? super ComponentMetadataDetails> ruleAction) {
        rules.add(ruleAction);
        return this;
    }

    private SpecRuleAction<? super ComponentMetadataDetails> createAllSpecRuleAction(RuleAction<? super ComponentMetadataDetails> ruleAction) {
        return new SpecRuleAction<ComponentMetadataDetails>(ruleAction, Specs.<ComponentMetadataDetails>satisfyAll());
    }

    private SpecRuleAction<? super ComponentMetadataDetails> createSpecRuleActionForModule(Object id, RuleAction<? super ComponentMetadataDetails> ruleAction) {
        ModuleIdentifier moduleIdentifier;

        try {
            moduleIdentifier = moduleIdentifierNotationParser.parseNotation(id);
        } catch (UnsupportedNotationException e) {
            throw new InvalidUserCodeException(String.format(INVALID_SPEC_ERROR, id == null ? "null" : id.toString()), e);
        }

        Spec<ComponentMetadataDetails> spec = new ComponentMetadataDetailsMatchingSpec(moduleIdentifier);
        return new SpecRuleAction<ComponentMetadataDetails>(ruleAction, spec);
    }

    public ComponentMetadataHandler all(Action<? super ComponentMetadataDetails> rule) {
        return addRule(createAllSpecRuleAction(ruleActionAdapter.createFromAction(rule)));
    }

    public ComponentMetadataHandler all(Closure<?> rule) {
        return addRule(createAllSpecRuleAction(ruleActionAdapter.createFromClosure(ComponentMetadataDetails.class, rule)));
    }

    public ComponentMetadataHandler all(Object ruleSource) {
        return addRule(createAllSpecRuleAction(ruleActionAdapter.createFromRuleSource(ComponentMetadataDetails.class, ruleSource)));
    }

    public ComponentMetadataHandler withModule(Object id, Action<? super ComponentMetadataDetails> rule) {
        return addRule(createSpecRuleActionForModule(id, ruleActionAdapter.createFromAction(rule)));
    }

    public ComponentMetadataHandler withModule(Object id, Closure<?> rule) {
        return addRule(createSpecRuleActionForModule(id, ruleActionAdapter.createFromClosure(ComponentMetadataDetails.class, rule)));
    }

    public ComponentMetadataHandler withModule(Object id, Object ruleSource) {
        return addRule(createSpecRuleActionForModule(id, ruleActionAdapter.createFromRuleSource(ComponentMetadataDetails.class, ruleSource)));
    }

    public void processMetadata(MutableModuleComponentResolveMetadata metadata) {
        ComponentMetadataDetails details = instantiator.newInstance(ComponentMetadataDetailsAdapter.class, metadata);
        processAllRules(metadata, details);
        if (!metadata.getStatusScheme().contains(metadata.getStatus())) {
            throw new ModuleVersionResolveException(metadata.getId(), String.format("Unexpected status '%s' specified for %s. Expected one of: %s", metadata.getStatus(), metadata.getComponentId().getDisplayName(), metadata.getStatusScheme()));
        }
    }

    private void processAllRules(ModuleComponentResolveMetadata metadata, ComponentMetadataDetails details) {
        for (SpecRuleAction<? super ComponentMetadataDetails> rule : rules) {
            processRule(rule, metadata, details);
        }
    }

    private void processRule(SpecRuleAction<? super ComponentMetadataDetails> specRuleAction, ModuleComponentResolveMetadata metadata, ComponentMetadataDetails details) {
        if (!specRuleAction.getSpec().isSatisfiedBy(details)) {
            return;
        }

        List<Object> inputs = Lists.newArrayList();
        for (Class<?> inputType : specRuleAction.getAction().getInputTypes()) {
            if (inputType == IvyModuleDescriptor.class) {
                // Ignore the rule if it expects Ivy metadata and this isn't an Ivy module
                if (!(metadata instanceof IvyModuleResolveMetadata)) {
                    return;
                }

                IvyModuleResolveMetadata ivyMetadata = (IvyModuleResolveMetadata) metadata;
                inputs.add(new DefaultIvyModuleDescriptor(ivyMetadata.getExtraInfo(), ivyMetadata.getBranch(), ivyMetadata.getStatus()));
                continue;
            }

            // We've already validated the inputs: should never get here.
            throw new IllegalStateException();
        }

        try {
            specRuleAction.getAction().execute(details, inputs);
        } catch (Exception e) {
            throw new InvalidUserCodeException(String.format("There was an error while evaluating a component metadata rule for %s.", details.getId()), e);
        }
    }

    static class ComponentMetadataDetailsMatchingSpec implements Spec<ComponentMetadataDetails> {
        private ModuleIdentifier target;

        ComponentMetadataDetailsMatchingSpec(ModuleIdentifier target) {
            this.target = target;
        }

        public boolean isSatisfiedBy(ComponentMetadataDetails componentMetadataDetails) {
            return componentMetadataDetails.getId().getGroup().equals(target.getGroup()) && componentMetadataDetails.getId().getName().equals(target.getName());
        }
    }
}
