org.droitateddb.builder.provider.ContentProviderBuilder Maven / Gradle / Ivy

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/*
 * Copyright (C) 2014 The droitated DB 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.droitateddb.builder.provider;

import org.droitateddb.entity.Entity;

import javax.annotation.processing.Messager;
import javax.lang.model.element.Element;
import javax.lang.model.element.VariableElement;
import javax.tools.Diagnostic.Kind;
import java.util.Locale;

import static org.droitateddb.builder.Constants.GENERATED_COMMENT;
import static org.droitateddb.builder.Constants.TAB;
import static org.droitateddb.schema.SchemaConstants.*;

/**
 * Generates Java source file content a ContentProvider depending on a {@link Entity} annotated class.
 *
 * @author Alexander Frank
 * @author Falk Appel
 */
public class ContentProviderBuilder {

    private final Element entityElement;
    private final Entity entity;
    private final String packageName;
    private final String entityName;
    private final VariableElement primaryKey;
    private final Messager messager;

    public static final String CONTENT_PROVIDER_SUFFIX = "ContentProvider";

    public ContentProviderBuilder(final String packageName, final Element entityElement, final Messager messager) {
        this.packageName = packageName;
        this.entityElement = entityElement;
        this.messager = messager;
        entityName = entityElement.getSimpleName().toString();
        entity = entityElement.getAnnotation(Entity.class);
        primaryKey = getPrimaryKey();
    }

    private VariableElement getPrimaryKey() {
        for (Element element : entityElement.getEnclosedElements()) {
            VariableElement variableElement = element.accept(new PrimaryKeyVisitor(), null);
            if (variableElement != null) {
                return variableElement;
            }
        }
        String error = "The @Entity " + entityName + " has no @PrimaryKey. @PrimaryKey is required";
        messager.printMessage(Kind.ERROR, error, entityElement);
        throw new IllegalStateException(error);
    }

    public SourceContentProviderData build() {

        String providerName = entityName + CONTENT_PROVIDER_SUFFIX;
        String authority = getAuthority();

        StringBuilder builder = new StringBuilder();
        addSignature(builder, providerName);
        overrideEntityUriPart(builder);
        overrideGetAuthority(builder, authority);
        overrideGetEntityInfo(builder);
        overrideGetIdAttribute(builder);
        addEnd(builder);
        String source = builder.toString();
        return new SourceContentProviderData(packageName, providerName, source, authority, entity.exported());
    }

    private void addSignature(final StringBuilder builder, final String providerName) {
        builder.append(GENERATED_COMMENT);
        builder.append("package ").append(packageName).append(";\n\n") //
                .append("import ").append("org.droitateddb.schema.*;\n") //
                .append("import ").append("org.droitateddb.*;\n") //
                .append("public class ").append(providerName).append(" extends BaseContentProvider {\n\n");
    }

    private void overrideEntityUriPart(final StringBuilder builder) {
        builder.append(TAB).append("@Override\n") //
                .append(TAB).append("protected String getEntityURIPart() {\n") //
                .append(TAB).append(TAB).append("return \"").append(entityName.toLowerCase(Locale.getDefault())).append("\";\n") //
                .append(TAB).append("}\n\n");
    }

    private void overrideGetAuthority(final StringBuilder builder, final String authority) {
        builder.append(TAB).append("@Override\n") //
                .append(TAB).append("protected String getAuthority() {\n") //
                .append(TAB).append("return \"").append(authority).append("\";\n") //
                .append(TAB).append("}\n\n");
    }

    private void overrideGetEntityInfo(final StringBuilder builder) {
        builder.append(TAB).append("@Override\n");
        builder.append(TAB).append("protected EntityInfo getEntityInfo() {\n");
        builder.append(TAB).append(TAB).append("return ").append(DB).append(".").append(entityName).append(INFO_SUFFIX).append(";\n");
        builder.append(TAB).append("}\n\n");
    }

    private void overrideGetIdAttribute(final StringBuilder builder) {
        builder.append(TAB).append("@Override\n");
        builder.append(TAB).append("protected AbstractAttribute getIdAttribute() {\n");
        builder.append(TAB).append(TAB).append("return ").append(DB).append(".").append(entityName).append(TABLE).append(".")
                .append(primaryKey.getSimpleName().toString().toUpperCase(Locale.getDefault())).append(";\n");
        builder.append(TAB).append("}\n");

    }

    private void addEnd(final StringBuilder builder) {
        builder.append("}");
    }

    private String getAuthority() {
        String authority = entity.authority();
        if (authority == null || authority.equals("")) {
            return packageName + ".provider." + entityName.toLowerCase(Locale.getDefault());
        }
        return authority;
    }

}