/*
 * Copyright 2016 Open Networking Laboratory
 *
 * 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.onosproject.yangutils.datamodel;

import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
import static org.onosproject.yangutils.datamodel.utils.DataModelUtils.detectCollidingChildUtil;
import org.onosproject.yangutils.parser.Parsable;
import org.onosproject.yangutils.translator.CachedFileHandle;
import org.onosproject.yangutils.translator.CodeGenerator;
import org.onosproject.yangutils.translator.GeneratedFileType;
import org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax;
import org.onosproject.yangutils.utils.UtilConstants;
import org.onosproject.yangutils.utils.YangConstructType;
import org.onosproject.yangutils.utils.io.impl.FileSystemUtil;

import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

/*-
 * Reference:RFC 6020.
 * The "module" statement defines the module's name,
 * and groups all statements that belong to the module together. The "module"
 * statement's argument is the name of the module, followed by a block of
 * sub statements that hold detailed module information.
 * The module's sub statements
 *
 *                +--------------+---------+-------------+-----------------------+
 *                |sub statement | section | cardinality | data model mapping    |
 *                +--------------+---------+-------------+-----------------------+
 *                | anyxml       | 7.10    | 0..n        | not supported         |
 *                | augment      | 7.15    | 0..n        | child nodes           |
 *                | choice       | 7.9     | 0..n        | child nodes           |
 *                | contact      | 7.1.8   | 0..1        | string                |
 *                | container    | 7.5     | 0..n        | child nodes           |
 *                | description  | 7.19.3  | 0..1        | string                |
 *                | deviation    | 7.18.3  | 0..n        | TODO                  |
 *                | extension    | 7.17    | 0..n        | TODO                  |
 *                | feature      | 7.18.1  | 0..n        | TODO                  |
 *                | grouping     | 7.11    | 0..n        | child nodes           |
 *                | identity     | 7.16    | 0..n        | TODO                  |
 *                | import       | 7.1.5   | 0..n        | list of import info   |
 *                | include      | 7.1.6   | 0..n        | list of include info  |
 *                | leaf         | 7.6     | 0..n        | list of leaf info     |
 *                | leaf-list    | 7.7     | 0..n        | list of leaf-list info|
 *                | list         | 7.8     | 0..n        | child nodes           |
 *                | namespace    | 7.1.3   | 1           | string/uri            |
 *                | notification | 7.14    | 0..n        | TODO                  |
 *                | organization | 7.1.7   | 0..1        | string                |
 *                | prefix       | 7.1.4   | 1           | string                |
 *                | reference    | 7.19.4  | 0..1        | string                |
 *                | revision     | 7.1.9   | 0..n        | revision              |
 *                | rpc          | 7.13    | 0..n        | TODO                  |
 *                | typedef      | 7.3     | 0..n        | child nodes           |
 *                | uses         | 7.12    | 0..n        | child nodes           |
 *                | YANG-version | 7.1.2   | 0..1        | int                   |
 *                +--------------+---------+-------------+-----------------------+
 */

/**
 * Data model node to maintain information defined in YANG module.
 */
public class YangModule extends YangNode
        implements YangLeavesHolder, YangDesc, YangReference, Parsable, CodeGenerator, CollisionDetector {

    /**
     * Name of the module.
     */
    private String name;

    /**
     * Reference:RFC 6020.
     *
     * The "contact" statement provides contact information for the module. The
     * argument is a string that is used to specify contact information for the
     * person or persons to whom technical queries concerning this module should
     * be sent, such as their name, postal address, telephone number, and
     * electronic mail address.
     */
    private String contact;

    /**
     * Reference:RFC 6020.
     *
     * The "description" statement takes as an argument a string that contains a
     * human-readable textual description of this definition. The text is
     * provided in a language (or languages) chosen by the module developer; for
     * the sake of interoperability.
     */
    private String description;

    /**
     * List of YANG modules imported.
     */
    private List<YangImport> importList;

    /**
     * List of YANG sub-modules included.
     */
    private List<YangInclude> includeList;

    /**
     * List of leaves at root level in the module.
     */
    private List<YangLeaf> listOfLeaf;

    /**
     * List of leaf-lists at root level in the module.
     */
    private List<YangLeafList> listOfLeafList;

    /**
     * Name space of the module.
     */
    private YangNameSpace nameSpace;

    /**
     * Reference:RFC 6020.
     *
     * The "organization" statement defines the party responsible for this
     * module. The argument is a string that is used to specify a textual
     * description of the organization(s) under whose auspices this module was
     * developed.
     */
    private String organization;

    /**
     * Prefix to refer to the objects in module.
     */
    private String prefix;

    /**
     * Reference of the module.
     */
    private String reference;

    /**
     * Revision info of the module.
     */
    private YangRevision revision;

    /**
     * YANG version.
     */
    private byte version;

    /**
     * Package of the generated java code.
     */
    private String pkg;

    /**
     * Cached Java File Handle.
     */
    private CachedFileHandle fileHandle;

    /*-
     * Nested typedefs and groupings.
     * Typedefs and groupings may appear nested under many YANG statements,
     * allowing these to be lexically scoped by the hierarchy under which
     * they appear.  This allows types and groupings to be defined near
     * where they are used, rather than placing them at the top level of the
     * hierarchy.  The close proximity increases readability.
     *
     * Scoping also allows types to be defined without concern for naming
     * conflicts between types in different submodules.  Type names can be
     * specified without adding leading strings designed to prevent name
     * collisions within large modules.
     *
     * Finally, scoping allows the module author to keep types and groupings
     * private to their module or submodule, preventing their reuse.  Since
     * only top-level types and groupings (i.e., those appearing as
     * sub-statements to a module or submodule statement) can be used outside
     * the module or submodule, the developer has more control over what
     * pieces of their module are presented to the outside world, supporting
     * the need to hide internal information and maintaining a boundary
     * between what is shared with the outside world and what is kept
     * private.
     *
     * Scoped definitions MUST NOT shadow definitions at a higher scope.  A
     * type or grouping cannot be defined if a higher level in the schema
     * hierarchy has a definition with a matching identifier.
     *
     * A reference to an unprefixed type or grouping, or one which uses the
     * prefix of the current module, is resolved by locating the closest
     * matching "typedef" or "grouping" statement among the immediate
     * sub-statements of each ancestor statement.
     */
    /**
     * List of nodes which require nested reference resolution.
     */
    private List<YangNode> nestedReferenceResoulutionList;

    /**
     * Create a YANG node of module type.
     */
    public YangModule() {
        super(YangNodeType.MODULE_NODE);
    }

    /**
     * Get name of the module.
     *
     * @return module name.
     */
    @Override
    public String getName() {
        return name;
    }

    /**
     * Set module name.
     *
     * @param moduleName module name.
     */
    @Override
    public void setName(String moduleName) {
        name = moduleName;
    }

    /**
     * Get the contact details of the module owner.
     *
     * @return the contact details of YANG owner.
     */
    public String getContact() {
        return contact;
    }

    /**
     * Set the contact details of the module owner.
     *
     * @param contact the contact details of YANG owner.
     */
    public void setContact(String contact) {
        this.contact = contact;
    }

    /**
     * Get the description of module.
     *
     * @return the description of YANG module.
     */
    @Override
    public String getDescription() {
        return description;
    }

    /**
     * Set the description of module.
     *
     * @param description set the description of YANG module.
     */
    @Override
    public void setDescription(String description) {
        this.description = description;
    }

    /**
     * Get the list of imported modules.
     *
     * @return the list of imported modules.
     */
    public List<YangImport> getImportList() {
        return importList;
    }

    /**
     * prevent setting the import list from outside.
     *
     * @param importList the import list to set.
     */
    private void setImportList(List<YangImport> importList) {
        this.importList = importList;
    }

    /**
     * Add the imported module information to the import list.
     *
     * @param importedModule module being imported.
     */
    public void addImportedInfo(YangImport importedModule) {

        if (getImportList() == null) {
            setImportList(new LinkedList<YangImport>());
        }

        getImportList().add(importedModule);

        return;
    }

    /**
     * Get the list of included sub modules.
     *
     * @return the included list of sub modules.
     */
    public List<YangInclude> getIncludeList() {
        return includeList;
    }

    /**
     * Set the list of included sub modules.
     *
     * @param includeList the included list to set.
     */
    private void setIncludeList(List<YangInclude> includeList) {
        this.includeList = includeList;
    }

    /**
     * Add the included sub module information to the include list.
     *
     * @param includeModule submodule being included.
     */
    public void addIncludedInfo(YangInclude includeModule) {

        if (getIncludeList() == null) {
            setIncludeList(new LinkedList<YangInclude>());
        }

        getIncludeList().add(includeModule);
        return;
    }

    /**
     * Get the list of leaves in module.
     *
     * @return the list of leaves.
     */
    @Override
    public List<YangLeaf> getListOfLeaf() {
        return listOfLeaf;
    }

    /**
     * Set the list of leaf in module.
     *
     * @param leafsList the list of leaf to set.
     */
    private void setListOfLeaf(List<YangLeaf> leafsList) {
        listOfLeaf = leafsList;
    }

    /**
     * Add a leaf in module.
     *
     * @param leaf the leaf to be added.
     */
    @Override
    public void addLeaf(YangLeaf leaf) {
        if (getListOfLeaf() == null) {
            setListOfLeaf(new LinkedList<YangLeaf>());
        }

        getListOfLeaf().add(leaf);
    }

    /**
     * Get the list of leaf-list from module.
     *
     * @return the list of leaf-list.
     */
    @Override
    public List<YangLeafList> getListOfLeafList() {
        return listOfLeafList;
    }

    /**
     * Set the list of leaf-list in module.
     *
     * @param listOfLeafList the list of leaf-list to set.
     */
    private void setListOfLeafList(List<YangLeafList> listOfLeafList) {
        this.listOfLeafList = listOfLeafList;
    }

    /**
     * Add a leaf-list in module.
     *
     * @param leafList the leaf-list to be added.
     */
    @Override
    public void addLeafList(YangLeafList leafList) {
        if (getListOfLeafList() == null) {
            setListOfLeafList(new LinkedList<YangLeafList>());
        }

        getListOfLeafList().add(leafList);
    }

    /**
     * Get the name space of module elements.
     *
     * @return the nameSpace.
     */
    public YangNameSpace getNameSpace() {
        return nameSpace;
    }

    /**
     * Set the name space of module elements.
     *
     * @param nameSpace the nameSpace to set.
     */
    public void setNameSpace(YangNameSpace nameSpace) {
        this.nameSpace = nameSpace;
    }

    /**
     * Get the modules organization.
     *
     * @return the organization.
     */
    public String getOrganization() {
        return organization;
    }

    /**
     * Set the modules organization.
     *
     * @param org the organization to set.
     */
    public void setOrganization(String org) {
        organization = org;
    }

    /**
     * Get the prefix.
     *
     * @return the prefix
     */
    public String getPrefix() {
        return prefix;
    }

    /**
     * Set the prefix.
     *
     * @param prefix the prefix to set.
     */
    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }

    /**
     * Get the textual reference.
     *
     * @return the reference.
     */
    @Override
    public String getReference() {
        return reference;
    }

    /**
     * Set the textual reference.
     *
     * @param reference the reference to set.
     */
    @Override
    public void setReference(String reference) {
        this.reference = reference;
    }

    /**
     * Get the revision.
     *
     * @return the revision.
     */
    public YangRevision getRevision() {
        return revision;
    }

    /**
     * Set the revision.
     *
     * @param revision the revision to set.
     */
    public void setRevision(YangRevision revision) {
        this.revision = revision;
    }

    /**
     * Get the version.
     *
     * @return the version.
     */
    public byte getVersion() {
        return version;
    }

    /**
     * Set the version.
     *
     * @param version the version to set.
     */
    public void setVersion(byte version) {
        this.version = version;
    }

    /**
     * Get the mapped java package.
     *
     * @return the java package
     */
    @Override
    public String getPackage() {
        return pkg;
    }

    /**
     * Set the mapped java package.
     *
     * @param pcg the package to set
     */
    @Override
    public void setPackage(String pcg) {
        pkg = pcg;
    }

    /**
     * Get the cached file handle.
     *
     * @return the fileHandle
     */
    @Override
    public CachedFileHandle getFileHandle() {
        return fileHandle;
    }

    /**
     * Set the cached file handle.
     *
     * @param handle the fileHandle to set
     */
    @Override
    public void setFileHandle(CachedFileHandle handle) {
        fileHandle = handle;
    }

    /**
     * Get the list of nested reference's which required resolution.
     *
     * @return list of nested reference's which required resolution.
     */
    public List<YangNode> getNestedReferenceResoulutionList() {
        return nestedReferenceResoulutionList;
    }

    /**
     * Set list of nested reference's which requires resolution.
     *
     * @param nestedReferenceResoulutionList list of nested reference's which
     *            requires resolution.
     */
    private void setNestedReferenceResoulutionList(List<YangNode> nestedReferenceResoulutionList) {
        this.nestedReferenceResoulutionList = nestedReferenceResoulutionList;
    }

    /**
     * Set list of nested reference's which requires resolution.
     *
     * @param nestedReference nested reference which requires resolution.
     */
    public void addToNestedReferenceResoulutionList(YangNode nestedReference) {
        if (getNestedReferenceResoulutionList() == null) {
            setNestedReferenceResoulutionList(new LinkedList<YangNode>());
        }
        getNestedReferenceResoulutionList().add(nestedReference);
    }

    /**
     * Returns the type of the parsed data.
     *
     * @return returns MODULE_DATA.
     */
    @Override
    public YangConstructType getYangConstructType() {
        return YangConstructType.MODULE_DATA;
    }

    /**
     * Validate the data on entering the corresponding parse tree node.
     *
     * @throws DataModelException a violation of data model rules
     */
    @Override
    public void validateDataOnEntry() throws DataModelException {
        /*
         * Module is root in the data model tree, hence there is no entry
         * validation
         */
    }

    /**
     * Validate the data on exiting the corresponding parse tree node.
     *
     * @throws DataModelException a violation of data model rules
     */
    @Override
    public void validateDataOnExit() throws DataModelException {
        /*
         * TODO: perform symbol linking for the imported or included YANG info.
         * TODO: perform symbol resolution for referred YANG entities.
         */
    }

    /**
     * Generates java code for module.
     *
     * @throws IOException when fails to generate the source files.
     */
    @Override
    public void generateJavaCodeEntry() throws IOException {
        String modPkg = JavaIdentifierSyntax.getRootPackage(getVersion(), getNameSpace().getUri(),
                getRevision().getRevDate());
        setPackage(modPkg);

        CachedFileHandle handle = null;
        try {
            FileSystemUtil.createPackage(UtilConstants.YANG_GEN_DIR + getPackage(), getName());
            handle = FileSystemUtil.createSourceFiles(getPackage(), getName(), GeneratedFileType.ALL);
            handle.setFilePath(UtilConstants.YANG_GEN_DIR + getPackage().replace(".", "/"));
        } catch (IOException e) {
            throw new IOException("Failed to create the source files.");
        }
        setFileHandle(handle);
        addLeavesAttributes();
        addLeafListAttributes();
    }

    @Override
    public void generateJavaCodeExit() throws IOException {
        getFileHandle().close();
        return;
    }

    /**
     * Adds leaf attributes in generated files.
     */
    private void addLeavesAttributes() {

        List<YangLeaf> leaves = getListOfLeaf();
        if (leaves != null) {
            for (YangLeaf leaf : leaves) {
                getFileHandle().addAttributeInfo(leaf.getDataType(), leaf.getLeafName(), false);
            }
        }
    }

    /**
     * Adds leaf list's attributes in generated files.
     */
    private void addLeafListAttributes() {
        List<YangLeafList> leavesList = getListOfLeafList();
        if (leavesList != null) {
            for (YangLeafList leafList : leavesList) {
                getFileHandle().addAttributeInfo(leafList.getDataType(), leafList.getLeafName(), true);
            }
        }
    }

    /**
     * Add a type to resolve the nested references.
     *
     * @param node grouping or typedef node which needs to be resolved.
     * @throws DataModelException data model exception.
     */
    public static void addToResolveList(YangNode node) throws DataModelException {
        /* get the module node to add maintain the list of nested reference */
        YangModule module;
        YangNode curNode = node;
        while (curNode.getNodeType() != YangNodeType.MODULE_NODE) {
            curNode = curNode.getParent();
            if (curNode == null) {
                break;
            }
        }
        if (curNode == null) {
            throw new DataModelException("Datamodel tree is not correct");
        }

        module = (YangModule) curNode;
        module.addToNestedReferenceResoulutionList(node);
        return;
    }

    @Override
    public void detectCollidingChild(String identifierName, YangConstructType dataType) throws DataModelException {
        // Asks helper to detect colliding child.
        detectCollidingChildUtil(identifierName, dataType, this);
    }

    @Override
    public void detectSelfCollision(String identifierName, YangConstructType dataType) throws DataModelException {
        // Not required as module doesn't have any parent.
    }
}