/*

 * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.javadoc.internal.doclets.toolkit.util;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.io.UnsupportedEncodingException;

import java.io.Writer;

import java.nio.file.DirectoryStream;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Objects;

import java.util.Set;

import javax.tools.DocumentationTool;

import javax.tools.FileObject;

import javax.tools.JavaFileManager.Location;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardLocation;

import com.sun.tools.javac.util.Assert;

import jdk.javadoc.internal.doclets.toolkit.BaseConfiguration;

/**

 * Implementation of DocFileFactory using a {@link StandardJavaFileManager}.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 *

 */

class StandardDocFileFactory extends DocFileFactory {

    private final StandardJavaFileManager fileManager;

    private Path destDir;

    public StandardDocFileFactory(BaseConfiguration configuration) {

        super(configuration);

        fileManager = (StandardJavaFileManager) configuration.getFileManager();

    }

    @Override

    public void setDestDir(String destDirName) throws SimpleDocletException {

        if (destDir != null)

            throw new AssertionError("destDir already initialized: " + destDir);

        if (!destDirName.isEmpty()

                || !fileManager.hasLocation(DocumentationTool.Location.DOCUMENTATION_OUTPUT)) {

            try {

                String dirName = destDirName.isEmpty() ? "." : destDirName;

                Path dir = Paths.get(dirName);

                fileManager.setLocationFromPaths(DocumentationTool.Location.DOCUMENTATION_OUTPUT, Arrays.asList(dir));

            } catch (IOException e) {

                // generic IOException from file manager, setting location, e.g. file not a directory

                String message = configuration.getResources().getText("doclet.error.initializing.dest.dir", e);

                throw new SimpleDocletException(message, e);

            }

        }

        destDir = fileManager.getLocationAsPaths(DocumentationTool.Location.DOCUMENTATION_OUTPUT).iterator().next();

    }

    private Path getDestDir() {

        Objects.requireNonNull(destDir, "destDir not initialized");

        return destDir;

    }

    @Override

    public DocFile createFileForDirectory(String file) {

        return new StandardDocFile(Paths.get(file));

    }

    @Override

    public DocFile createFileForInput(String file) {

        return new StandardDocFile(Paths.get(file));

    }

    @Override

    public DocFile createFileForOutput(DocPath path) {

        return new StandardDocFile(DocumentationTool.Location.DOCUMENTATION_OUTPUT, path);

    }

    @Override

    Iterable<DocFile> list(Location location, DocPath path) {

        Location l = ((location == StandardLocation.SOURCE_PATH)

                && !fileManager.hasLocation(StandardLocation.SOURCE_PATH))

                ? StandardLocation.CLASS_PATH

                : location;

        Set<DocFile> files = new LinkedHashSet<>();

        for (Path f: fileManager.getLocationAsPaths(l)) {

            if (Files.isDirectory(f)) {

                f = f.resolve(path.getPath());

                if (Files.exists(f))

                    files.add(new StandardDocFile(f));

            }

        }

        return files;

    }

    private static Path newFile(Path dir, String path) {

        return (dir == null) ? Paths.get(path) : dir.resolve(path);

    }

    class StandardDocFile extends DocFile {

        private final Path file;

        /** Create a StandardDocFile for a given file. */

        private StandardDocFile(Path file) {

            this.file = file;

        }

        /** Create a StandardDocFile for a given location and relative path. */

        private StandardDocFile(Location location, DocPath path) {

            super(location, path);

            Assert.check(location == DocumentationTool.Location.DOCUMENTATION_OUTPUT);

            this.file = newFile(getDestDir(), path.getPath());

        }

        @Override

        public FileObject getFileObject()  {

            return getJavaFileObjectForInput(file);

        }

        /**

         * Open an input stream for the file.

         *

         * @throws DocFileIOException if there is a problem while opening stream

         */

        @Override

        public InputStream openInputStream() throws DocFileIOException {

            try {

                JavaFileObject fo = getJavaFileObjectForInput(file);

                return new BufferedInputStream(fo.openInputStream());

            } catch (IOException e) {

                throw new DocFileIOException(this, DocFileIOException.Mode.READ, e);

            }

        }

        /**

         * Open an output stream for the file.

         * The file must have been created with a location of

         * {@link DocumentationTool.Location#DOCUMENTATION_OUTPUT} and a corresponding relative path.

         *

         * @throws DocFileIOException if there is a problem while opening stream

         */

        @Override

        public OutputStream openOutputStream() throws DocFileIOException {

            if (location != DocumentationTool.Location.DOCUMENTATION_OUTPUT)

                throw new IllegalStateException();

            try {

                OutputStream out = getFileObjectForOutput(path).openOutputStream();

                return new BufferedOutputStream(out);

            } catch (IOException e) {

                throw new DocFileIOException(this, DocFileIOException.Mode.WRITE, e);

            }

        }

        /**

         * Open an writer for the file, using the encoding (if any) given in the

         * doclet configuration.

         * The file must have been created with a location of

         * {@link DocumentationTool.Location#DOCUMENTATION_OUTPUT} and a corresponding relative path.

         *

         * @throws DocFileIOException if there is a problem while opening stream

         * @throws UnsupportedEncodingException if the configured encoding is not supported

         */

        @Override

        public Writer openWriter() throws DocFileIOException, UnsupportedEncodingException {

            if (location != DocumentationTool.Location.DOCUMENTATION_OUTPUT)

                throw new IllegalStateException();

            try {

                OutputStream out = getFileObjectForOutput(path).openOutputStream();

                return new BufferedWriter(new OutputStreamWriter(out, configuration.docencoding));

            } catch (IOException e) {

                throw new DocFileIOException(this, DocFileIOException.Mode.WRITE, e);

            }

        }

        /** Return true if the file can be read. */

        @Override

        public boolean canRead() {

            return Files.isReadable(file);

        }

        /** Return true if the file can be written. */

        @Override

        public boolean canWrite() {

            return Files.isWritable(file);

        }

        /** Return true if the file exists. */

        @Override

        public boolean exists() {

            return Files.exists(file);

        }

        /** Return the base name (last component) of the file name. */

        @Override

        public String getName() {

            return file.getFileName().toString();

        }

        /** Return the file system path for this file. */

        @Override

        public String getPath() {

            return file.toString();

        }

        /** Return true is file has an absolute path name. */

        @Override

        public boolean isAbsolute() {

            return file.isAbsolute();

        }

        /** Return true is file identifies a directory. */

        @Override

        public boolean isDirectory() {

            return Files.isDirectory(file);

        }

        /** Return true is file identifies a file. */

        @Override

        public boolean isFile() {

            return Files.isRegularFile(file);

        }

        /** Return true if this file is the same as another. */

        @Override

        public boolean isSameFile(DocFile other) {

            if (!(other instanceof StandardDocFile))

                return false;

            try {

                return Files.isSameFile(file, ((StandardDocFile) other).file);

            } catch (IOException e) {

                return false;

            }

        }

        /** If the file is a directory, list its contents. */

        @Override

        public Iterable<DocFile> list() throws DocFileIOException {

            List<DocFile> files = new ArrayList<>();

            try (DirectoryStream<Path> ds = Files.newDirectoryStream(file)) {

                for (Path f: ds) {

                    files.add(new StandardDocFile(f));

                }

            } catch (IOException e) {

                throw new DocFileIOException(this, DocFileIOException.Mode.READ, e);

            }

            return files;

        }

        /** Create the file as a directory, including any parent directories. */

        @Override

        public boolean mkdirs() {

            try {

                Files.createDirectories(file);

                return true;

            } catch (IOException e) {

                return false;

            }

        }

        /**

         * Derive a new file by resolving a relative path against this file.

         * The new file will inherit the configuration and location of this file

         * If this file has a path set, the new file will have a corresponding

         * new path.

         */

        @Override

        public DocFile resolve(DocPath p) {

            return resolve(p.getPath());

        }

        /**

         * Derive a new file by resolving a relative path against this file.

         * The new file will inherit the configuration and location of this file

         * If this file has a path set, the new file will have a corresponding

         * new path.

         */

        @Override

        public DocFile resolve(String p) {

            if (location == null && path == null) {

                return new StandardDocFile(file.resolve(p));

            } else {

                return new StandardDocFile(location, path.resolve(p));

            }

        }

        /**

         * Resolve a relative file against the given output location.

         * @param locn Currently, only

         * {@link DocumentationTool.Location.DOCUMENTATION_OUTPUT} is supported.

         */

        @Override

        public DocFile resolveAgainst(Location locn) {

            if (locn != DocumentationTool.Location.DOCUMENTATION_OUTPUT)

                throw new IllegalArgumentException();

            return new StandardDocFile(getDestDir().resolve(file));

        }

        /** Return a string to identify the contents of this object,

         * for debugging purposes.

         */

        @Override

        public String toString() {

            StringBuilder sb = new StringBuilder();

            sb.append("StandardDocFile[");

            if (location != null)

                sb.append("locn:").append(location).append(",");

            if (path != null)

                sb.append("path:").append(path.getPath()).append(",");

            sb.append("file:").append(file);

            sb.append("]");

            return sb.toString();

        }

        private JavaFileObject getJavaFileObjectForInput(Path file) {

            return fileManager.getJavaFileObjects(file).iterator().next();

        }

        private FileObject getFileObjectForOutput(DocPath path) throws IOException {

            // break the path into a package-part and the rest, by finding

            // the position of the last '/' before an invalid character for a

            // package name, such as the "." before an extension or the "-"

            // in filenames like package-summary.html, doc-files or src-html.

            String p = path.getPath();

            int lastSep = -1;

            for (int i = 0; i < p.length(); i++) {

                char ch = p.charAt(i);

                if (ch == '/') {

                    lastSep = i;

                } else if (i == lastSep + 1 && !Character.isJavaIdentifierStart(ch)

                        || !Character.isJavaIdentifierPart(ch)) {

                    break;

                }

            }

            String pkg = (lastSep == -1) ? "" : p.substring(0, lastSep);

            String rest = p.substring(lastSep + 1);

            return fileManager.getFileForOutput(location, pkg, rest, null);

        }

    }

}