/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

package org.antlr.v4.tool;

import org.antlr.v4.Tool;
import org.antlr.v4.codegen.CodeGenerator;
import org.antlr.v4.parse.ANTLRParser;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.STGroup;
import org.stringtemplate.v4.STGroupFile;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

Given a grammar file, show the dependencies on .tokens etc...
 Using ST, emit a simple "make compatible" list of dependencies.
 For example, combined grammar T.g (no token import) generates:
 	TParser.java : T.g
 	T.tokens : T.g
 	TLexer.java : T.g
 If we are using the listener pattern (-listener on the command line)
 then we add:
     TListener.java : T.g
     TBaseListener.java : T.g
 If we are using the visitor pattern (-visitor on the command line)
 then we add:
     TVisitor.java : T.g
     TBaseVisitor.java : T.g
 If "-lib libdir" is used on command-line with -depend and option
 tokenVocab=A in grammar, then include the path like this:
		T.g: libdir/A.tokens
 Pay attention to -o as well:
		outputdir/TParser.java : T.g
 So this output shows what the grammar depends on *and* what it generates.
 Operate on one grammar file at a time.  If given a list of .g on the
 command-line with -depend, just emit the dependencies.  The grammars
 may depend on each other, but the order doesn't matter.  Build tools,
 reading in this output, will know how to organize it.
 This code was obvious until I removed redundant "./" on front of files
 and had to escape spaces in filenames :(
 I literally copied from v3 so might be slightly inconsistent with the
 v4 code base.
/** Given a grammar file, show the dependencies on .tokens etc...
 *  Using ST, emit a simple "make compatible" list of dependencies.
 *  For example, combined grammar T.g (no token import) generates:
 *
 *  	TParser.java : T.g
 *  	T.tokens : T.g
 *  	TLexer.java : T.g
 *
 *  If we are using the listener pattern (-listener on the command line)
 *  then we add:
 *
 *      TListener.java : T.g
 *      TBaseListener.java : T.g
 *
 *  If we are using the visitor pattern (-visitor on the command line)
 *  then we add:
 *
 *      TVisitor.java : T.g
 *      TBaseVisitor.java : T.g
 *
 *  If "-lib libdir" is used on command-line with -depend and option
 *  tokenVocab=A in grammar, then include the path like this:
 *
 * 		T.g: libdir/A.tokens
 *
 *  Pay attention to -o as well:
 *
 * 		outputdir/TParser.java : T.g
 *
 *  So this output shows what the grammar depends on *and* what it generates.
 *
 *  Operate on one grammar file at a time.  If given a list of .g on the
 *  command-line with -depend, just emit the dependencies.  The grammars
 *  may depend on each other, but the order doesn't matter.  Build tools,
 *  reading in this output, will know how to organize it.
 *
 *  This code was obvious until I removed redundant "./" on front of files
 *  and had to escape spaces in filenames :(
 *
 *  I literally copied from v3 so might be slightly inconsistent with the
 *  v4 code base.
 */
public class BuildDependencyGenerator {
    protected Tool tool;
    protected Grammar g;
    protected CodeGenerator generator;
    protected STGroup templates;

    public BuildDependencyGenerator(Tool tool, Grammar g) {
        this.tool = tool;
		this.g = g;
		String language = g.getOptionString("language");
		generator = new CodeGenerator(tool, g, language);
    }

    
From T.g return a list of File objects that
 name files ANTLR will emit from T.g.
/** From T.g return a list of File objects that
     *  name files ANTLR will emit from T.g.
     */
    public List<File> getGeneratedFileList() {
        List<File> files = new ArrayList<File>();

        // add generated recognizer; e.g., TParser.java
        if (generator.getTarget().needsHeader()) {
          files.add(getOutputFile(generator.getRecognizerFileName(true)));
        }
        files.add(getOutputFile(generator.getRecognizerFileName(false)));
        // add output vocab file; e.g., T.tokens. This is always generated to
        // the base output directory, which will be just . if there is no -o option
        //
		files.add(getOutputFile(generator.getVocabFileName()));
        // are we generating a .h file?
        ST headerExtST = null;
        ST extST = generator.getTemplates().getInstanceOf("codeFileExtension");
        if (generator.getTemplates().isDefined("headerFile")) {
            headerExtST = generator.getTemplates().getInstanceOf("headerFileExtension");
            String suffix = Grammar.getGrammarTypeToFileNameSuffix(g.getType());
            String fileName = g.name + suffix + headerExtST.render();
            files.add(getOutputFile(fileName));
        }
        if ( g.isCombined() ) {
            // add autogenerated lexer; e.g., TLexer.java TLexer.h TLexer.tokens

            String suffix = Grammar.getGrammarTypeToFileNameSuffix(ANTLRParser.LEXER);
            String lexer = g.name + suffix + extST.render();
            files.add(getOutputFile(lexer));
            String lexerTokens = g.name + suffix + CodeGenerator.VOCAB_FILE_EXTENSION;
            files.add(getOutputFile(lexerTokens));

            // TLexer.h
            if (headerExtST != null) {
                String header = g.name + suffix + headerExtST.render();
                files.add(getOutputFile(header));
            }
        }

        if ( g.tool.gen_listener ) {
          // add generated listener; e.g., TListener.java
          if (generator.getTarget().needsHeader()) {
            files.add(getOutputFile(generator.getListenerFileName(true)));
          }
          files.add(getOutputFile(generator.getListenerFileName(false)));

          // add generated base listener; e.g., TBaseListener.java
          if (generator.getTarget().needsHeader()) {
            files.add(getOutputFile(generator.getBaseListenerFileName(true)));
          }
          files.add(getOutputFile(generator.getBaseListenerFileName(false)));
        }

        if ( g.tool.gen_visitor ) {
          // add generated visitor; e.g., TVisitor.java
          if (generator.getTarget().needsHeader()) {
            files.add(getOutputFile(generator.getVisitorFileName(true)));
          }
          files.add(getOutputFile(generator.getVisitorFileName(false)));

          // add generated base visitor; e.g., TBaseVisitor.java
          if (generator.getTarget().needsHeader()) {
            files.add(getOutputFile(generator.getBaseVisitorFileName(true)));
          }
          files.add(getOutputFile(generator.getBaseVisitorFileName(false)));
        }


		// handle generated files for imported grammars
		List<Grammar> imports = g.getAllImportedGrammars();
		if ( imports!=null ) {
			for (Grammar g : imports) {
//				File outputDir = tool.getOutputDirectory(g.fileName);
//				String fname = groomQualifiedFileName(outputDir.toString(), g.getRecognizerName() + extST.render());
//				files.add(new File(outputDir, fname));
				files.add(getOutputFile(g.fileName));
			}
		}

		if (files.isEmpty()) {
			return null;
		}
		return files;
	}

	public File getOutputFile(String fileName) {
		File outputDir = tool.getOutputDirectory(g.fileName);
		if ( outputDir.toString().equals(".") ) {
			// pay attention to -o then
			outputDir = tool.getOutputDirectory(fileName);
		}
		if ( outputDir.toString().equals(".") ) {
			return new File(fileName);
		}
		if (outputDir.getName().equals(".")) {
			String fname = outputDir.toString();
			int dot = fname.lastIndexOf('.');
			outputDir = new File(outputDir.toString().substring(0,dot));
		}

		if (outputDir.getName().indexOf(' ') >= 0) { // has spaces?
			String escSpaces = outputDir.toString().replace(" ", "\\ ");
			outputDir = new File(escSpaces);
		}
		return new File(outputDir, fileName);
	}

    
Return a list of File objects that name files ANTLR will read
to process T.g; This can be .tokens files if the grammar uses the tokenVocab option
as well as any imported grammar files.
/**
     * Return a list of File objects that name files ANTLR will read
     * to process T.g; This can be .tokens files if the grammar uses the tokenVocab option
     * as well as any imported grammar files.
     */
    public List<File> getDependenciesFileList() {
        // Find all the things other than imported grammars
        List<File> files = getNonImportDependenciesFileList();

        // Handle imported grammars
        List<Grammar> imports = g.getAllImportedGrammars();
        if ( imports!=null ) {
			for (Grammar g : imports) {
				String libdir = tool.libDirectory;
				String fileName = groomQualifiedFileName(libdir, g.fileName);
				files.add(new File(fileName));
			}
		}

        if (files.isEmpty()) {
            return null;
        }
        return files;
    }

    
Return a list of File objects that name files ANTLR will read
to process T.g; This can only be .tokens files and only
if they use the tokenVocab option.
Returns:
List of dependencies other than imported grammars/**
     * Return a list of File objects that name files ANTLR will read
     * to process T.g; This can only be .tokens files and only
     * if they use the tokenVocab option.
     *
     * @return List of dependencies other than imported grammars
     */
    public List<File> getNonImportDependenciesFileList() {
        List<File> files = new ArrayList<File>();

        // handle token vocabulary loads
        String tokenVocab = g.getOptionString("tokenVocab");
        if (tokenVocab != null) {
			String fileName =
				tokenVocab + CodeGenerator.VOCAB_FILE_EXTENSION;
			File vocabFile;
			if ( tool.libDirectory.equals(".") ) {
				vocabFile = new File(fileName);
			}
			else {
				vocabFile = new File(tool.libDirectory, fileName);
			}
			files.add(vocabFile);
		}

        return files;
    }

    public ST getDependencies() {
        loadDependencyTemplates();
        ST dependenciesST = templates.getInstanceOf("dependencies");
        dependenciesST.add("in", getDependenciesFileList());
        dependenciesST.add("out", getGeneratedFileList());
        dependenciesST.add("grammarFileName", g.fileName);
        return dependenciesST;
    }

    public void loadDependencyTemplates() {
        if (templates != null) return;
        String fileName = "org/antlr/v4/tool/templates/depend.stg";
        templates = new STGroupFile(fileName, "UTF-8");
    }

    public CodeGenerator getGenerator() {
        return generator;
    }

    public String groomQualifiedFileName(String outputDir, String fileName) {
        if (outputDir.equals(".")) {
            return fileName;
        }
		else if (outputDir.indexOf(' ') >= 0) { // has spaces?
            String escSpaces = outputDir.replace(" ", "\\ ");
            return escSpaces + File.separator + fileName;
        }
		else {
            return outputDir + File.separator + fileName;
        }
    }
}