/*
 * [The "BSD license"]
 *  Copyright (c) 2011 Terence Parr
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.stringtemplate.v4.compiler;

import org.antlr.runtime.*;
import org.antlr.runtime.tree.CommonTree;
import org.stringtemplate.v4.*;
import org.stringtemplate.v4.misc.*;

import java.io.*;
import java.util.*;

The result of compiling an ST. Contains all the bytecode instructions, string table, bytecode address to source code map, and other bookkeeping info. It's the implementation of an ST you might say. All instances of the same template share a single implementation (ST.impl field). /** The result of compiling an {@link ST}.  Contains all the bytecode instructions,
 *  string table, bytecode address to source code map, and other bookkeeping
 *  info.  It's the implementation of an ST you might say.  All instances
 *  of the same template share a single implementation ({@link ST#impl} field).
 */
public class CompiledST implements Cloneable {
    public String name;

	
Every template knows where it is relative to the group that loaded it. The prefix is the relative path from the root. "/prefix/name" is the fully qualified name of this template. All calls to STGroup.getInstanceOf calls must use fully qualified names. A "/" is added to the front if you don't specify one. Template references within template code, however, uses relative names, unless of course the name starts with "/". 

This has nothing to do with the outer filesystem path to the group dir or
group file.

We set this as we load/compile the template.
 Always ends with "/".
/**
	 * Every template knows where it is relative to the group that loaded it.
	 * The prefix is the relative path from the root. {@code "/prefix/name"} is
	 * the fully qualified name of this template. All calls to
	 * {@link STGroup#getInstanceOf} calls must use fully qualified names. A
	 * {@code "/"} is added to the front if you don't specify one. Template
	 * references within template code, however, uses relative names, unless of
	 * course the name starts with {@code "/"}.
	 * <p>
	 * This has nothing to do with the outer filesystem path to the group dir or
	 * group file.</p>
	 * <p>
	 * We set this as we load/compile the template.</p>
	 * <p>
	 * Always ends with {@code "/"}.</p>
	 */
	public String prefix = "/";

    
The original, immutable pattern (not really used again after
 initial "compilation"). Useful for debugging.  Even for
 subtemplates, this is entire overall template.
/** The original, immutable pattern (not really used again after
     *  initial "compilation"). Useful for debugging.  Even for
	 *  subtemplates, this is entire overall template.
     */
    public String template;

	
The token that begins template definition; could be <@r> of region. /** The token that begins template definition; could be {@code <@r>} of region. */
	public Token templateDefStartToken;

	
Overall token stream for template (debug only). /** Overall token stream for template (debug only). */
	public TokenStream tokens;

	
How do we interpret syntax of template? (debug only) /** How do we interpret syntax of template? (debug only) */
	public CommonTree ast;

    public Map<String, FormalArgument> formalArguments;

	public boolean hasFormalArgs;

	public int numberOfArgsWithDefaultValues;

    
A list of all regions and subtemplates. /** A list of all regions and subtemplates. */
    public List<CompiledST> implicitlyDefinedTemplates;

	
The group that physically defines this ST definition. We use it to initiate interpretation via ST.toString. From there, it becomes field Interpreter.group and is fixed until rendering completes. /**
	 * The group that physically defines this {@link ST} definition. We use it
	 * to initiate interpretation via {@link ST#toString}. From there, it
	 * becomes field {@link Interpreter#group} and is fixed until rendering
	 * completes.
	 */
    public STGroup nativeGroup = STGroup.defaultGroup;

    
Does this template come from a <@region>...<@end> embedded in another template? /** Does this template come from a {@code <@region>...<@end>} embedded in
     *  another template?
     */
    public boolean isRegion;

	
If someone refs <@r()> in template t, an implicit 
 @t.r() ::= ""
 is defined, but you can overwrite this def by defining your own. We need to prevent more than one manual def though. Between this var and isRegion we can determine these cases.
/**
	 * If someone refs {@code <@r()>} in template t, an implicit
	 *
	 * <p>
	 * {@code @t.r() ::= ""}</p>
	 * <p>
	 * is defined, but you can overwrite this def by defining your own. We need
	 * to prevent more than one manual def though. Between this var and
	 * {@link #isRegion} we can determine these cases.</p>
	 */
    public ST.RegionType regionDefType;

    public boolean isAnonSubtemplate; // {...}

    public String[] strings;     // string operands of instructions
    public byte[] instrs;        // byte-addressable code memory.
    public int codeSize;
    public Interval[] sourceMap; // maps IP to range in template pattern

	public CompiledST() {
        instrs = new byte[Compiler.TEMPLATE_INITIAL_CODE_SIZE];
        sourceMap = new Interval[Compiler.TEMPLATE_INITIAL_CODE_SIZE];
		template = "";
	}

	
Cloning the CompiledST for an ST instance allows ST.add to be called safely during interpretation for templates that do not contain formal arguments. 
Throws:
CloneNotSupportedException – If the current instance cannot be
cloned.
Returns:
A copy of the current CompiledST instance. The copy is a shallow copy, with the exception of the formalArguments field which is also cloned./**
	 * Cloning the {@link CompiledST} for an {@link ST} instance allows
	 * {@link ST#add} to be called safely during interpretation for templates
	 * that do not contain formal arguments.
	 *
	 * @return A copy of the current {@link CompiledST} instance. The copy is a
	 * shallow copy, with the exception of the {@link #formalArguments} field
	 * which is also cloned.
	 *
	 * @exception CloneNotSupportedException If the current instance cannot be
	 * cloned.
	 */
	@Override
	public CompiledST clone() throws CloneNotSupportedException {
		CompiledST clone = (CompiledST)super.clone();
		if (formalArguments != null) {
			formalArguments = Collections.synchronizedMap(new LinkedHashMap<String,FormalArgument>(formalArguments));
		}

		return clone;
	}

    public void addImplicitlyDefinedTemplate(CompiledST sub) {
		sub.prefix = this.prefix;
		if ( sub.name.charAt(0)!='/' ) sub.name = sub.prefix+sub.name;
        if ( implicitlyDefinedTemplates == null ) {
            implicitlyDefinedTemplates = new ArrayList<CompiledST>();
        }
        implicitlyDefinedTemplates.add(sub);
    }

	public void defineArgDefaultValueTemplates(STGroup group) {
		if ( formalArguments==null ) return;
		for (String a : formalArguments.keySet()) {
			FormalArgument fa = formalArguments.get(a);
			if ( fa.defaultValueToken!=null ) {
				numberOfArgsWithDefaultValues++;
				switch (fa.defaultValueToken.getType()) {
				case GroupParser.ANONYMOUS_TEMPLATE:
					String argSTname = fa.name + "_default_value";
					Compiler c2 = new Compiler(group);
					String defArgTemplate =
						Misc.strip(fa.defaultValueToken.getText(), 1);
					fa.compiledDefaultValue =
						c2.compile(group.getFileName(), argSTname, null,
								   defArgTemplate, fa.defaultValueToken);
					fa.compiledDefaultValue.name = argSTname;
					fa.compiledDefaultValue.defineImplicitlyDefinedTemplates(group);
					break;

				case GroupParser.STRING:
					fa.defaultValue = Misc.strip(fa.defaultValueToken.getText(), 1);
					break;

				case GroupParser.LBRACK:
					fa.defaultValue = Collections.emptyList();
					break;

				case GroupParser.TRUE:
				case GroupParser.FALSE:
					fa.defaultValue = fa.defaultValueToken.getType()==GroupParser.TRUE;
					break;

				default:
					throw new UnsupportedOperationException("Unexpected default value token type.");
				}
			}
		}
	}

	public void defineFormalArgs(List<FormalArgument> args) {
		hasFormalArgs = true; // even if no args; it's formally defined
		if ( args == null ) formalArguments = null;
		else for (FormalArgument a : args) addArg(a);
	}

	
Used by ST.add to add args one by one without turning on full formal args definition signal. /** Used by {@link ST#add} to add args one by one without turning on full formal args definition signal. */
	public void addArg(FormalArgument a) {
		if ( formalArguments==null ) {
			formalArguments = Collections.synchronizedMap(new LinkedHashMap<String,FormalArgument>());
		}
		else if (formalArguments.containsKey(a.name)) {
			throw new IllegalArgumentException(String.format("Formal argument %s already exists.", a.name));
		}

		a.index = formalArguments.size();
		formalArguments.put(a.name, a);
	}

	public void defineImplicitlyDefinedTemplates(STGroup group) {
		if ( implicitlyDefinedTemplates !=null ) {
            for (CompiledST sub : implicitlyDefinedTemplates) {
                group.rawDefineTemplate(sub.name, sub, sub.templateDefStartToken);
                sub.defineImplicitlyDefinedTemplates(group);
            }
        }
    }

	public String getTemplateSource() {
		Interval r = getTemplateRange();
		return template.substring(r.a, r.b+1);
	}

	public Interval getTemplateRange() {
		if ( isAnonSubtemplate ) {
			int start = Integer.MAX_VALUE;
			int stop = Integer.MIN_VALUE;
			for (Interval interval : sourceMap) {
				if (interval == null) {
					continue;
				}

				start = Math.min(start, interval.a);
				stop = Math.max(stop, interval.b);
			}

			if (start <= stop + 1) {
				return new Interval(start, stop);
			}
		}
		return new Interval(0, template.length()-1);
	}

    public String instrs() {
        BytecodeDisassembler dis = new BytecodeDisassembler(this);
        return dis.instrs();
    }

    public void dump() {
        BytecodeDisassembler dis = new BytecodeDisassembler(this);
		System.out.println(name+":");
        System.out.println(dis.disassemble());
        System.out.println("Strings:");
        System.out.println(dis.strings());
        System.out.println("Bytecode to template map:");
        System.out.println(dis.sourceMap());
    }

    public String disasm() {
        BytecodeDisassembler dis = new BytecodeDisassembler(this);
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        pw.println(dis.disassemble());
        pw.println("Strings:");
        pw.println(dis.strings());
        pw.println("Bytecode to template map:");
        pw.println(dis.sourceMap());
        pw.close();
        return sw.toString();
    }
}