package Sequenic.T2.export;

import java.io.FileNotFoundException;
import java.io.PrintStream;

import Sequenic.T2.Seq.CALL_METHOD;
import Sequenic.T2.Seq.CONST;
import Sequenic.T2.Seq.CREATE_OBJECT;
import Sequenic.T2.Seq.MkValStep;
import Sequenic.T2.Seq.REF;
import Sequenic.T2.Seq.Trace;
import Sequenic.T2.Seq.TraceStep;

/**
 * This class can print the steps in a trace file to a JUnit test class.
 * 
 * @author Christiaan Hees
 */
public class JUnitPrinter extends TraceExporter {
	
	/**
	 * If this value is true then it will show the original steps of T2
	 * using comments in the output.
	 */
	private boolean showT2Steps = true;
	
	/**
	 * You can limit the amount of traces exported with this variable.
	 */
	private int maxTraceCount = 10;
	
	public JUnitPrinter(String trFileString) {
		super(trFileString);
		visitor = new JUnitVisitor();
	}
	
	@Override
	protected void print() {
		printPackage(trFile.CUTname);
		printImports();
		printClassHeader(trFile.CUTname);
		
		int traceCount = 0;
		for(Trace t : trFile.traces) {
			if(traceCount >= maxTraceCount) break;
			traceCount++;
			
			printTrace(t, traceCount);
		}
		
		printClassFooter();
	}

	private void printPackage(String cutName) {
		String pack = cutName.substring(0, cutName.lastIndexOf("."));
		if(!"".equals(pack))
			out.println("package "+pack+";\n");
	}
	
	private void printImports() {
		out.println("import org.junit.Test;\n");
	}
	
	private void printClassHeader(String cutName) {
		out.println("/**");
		out.println(" * This file is auto-generated by JUnitPrinter.");
		out.println(" * Warning: This exporter is experimental so you might want to check if");
		out.println(" *          the generated code matches the T2 steps in the comments.");
		if(maxTraceCount < Integer.MAX_VALUE)
			out.println(" * The first "+maxTraceCount+" traces were exported.");
		out.println(" */");
		out.println("public class " + 
				cutName.substring(cutName.lastIndexOf(".")+1)+"ExportedTest {");
	}
	
	private void printTrace(Trace t, int traceCount) {
		((JUnitVisitor)visitor).reset();
		
		out.println("\t@Test");
		out.println("\tpublic void trace"+traceCount+"() {");
		
		if(showT2Steps) out.println("//"+t.creation);
		t.creation.visit(visitor);
		for(TraceStep ts : t.trace) {
			if(showT2Steps) out.println("//"+ts);
			ts.visit(visitor);
		}
		
		out.println("\t}");
	}
	
	private void printClassFooter() {
		out.println("}");
	}
	
	/**
	 * Prints the steps in a trace file to a JUnit test class.
	 * The first argument should be the name of the trace file.
	 */
	public static void main(String[] args) {
		if(args.length < 1) {
			System.out.println(
					"Usage: java Sequenic.T2.export.JUnitPrinter <TraceFile> [OutputFile]");
			System.exit(0);
		}
		JUnitPrinter jp = new JUnitPrinter(args[0]);
		if(args.length > 1) {
			try {
				jp.out = new PrintStream(args[1]);
			} catch (FileNotFoundException e) {
				System.out.println("ERROR: failed to open "+args[1]);
				System.exit(1);
			}
		}
		jp.print();
	}
	
	private class JUnitVisitor extends Visitor {

		private int refCount;
		private int constCount;

		@Override
		public void visit(MkValStep mvs) {
			out.println("ERROR missing visitor: mvs "+mvs);
			System.exit(1);
		}

		@Override
		public void visit(CREATE_OBJECT co) {
			//out.println("DEBUG: co "+co);
			out.print("\t\t"+co.con.getName()+" ref"+refCount+" = ");
			refCount++;
			out.print("new "+co.con.getName()+"(");
			for(int i=co.params.length; i>0; i--) {
				out.print("const"+(constCount-i)); // FIXME
				// TODO ref and create object?
				if(i>1) out.print(", ");
			}
			
			out.println(");");
		}

		@Override
		public void visit(TraceStep ts) {
			out.println("ERROR missing visitor: ts "+ts);
			System.exit(1);
		}

		@Override
		public void visit(CALL_METHOD cm) {
			//out.println("DEBUG: cm "+cm);
			// TODO check what happens when it's a static method call without a receiver
			// TODO check what happens when there's a mix of CONST and REF parameters
			
			if(!(cm.receiver instanceof REF)) {
				out.print("\t\tref"+(refCount-1));
			}
			
			int consts = 0;
			out.print("."+cm.method.getName()+"(");
			StringBuffer pString = new StringBuffer();
			for(int i=cm.params.length; i>0; i--) {
				MkValStep param = cm.params[i-1];
				if(param instanceof CONST) {
					consts++;
					pString.insert(0, "const"+(constCount-consts));
				} else if(param instanceof REF) {
					pString.insert(0, "ref"+((REF)param).index);
				//} else if(param instanceof CREATE_OBJECT) {
				//	pString.insert(0, "ref?"); // TODO
				} else {
					out.println(pString);
					out.println("ERROR unexpected parameter: "+param);
					System.exit(1);
				}
				if(i>1) pString.insert(0, ", ");
			}
			out.print(pString);
			out.println(");");
		}

		@Override
		public void visit(REF ref) {
			out.print("\t\tref"+ref.index);
		}

		@Override
		public void visit(CONST c) {
			out.print("\t\t");
			out.print(c.getObjectClassName());
			out.print(" const"+constCount+" = ");
			constCount++;
			
			// FIXME this could go wrong with some values?
			//       Yes it does...
			if(c.isNull()) {
				out.println("null;");
			} else {
				out.println("new "+c.getObjectClassName()+"("+stringToJava(c.getObject().toString())+");");
			}
		}
		
		public void reset() {
			refCount = 0;
			constCount = 0;
		}
		
		private String stringToJava(String s) {
			return s; // TODO filter unprintable characters and quotes and newlines
		}
	}
}