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/**

 * @test

 * @bug 8003280

 * @summary Add lambda tests

 *   Test SAM conversion of lambda expressions in combinations of different contexts,

 *           lambda body types(statement/expression), explict/implicit target type etc, to verify

 *           SAM conversion being conducted successfully as expected.

 */

import com.sun.source.util.JavacTask;

import java.net.URI;

import java.util.Arrays;

import javax.tools.Diagnostic;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.SimpleJavaFileObject;

import javax.tools.ToolProvider;

public class SamConversionComboTest {

    enum FInterface {

        A("A", "interface A { Integer m(int i); }"),

        B("B", "interface B { int m(Integer i); }"),

        C("C", "interface C { int m(Integer i) throws Exception; }");

        String interfaceType;

        String interfaceDef;

        FInterface(String interfaceType, String interfaceDef) {

            this.interfaceType = interfaceType;

            this.interfaceDef = interfaceDef;

        }

        String getParameterType() {

            switch(this) {

            case A:

                return "int";

            case B:

            case C:

                return "Integer";

            default:

                return null;

            }

        }

    }

    enum Context {

        ASSIGNMENT("#FType f = #LBody;"),

        METHOD_CALL("void method1(#FType f) { }\n" +

                    "    void method2() {\n" +

                    "        method1(#LBody);\n" +

                    "    }"),

        CONSTRUCTOR("X x = new X(#LBody);"),

        RETURN_OF_METHOD("#FType method1() {\n" +

                         "    return #LBody;\n" +

                         "}"),

        ARRAY_INITIALIZER("Object[] oarray = {\"a\", 1, (#FType)#LBody};"),

        LAMBDA_BODY("#FType f = n -> ((#FType)#LBody).m(n);"),

        CAST("void test() throws Exception { int n = ((#FType)#LBody).m(1); }"),

        CONDITIONAL_EXPRESSION("#FType f = 2 > 1 ? #LBody : null;");

        String context;

        Context(String context) {

            this.context = context;

        }

        String getContext(FInterface f, LambdaKind lk, LambdaBody lb, ReturnValue rv) {

            return context.replace("#FType", f.interfaceType).replace("#LBody", lb.getLambdaBody(f, lk, rv));

        }

    }

    enum LambdaKind {

        EXPRESSION("#VAL"),

        STATEMENT("{return #VAL;}"),

        EXCEPTION_STMT("{throw new Exception();}");

        String stmt;

        LambdaKind(String stmt) {

            this.stmt = stmt;

        }

    }

    enum ReturnValue {

        INT("i + 1"),

        INTEGER("new Integer(i+1)"),

        INT2("i.intValue() + 1"),

        STRING("i + \"\""),

        DOUBLE("i * 1.0");

        String rValue;

        ReturnValue(String rValue) {

            this.rValue = rValue;

        }

    }

    enum LambdaBody {

        IMPLICIT("i -> #RET"),//type inferred

        EXPLICIT("(#Type i) -> #RET");//explicit type

        String bodyStr;

        LambdaBody(String bodyStr) {

            this.bodyStr = bodyStr;

        }

        String getLambdaBody(FInterface fi, LambdaKind lk, ReturnValue rv) {

            return bodyStr.replace("#Type", fi.getParameterType()).replace("#RET", lk.stmt.replace("#VAL", rv.rValue));

        }

    }

    boolean checkSamConversion() {

        if(lambdaKind != LambdaKind.EXCEPTION_STMT && (returnValue == ReturnValue.DOUBLE || returnValue == ReturnValue.STRING)) //return type mismatch

            return false;

        if(context != Context.CONSTRUCTOR) {//context other than construcotr argument

            if(fInterface != FInterface.C && lambdaKind == LambdaKind.EXCEPTION_STMT)

                return false;

            if(fInterface == FInterface.A && returnValue == ReturnValue.INT2)

                return false;

        }

        else { //constructor argument context

            //match X(A a) or X(B b) or X(C c)

            if (lambdaKind == LambdaKind.EXCEPTION_STMT) {

                return false; //ambiguous target type

            }

            else if(lambdaBody == LambdaBody.IMPLICIT) {

                return false;

            }

            else { //explicit parameter type

                if(fInterface.getParameterType().equals("Integer")) //ambiguous target type

                //e.g. X x = new X((Integer i) -> i + 1);

                    return false;

                if(returnValue == ReturnValue.INT2)

                //e.g. X x = new X(int i -> i.intValue() + 1);

                    return false;

            }

        }

        return true;

    }

    SourceFile samSourceFile = new SourceFile("FInterface.java", "#C") {

        public String toString() {

            String interfaces = "";

            for(FInterface fi : FInterface.values())

                interfaces += fi.interfaceDef + "\n";

            return template.replace("#C", interfaces);

        }

    };

    String clientTemplate = "class Client {\n" +

                            "    #Context\n" +

                            "}\n\n" +

                            "class X {\n" +

                            "    int value = 0;\n\n" +

                            "    X(A a) {\n" +

                            "        value = a.m(6);\n" +

                            "    }\n\n" +

                            "    X(B b) {\n" +

                            "        value = b.m(7);\n" +

                            "    }\n\n" +

                            "    X(C c) {\n" +

                            "        try {\n" +

                            "            value = c.m(8);\n" +

                            "        } catch (Exception e){}\n" +

                            "    }\n" +

                            "}";

    SourceFile clientSourceFile = new SourceFile("Client.java", clientTemplate) {

        public String toString() {

            return template.replace("#Context", context.getContext(fInterface, lambdaKind, lambdaBody, returnValue));

        }

    };

    void test() throws Exception {

        System.out.println("\n====================================");

        System.out.println(fInterface + ", " +  context + ", " + lambdaKind + ", " + lambdaBody + ", " + returnValue);

        System.out.println(samSourceFile + "\n");

        String clientFileStr = clientSourceFile.toString();

        System.out.println(clientFileStr.substring(0, clientFileStr.indexOf("\n\n")));

        DiagnosticChecker dc = new DiagnosticChecker();

        JavacTask ct = (JavacTask)comp.getTask(null, fm, dc, null, null, Arrays.asList(samSourceFile, clientSourceFile));

        try {

            ct.analyze();

        } catch (Exception e) {

            throw new AssertionError("failing SAM source file \n" + samSourceFile + "\n\n" + "failing client source file \n"+ clientSourceFile);

        }

        if (dc.errorFound == checkSamConversion()) {

            throw new AssertionError(samSourceFile + "\n\n" + clientSourceFile);

        }

        count++;

    }

    abstract class SourceFile extends SimpleJavaFileObject {

        protected String template;

        public SourceFile(String filename, String template) {

            super(URI.create("myfo:/" + filename), JavaFileObject.Kind.SOURCE);

            this.template = template;

        }

        @Override

        public CharSequence getCharContent(boolean ignoreEncodingErrors) {

            return toString();

        }

        public abstract String toString();

    }

    static class DiagnosticChecker implements javax.tools.DiagnosticListener<JavaFileObject> {

        boolean errorFound = false;

        public void report(Diagnostic<? extends JavaFileObject> diagnostic) {

            if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {

                errorFound = true;

            }

        }

    }

    FInterface fInterface;

    Context context;

    LambdaBody lambdaBody;

    LambdaKind lambdaKind;

    ReturnValue returnValue;

    static int count = 0;

    static JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    static JavaFileManager fm = comp.getStandardFileManager(null, null, null);

    SamConversionComboTest(FInterface f, Context c, LambdaBody lb, LambdaKind lk, ReturnValue rv) {

        fInterface = f;

        context = c;

        lambdaKind = lk;

        lambdaBody = lb;

        returnValue = rv;

    }

    public static void main(String[] args) throws Exception {

        try {

            for(Context ct : Context.values()) {

                for (FInterface fi : FInterface.values()) {

                    for (LambdaKind lk: LambdaKind.values()) {

                        for (LambdaBody lb : LambdaBody.values()) {

                            for(ReturnValue rv : ReturnValue.values()) {

                                new SamConversionComboTest(fi, ct, lb, lk, rv).test();

                            }

                        }

                    }

                }

            }

        System.out.println("total tests: " + count);

        } finally {

            fm.close();

        }

    }

}