// Keep somewhat in sync with
// langtools/test/tools/javac/annotations/typeAnnotations/referenceinfos/ReferenceInfoUtil.java
// Adapted to handled the same type qualifier appearing multiple times.

import com.sun.tools.classfile.Attribute;
import com.sun.tools.classfile.ClassFile;
import com.sun.tools.classfile.Code_attribute;
import com.sun.tools.classfile.ConstantPool.InvalidIndex;
import com.sun.tools.classfile.ConstantPool.UnexpectedEntry;
import com.sun.tools.classfile.Field;
import com.sun.tools.classfile.Method;
import com.sun.tools.classfile.RuntimeTypeAnnotations_attribute;
import com.sun.tools.classfile.TypeAnnotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.checkerframework.javacutil.Pair;
import org.checkerframework.javacutil.PluginUtil;

public class ReferenceInfoUtil {

    public static final int IGNORE_VALUE = -321;

    public static List<TypeAnnotation> extendedAnnotationsOf(ClassFile cf) {
        List<TypeAnnotation> annos = new ArrayList<>();
        findAnnotations(cf, annos);
        return annos;
    }

    /////////////////// Extract type annotations //////////////////
    private static void findAnnotations(ClassFile cf, List<TypeAnnotation> annos) {
        findAnnotations(cf, Attribute.RuntimeVisibleTypeAnnotations, annos);
        findAnnotations(cf, Attribute.RuntimeInvisibleTypeAnnotations, annos);

        for (Field f : cf.fields) {
            findAnnotations(cf, f, annos);
        }
        for (Method m : cf.methods) {
            findAnnotations(cf, m, annos);
        }
    }

    private static void findAnnotations(ClassFile cf, Method m, List<TypeAnnotation> annos) {
        findAnnotations(cf, m, Attribute.RuntimeVisibleTypeAnnotations, annos);
        findAnnotations(cf, m, Attribute.RuntimeInvisibleTypeAnnotations, annos);
    }

    private static void findAnnotations(ClassFile cf, Field m, List<TypeAnnotation> annos) {
        findAnnotations(cf, m, Attribute.RuntimeVisibleTypeAnnotations, annos);
        findAnnotations(cf, m, Attribute.RuntimeInvisibleTypeAnnotations, annos);
    }

    /**
     * Test the result of Attributes.getIndex according to expectations encoded in the method's
     * name.
     */
    private static void findAnnotations(ClassFile cf, String name, List<TypeAnnotation> annos) {
        int index = cf.attributes.getIndex(cf.constant_pool, name);
        if (index != -1) {
            Attribute attr = cf.attributes.get(index);
            assert attr instanceof RuntimeTypeAnnotations_attribute;
            RuntimeTypeAnnotations_attribute tAttr = (RuntimeTypeAnnotations_attribute) attr;
            annos.addAll(Arrays.asList(tAttr.annotations));
        }
    }

    /**
     * Test the result of Attributes.getIndex according to expectations encoded in the method's
     * name.
     */
    private static void findAnnotations(
            ClassFile cf, Method m, String name, List<TypeAnnotation> annos) {
        int index = m.attributes.getIndex(cf.constant_pool, name);
        if (index != -1) {
            Attribute attr = m.attributes.get(index);
            assert attr instanceof RuntimeTypeAnnotations_attribute;
            RuntimeTypeAnnotations_attribute tAttr = (RuntimeTypeAnnotations_attribute) attr;
            annos.addAll(Arrays.asList(tAttr.annotations));
        }

        int cindex = m.attributes.getIndex(cf.constant_pool, Attribute.Code);
        if (cindex != -1) {
            Attribute cattr = m.attributes.get(cindex);
            assert cattr instanceof Code_attribute;
            Code_attribute cAttr = (Code_attribute) cattr;
            index = cAttr.attributes.getIndex(cf.constant_pool, name);
            if (index != -1) {
                Attribute attr = cAttr.attributes.get(index);
                assert attr instanceof RuntimeTypeAnnotations_attribute;
                RuntimeTypeAnnotations_attribute tAttr = (RuntimeTypeAnnotations_attribute) attr;
                annos.addAll(Arrays.asList(tAttr.annotations));
            }
        }
    }

    /**
     * Test the result of Attributes.getIndex according to expectations encoded in the method's
     * name.
     */
    private static void findAnnotations(
            ClassFile cf, Field m, String name, List<TypeAnnotation> annos) {
        int index = m.attributes.getIndex(cf.constant_pool, name);
        if (index != -1) {
            Attribute attr = m.attributes.get(index);
            assert attr instanceof RuntimeTypeAnnotations_attribute;
            RuntimeTypeAnnotations_attribute tAttr = (RuntimeTypeAnnotations_attribute) attr;
            annos.addAll(Arrays.asList(tAttr.annotations));
        }
    }

    /////////////////////// Equality testing /////////////////////
    private static boolean areEquals(int a, int b) {
        return a == b || a == IGNORE_VALUE || b == IGNORE_VALUE;
    }

    private static boolean areEquals(int[] a, int[] a2) {
        if (a == a2) {
            return true;
        }
        if (a == null || a2 == null) {
            return false;
        }

        int length = a.length;
        if (a2.length != length) {
            return false;
        }

        for (int i = 0; i < length; i++) {
            if (areEquals(a[i], a2[i])) {
                return false;
            }
        }

        return true;
    }

    public static boolean areEquals(TypeAnnotation.Position p1, TypeAnnotation.Position p2) {
        if (p1 == p2) {
            return true;
        }
        if (p1 == null || p2 == null) {
            return false;
        }

        boolean result =
                ((p1.type == p2.type)
                        && (p1.location.equals(p2.location))
                        && areEquals(p1.offset, p2.offset)
                        && areEquals(p1.lvarOffset, p2.lvarOffset)
                        && areEquals(p1.lvarLength, p2.lvarLength)
                        && areEquals(p1.lvarIndex, p2.lvarIndex)
                        && areEquals(p1.bound_index, p2.bound_index)
                        && areEquals(p1.parameter_index, p2.parameter_index)
                        && areEquals(p1.type_index, p2.type_index)
                        && areEquals(p1.exception_index, p2.exception_index));
        return result;
    }

    public static String positionCompareStr(
            TypeAnnotation.Position p1, TypeAnnotation.Position p2) {
        return PluginUtil.joinLines(
                "type = " + p1.type + ", " + p2.type,
                "offset = " + p1.offset + ", " + p2.offset,
                "lvarOffset = " + p1.lvarOffset + ", " + p2.lvarOffset,
                "lvarLength = " + p1.lvarLength + ", " + p2.lvarLength,
                "lvarIndex = " + p1.lvarIndex + ", " + p2.lvarIndex,
                "bound_index = " + p1.bound_index + ", " + p2.bound_index,
                "parameter_index = " + p1.parameter_index + ", " + p2.parameter_index,
                "type_index = " + p1.type_index + ", " + p2.type_index,
                "exception_index = " + p1.exception_index + ", " + p2.exception_index,
                "");
    }

    private static TypeAnnotation findAnnotation(
            String name,
            TypeAnnotation.Position expected,
            List<TypeAnnotation> annotations,
            ClassFile cf)
            throws InvalidIndex, UnexpectedEntry {
        String properName = "L" + name + ";";
        for (TypeAnnotation anno : annotations) {
            String actualName = cf.constant_pool.getUTF8Value(anno.annotation.type_index);

            if (properName.equals(actualName)) {
                System.out.println("For Anno: " + actualName);
            }

            if (properName.equals(actualName) && areEquals(expected, anno.position)) {
                return anno;
            }
        }
        return null;
    }

    public static boolean compare(
            List<Pair<String, TypeAnnotation.Position>> expectedAnnos,
            List<TypeAnnotation> actualAnnos,
            ClassFile cf)
            throws InvalidIndex, UnexpectedEntry {
        if (actualAnnos.size() != expectedAnnos.size()) {
            throw new ComparisonException(
                    "Wrong number of annotations", expectedAnnos, actualAnnos);
        }

        for (Pair<String, TypeAnnotation.Position> e : expectedAnnos) {
            String aName = e.first;
            TypeAnnotation.Position expected = e.second;
            TypeAnnotation actual = findAnnotation(aName, expected, actualAnnos, cf);
            if (actual == null) {
                throw new ComparisonException(
                        "Expected annotation not found: " + aName + " position: " + expected,
                        expectedAnnos,
                        actualAnnos);
            }
        }
        return true;
    }
}

class ComparisonException extends RuntimeException {
    private static final long serialVersionUID = -3930499712333815821L;

    public final List<Pair<String, TypeAnnotation.Position>> expected;
    public final List<TypeAnnotation> found;

    public ComparisonException(
            String message,
            List<Pair<String, TypeAnnotation.Position>> expected,
            List<TypeAnnotation> found) {
        super(message);
        this.expected = expected;
        this.found = found;
    }

    public String toString() {
        return PluginUtil.joinLines(
                super.toString(),
                "\tExpected: "
                        + expected.size()
                        + " annotations; but found: "
                        + found.size()
                        + " annotations",
                "  Expected: " + expected,
                "  Found: " + found);
    }
}