/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.cts.apicoverage;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;

/** Representation of a class in the API with constructors and methods. */
class ApiClass implements Comparable<ApiClass>, HasCoverage {

    private static final String VOID = "void";

    private final String mName;

    private final boolean mDeprecated;

    private final boolean mAbstract;

    private final List<ApiConstructor> mApiConstructors = Collections.synchronizedList(new ArrayList<>());

    private final List<ApiMethod> mApiMethods = Collections.synchronizedList(new ArrayList<>());

    private final String mSuperClassName;

    private ApiClass mSuperClass;

    private Map<String, ApiClass> mInterfaceMap = new HashMap<String, ApiClass>();

    /**
     * @param name The name of the class
     * @param deprecated true iff the class is marked as deprecated
     * @param classAbstract true iff the class is abstract
     * @param superClassName The fully qualified name of the super class
     */
    ApiClass(
            String name,
            boolean deprecated,
            boolean classAbstract,
            String superClassName) {
        mName = name;
        mDeprecated = deprecated;
        mAbstract = classAbstract;
        mSuperClassName = superClassName;
    }

    @Override
    public int compareTo(ApiClass another) {
        return mName.compareTo(another.mName);
    }

    @Override
    public String getName() {
        return mName;
    }

    public boolean isDeprecated() {
        return mDeprecated;
    }

    public String getSuperClassName() {
        return mSuperClassName;
    }

    public boolean isAbstract() {
        return mAbstract;
    }

    public void setSuperClass(ApiClass superClass) { mSuperClass = superClass; }

    public void addInterface(String interfaceName) {
        mInterfaceMap.put(interfaceName, null);
    }

    public void resolveInterface(String interfaceName, ApiClass apiInterface) {
        mInterfaceMap.replace(interfaceName, apiInterface);
    }

    public Set<String> getInterfaceNames() {
        return mInterfaceMap.keySet();
    }

    public void addConstructor(ApiConstructor constructor) {
        mApiConstructors.add(constructor);
    }

    public Collection<ApiConstructor> getConstructors() {
        return Collections.unmodifiableList(mApiConstructors);
    }

    public void addMethod(ApiMethod method) {
        mApiMethods.add(method);
    }

    /** Look for a matching constructor and mark it as covered */
    public void markConstructorCovered(List<String> parameterTypes, String coveredbyApk) {
        if (mSuperClass != null) {
            // Mark matching constructors in the superclass
            mSuperClass.markConstructorCovered(parameterTypes, coveredbyApk);
        }
        Optional<ApiConstructor> apiConstructor = getConstructor(parameterTypes);
        apiConstructor.ifPresent(constructor -> constructor.setCovered(coveredbyApk));
    }

    /** Look for a matching method and if found and mark it as covered */
    public void markMethodCovered(String name, List<String> parameterTypes, String coveredbyApk) {
        if (mSuperClass != null) {
            // Mark matching methods in the super class
            mSuperClass.markMethodCovered(name, parameterTypes, coveredbyApk);
        }
        if (!mInterfaceMap.isEmpty()) {
            // Mark matching methods in the interfaces
            for (ApiClass mInterface : mInterfaceMap.values()) {
                if (mInterface != null) {
                    mInterface.markMethodCovered(name, parameterTypes, coveredbyApk);
                }
            }
        }
        Optional<ApiMethod> apiMethod = getMethod(name, parameterTypes);
        apiMethod.ifPresent(method -> method.setCovered(coveredbyApk));
    }

    public Collection<ApiMethod> getMethods() {
        return Collections.unmodifiableList(mApiMethods);
    }

    public int getNumCoveredMethods() {
        int numCovered = 0;
        for (ApiConstructor constructor : mApiConstructors) {
            if (constructor.isCovered()) {
                numCovered++;
            }
        }
        for (ApiMethod method : mApiMethods) {
            if (method.isCovered()) {
                numCovered++;
            }
        }
        return numCovered;
    }

    public int getTotalMethods() {
        return mApiConstructors.size() + mApiMethods.size();
    }

    @Override
    public float getCoveragePercentage() {
        if (getTotalMethods() == 0) {
            return 100;
        } else {
            return (float) getNumCoveredMethods() / getTotalMethods() * 100;
        }
    }

    @Override
    public int getMemberSize() {
        return getTotalMethods();
    }

    private Optional<ApiMethod> getMethod(String name, List<String> parameterTypes) {
        for (ApiMethod method : mApiMethods) {
            boolean methodNameMatch = name.equals(method.getName());
            boolean parameterTypeMatch =
                    compareParameterTypes(method.getParameterTypes(), parameterTypes);
            if (methodNameMatch && parameterTypeMatch) {
                return Optional.of(method);
            }
        }
        return Optional.empty();
    }

    /**
     * The method compares two lists of parameters. If the {@code apiParameterTypeList} contains
     * generic types, test parameter types are ignored.
     *
     * @param apiParameterTypeList The list of parameter types from the API
     * @param testParameterTypeList The list of parameter types used in a test
     * @return true iff the list of types are the same.
     */
    private static boolean compareParameterTypes(
            List<String> apiParameterTypeList, List<String> testParameterTypeList) {
        if (apiParameterTypeList.equals(testParameterTypeList)) {
            return true;
        }
        if (apiParameterTypeList.size() != testParameterTypeList.size()) {
            return false;
        }

        for (int i = 0; i < apiParameterTypeList.size(); i++) {
            String apiParameterType = apiParameterTypeList.get(i);
            String testParameterType = testParameterTypeList.get(i);
            if (!compareType(apiParameterType, testParameterType)) {
                return false;
            }
        }
        return true;
    }

    /**
     * @return true iff the parameter is a var arg parameter.
     */
    private static boolean isVarArg(String parameter) {
        return parameter.endsWith("...");
    }

    /**
     * Compare class types.
     * @param apiType The type as reported by the api
     * @param testType The type as found used in a test
     * @return true iff the strings are equal,
     * or the apiType is generic and the test type is not void
     */
    private static boolean compareType(String apiType, String testType) {
        return apiType.equals(testType) ||
                isGenericType(apiType) && !testType.equals(VOID) ||
                isGenericArrayType(apiType) && isArrayType(testType) ||
                isVarArg(apiType) && isArrayType(testType) &&
                        apiType.startsWith(testType.substring(0, testType.indexOf("[")));
    }

    /**
     * @return true iff the given parameterType is a generic type.
     */
    private static boolean isGenericType(String type) {
        return type.length() == 1 &&
                type.charAt(0) >= 'A' &&
                type.charAt(0) <= 'Z';
    }

    /**
     * @return true iff {@code type} ends with an [].
     */
    private static boolean isArrayType(String type) {
        return type.endsWith("[]");
    }

    /**
     * @return true iff the given parameterType is an array of generic type.
     */
    private static boolean isGenericArrayType(String type) {
        return type.length() == 3 && isGenericType(type.substring(0, 1)) && isArrayType(type);
    }

    private Optional<ApiConstructor> getConstructor(List<String> parameterTypes) {
        for (ApiConstructor constructor : mApiConstructors) {
            if (compareParameterTypes(constructor.getParameterTypes(), parameterTypes)) {
                return Optional.of(constructor);
            }
        }
        return Optional.empty();
    }
}