/*
 * Copyright (C) 2016 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.
 */

#include "FQName.h"

#include <android-base/logging.h>
#include <iostream>
#include <regex>
#include <sstream>

#define RE_COMPONENT    "[a-zA-Z_][a-zA-Z_0-9]*"
#define RE_PATH         RE_COMPONENT "([.]" RE_COMPONENT ")*"
#define RE_VERSION      "@[0-9]+[.][0-9]+"

static const std::regex kRE1("(" RE_PATH ")(" RE_VERSION ")?::(" RE_PATH ")");
static const std::regex kRE2("(" RE_VERSION ")::(" RE_PATH ")");
static const std::regex kRE3("(" RE_PATH ")(" RE_VERSION ")");
static const std::regex kRE4(RE_PATH);

namespace android {

FQName::FQName()
    : mValid(false) {
}

FQName::FQName(const std::string &s)
    : mValid(false) {
    setTo(s);
}

FQName::FQName(
        const std::string &package,
        const std::string &version,
        const std::string &name)
    : mValid(true),
      mPackage(package),
      mVersion(version),
      mName(name) {
}

bool FQName::isValid() const {
    return mValid;
}

bool FQName::isFullyQualified() const {
    return !mPackage.empty() && !mVersion.empty() && !mName.empty();
}

bool FQName::setTo(const std::string &s) {
    mPackage.clear();
    mVersion.clear();
    mName.clear();

    mValid = true;

    std::smatch match;
    if (std::regex_match(s, match, kRE1)) {
        CHECK_EQ(match.size(), 6u);

        mPackage = match.str(1);
        mVersion = match.str(3);
        mName = match.str(4);
    } else if (std::regex_match(s, match, kRE2)) {
        CHECK_EQ(match.size(), 4u);

        mVersion = match.str(1);
        mName = match.str(2);
    } else if (std::regex_match(s, match, kRE3)) {
        CHECK_EQ(match.size(), 4u);

        mPackage = match.str(1);
        mVersion = match.str(3);
    } else if (std::regex_match(s, match, kRE4)) {
        mName = match.str(0);
    } else {
        mValid = false;
    }

    return isValid();
}

std::string FQName::package() const {
    return mPackage;
}

std::string FQName::version() const {
    return mVersion;
}

std::string FQName::name() const {
    return mName;
}

std::vector<std::string> FQName::names() const {
    std::vector<std::string> res {};
    std::istringstream ss(name());
    std::string s;
    while (std::getline(ss, s, '.')) {
        res.push_back(s);
    }
    return res;
}

void FQName::applyDefaults(
        const std::string &defaultPackage,
        const std::string &defaultVersion) {
    if (mPackage.empty()) {
        mPackage = defaultPackage;
    }

    if (mVersion.empty()) {
        mVersion = defaultVersion;
    }
}

std::string FQName::string() const {
    CHECK(mValid);

    std::string out;
    out.append(mPackage);
    out.append(mVersion);
    if (!mName.empty()) {
        if (!mPackage.empty() || !mVersion.empty()) {
            out.append("::");
        }
        out.append(mName);
    }

    return out;
}

void FQName::print() const {
    if (!mValid) {
        LOG(INFO) << "INVALID";
        return;
    }

    LOG(INFO) << string();
}

bool FQName::operator<(const FQName &other) const {
    return string() < other.string();
}

bool FQName::operator==(const FQName &other) const {
    return string() == other.string();
}

static void SplitString(
        const std::string &s, char c, std::vector<std::string> *components) {
    components->clear();

    size_t startPos = 0;
    size_t matchPos;
    while ((matchPos = s.find(c, startPos)) != std::string::npos) {
        components->push_back(s.substr(startPos, matchPos - startPos));
        startPos = matchPos + 1;
    }

    if (startPos + 1 < s.length()) {
        components->push_back(s.substr(startPos));
    }
}

// static
std::string FQName::JoinStrings(
        const std::vector<std::string> &components,
        const std::string &separator) {
    std::string out;
    bool first = true;
    for (const auto &component : components) {
        if (!first) {
            out += separator;
        }
        out += component;

        first = false;
    }

    return out;
}

std::string FQName::cppNamespace() const {
    std::vector<std::string> components;
    getPackageAndVersionComponents(&components, true /* cpp_compatible */);

    std::string out = "::";
    out += JoinStrings(components, "::");

    return out;
}

std::string FQName::cppName() const {
    std::string out = cppNamespace();

    std::vector<std::string> components;
    SplitString(name(), '.', &components);
    out += "::";
    out += JoinStrings(components, "::");

    return out;
}

std::string FQName::javaPackage() const {
    std::vector<std::string> components;
    getPackageAndVersionComponents(&components, true /* cpp_compatible */);

    return JoinStrings(components, ".");
}

std::string FQName::javaName() const {
    return javaPackage() + "." + name();
}

void FQName::getPackageComponents(std::vector<std::string> *components) const {
    SplitString(package(), '.', components);
}

void FQName::getPackageAndVersionComponents(
        std::vector<std::string> *components,
        bool cpp_compatible) const {
    getPackageComponents(components);

    const std::string packageVersion = version();
    CHECK(packageVersion[0] == '@');

    if (!cpp_compatible) {
        components->push_back(packageVersion.substr(1));
        return;
    }

    const size_t dotPos = packageVersion.find('.');

    // Form "Vmajor_minor".
    std::string versionString = "V";
    versionString.append(packageVersion.substr(1, dotPos - 1));
    versionString.append("_");
    versionString.append(packageVersion.substr(dotPos + 1));

    components->push_back(versionString);
}

bool FQName::endsWith(const FQName &other) const {
    std::string s1 = string();
    std::string s2 = other.string();

    size_t pos = s1.rfind(s2);
    if (pos == std::string::npos || pos + s2.size() != s1.size()) {
        return false;
    }

    if (pos > 0) {
        // A match is only a match if it is preceded by a "boundary", i.e.
        // we perform a component-wise match from the end.
        // "az" is not a match for "android.hardware.foo@1.0::IFoo.bar.baz",
        // "baz", "bar.baz", "IFoo.bar.baz" are.

        char separator = s1[pos - 1];
        if (separator != '.' && separator != ':') {
            return false;
        }
    }

    return true;
}

}  // namespace android