/*
 * 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 <gtest/gtest.h>
#include <unistd.h>

#include <atomic>
#include <condition_variable>
#include <thread>

#include "adb_io.h"
#include "sysdeps.h"
#include "sysdeps/chrono.h"

#if defined(_WIN32)
#include <windows.h>
static bool IsWine() {
    HMODULE ntdll = GetModuleHandleW(L"ntdll.dll");
    if (!ntdll) {
        return false;
    }
    return GetProcAddress(ntdll, "wine_get_version") != nullptr;
}
#else
static bool IsWine() {
    return false;
}
#endif

TEST(sysdeps_socketpair, smoke) {
    int fds[2];
    ASSERT_EQ(0, adb_socketpair(fds)) << strerror(errno);
    ASSERT_TRUE(WriteFdExactly(fds[0], "foo", 4));
    ASSERT_TRUE(WriteFdExactly(fds[1], "bar", 4));

    char buf[4];
    ASSERT_TRUE(ReadFdExactly(fds[1], buf, 4));
    ASSERT_STREQ(buf, "foo");
    ASSERT_TRUE(ReadFdExactly(fds[0], buf, 4));
    ASSERT_STREQ(buf, "bar");
    ASSERT_EQ(0, adb_close(fds[0]));
    ASSERT_EQ(0, adb_close(fds[1]));
}

TEST(sysdeps_fd, exhaustion) {
    std::vector<int> fds;
    int socketpair[2];

    while (adb_socketpair(socketpair) == 0) {
        fds.push_back(socketpair[0]);
        fds.push_back(socketpair[1]);
    }

    ASSERT_EQ(EMFILE, errno) << strerror(errno);
    for (int fd : fds) {
        ASSERT_EQ(0, adb_close(fd));
    }
    ASSERT_EQ(0, adb_socketpair(socketpair));
    ASSERT_EQ(socketpair[0], fds[0]);
    ASSERT_EQ(socketpair[1], fds[1]);
    ASSERT_EQ(0, adb_close(socketpair[0]));
    ASSERT_EQ(0, adb_close(socketpair[1]));
}

class sysdeps_poll : public ::testing::Test {
  protected:
    int fds[2];
    void SetUp() override {
        ASSERT_EQ(0, adb_socketpair(fds)) << strerror(errno);
    }

    void TearDown() override {
        if (fds[0] >= 0) {
            ASSERT_EQ(0, adb_close(fds[0]));
        }
        if (fds[1] >= 0) {
            ASSERT_EQ(0, adb_close(fds[1]));
        }
    }
};

TEST_F(sysdeps_poll, smoke) {
    adb_pollfd pfd[2] = {};
    pfd[0].fd = fds[0];
    pfd[0].events = POLLRDNORM;
    pfd[1].fd = fds[1];
    pfd[1].events = POLLWRNORM;

    pfd[0].revents = -1;
    pfd[1].revents = -1;
    EXPECT_EQ(1, adb_poll(pfd, 2, 0));
    EXPECT_EQ(0, pfd[0].revents);
    EXPECT_EQ(POLLWRNORM, pfd[1].revents);

    ASSERT_TRUE(WriteFdExactly(fds[1], "foo", 4));

    // Wait for the socketpair to be flushed.
    pfd[0].revents = -1;
    EXPECT_EQ(1, adb_poll(pfd, 1, 100));
    EXPECT_EQ(POLLRDNORM, pfd[0].revents);
    pfd[0].revents = -1;
    pfd[1].revents = -1;
    EXPECT_EQ(2, adb_poll(pfd, 2, 0));
    EXPECT_EQ(POLLRDNORM, pfd[0].revents);
    EXPECT_EQ(POLLWRNORM, pfd[1].revents);
}

TEST_F(sysdeps_poll, timeout) {
    adb_pollfd pfd = {};
    pfd.fd = fds[0];
    pfd.events = POLLRDNORM;

    EXPECT_EQ(0, adb_poll(&pfd, 1, 100));
    EXPECT_EQ(0, pfd.revents);

    ASSERT_TRUE(WriteFdExactly(fds[1], "foo", 4));

    EXPECT_EQ(1, adb_poll(&pfd, 1, 100));
    EXPECT_EQ(POLLRDNORM, pfd.revents);
}

TEST_F(sysdeps_poll, invalid_fd) {
    adb_pollfd pfd[3] = {};
    pfd[0].fd = fds[0];
    pfd[0].events = POLLRDNORM;
    pfd[0].revents = ~0;
    pfd[1].fd = INT_MAX;
    pfd[1].events = POLLRDNORM;
    pfd[1].revents = ~0;
    pfd[2].fd = fds[1];
    pfd[2].events = POLLWRNORM;
    pfd[2].revents = ~0;

    ASSERT_TRUE(WriteFdExactly(fds[1], "foo", 4));

    // Wait for the socketpair to be flushed.
    EXPECT_EQ(1, adb_poll(pfd, 1, 100));
    EXPECT_EQ(POLLRDNORM, pfd[0].revents);

    EXPECT_EQ(3, adb_poll(pfd, 3, 0));
    EXPECT_EQ(POLLRDNORM, pfd[0].revents);
    EXPECT_EQ(POLLNVAL, pfd[1].revents);
    EXPECT_EQ(POLLWRNORM, pfd[2].revents);

    // Make sure that we return immediately if an invalid FD is given.
    pfd[0].fd = fds[0];
    pfd[0].events = POLLRDNORM;
    pfd[0].revents = ~0;
    pfd[1].fd = INT_MAX;
    pfd[1].events = POLLRDNORM;
    pfd[1].revents = ~0;
    EXPECT_EQ(2, adb_poll(pfd, 2, -1));
    EXPECT_EQ(POLLRDNORM, pfd[0].revents);
    EXPECT_EQ(POLLNVAL, pfd[1].revents);
}

TEST_F(sysdeps_poll, duplicate_fd) {
#ifndef __APPLE__
    adb_pollfd pfd[2] = {};
    pfd[0].fd = fds[0];
    pfd[0].events = POLLRDNORM;
    pfd[1] = pfd[0];

    EXPECT_EQ(0, adb_poll(pfd, 2, 0));
    EXPECT_EQ(0, pfd[0].revents);
    EXPECT_EQ(0, pfd[1].revents);

    ASSERT_TRUE(WriteFdExactly(fds[1], "foo", 4));

    EXPECT_EQ(2, adb_poll(pfd, 2, 100));  // On __APPLE__, only *one* fd is set.
    // Like so: EXPECT_EQ(1, adb_poll(pfd, 2, 100));

    EXPECT_EQ(POLLRDNORM, pfd[0].revents);  // On __APPLE__, it appears there is
    // *no* data to be read (even for the single fd): EXPECT_EQ(0, pfd[0].revents);

    EXPECT_EQ(POLLRDNORM, pfd[1].revents);
#else
    // Behavior on __APPLE__ diverges from BSD.
    GTEST_SKIP() << " When poll() returns on __APPLE__, only the read socket is set";
#endif
}

TEST_F(sysdeps_poll, disconnect) {
    adb_pollfd pfd = {};
    pfd.fd = fds[0];
    pfd.events = POLLIN;

    EXPECT_EQ(0, adb_poll(&pfd, 1, 0));
    EXPECT_EQ(0, pfd.revents);

    EXPECT_EQ(0, adb_close(fds[1]));
    fds[1] = -1;

    EXPECT_EQ(1, adb_poll(&pfd, 1, 100));

    if (!IsWine()) {
        // Linux returns POLLIN | POLLHUP, Windows returns just POLLHUP.
        EXPECT_EQ(POLLHUP, pfd.revents & POLLHUP);
    }
}

TEST_F(sysdeps_poll, fd_count) {
    // https://code.google.com/p/android/issues/detail?id=12141
    static constexpr int num_sockets = 256;
    std::vector<int> sockets;
    std::vector<adb_pollfd> pfds;
    sockets.resize(num_sockets * 2);
    for (int32_t i = 0; i < num_sockets; ++i) {
        ASSERT_EQ(0, adb_socketpair(&sockets[i * 2])) << strerror(errno);
        ASSERT_TRUE(WriteFdExactly(sockets[i * 2], &i, sizeof(i)));
        adb_pollfd pfd;
        pfd.events = POLLIN;
        pfd.fd = sockets[i * 2 + 1];
        pfds.push_back(pfd);
    }

    ASSERT_EQ(num_sockets, adb_poll(pfds.data(), pfds.size(), 0));
    for (int i = 0; i < num_sockets; ++i) {
        ASSERT_NE(0, pfds[i].revents & POLLIN);

        int32_t buf[2] = { -1, -1 };
        ASSERT_EQ(adb_read(pfds[i].fd, buf, sizeof(buf)), static_cast<ssize_t>(sizeof(int32_t)));
        ASSERT_EQ(i, buf[0]);
    }

    for (int fd : sockets) {
        adb_close(fd);
    }
}

TEST(sysdeps_condition_variable, smoke) {
    static std::mutex &m = *new std::mutex;
    static std::condition_variable &cond = *new std::condition_variable;
    static volatile bool flag = false;

    std::unique_lock<std::mutex> lock(m);
    std::thread thread([]() {
        m.lock();
        flag = true;
        cond.notify_one();
        m.unlock();
    });

    while (!flag) {
        cond.wait(lock);
    }

    thread.join();
}