// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <fcntl.h>
#include <unistd.h>

#include <fbl/unique_fd.h>
#include <fuchsia/io/c/fidl.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/fdio/fd.h>
#include <lib/memfs/memfs.h>
#include <lib/fzl/fdio.h>
#include <unittest/unittest.h>

#include <utility>

namespace {

bool TryFilesystemOperations(const fzl::FdioCaller& caller) {
    BEGIN_HELPER;

    const char* golden = "foobar";
    zx_status_t status;
    uint64_t actual;
    ASSERT_EQ(fuchsia_io_FileWriteAt(caller.borrow_channel(),
                                     reinterpret_cast<const uint8_t*>(golden),
                                     strlen(golden), 0, &status, &actual),
              ZX_OK);
    ASSERT_EQ(status, ZX_OK);
    ASSERT_EQ(actual, strlen(golden));

    char buf[256];
    ASSERT_EQ(fuchsia_io_FileReadAt(caller.borrow_channel(), static_cast<uint64_t>(sizeof(buf)), 0,
                                  &status, reinterpret_cast<uint8_t*>(buf), sizeof(buf), &actual),
              ZX_OK);
    ASSERT_EQ(status, ZX_OK);
    ASSERT_EQ(actual, strlen(golden));
    ASSERT_EQ(memcmp(buf, golden, strlen(golden)), 0);

    END_HELPER;
}

class Harness {
public:
    Harness() {}

    ~Harness() {
        if (memfs_) {
            sync_completion_t unmounted;
            memfs_free_filesystem(memfs_, &unmounted);
            sync_completion_wait(&unmounted, ZX_SEC(3));
        }
    }

    bool Setup() {
        BEGIN_HELPER;
        ASSERT_EQ(loop_.StartThread(), ZX_OK);
        zx_handle_t root;
        ASSERT_EQ(memfs_create_filesystem(loop_.dispatcher(), &memfs_, &root), ZX_OK);
        int fd;
        ASSERT_EQ(fdio_fd_create(root, &fd), ZX_OK);
        fbl::unique_fd dir(fd);
        ASSERT_TRUE(dir);
        fd_.reset(openat(dir.get(), "my-file", O_CREAT | O_RDWR));
        ASSERT_TRUE(fd_);

        END_HELPER;
    }

    fbl::unique_fd fd() { return std::move(fd_); }

private:
    async::Loop loop_ = async::Loop(&kAsyncLoopConfigNoAttachToThread);
    memfs_filesystem_t* memfs_ = nullptr;
    fbl::unique_fd fd_;
};

bool FdioCallerFile() {
    BEGIN_TEST;

    Harness harness;
    ASSERT_TRUE(harness.Setup());
    auto fd = harness.fd();

    // Try some filesystem operations.
    fzl::FdioCaller caller(std::move(fd));
    ASSERT_TRUE(caller);
    ASSERT_TRUE(TryFilesystemOperations(caller));

    // Re-acquire the underlying fd.
    fd = caller.release();
    ASSERT_EQ(close(fd.release()), 0);

    END_TEST;
}

bool FdioCallerMoveAssignment() {
    BEGIN_TEST;

    Harness harness;
    ASSERT_TRUE(harness.Setup());
    auto fd = harness.fd();

    fzl::FdioCaller caller(std::move(fd));
    fzl::FdioCaller move_assignment_caller = std::move(caller);
    ASSERT_TRUE(move_assignment_caller);
    ASSERT_FALSE(caller);
    ASSERT_TRUE(TryFilesystemOperations(move_assignment_caller));

    END_TEST;
}

bool FdioCallerMoveConstructor() {
    BEGIN_TEST;

    Harness harness;
    ASSERT_TRUE(harness.Setup());
    auto fd = harness.fd();

    fzl::FdioCaller caller(std::move(fd));
    fzl::FdioCaller move_ctor_caller(std::move(caller));
    ASSERT_TRUE(move_ctor_caller);
    ASSERT_FALSE(caller);
    ASSERT_TRUE(TryFilesystemOperations(move_ctor_caller));

    END_TEST;
}

}  // namespace

BEGIN_TEST_CASE(FdioCallTests)
RUN_TEST(FdioCallerFile)
RUN_TEST(FdioCallerMoveAssignment)
RUN_TEST(FdioCallerMoveConstructor)
END_TEST_CASE(FdioCallTests)