// 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 <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <threads.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/util.h>
#include <lib/fzl/fdio.h>
#include <lib/memfs/memfs.h>
#include <unittest/unittest.h>
#include <zircon/device/vfs.h>
#include <zircon/processargs.h>
#include <zircon/syscalls.h>

#include <utility>

namespace {

bool TestFidlBasic() {
    BEGIN_TEST;

    async::Loop loop(&kAsyncLoopConfigNoAttachToThread);
    ASSERT_EQ(loop.StartThread(), ZX_OK);

    ASSERT_EQ(memfs_install_at(loop.dispatcher(), "/fidltmp"), ZX_OK);
    fbl::unique_fd fd(open("/fidltmp", O_DIRECTORY | O_RDONLY));
    ASSERT_GE(fd.get(), 0);

    // Create a file
    const char* filename = "file-a";
    fd.reset(openat(fd.get(), filename, O_CREAT | O_RDWR));
    ASSERT_GE(fd.get(), 0);
    const char* data = "hello";
    ssize_t datalen = strlen(data);
    ASSERT_EQ(write(fd.get(), data, datalen), datalen);
    fd.reset();

    zx_handle_t h, request;
    ASSERT_EQ(zx_channel_create(0, &h, &request), ZX_OK);
    ASSERT_EQ(fdio_service_connect("/fidltmp/file-a", request), ZX_OK);

    fuchsia_io_NodeInfo info = {};
    ASSERT_EQ(fuchsia_io_FileDescribe(h, &info), ZX_OK);
    ASSERT_EQ(info.tag, fuchsia_io_NodeInfoTag_file);
    ASSERT_EQ(info.file.event, ZX_HANDLE_INVALID);
    zx_handle_close(h);

    loop.Shutdown();

    // No way to clean up the namespace entry. See ZX-2013 for more details.

    END_TEST;
}

bool TestFidlOpenReadOnly() {
    BEGIN_TEST;

    async::Loop loop(&kAsyncLoopConfigNoAttachToThread);
    ASSERT_EQ(loop.StartThread(), ZX_OK);

    ASSERT_EQ(memfs_install_at(loop.dispatcher(), "/fidltmp-ro"), ZX_OK);
    fbl::unique_fd fd(open("/fidltmp-ro", O_DIRECTORY | O_RDONLY));
    ASSERT_GE(fd.get(), 0);

    // Create a file
    const char* filename = "file-ro";
    fd.reset(openat(fd.get(), filename, O_CREAT | O_RDWR));
    ASSERT_GE(fd.get(), 0);
    fd.reset();

    zx_handle_t h, request;
    ASSERT_EQ(zx_channel_create(0, &h, &request), ZX_OK);
    ASSERT_EQ(fdio_open("/fidltmp-ro/file-ro", ZX_FS_RIGHT_READABLE, request), ZX_OK);

    zx_status_t status;
    uint32_t flags;
    ASSERT_EQ(fuchsia_io_FileGetFlags(h, &status, &flags), ZX_OK);
    ASSERT_EQ(status, ZX_OK);
    ASSERT_EQ(flags, ZX_FS_RIGHT_READABLE);
    zx_handle_close(h);

    loop.Shutdown();

    // No way to clean up the namespace entry. See ZX-2013 for more details.

    END_TEST;
}

bool QueryInfo(const char* path, fuchsia_io_FilesystemInfo* info) {
    BEGIN_HELPER;
    fbl::unique_fd fd(open(path, O_RDONLY | O_DIRECTORY));
    ASSERT_TRUE(fd);
    zx_status_t status;
    fzl::FdioCaller caller(std::move(fd));
    ASSERT_EQ(fuchsia_io_DirectoryAdminQueryFilesystem(caller.borrow_channel(), &status, info),
              ZX_OK);
    ASSERT_EQ(status, ZX_OK);
    const char* kFsName = "memfs";
    const char* name = reinterpret_cast<const char*>(info->name);
    ASSERT_EQ(strncmp(name, kFsName, strlen(kFsName)), 0, "Unexpected filesystem mounted");
    ASSERT_EQ(info->block_size, ZX_PAGE_SIZE);
    ASSERT_EQ(info->max_filename_size, NAME_MAX);
    ASSERT_EQ(info->fs_type, VFS_TYPE_MEMFS);
    ASSERT_NE(info->fs_id, 0);
    ASSERT_EQ(info->used_bytes % info->block_size, 0);
    END_HELPER;
}

bool TestFidlQueryFilesystem() {
    BEGIN_TEST;

    {
        async::Loop loop(&kAsyncLoopConfigNoAttachToThread);
        ASSERT_EQ(loop.StartThread(), ZX_OK);

        ASSERT_EQ(memfs_install_at(loop.dispatcher(), "/fidltmp-basic"), ZX_OK);
        fbl::unique_fd fd(open("/fidltmp-basic", O_DIRECTORY | O_RDONLY));
        ASSERT_GE(fd.get(), 0);

        // Sanity checks
        fuchsia_io_FilesystemInfo info;
        ASSERT_TRUE(QueryInfo("/fidltmp-basic", &info));

        // Query number of blocks
        ASSERT_EQ(info.total_bytes, UINT64_MAX);
        ASSERT_EQ(info.used_bytes, 0);

        loop.Shutdown();
    }

    // Query disk pressure in a page-limited scenario
    {
        async::Loop loop(&kAsyncLoopConfigNoAttachToThread);
        ASSERT_EQ(loop.StartThread(), ZX_OK);

        size_t max_num_pages = 3;
        ASSERT_EQ(memfs_install_at_with_page_limit(loop.dispatcher(),
                                                   max_num_pages, "/fidltmp-limited"), ZX_OK);
        fbl::unique_fd fd(open("/fidltmp-limited", O_DIRECTORY | O_RDONLY));
        ASSERT_GE(fd.get(), 0);

        fuchsia_io_FilesystemInfo info;
        ASSERT_TRUE(QueryInfo("/fidltmp-limited", &info));

        // When space is limited, total_bytes must be a multiple of block_size
        ASSERT_EQ(info.total_bytes % info.block_size, 0);

        // Query number of blocks
        ASSERT_EQ(info.total_bytes, 3 * info.block_size);
        ASSERT_EQ(info.used_bytes, 0);

        // Create a file with a size smaller than ZX_PAGE_SIZE
        DIR* d = fdopendir(fd.release());
        const char* filename = "file-a";
        fd.reset(openat(dirfd(d), filename, O_CREAT | O_RDWR));
        ASSERT_GE(fd.get(), 0);
        const char* data = "hello";
        ssize_t datalen = strlen(data);
        ASSERT_EQ(write(fd.get(), data, datalen), datalen);

        // Query should now indicate an entire page is used
        ASSERT_TRUE(QueryInfo("/fidltmp-limited", &info));
        ASSERT_EQ(info.used_bytes, 1 * info.block_size);

        // Unlink and close the file
        ASSERT_EQ(unlinkat(dirfd(d), filename, 0), 0);
        ASSERT_EQ(close(fd.get()), 0);
        fd.reset();

        // Query should now indicate 0 bytes used
        ASSERT_TRUE(QueryInfo("/fidltmp-limited", &info));
        ASSERT_EQ(info.used_bytes, 0);

        closedir(d);
        loop.Shutdown();
    }

    // No way to clean up the namespace entry. See ZX-2013 for more details.

    END_TEST;
}

} // namespace

BEGIN_TEST_CASE(fidl_tests)
RUN_TEST(TestFidlBasic)
RUN_TEST(TestFidlOpenReadOnly)
RUN_TEST(TestFidlQueryFilesystem)
END_TEST_CASE(fidl_tests)