// 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 "root-mock-device.h"

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <threads.h>

#include <fbl/auto_call.h>
#include <fuchsia/device/test/c/fidl.h>
#include <lib/devmgr-integration-test/fixture.h>
#include <lib/fdio/unsafe.h>
#include <lib/fdio/util.h>
#include <zircon/assert.h>
#include <zircon/device/device.h>

#define DRIVER_TEST_DIR "/boot/driver/test"
#define MOCK_DEVICE_LIB "/boot/driver/test/mock-device.so"

namespace libdriver_integration_test {

RootMockDevice::RootMockDevice(
        std::unique_ptr<MockDeviceHooks> hooks,
        fidl::InterfacePtr<fuchsia::device::test::Device> test_device,
        fidl::InterfaceRequest<fuchsia::device::mock::MockDevice> controller,
        async_dispatcher_t* dispatcher, std::string path)
    : test_device_(std::move(test_device)), path_(std::move(path)),
      mock_(std::move(controller), dispatcher, "") {

    mock_.set_hooks(std::move(hooks));
}

RootMockDevice::~RootMockDevice() {
    // This will trigger unbind() to be called on any device that was added in
    // the bind hook.
    test_device_->Destroy();
}

// |*test_device_out| will be a channel to the test device that the mock device
// bound to.  This is provided so we can trigger unbinding of the mock device.
// |*control_out| will be a channel for fulfilling requests from the mock
// device.
zx_status_t RootMockDevice::Create(const IsolatedDevmgr& devmgr,
                                   async_dispatcher_t* dispatcher,
                                   std::unique_ptr<MockDeviceHooks> hooks,
                                   std::unique_ptr<RootMockDevice>* mock_out) {
    // Wait for /dev/test/test to appear
    fbl::unique_fd fd;
    zx_status_t status = devmgr_integration_test::RecursiveWaitForFile(
            devmgr.devfs_root(), "test/test", zx::deadline_after(zx::sec(5)), &fd);
    if (status != ZX_OK) {
        return status;
    }

    zx::channel test_root_chan;
    status = fdio_get_service_handle(fd.release(), test_root_chan.reset_and_get_address());
    if (status != ZX_OK) {
        return status;
    }

    fidl::SynchronousInterfacePtr<fuchsia::device::test::RootDevice> test_root;
    test_root.Bind(std::move(test_root_chan));

    fidl::StringPtr devpath;
    zx_status_t call_status;
    status = test_root->CreateDevice("mock", &call_status, &devpath);
    if (status != ZX_OK) {
        return status;
    }
    if (call_status != ZX_OK) {
        return call_status;
    }

    const char* kDevPrefix = "/dev/";
    if (devpath.get().find(kDevPrefix) != 0) {
        return ZX_ERR_BAD_STATE;
    }
    std::string relative_devpath(devpath.get(), strlen(kDevPrefix));
    fd.reset(openat(devmgr.devfs_root().get(), relative_devpath.c_str(), O_RDWR));
    if (!fd.is_valid()) {
        return ZX_ERR_NOT_FOUND;
    }

    fdio_t* io = fdio_unsafe_fd_to_io(fd.get());
    auto release_fdio = fbl::MakeAutoCall([io]() {
        fdio_unsafe_release(io);
    });

    zx::unowned_channel test_channel(fdio_unsafe_borrow_channel(io));
    auto destroy_device = fbl::MakeAutoCall([&test_channel] {
        fuchsia_device_test_DeviceDestroy(test_channel->get());
    });

    fidl::InterfaceHandle<fuchsia::device::mock::MockDevice> client;
    fidl::InterfaceRequest<fuchsia::device::mock::MockDevice> server(client.NewRequest());
    if (!server.is_valid()) {
        return ZX_ERR_BAD_STATE;
    }

    status = fuchsia_device_test_DeviceSetChannel(test_channel->get(),
                                                  client.TakeChannel().release());
    if (status != ZX_OK) {
        return status;
    }

    // Open a new connection to the test device to return.  We do to simplify
    // handling around the blocking nature of ioctl_device_bind.  Needs to
    // happen before the bind(), since ioctl_device_bind() will cause us to get
    // blocked in the mock device driver waiting for input on what to do.
    zx::channel test_device_channel;
    fbl::unique_fd new_connection(openat(devmgr.devfs_root().get(), relative_devpath.c_str(),
                                         O_RDWR));
    status = fdio_get_service_handle(new_connection.release(),
                                     test_device_channel.reset_and_get_address());
    if (status != ZX_OK) {
        return status;
    }
    fidl::InterfacePtr<fuchsia::device::test::Device> test_device;
    status = test_device.Bind(std::move(test_device_channel), dispatcher);
    if (status != ZX_OK) {
        return status;
    }

    // Bind the mock device driver in a separate thread, since this call is
    // synchronous.
    thrd_t thrd;
    int ret = thrd_create(&thrd, [](void* ctx) {
        int fd = static_cast<int>(reinterpret_cast<uintptr_t>(ctx));
        ioctl_device_bind(fd, MOCK_DEVICE_LIB, sizeof(MOCK_DEVICE_LIB));
        close(fd);
        return 0;
    }, reinterpret_cast<void*>(static_cast<uintptr_t>(fd.release())));
    ZX_ASSERT(ret == thrd_success);
    thrd_detach(thrd);

    destroy_device.cancel();

    auto mock = std::make_unique<RootMockDevice>(std::move(hooks), std::move(test_device),
                                                 std::move(server), dispatcher,
                                                 std::move(relative_devpath));
    *mock_out = std::move(mock);
    return ZX_OK;
}

} // namespace libdriver_integration_test