#ifdef __WIN32__
// For alloca
#include <malloc.h>
#endif

#include "rust_globals.h"
#include "rust_task.h"
#include "uv.h"

// crust fn pointers
typedef void (*crust_async_op_cb)(uv_loop_t* loop, void* data,
                                  uv_async_t* op_handle);
typedef void (*crust_simple_cb)(uint8_t* id_buf, void* loop_data);
typedef void (*crust_close_cb)(uint8_t* id_buf, void* handle,
                                                          void* data);

// data types
#define RUST_UV_HANDLE_LEN 16

struct handle_data {
        uint8_t id_buf[RUST_UV_HANDLE_LEN];
        crust_simple_cb cb;
        crust_close_cb close_cb;
};

// helpers
static void*
current_kernel_malloc(size_t size, const char* tag) {
  void* ptr = rust_get_current_task()->kernel->malloc(size, tag);
  return ptr;
}

static void
current_kernel_free(void* ptr) {
  rust_get_current_task()->kernel->free(ptr);
}

static handle_data*
new_handle_data_from(uint8_t* buf, crust_simple_cb cb) {
        handle_data* data = (handle_data*)current_kernel_malloc(
                sizeof(handle_data),
                "handle_data");
        memcpy(data->id_buf, buf, RUST_UV_HANDLE_LEN);
        data->cb = cb;
        return data;
}

// libuv callback impls
static void
native_crust_async_op_cb(uv_async_t* handle, int status) {
    crust_async_op_cb cb = (crust_async_op_cb)handle->data;
        void* loop_data = handle->loop->data;
        cb(handle->loop, loop_data, handle);
}

static void
native_async_cb(uv_async_t* handle, int status) {
        handle_data* handle_d = (handle_data*)handle->data;
        void* loop_data = handle->loop->data;
        handle_d->cb(handle_d->id_buf, loop_data);
}

static void
native_timer_cb(uv_timer_t* handle, int status) {
        handle_data* handle_d = (handle_data*)handle->data;
        void* loop_data = handle->loop->data;
        handle_d->cb(handle_d->id_buf, loop_data);
}

static void
native_close_cb(uv_handle_t* handle) {
        handle_data* data = (handle_data*)handle->data;
        data->close_cb(data->id_buf, handle, handle->loop->data);
}

static void
native_close_op_cb(uv_handle_t* op_handle) {
  current_kernel_free(op_handle);
  // uv_run() should return after this..
}

// native fns bound in rust
extern "C" void
rust_uv_free(void* ptr) {
  current_kernel_free(ptr);
}
extern "C" void*
rust_uv_loop_new() {
    return (void*)uv_loop_new();
}

extern "C" void
rust_uv_loop_delete(uv_loop_t* loop) {
    // FIXME: This is a workaround for #1815. libev uses realloc(0) to
    // free the loop, which valgrind doesn't like. We have suppressions
    // to make valgrind ignore them.
    //
    // Valgrind also has a sanity check when collecting allocation backtraces
    // that the stack pointer must be at least 512 bytes into the stack (at
    // least 512 bytes of frames must have come before). When this is not
    // the case it doesn't collect the backtrace.
    //
    // Unfortunately, with our spaghetti stacks that valgrind check triggers
    // sometimes and we don't get the backtrace for the realloc(0), it
    // fails to be suppressed, and it gets reported as 0 bytes lost
    // from a malloc with no backtrace.
    //
    // This pads our stack with some extra space before deleting the loop
    alloca(512);
    uv_loop_delete(loop);
}

extern "C" void
rust_uv_loop_set_data(uv_loop_t* loop, void* data) {
    loop->data = data;
}

extern "C" void*
rust_uv_bind_op_cb(uv_loop_t* loop, crust_async_op_cb cb) {
        uv_async_t* async = (uv_async_t*)current_kernel_malloc(
                sizeof(uv_async_t),
                "uv_async_t");
        uv_async_init(loop, async, native_crust_async_op_cb);
        async->data = (void*)cb;
        // decrement the ref count, so that our async bind
        // doesn't count towards keeping the loop alive
        //uv_unref(loop);
        return async;
}

extern "C" void
rust_uv_stop_op_cb(uv_handle_t* op_handle) {
  uv_close(op_handle, native_close_op_cb);
}

extern "C" void
rust_uv_run(uv_loop_t* loop) {
        uv_run(loop);
}

extern "C" void
rust_uv_close(uv_handle_t* handle, crust_close_cb cb) {
        handle_data* data = (handle_data*)handle->data;
        data->close_cb = cb;
        uv_close(handle, native_close_cb);
}

extern "C" void
rust_uv_close_async(uv_async_t* handle) {
  current_kernel_free(handle->data);
  current_kernel_free(handle);
}

extern "C" void
rust_uv_close_timer(uv_async_t* handle) {
  current_kernel_free(handle->data);
  current_kernel_free(handle);
}

extern "C" void
rust_uv_async_send(uv_async_t* handle) {
    uv_async_send(handle);
}

extern "C" void*
rust_uv_async_init(uv_loop_t* loop, crust_simple_cb cb,
                                                 uint8_t* buf) {
        uv_async_t* async = (uv_async_t*)current_kernel_malloc(
                sizeof(uv_async_t),
                "uv_async_t");
        uv_async_init(loop, async, native_async_cb);
        handle_data* data = new_handle_data_from(buf, cb);
        async->data = data;

        return async;
}

extern "C" void*
rust_uv_timer_init(uv_loop_t* loop, crust_simple_cb cb,
                                                 uint8_t* buf) {
        uv_timer_t* new_timer = (uv_timer_t*)current_kernel_malloc(
                sizeof(uv_timer_t),
                "uv_timer_t");
        uv_timer_init(loop, new_timer);
        handle_data* data = new_handle_data_from(buf, cb);
        new_timer->data = data;

        return new_timer;
}

extern "C" void
rust_uv_timer_start(uv_timer_t* the_timer, uint32_t timeout,
                                                  uint32_t repeat) {
        uv_timer_start(the_timer, native_timer_cb, timeout, repeat);
}

extern "C" void
rust_uv_timer_stop(uv_timer_t* the_timer) {
	uv_timer_stop(the_timer); 
}

extern "C" int
rust_uv_tcp_init(uv_loop_t* loop, uv_tcp_t* handle) {
	return uv_tcp_init(loop, handle);
}

extern "C" size_t
rust_uv_helper_uv_tcp_t_size() {
	return sizeof(uv_tcp_t);
}
extern "C" size_t
rust_uv_helper_uv_connect_t_size() {
	return sizeof(uv_connect_t);
}
extern "C" size_t
rust_uv_helper_uv_buf_t_size() {
	return sizeof(uv_buf_t);
}
extern "C" size_t
rust_uv_helper_uv_write_t_size() {
	return sizeof(uv_write_t);
}
extern "C" size_t
rust_uv_helper_uv_err_t_size() {
	return sizeof(uv_err_t);
}
extern "C" size_t
rust_uv_helper_sockaddr_in_size() {
	return sizeof(sockaddr_in);
}

extern "C" uv_stream_t*
rust_uv_get_stream_handle_for_connect(uv_connect_t* connect) {
	return connect->handle;
}

extern "C" uv_buf_t
current_kernel_malloc_alloc_cb(uv_handle_t* handle,
							   size_t suggested_size) {
	char* base_ptr = (char*)current_kernel_malloc(sizeof(char)
											  * suggested_size,
										   "uv_buf_t_base_val");
	return uv_buf_init(base_ptr, suggested_size);
}

// FIXME see issue #1402
extern "C" uv_buf_t
rust_uv_buf_init(char* base, size_t len) {
	return uv_buf_init(base, len);
}

extern "C" uv_loop_t*
rust_uv_get_loop_for_uv_handle(uv_handle_t* handle) {
	return handle->loop;
}

extern "C" void*
rust_uv_get_data_for_uv_handle(uv_handle_t* handle) {
	return handle->data;
}

extern "C" void
rust_uv_set_data_for_uv_handle(uv_handle_t* handle,
							   void* data) {
	handle->data = data;
}

extern "C" void*
rust_uv_get_data_for_req(uv_req_t* req) {
	return req->data;
}

extern "C" void
rust_uv_set_data_for_req(uv_req_t* req, void* data) {
	req->data = data;
}

extern "C" uv_err_t
rust_uv_last_error(uv_loop_t* loop) {
	return uv_last_error(loop);
}

extern "C" int
rust_uv_tcp_connect(uv_connect_t* connect_ptr,
					uv_tcp_t* tcp_ptr,
					struct sockaddr_in addr,
					uv_connect_cb cb) {
	//return uv_tcp_connect(connect_ptr, tcp_ptr, addr, cb);
	printf("inside rust_uv_tcp_connect\n");
	//sockaddr_in addr_tmp = *((sockaddr_in*)addr_ptr);
	//sockaddr_in addr = addr_tmp;
	printf("before tcp_connect .. port: %d\n", addr.sin_port);
	int result = uv_tcp_connect(connect_ptr, tcp_ptr, addr, cb);
	printf ("leaving rust_uv_tcp_connect.. and result: %d\n",
			result);
	return result;
}

extern "C" int
rust_uv_write(uv_write_t* req, uv_stream_t* handle,
			  uv_buf_t* bufs, int buf_cnt,
			  uv_write_cb cb) {
	return uv_write(req, handle, bufs, buf_cnt, cb);
}

extern "C" struct sockaddr_in
rust_uv_ip4_addr(const char* ip, int port) {
	printf("before creating addr_ptr.. ip %s port %d\n", ip, port);
	struct sockaddr_in addr = uv_ip4_addr(ip, port);
	printf("after creating .. port: %d\n", addr.sin_port);
	return addr;
}

extern "C" bool
rust_uv_ip4_test_verify_port_val(struct sockaddr_in addr,
								 unsigned int expected) {
	printf("inside c++ ip4_test .. port: %u\n", addr.sin_port);
	return addr.sin_port == expected;
}