#include "ppsspp_config.h"

#include <errno.h>
#include <cmath>
#include <cstdio>
#ifndef _WIN32
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/select.h>
#include <unistd.h>
#else
#include <io.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#endif
#include <fcntl.h>

#include "Common/CommonTypes.h"
#include "Common/Data/Encoding/Utf8.h"
#include "Common/File/FileDescriptor.h"
#include "Common/Log.h"

namespace fd_util {

// Slow as hell and should only be used for prototyping.
// Reads from a socket, up to an '\n'. This means that if the line ends
// with '\r', the '\r' will be returned.
size_t ReadLine(int fd, char *vptr, size_t buf_size) {
	char *buffer = vptr;
	size_t n;
	for (n = 1; n < buf_size; n++) {
		char c;
		size_t rc;
		if ((rc = read(fd, &c, 1)) == 1) {
			*buffer++ = c;
			if (c == '\n')
				break;
		} else if (rc == 0) {
			if (n == 1)
				return 0;
			else
				break;
		} else {
			if (errno == EINTR)
				continue;
			_assert_msg_(false, "Error in Readline()");
		}
	}

	*buffer = 0;
	return n;
}

// Misnamed, it just writes raw data in a retry loop.
size_t WriteLine(int fd, const char *vptr, size_t n) {
	const char *buffer = vptr;
	size_t nleft = n;

	while (nleft > 0) {
		int nwritten;
		if ((nwritten = (int)write(fd, buffer, (unsigned int)nleft)) <= 0) {
			if (errno == EINTR)
				nwritten = 0;
			else
				_assert_msg_(false, "Error in Writeline()");
		}
		nleft  -= nwritten;
		buffer += nwritten;
	}

	return n;
}

size_t WriteLine(int fd, const char *buffer) {
	return WriteLine(fd, buffer, strlen(buffer));
}

size_t Write(int fd, const std::string &str) {
	return WriteLine(fd, str.c_str(), str.size());
}

bool WaitUntilReady(int fd, double timeout, bool for_write) {
	struct timeval tv;
	tv.tv_sec = (long)floor(timeout);
	tv.tv_usec = (long)((timeout - floor(timeout)) * 1000000.0);

	fd_set fds;
	FD_ZERO(&fds);
	FD_SET(fd, &fds);
	// First argument to select is the highest socket in the set + 1.
	int rval;
	if (for_write) {
		rval = select(fd + 1, nullptr, &fds, nullptr, &tv);
	} else {
		rval = select(fd + 1, &fds, nullptr, nullptr, &tv);
	}

	if (rval < 0) {
		// Error calling select.
		return false;
	} else if (rval == 0) {
		// Timeout.
		return false;
	} else {
		// Socket is ready.
		return true;
	}
}

void SetNonBlocking(int sock, bool non_blocking) {
#ifndef _WIN32
	int opts = fcntl(sock, F_GETFL);
	if (opts < 0) {
		perror("fcntl(F_GETFL)");
		ERROR_LOG(IO, "Error getting socket status while changing nonblocking status");
	}
	if (non_blocking) {
		opts = (opts | O_NONBLOCK);
	} else {
		opts = (opts & ~O_NONBLOCK);
	}

	if (fcntl(sock, F_SETFL, opts) < 0) {
		perror("fcntl(F_SETFL)");
		ERROR_LOG(IO, "Error setting socket nonblocking status");
	}
#else
	u_long val = non_blocking ? 1 : 0;
	if (ioctlsocket(sock, FIONBIO, &val) != 0) {
		ERROR_LOG(IO, "Error setting socket nonblocking status");
	}
#endif
}

std::string GetLocalIP(int sock) {
	union {
		struct sockaddr sa;
		struct sockaddr_in ipv4;
#if !PPSSPP_PLATFORM(SWITCH)
		struct sockaddr_in6 ipv6;
#endif
	} server_addr;
	memset(&server_addr, 0, sizeof(server_addr));
	socklen_t len = sizeof(server_addr);
	if (getsockname(sock, (struct sockaddr *)&server_addr, &len) == 0) {
		char temp[64]{};

		// We clear the port below for WSAAddressToStringA.
		void *addr = nullptr;
#if !PPSSPP_PLATFORM(SWITCH)
		if (server_addr.sa.sa_family == AF_INET6) {
			server_addr.ipv6.sin6_port = 0;
			addr = &server_addr.ipv6.sin6_addr;
		}
#endif
		if (addr == nullptr) {
			server_addr.ipv4.sin_port = 0;
			addr = &server_addr.ipv4.sin_addr;
		}
#ifdef _WIN32
		wchar_t wtemp[sizeof(temp)];
		DWORD len = (DWORD)sizeof(temp);
		// Windows XP doesn't support inet_ntop.
		if (WSAAddressToStringW((struct sockaddr *)&server_addr, sizeof(server_addr), nullptr, wtemp, &len) == 0) {
			return ConvertWStringToUTF8(wtemp);
		}
#else
		const char *result = inet_ntop(server_addr.sa.sa_family, addr, temp, sizeof(temp));
		if (result) {
			return result;
		}
#endif
	}
	return "";
}

}  // fd_util