/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <stdbool.h>

#define ARRAY_LEN(a) (sizeof(a) / sizeof(a[0]))
#define BIT(x) x##Bit, x = 1 << x##Bit, x##Bit_ = x##Bit

typedef unsigned char byte;

#define ENUM_CAP \
	X("sasl", CapSASL) \
	X("server-time", CapServerTime) \
	X("userhost-in-names", CapUserhostInNames)

enum Cap {
#define X(name, id) BIT(id),
	ENUM_CAP
#undef X
};

extern struct Self {
	enum Cap caps;
	char *plain;
	char *nick;
	const char *join;
} self;

#define ENUM_TAG \
	X("time", TagTime)

enum Tag {
#define X(name, id) id,
	ENUM_TAG
#undef X
	TagCap,
};

enum { ParamCap = 15 };
struct Message {
	char *tags[TagCap];
	char *nick;
	char *user;
	char *host;
	char *cmd;
	char *params[ParamCap];
};

void ircConfig(bool insecure, const char *cert, const char *priv);
int ircConnect(const char *host, const char *port);
void ircRecv(void);
void ircSend(const char *ptr, size_t len);
void ircFormat(const char *format, ...)
	__attribute__((format(printf, 1, 2)));

void handle(struct Message msg);

#define BASE64_SIZE(len) (1 + ((len) + 2) / 3 * 4)

static const char Base64[64] = {
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
};

static inline void base64(char *dst, const byte *src, size_t len) {
	size_t i = 0;
	while (len > 2) {
		dst[i++] = Base64[0x3F & (src[0] >> 2)];
		dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)];
		dst[i++] = Base64[0x3F & (src[1] << 2 | src[2] >> 6)];
		dst[i++] = Base64[0x3F & src[2]];
		src += 3;
		len -= 3;
	}
	if (len) {
		dst[i++] = Base64[0x3F & (src[0] >> 2)];
		if (len > 1) {
			dst[i++] = Base64[0x3F & (src[0] << 4 | src[1] >> 4)];
			dst[i++] = Base64[0x3F & (src[1] << 2)];
		} else {
			dst[i++] = Base64[0x3F & (src[0] << 4)];
			dst[i++] = '=';
		}
		dst[i++] = '=';
	}
	dst[i] = '\0';
}

// Defined in libcrypto if missing from libc:
void explicit_bzero(void *b, size_t len);