/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

#include "net.h"
#include "netops.h"

#include <ctype.h>
#include "git2/errors.h"

#include "posix.h"
#include "buffer.h"
#include "http_parser.h"
#include "global.h"

#define DEFAULT_PORT_HTTP  "80"
#define DEFAULT_PORT_HTTPS "443"
#define DEFAULT_PORT_GIT   "9418"
#define DEFAULT_PORT_SSH   "22"

static const char *default_port_for_scheme(const char *scheme)
{
	if (strcmp(scheme, "http") == 0)
		return DEFAULT_PORT_HTTP;
	else if (strcmp(scheme, "https") == 0)
		return DEFAULT_PORT_HTTPS;
	else if (strcmp(scheme, "git") == 0)
		return DEFAULT_PORT_GIT;
	else if (strcmp(scheme, "ssh") == 0)
		return DEFAULT_PORT_SSH;

	return NULL;
}

int git_net_url_parse(git_net_url *url, const char *given)
{
	struct http_parser_url u = {0};
	bool has_scheme, has_host, has_port, has_path, has_query, has_userinfo;
	git_buf scheme = GIT_BUF_INIT,
		host = GIT_BUF_INIT,
		port = GIT_BUF_INIT,
		path = GIT_BUF_INIT,
		username = GIT_BUF_INIT,
		password = GIT_BUF_INIT,
		query = GIT_BUF_INIT;
	int error = GIT_EINVALIDSPEC;

	if (http_parser_parse_url(given, strlen(given), false, &u)) {
		git_error_set(GIT_ERROR_NET, "malformed URL '%s'", given);
		goto done;
	}

	has_scheme = !!(u.field_set & (1 << UF_SCHEMA));
	has_host = !!(u.field_set & (1 << UF_HOST));
	has_port = !!(u.field_set & (1 << UF_PORT));
	has_path = !!(u.field_set & (1 << UF_PATH));
	has_query = !!(u.field_set & (1 << UF_QUERY));
	has_userinfo = !!(u.field_set & (1 << UF_USERINFO));

	if (has_scheme) {
		const char *url_scheme = given + u.field_data[UF_SCHEMA].off;
		size_t url_scheme_len = u.field_data[UF_SCHEMA].len;
		git_buf_put(&scheme, url_scheme, url_scheme_len);
		git__strntolower(scheme.ptr, scheme.size);
	} else {
		git_error_set(GIT_ERROR_NET, "malformed URL '%s'", given);
		goto done;
	}

	if (has_host) {
		const char *url_host = given + u.field_data[UF_HOST].off;
		size_t url_host_len = u.field_data[UF_HOST].len;
		git_buf_decode_percent(&host, url_host, url_host_len);
	}

	if (has_port) {
		const char *url_port = given + u.field_data[UF_PORT].off;
		size_t url_port_len = u.field_data[UF_PORT].len;
		git_buf_put(&port, url_port, url_port_len);
	} else {
		const char *default_port = default_port_for_scheme(scheme.ptr);

		if (default_port == NULL) {
			git_error_set(GIT_ERROR_NET, "unknown scheme for URL '%s'", given);
			goto done;
		}

		git_buf_puts(&port, default_port);
	}

	if (has_path) {
		const char *url_path = given + u.field_data[UF_PATH].off;
		size_t url_path_len = u.field_data[UF_PATH].len;
		git_buf_put(&path, url_path, url_path_len);
	} else {
		git_buf_puts(&path, "/");
	}

	if (has_query) {
		const char *url_query = given + u.field_data[UF_QUERY].off;
		size_t url_query_len = u.field_data[UF_QUERY].len;
		git_buf_decode_percent(&query, url_query, url_query_len);
	}

	if (has_userinfo) {
		const char *url_userinfo = given + u.field_data[UF_USERINFO].off;
		size_t url_userinfo_len = u.field_data[UF_USERINFO].len;
		const char *colon = memchr(url_userinfo, ':', url_userinfo_len);

		if (colon) {
			const char *url_username = url_userinfo;
			size_t url_username_len = colon - url_userinfo;
			const char *url_password = colon + 1;
			size_t url_password_len = url_userinfo_len - (url_username_len + 1);

			git_buf_decode_percent(&username, url_username, url_username_len);
			git_buf_decode_percent(&password, url_password, url_password_len);
		} else {
			git_buf_decode_percent(&username, url_userinfo, url_userinfo_len);
		}
	}

	if (git_buf_oom(&scheme) ||
	    git_buf_oom(&host) ||
	    git_buf_oom(&port) ||
	    git_buf_oom(&path) ||
	    git_buf_oom(&query) ||
	    git_buf_oom(&username) ||
	    git_buf_oom(&password))
		return -1;

	url->scheme = git_buf_detach(&scheme);
	url->host = git_buf_detach(&host);
	url->port = git_buf_detach(&port);
	url->path = git_buf_detach(&path);
	url->query = git_buf_detach(&query);
	url->username = git_buf_detach(&username);
	url->password = git_buf_detach(&password);

	error = 0;

done:
	git_buf_dispose(&scheme);
	git_buf_dispose(&host);
	git_buf_dispose(&port);
	git_buf_dispose(&path);
	git_buf_dispose(&query);
	git_buf_dispose(&username);
	git_buf_dispose(&password);
	return error;
}

int git_net_url_is_default_port(git_net_url *url)
{
	return (strcmp(url->port, default_port_for_scheme(url->scheme)) == 0);
}

void git_net_url_swap(git_net_url *a, git_net_url *b)
{
	git_net_url tmp = GIT_NET_URL_INIT;

	memcpy(&tmp, a, sizeof(git_net_url));
	memcpy(a, b, sizeof(git_net_url));
	memcpy(b, &tmp, sizeof(git_net_url));
}

void git_net_url_dispose(git_net_url *url)
{
	if (url->username)
		git__memzero(url->username, strlen(url->username));

	if (url->password)
		git__memzero(url->password, strlen(url->password));

	git__free(url->scheme); url->scheme = NULL;
	git__free(url->host); url->host = NULL;
	git__free(url->port); url->port = NULL;
	git__free(url->path); url->path = NULL;
	git__free(url->username); url->username = NULL;
	git__free(url->password); url->password = NULL;
}