/* 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 <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <time.h>

#include "archive.h"

static char *atomID(const char *messageID) {
	struct Variable vars[] = {
		{ "messageID", messageID },
		{0},
	};
	return templateURL("mailto:?In-Reply-To=[messageID]", vars);
}

int atomEntryHead(FILE *file, const struct Envelope *envelope) {
	char *id = atomID(envelope->messageID);
	char date[sizeof("0000-00-00T00:00:00Z")];
	strftime(date, sizeof(date), "%FT%TZ", gmtime(&envelope->utc));
	struct Variable vars[] = {
		{ "subject", envelope->subject },
		{ "from.name", addressName(envelope->from) },
		{ "from.mailbox", envelope->from.mailbox },
		{ "from.host", envelope->from.host },
		{ "date", date },
		{ "id", id },
		{0},
	};
	const char *Entry = TEMPLATE(
		<entry>
		<title>[subject]</title>
		<author>
			<name>[from.name]</name>
			<email>[from.mailbox]@[from.host]</email>
		</author>
		<updated>[date]</updated>
		<id>[id]</id>
	);
	int error = templateRender(file, Entry, vars, escapeXML);
	free(id);
	return error;
}

int atomEntryTail(FILE *file) {
	int n = fprintf(file, "</entry>\n");
	return (n < 0 ? n : 0);
}

int atomFeedHead(FILE *file, const struct Envelope *envelope) {
	char *id = atomID(envelope->messageID);
	char date[sizeof("0000-00-00T00:00:00Z")];
	strftime(date, sizeof(date), "%FT%TZ", gmtime(&(time_t) { time(NULL) }));
	struct Variable vars[] = {
		{ "subject", envelope->subject },
		{ "from.name", addressName(envelope->from) },
		{ "from.mailbox", envelope->from.mailbox },
		{ "from.host", envelope->from.host },
		{ "date", date },
		{ "id", id },
		{ "q", "?" },
		{0},
	};
	const char *Feed = TEMPLATE(
		<[q]xml version="1.0" encoding="utf-8"[q]>
		<feed xmlns="http://www.w3.org/2005/Atom">
		<title>[subject]</title>
		<author>
			<name>[from.name]</name>
			<email>[from.mailbox]@[from.host]</email>
		</author>
		<updated>[date]</updated>
		<id>[id]</id>
	);
	int error = templateRender(file, Feed, vars, escapeXML);
	free(id);
	return error;
}

int atomFeedTail(FILE *file) {
	int n = fprintf(file, "</feed>\n");
	return (n < 0 ? n : 0);
}