/* 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/>.
 *
 * Additional permission under GNU GPL version 3 section 7:
 *
 * If you modify this Program, or any covered work, by linking or
 * combining it with OpenSSL (or a modified version of that library),
 * containing parts covered by the terms of the OpenSSL License and the
 * original SSLeay license, the licensors of this Program grant you
 * additional permission to convey the resulting work. Corresponding
 * Source for a non-source form of such a combination shall include the
 * source code for the parts of OpenSSL used as well as that of the
 * covered work.
 */

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <time.h>

#include "archive.h"

static char *atomID(const struct Envelope *envelope) {
	struct Variable vars[] = {
		{ "messageID", envelope->messageID },
		{0},
	};
	return templateString("mid:[messageID]", vars, escapeURL);
}

static char *atomEntryURL(const struct Envelope *envelope) {
	struct Variable vars[] = {
		{ "messageID", envelope->messageID },
		{ "type", "mbox" },
		{0},
	};
	return templateString("/" PATH_MESSAGE, vars, escapeURL);
}

static int atomAuthor(FILE *file, struct Address addr) {
	const char *template = Q(
		<author>
			<name>[name]</name>
			<email>[mailbox]@[host]</email>
		</author>
	);
	struct Variable vars[] = {
		{ "name", addressName(addr) },
		{ "mailbox", addr.mailbox },
		{ "host", addr.host },
		{0},
	};
	return templateRender(file, template, vars, escapeXML);
}

int atomEntryOpen(FILE *file, const struct Envelope *envelope) {
	char *id = atomID(envelope);
	char *url = atomEntryURL(envelope);
	const char *template = Q(
		<entry>
		<id>[id]</id>
		<title>[title]</title>
		<updated>[updated]</updated>
		<link rel="alternate" type="application/mbox" href="[base][url]"/>
	);
	struct Variable vars[] = {
		{ "id", id },
		{ "title", envelope->subject },
		{ "updated", iso8601(envelope->time).s },
		{ "base", baseURL },
		{ "url", url },
		{0},
	};
	int error = 0
		|| templateRender(file, template, vars, escapeXML)
		|| atomAuthor(file, envelope->from);
	free(id);
	free(url);
	return error;
}

int atomContent(FILE *file, const char *content) {
	const char *template = Q(
		<content type="xhtml">
			<div xmlns="http://www.w3.org/1999/xhtml">
				<pre>[content]</pre>
			</div>
		</content>
	);
	struct Variable vars[] = {
		{ "content", content },
		{0},
	};
	return templateRender(file, template, vars, escapeXML);
}

int atomEntryClose(FILE *file) {
	return templateRender(file, Q(</entry>), NULL, NULL);
}

static char *atomThreadURL(const struct Envelope *envelope, const char *type) {
	struct Variable vars[] = {
		{ "messageID", envelope->messageID },
		{ "type", type },
		{0},
	};
	return templateString("/" PATH_THREAD, vars, escapeURL);
}

#define XML_DECL "<?" Q(xml version="1.0" encoding="utf-8") "?>"

int atomThreadOpen(FILE *file, const struct Envelope *envelope) {
	char *id = atomID(envelope);
	char *atom = atomThreadURL(envelope, "atom");
	char *html = atomThreadURL(envelope, "html");
	char *mbox = atomThreadURL(envelope, "mbox");
	const char *template = XML_DECL Q(
		<feed xmlns="http://www.w3.org/2005/Atom">
		<generator uri="[generator]">bubger</generator>
		<id>[id]</id>
		<title>[title]</title>
		<updated>[updated]</updated>
		<link rel="self" href="[base][atom]"/>
		<link rel="alternate" type="text/html" href="[base][html]"/>
		<link rel="alternate" type="application/mbox" href="[base][mbox]"/>
	);
	struct Variable vars[] = {
		{ "generator", GENERATOR_URL },
		{ "id", id },
		{ "title", envelope->subject },
		{ "updated", iso8601(time(NULL)).s },
		{ "base", baseURL },
		{ "atom", atom },
		{ "html", html },
		{ "mbox", mbox },
		{0},
	};
	int error = 0
		|| templateRender(file, template, vars, escapeXML)
		|| atomAuthor(file, envelope->from);
	free(id);
	free(atom);
	free(html);
	free(mbox);
	return error;
}

int atomThreadClose(FILE *file) {
	return templateRender(file, Q(</feed>), NULL, NULL);
}

static char *atomIndexURL(const char *name, const char *type) {
	struct Variable vars[] = {
		{ "name", name },
		{ "type", type },
		{0},
	};
	return templateString("/" PATH_INDEX, vars, escapeURL);
}

int atomIndexOpen(FILE *file, const char *name) {
	char *atom = atomIndexURL(name, "atom");
	char *html = atomIndexURL(name, "html");
	const char *template = XML_DECL Q(
		<feed xmlns="http://www.w3.org/2005/Atom">
		<generator uri="[generator]">bubger</generator>
		<id>[base][atom]</id>
		<title>[+name][name] - [-][title]</title>
		<updated>[updated]</updated>
		<link rel="self" href="[base][atom]"/>
		<link rel="alternate" type="text/html" href="[base][html]"/>
	);
	struct Variable vars[] = {
		{ "generator", GENERATOR_URL },
		{ "name", (strcmp(name, "index") ? name : NULL) },
		{ "title", baseTitle },
		{ "updated", iso8601(time(NULL)).s },
		{ "base", baseURL },
		{ "atom", atom },
		{ "html", html },
		{0},
	};
	int error = templateRender(file, template, vars, escapeXML);
	free(atom);
	free(html);
	return error;
}

int atomIndexClose(FILE *file) {
	return templateRender(file, Q(</feed>), NULL, NULL);
}