/* 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 Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

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

#include "server.h"

const char *EventsAfterQuery = SQL(
	SELECT
		events.event,
		events.time,
		events.type,
		names.nick,
		names.user,
		names.host,
		events.target,
		events.message
	FROM events
	JOIN contexts USING (context)
	JOIN names USING (name)
	WHERE contexts.network = :network
		AND contexts.name = :context
		AND coalesce(contexts.query = :query, true)
		AND events.time >= strftime('%s', :time)
	ORDER BY events.time
	LIMIT :limit;
);

const char *EventsBeforeQuery = SQL(
	WITH before AS (
		SELECT
			events.event,
			events.time,
			events.type,
			names.nick,
			names.user,
			names.host,
			events.target,
			events.message
		FROM events
		JOIN contexts USING (context)
		JOIN names USING (name)
		WHERE contexts.network = :network
			AND contexts.name = :context
			AND coalesce(contexts.query = :query, true)
			AND events.time < strftime('%s', :time)
		ORDER BY events.time DESC
		LIMIT :limit
	)
	SELECT *
	FROM before
	ORDER BY time;
);

enum kcgi_err pageEvents(struct kreq *req) {
	if (!req->fieldmap[Network] || !req->fieldmap[Context]) {
		return httpFail(req, KHTTP_400);
	}
	const char *network = req->fieldmap[Network]->parsed.s;
	const char *context = req->fieldmap[Context]->parsed.s;

	if (!req->fieldmap[After] && !req->fieldmap[Before]) {
		struct tm *tm = gmtime(&(time_t) { time(NULL) });
		if (!tm) err(EX_OSERR, "gmtime");

		char time[sizeof("0000-00-00T00:00:00")];
		strftime(time, sizeof(time), "%FT%T", tm);

		char *url = khttp_urlpart(
			NULL, NULL, Pages[Events],
			Keys[Network].name, network,
			Keys[Context].name, context,
			Keys[Before].name, time,
			NULL
		);
		enum kcgi_err error = httpRedirect(req, url);
		free(url);
		return error;
	}

	const char *time = req->fieldmap[Before]
		? req->fieldmap[Before]->parsed.s
		: req->fieldmap[After]->parsed.s;

	enum kcgi_err error = httpHead(req, KHTTP_200, KMIME_TEXT_HTML);
	if (req->method == KMETHOD_HEAD) return error;

	struct khtmlreq html;
	error = error
		|| khttp_body(req)
		|| khtml_open(&html, req, KHTML_PRETTY)
		|| htmlHead(&html, context)
		|| htmlNav(&html, network, context);
	if (error) return error;

	sqlite3_stmt *events = stmt.eventsAfter;
	if (req->fieldmap[Before]) events = stmt.eventsBefore;

	dbBindText(events, ":network", network);
	dbBindText(events, ":context", context);
	if (pagePublic) dbBindInt(events, ":query", false);
	dbBindText(events, ":time", time);
	dbBindInt(events, ":limit", pageLimit);

	int result;
	while (SQLITE_ROW == (result = sqlite3_step(events))) {
		const char *msg = (const char *)sqlite3_column_text(events, 7);
		if (!msg) continue;
		error = 0
			|| khtml_puts(&html, msg)
			|| khtml_elem(&html, KELEM_BR);
		if (error) break;
	}
	if (result != SQLITE_DONE) errx(EX_SOFTWARE, "%s", sqlite3_errmsg(db));
	sqlite3_reset(events);

	return error
		|| htmlFooter(&html)
		|| khtml_close(&html);
}