/* 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"

static enum kcgi_err redirect(struct kreq *req, struct Scope scope) {
	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, scope.network,
		Keys[Context].name, scope.context,
		Keys[Before].name, time,
		NULL
	);
	enum kcgi_err error = httpRedirect(req, url);
	free(url);
	return error;
}

static enum kcgi_err
dateForm(struct khtmlreq *html, struct Scope scope, const char *_time) {
	struct tm tm = {0};
	if (!strptime(_time, "%F", &tm)) {
		struct tm *now = gmtime(&(time_t) { time(NULL) });
		if (!now) err(EX_OSERR, "gmtime");
		tm = *now;
	}
	char date[sizeof("0000-00-00")];
	strftime(date, sizeof(date), "%F", &tm);
	return 0
		|| khtml_attr(
			html, KELEM_FORM,
			KATTR_METHOD, "get",
			KATTR_ACTION, Pages[Events],
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "hidden",
			KATTR_NAME, Keys[Network].name,
			KATTR_VALUE, scope.network,
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "hidden",
			KATTR_NAME, Keys[Context].name,
			KATTR_VALUE, scope.context,
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "date",
			KATTR_NAME, Keys[After].name,
			KATTR_VALUE, date,
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "submit",
			KATTR_VALUE, "Jump",
			KATTR__MAX
		)
		|| khtml_closeelem(html, 1);
}

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 contexts.query <= NOT :public
		AND events.time >= strftime('%s', :time)
	ORDER BY events.time, events.event
	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 contexts.query <= NOT :public
			AND events.time < strftime('%s', :time)
		ORDER BY events.time DESC
		LIMIT :limit
	)
	SELECT * FROM before
	ORDER BY time, event;
);

enum kcgi_err pageEvents(struct kreq *req) {
	struct Scope scope = htmlScope(req);
	if (!scope.network || !scope.context) return httpFail(req, KHTTP_400);
	if (!req->fieldmap[After] && !req->fieldmap[Before]) {
		return redirect(req, scope);
	}
	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, scope.context)
		|| htmlNav(&html, scope)
		|| dateForm(&html, scope, time)
		|| khtml_elem(&html, KELEM_TABLE);
	if (error) return error;

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

	sqlite3_reset(events);
	dbBindText(events, ":network", scope.network);
	dbBindText(events, ":context", scope.context);
	dbBindText(events, ":time", time);
	dbBindInt(events, ":public", pagePublic);
	dbBindInt(events, ":limit", pageLimit);

	int result;
	while (SQLITE_ROW == (result = sqlite3_step(events))) {
		int i = 0;
		struct Event event = {0};
		event.event = sqlite3_column_int64(events, i++);
		event.time = sqlite3_column_int64(events, i++);
		event.type = sqlite3_column_int(events, i++);
		event.nick = sqlite3_column_text(events, i++);
		event.user = sqlite3_column_text(events, i++);
		event.host = sqlite3_column_text(events, i++);
		event.target = sqlite3_column_text(events, i++);
		event.message = sqlite3_column_text(events, i++);
		error = htmlEvent(&html, scope, event);
		if (error) break;
	}
	if (result != SQLITE_DONE) errx(EX_SOFTWARE, "%s", sqlite3_errmsg(db));
	return error || htmlFooter(&html) || khtml_close(&html);
}