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

#include "server.h"

const char *htmlStylesheet = "stylesheet.css";

enum kcgi_err htmlHead(struct khtmlreq *html, const char *title) {
	return khtml_elem(html, KELEM_DOCTYPE)
		|| khtml_attr(html, KELEM_META, KATTR_CHARSET, "utf-8", KATTR__MAX)
		|| khtml_elem(html, KELEM_TITLE)
		|| khtml_puts(html, title)
		|| khtml_closeelem(html, 1)
		|| khtml_attr(
			html, KELEM_META,
			KATTR_NAME, "viewport",
			KATTR_CONTENT, "width=device-width, initial-scale=1.0",
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_LINK,
			KATTR_REL, "stylesheet",
			KATTR_HREF, htmlStylesheet,
			KATTR__MAX
		)
		|| khtml_elem(html, KELEM_H1)
		|| khtml_puts(html, title)
		|| khtml_closeelem(html, 1);
}

enum kcgi_err
htmlNav(struct khtmlreq *html, const char *network, const char *context) {
	enum kcgi_err error = 0
		|| khtml_elem(html, KELEM_NAV)
		|| khtml_elem(html, KELEM_OL)
		|| khtml_elem(html, KELEM_LI)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, Pages[Networks], KATTR__MAX)
		|| khtml_puts(html, "Networks")
		|| khtml_closeelem(html, 2);
	if (error) return error;

	if (network) {
		char *href = khttp_urlpart(
			NULL, NULL, Pages[Contexts],
			Keys[Network].name, network,
			NULL
		);
		if (!href) err(EX_OSERR, "khttp_urlpart");
		error = 0
			|| khtml_elem(html, KELEM_LI)
			|| khtml_attr(html, KELEM_A, KATTR_HREF, href, KATTR__MAX)
			|| khtml_puts(html, network)
			|| khtml_closeelem(html, 2);
		if (error) return error;
	}

	if (network && context) {
		char *href = khttp_urlpart(
			NULL, NULL, Pages[Events],
			Keys[Network].name, network,
			Keys[Context].name, context,
			NULL
		);
		if (!href) err(EX_OSERR, "khttp_urlpart");
		error = 0
			|| khtml_elem(html, KELEM_LI)
			|| khtml_attr(html, KELEM_A, KATTR_HREF, href, KATTR__MAX)
			|| khtml_puts(html, context)
			|| khtml_closeelem(html, 2);
		if (error) return error;
	}

	char label[256];
	snprintf(
		label, sizeof(label), "Search%s%s",
		(network ? " " : ""), (context ? context : network ? network : "")
	);

	error = 0
		|| khtml_closeelem(html, 1)
		|| khtml_attr(
			html, KELEM_FORM,
			KATTR_METHOD, "get",
			KATTR_ACTION, Pages[Search],
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "search",
			KATTR_NAME, Keys[Query].name,
			KATTR__MAX
		)
		|| khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "submit",
			KATTR_VALUE, label,
			KATTR__MAX
		)
		|| khtml_closeelem(html, 1);
	if (error) return error;

	if (network) {
		error = khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "hidden",
			KATTR_NAME, Keys[Network].name,
			KATTR_VALUE, network,
			KATTR__MAX
		);
		if (error) return error;
	}

	if (context) {
		error = khtml_attr(
			html, KELEM_INPUT,
			KATTR_TYPE, "hidden",
			KATTR_NAME, Keys[Context].name,
			KATTR_VALUE, context,
			KATTR__MAX
		);
		if (error) return error;
	}

	return khtml_closeelem(html, 2);
}

static const char *SourceURL = "https://git.causal.agency/scooper";
static const char *SyntaxURL = {
	"https://www.sqlite.org/fts5.html#full_text_query_syntax"
};
static const char *Columns = {
	"network, channel, query, nick, user, target, message"
};

enum kcgi_err htmlFooter(struct khtmlreq *html) {
	return 0
		|| khtml_closeto(html, 0)
		|| khtml_elem(html, KELEM_FOOTER)
		|| khtml_elem(html, KELEM_SPAN)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, SourceURL, KATTR__MAX)
		|| khtml_puts(html, "scooper is AGPLv3+")
		|| khtml_closeelem(html, 2)
		|| khtml_putc(html, ' ')
		|| khtml_elem(html, KELEM_SPAN)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, SyntaxURL, KATTR__MAX)
		|| khtml_puts(html, "Search syntax")
		|| khtml_closeelem(html, 1)
		|| khtml_putc(html, ' ')
		|| khtml_attr(html, KELEM_SPAN, KATTR_TITLE, Columns, KATTR__MAX)
		|| khtml_puts(html, "Columns")
		|| khtml_closeto(html, 0);
}

static enum kcgi_err eventTime(struct khtmlreq *html, struct Event event) {
	char time[sizeof("0000-00-00 00:00:00")];
	strftime(time, sizeof(time), "%F %T", gmtime(&event.time));

	char *base = NULL;
	if (event.network && event.context) {
		base = khttp_urlpart(
			NULL, NULL, Pages[Events],
			Keys[Network].name, event.network,
			Keys[Context].name, event.context,
			Keys[After].name, time,
			NULL
		);
		if (!base) err(EX_OSERR, "khttp_urlpart");
	}
	char *href = NULL;
	asprintf(&href, "%s#%" PRId64, (base ? base : ""), event.event);
	if (!href) err(EX_OSERR, "asprintf");
	if (base) free(base);

	enum kcgi_err error = 0
		|| khtml_attr(html, KELEM_TD, KATTR_CLASS, "time", KATTR__MAX)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, href, KATTR__MAX)
		|| khtml_attr(html, KELEM_TIME, KATTR_DATETIME, time, KATTR__MAX)
		|| khtml_puts(html, time)
		|| khtml_closeelem(html, 3);

	free(href);
	return error;
}

static enum kcgi_err eventNetwork(struct khtmlreq *html, struct Event event) {
	if (!event.network) return KCGI_OK;
	char *href = khttp_urlpart(
		NULL, NULL, Pages[Contexts],
		Keys[Network].name, event.network,
		NULL
	);
	if (!href) err(EX_OSERR, "khttp_urlpart");
	enum kcgi_err error = 0
		|| khtml_attr(html, KELEM_TD, KATTR_CLASS, "network", KATTR__MAX)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, href, KATTR__MAX)
		|| khtml_puts(html, event.network)
		|| khtml_closeelem(html, 2);
	free(href);
	return error;
}

static enum kcgi_err eventContext(struct khtmlreq *html, struct Event event) {
	if (!event.network || !event.context) return KCGI_OK;
	char *href = khttp_urlpart(
		NULL, NULL, Pages[Events],
		Keys[Network].name, event.network,
		Keys[Context].name, event.context,
		NULL
	);
	if (!href) err(EX_OSERR, "khttp_urlpart");
	enum kcgi_err error = 0
		|| khtml_attr(html, KELEM_TD, KATTR_CLASS, "context", KATTR__MAX)
		|| khtml_attr(html, KELEM_A, KATTR_HREF, href, KATTR__MAX)
		|| khtml_puts(html, event.context)
		|| khtml_closeelem(html, 2);
	free(href);
	return error;
}

static int hash(const char *str) {
	if (*str == '~') str++;
	uint32_t hash = 0;
	for (; *str; ++str) {
		hash = (hash << 5) | (hash >> 27);
		hash ^= *str;
		hash *= 0x27220A95;
	}
	return 2 + hash % 74;
}

static enum kcgi_err eventNick(struct khtmlreq *html, struct Event event) {
	char color[sizeof("fg99")];
	snprintf(color, sizeof(color), "fg%02d", hash(event.user));

	char *mask = NULL;
	asprintf(&mask, "%s!%s@%s", event.nick, event.user, event.host);
	if (!mask) err(EX_OSERR, "asprintf");

	enum kcgi_err error = 0
		|| khtml_attr(html, KELEM_TD, KATTR_CLASS, "nick", KATTR__MAX)
		|| khtml_attr(
			html, KELEM_SPAN,
			KATTR_CLASS, color,
			KATTR_TITLE, mask,
			KATTR__MAX
		)
		|| khtml_puts(html, event.nick)
		|| khtml_closeelem(html, 2);

	free(mask);
	return error;
}

static enum kcgi_err eventMessage(struct khtmlreq *html, struct Event event) {
	if (!event.message) return KCGI_OK;
	return 0
		|| khtml_attr(html, KELEM_TD, KATTR_CLASS, "message", KATTR__MAX)
		|| khtml_puts(html, event.message)
		|| khtml_closeelem(html, 1);
}

static const char *Types[TypesLen] = {
#define X(id, name) [id] = name,
	ENUM_TYPE
#undef X
};

enum kcgi_err htmlEvent(struct khtmlreq *html, struct Event event) {
	const char *type = (event.type < TypesLen ? Types[event.type] : "unknown");
	return 0
		|| khtml_attrx(
			html, KELEM_TR,
			KATTR_ID, KATTRX_INT, event.event,
			KATTR_CLASS, KATTRX_STRING, type,
			KATTR__MAX
		)
		|| eventTime(html, event)
		|| eventNetwork(html, event)
		|| eventContext(html, event)
		|| eventNick(html, event)
		|| eventMessage(html, event)
		|| khtml_closeelem(html, 1);
}