/*
 * Copyright (c) 2018 Markus Hennecke <markus-hennecke@markus-hennecke.de>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */


#include <sys/types.h>
#include <ctype.h>
#include <err.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <kcgi.h>

#include "../db.h"
#include "../util.h"


enum key {
	KEY_FROM,
	KEY_UNTIL,
	KEY_DEVICE,
	KEY__MAX
};


static const struct kvalid keys[KEY__MAX] = {
	{ validate_timestamp, "from" },
	{ validate_timestamp, "until" },
	{ kvalid_string, "device" },
};


enum pg {
	PG_DATA,
	PG_STATISTICS,
	PG_LATEST,
	PG_ERRORS,
	PG__MAX
};


static const char *pages[PG__MAX] = {
	"data",
	"statistics",
	"latest",
	"errors",
};


static bool (*query_funcs[PG__MAX])(struct kreq *r, char **, const char *,
		const char *) = {
	db_get_data_json,
	db_get_statistics_data_json,
	db_get_latest_json,
	NULL,
};


int
main(void)
{
	struct kreq	 r;
	enum kcgi_err	 er;

	tzset();

	if ((pledge("cpath getpw stdio proc wpath rpath dns inet",
	     NULL)) == (-1))
		err(EXIT_FAILURE, "pledge");

	er = khttp_parse(&r, keys, KEY__MAX, pages, PG__MAX, PG_DATA);
	if (KCGI_OK != er)
		return EXIT_FAILURE;

	/*
	 * Accept GET...
	 */
	if (KMETHOD_OPTIONS == r.method) {
		khttp_head(&r, kresps[KRESP_ALLOW], "OPTIONS GET");
		response(&r, KHTTP_200, r.mime, NULL);
	} else if (KMETHOD_GET == r.method) {
		char *json = NULL;
		const char *from = parameter(&r, KEY_FROM);
		const char *until = parameter(&r, KEY_UNTIL);
		const char *device = parameter(&r, KEY_DEVICE);

		switch (r.page) {
		case PG_DATA:
		case PG_STATISTICS:
		case PG_LATEST:
			if (r.fieldnmap[KEY_FROM] == NULL
			    && r.fieldnmap[KEY_UNTIL] == NULL
			    && query_funcs[r.page](&r, &json, from, until))
				response(&r, KHTTP_200, KMIME_APP_JSON, json);
			else
				response(&r, KHTTP_503, KMIME_TEXT_PLAIN, NULL);
			break;
		case PG_ERRORS:
			if (r.fieldnmap[KEY_DEVICE] == NULL
			    && db_get_errors_json(&r, &json, device))
				response(&r, KHTTP_200, KMIME_APP_JSON, json);
			else
				response(&r, KHTTP_503, KMIME_TEXT_PLAIN, NULL);
			break;
		default:
			response(&r, KHTTP_503, KMIME_TEXT_PLAIN,
			    "0 internal error");
			break;
		}
	} else {
		response(&r, KHTTP_404, r.mime, "0 page not found");
	}

	khttp_free(&r);
	return EXIT_SUCCESS;
}