/* 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 <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <unistd.h>

#include "server.h"

sqlite3 *db;
struct Statements stmt;

static void prepareAll(void) {
#define X(name, query) dbPrepare(&stmt.name, query);
	ENUM_STMTS
#undef X
}

static void finalizeAll(void) {
#define X(name, query) sqlite3_finalize(stmt.name);
	ENUM_STMTS
#undef X
	sqlite3_close(db);
}

const char *Pages[PagesLen] = {
#define X(path, page) [page] = path,
	ENUM_PAGES
#undef X
};

const struct kvalid Keys[KeysLen] = {
#define X(valid, name, key) [key] = { valid, name },
	ENUM_KEYS
#undef X
};

static enum kcgi_err stylesheet(struct kreq *req) {
	if (req->mime != KMIME_TEXT_CSS) return httpFail(req, KHTTP_404);
	enum kcgi_err error = 0
		|| httpHead(req, KHTTP_200, KMIME_TEXT_CSS)
		|| khttp_head(
			req, kresps[KRESP_CACHE_CONTROL],
			"public, max-age=86400, immutable"
		)
		|| khttp_body(req);
	if (req->method == KMETHOD_HEAD) return error;
	return error || khttp_puts(req, CSS);
}

static enum kcgi_err dispatch(struct kreq *req) {
	if (req->method != KMETHOD_HEAD && req->method != KMETHOD_GET) {
		return httpFail(req, KHTTP_405);
	}
	switch (req->page) {
		case Networks:   return networksPage(req);
		case Contexts:   return contextsPage(req);
		case Events:     return eventsPage(req);
		case Search:     return searchPage(req);
		case Stylesheet: return stylesheet(req);
		default:         return httpFail(req, KHTTP_404);
	}
}

#define ENV "SCOOPER_"

int main(int argc, char *argv[]) {
	const char *path = NULL;
	bool test = false;

	const char *val;
	if ((val = getenv(ENV "DATABASE"))) path = val;
	if ((val = getenv(ENV "GAP"))) eventsGap = strtol(val, NULL, 10);
	if ((val = getenv(ENV "HIDE_HOST"))) htmlHideHost = (val[0] != '0');
	if ((val = getenv(ENV "LIMIT"))) eventsLimit = strtol(val, NULL, 10);
	if ((val = getenv(ENV "OVERLAP"))) eventsOverlap = strtol(val, NULL, 10);
	if ((val = getenv(ENV "PUBLIC"))) contextsPublic = (val[0] != '0');
	if ((val = getenv(ENV "RECENT"))) contextsRecent = strtol(val, NULL, 10);
	if ((val = getenv(ENV "STYLESHEET"))) htmlStylesheet = val;

	for (int opt; 0 < (opt = getopt(argc, argv, "cg:hl:o:pr:s:"));) {
		switch (opt) {
			break; case 'c': test = true;
			break; case 'g': eventsGap = strtol(optarg, NULL, 10);
			break; case 'h': htmlHideHost = true;
			break; case 'l': eventsLimit = strtol(optarg, NULL, 10);
			break; case 'o': eventsOverlap = strtol(optarg, NULL, 10);
			break; case 'p': contextsPublic = true;
			break; case 'r': contextsRecent = strtol(optarg, NULL, 10);
			break; case 's': htmlStylesheet = optarg;
			break; default:  return EX_USAGE;
		}
	}
	if (optind < argc) path = argv[optind];
	if (!path) errx(EX_USAGE, "database path required");

	int error = sqlite3_open_v2(path, &db, SQLITE_OPEN_READONLY, NULL);
	if (error) errx(EX_NOINPUT, "%s: %s", path, sqlite3_errmsg(db));
	sqlite3_busy_timeout(db, 1000);
	atexit(finalizeAll);

	sqlite3_stmt *check;
	error = sqlite3_prepare_v2(
		db, SQL(PRAGMA user_version;), -1, &check, NULL
	);
	if (error) errx(EX_SOFTWARE, "%s", sqlite3_errmsg(db));

	error = sqlite3_step(check);
	if (error != SQLITE_ROW) errx(EX_SOFTWARE, "%s", sqlite3_errmsg(db));

	int version = sqlite3_column_int(check, 0);
	if (version < DatabaseVersionMin || version > DatabaseVersionMax) {
		errx(EX_DATAERR, "unsupported database version %d", version);
	}
	sqlite3_finalize(check);

	prepareAll();
	if (test) return EX_OK;
	
	if (khttp_fcgi_test()) {
		struct kfcgi *fcgi;
		enum kcgi_err error = khttp_fcgi_init(
			&fcgi, Keys, KeysLen, Pages, PagesLen, Networks
		);
		if (error) errx(EX_CONFIG, "khttp_fcgi_init: %s", kcgi_strerror(error));
		for (
			struct kreq req;
			KCGI_OK == (error = khttp_fcgi_parse(fcgi, &req));
			khttp_free(&req)
		) {
			error = dispatch(&req);
			if (error && error != KCGI_HUP) break;
		}
		if (error != KCGI_EXIT) {
			errx(EX_PROTOCOL, "khttp_fcgi_parse: %s", kcgi_strerror(error));
		}
		khttp_fcgi_free(fcgi);
	} else {
		struct kreq req;
		enum kcgi_err error = khttp_parse(
			&req, Keys, KeysLen, Pages, PagesLen, Networks
		);
		if (error) errx(EX_PROTOCOL, "khttp_parse: %s", kcgi_strerror(error));
		error = dispatch(&req);
		if (error) errx(EX_PROTOCOL, "%s", kcgi_strerror(error));
		khttp_free(&req);
	}
}