#include <assert.h>
#include <err.h>
#include <stdio.h>

#include <libical/ical.h>

#include "sqlite/sqlite3.h"

static char *SCHEMA = "CREATE TABLE event ("
		      "    start   TIMESTAMP,"
		      "    end     TIMESTAMP,"
		      "    summary TEXT"
		      ")";

static char *
read_stream(char *s, size_t size, void *d)
{
	return fgets(s, (int)size, (FILE *)d);
}

static void
component(sqlite3 *db, icalcomponent *c)
{
	struct icaltimetype dts = icalcomponent_get_dtstart(c);
	struct icaltimetype dte = icalcomponent_get_dtend(c);

	icaltimezone *utc = icaltimezone_get_utc_timezone();
	dts = icaltime_convert_to_zone(dts, utc);
	dte = icaltime_convert_to_zone(dte, utc);

	time_t start = icaltime_as_timet(dts);
	time_t end = icaltime_as_timet(dte);
	const char *summary = icalcomponent_get_summary(c);

	sqlite3_stmt *stmt = NULL;
	const char *sql = "INSERT INTO event (start, end, summary) VALUES ("
			  "datetime(?, 'unixepoch'),"
			  "datetime(?, 'unixepoch')"
			  ", ?)";
	if (sqlite3_prepare_v2(db, sql, -1, &stmt, NULL))
		errx(1, "sqlite3_prepare_v2");

	if (sqlite3_bind_int64(stmt, 1, start))
		errx(1, "sqlite3_bind_int64");
	if (sqlite3_bind_int64(stmt, 2, end))
		errx(1, "sqlite3_bind_int64");
	if (sqlite3_bind_text(stmt, 3, summary, -1, SQLITE_STATIC))
		errx(1, "sqlite3_bind_text");
	if (SQLITE_DONE != sqlite3_step(stmt))
		errx(1, "sqlite3_step");
}

int
main(int argc, const char *argv[static argc])
{
	if (2 != argc)
		errx(1, "usage: %s dbfile < icalfile", argv[0]);

	icalparser *parser = icalparser_new();
	assert(parser);
	FILE *stream = stdin;
	assert(stream);
	icalparser_set_gen_data(parser, stream);

	sqlite3 *db;
	char *errmsg = NULL;
	if (sqlite3_open(argv[1], &db))
		errx(1, "sqlite3_open: %s", errmsg);
	if (sqlite3_exec(db, "BEGIN", NULL, NULL, &errmsg))
		errx(1, "sqlite3_exec: %s", errmsg);
	if (sqlite3_exec(db, "DROP TABLE IF EXISTS event", NULL, NULL, &errmsg))
		errx(1, "sqlite3_exec: %s", errmsg);
	if (sqlite3_exec(db, SCHEMA, NULL, NULL, &errmsg))
		errx(1, "sqlite3_exec: %s", errmsg);
	for (;;) {
		char *line = icalparser_get_line(parser, read_stream);
		if (!line)
			break;
		icalcomponent *c = icalparser_add_line(parser, line);
		if (!c)
			continue;
		for (icalcompiter i = icalcomponent_begin_component(
			 c, ICAL_VEVENT_COMPONENT);
		     icalcompiter_deref(&i); icalcompiter_next(&i)) {
			icalcomponent *ic = icalcompiter_deref(&i);
			component(db, ic);
		}
		icalcomponent_free(c);
	}
	if (sqlite3_exec(db, "COMMIT", NULL, NULL, &errmsg))
		errx(1, "sqlite3_exec: %s", errmsg);
	sqlite3_close(db);

	icalparser_free(parser);
}