/* This file is part of Cinaest.
 *
 * Copyright (C) 2009 Philipp Zabel
 *
 * Cinaest is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Cinaest 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Cinaest. If not, see <http://www.gnu.org/licenses/>.
 */

using Sqlite;

class IMDbSqlite : Object {
	Database db;
	List<string> genres;

	public delegate void ReceiveMovieFunction (string title, int year, int rating);

	public IMDbSqlite (string filename) {
		int rc;

		genres = new List<string> ();

		rc = Database.open (filename, out db);
		if (rc != Sqlite.OK) {
			stderr.printf ("Can't open database: %d, %s\n", rc, db.errmsg ());
			return;
		}

		rc = db.exec ("PRAGMA journal_mode = OFF;", callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("Can't turn off journal mode: %d, %s\n", rc, db.errmsg ());
			return;
		}

		rc = db.exec ("PRAGMA locking_mode = EXCLUSIVE;", callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("Can't get exclusive lock: %d, %s\n", rc, db.errmsg ());
			return;
		}

		rc = db.exec ("PRAGMA synchronous = OFF;", callback, null);
		if (rc != Sqlite.OK)
			stderr.printf ("Can't turn off synchronous access: %d, %s\n", rc, db.errmsg ());

	}

	public static int callback (int n_columns, string[] values,
	                            string[] column_names) {
		for (int i = 0; i < n_columns; i++) {
			stdout.printf ("%s = %s\n", column_names[i], values[i]);
		}
		stdout.printf ("\n");

		return 0;
	}

	public int add_movie (string _title, int year) {
		string md5 = Checksum.compute_for_string (ChecksumType.MD5, _title);
		uint64 half_md5 = (md5.ndup (16)).to_uint64 (null, 16);

		string title = strip_year (_title, year);

		string sql = "INSERT INTO Movies(ID, Title, Year) VALUES (%lld, \"%s\", %d);".printf ((int64) half_md5, title, year);
		int rc;

		rc = db.exec (sql, callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("Failed to insert movie \"%s\" (%d): %d, %s\n", title, year, rc, db.errmsg ());
			return 1;
		}

		return 0;
	}

	private string strip_year (string title, int year) {
		string year_suffix = " (%d)".printf (year);
		if (title.has_suffix (year_suffix)) {
			return title.substring (0, title.length - year_suffix.length);
		} else {
			return title.dup ();
		}
	}

	public int movie_set_rating (string title, int rating) {
		string md5 = Checksum.compute_for_string (ChecksumType.MD5, title);
		uint64 half_md5 = (md5.ndup (16)).to_uint64 (null, 16);

		var sql = "UPDATE Movies SET Rating=%d WHERE ID=%lld;".printf (rating, (int64) half_md5);
		int rc;

		rc = db.exec (sql, callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("SQL error: %d, %s\n", rc, db.errmsg ());
			return 1;
		}

		return 0;
	}

	public int movie_add_genre (string title, string genre) {
		string md5 = Checksum.compute_for_string (ChecksumType.MD5, title);
		uint64 half_md5 = (md5.ndup (16)).to_uint64 (null, 16);
		string sql;
		int bit;
		int rc;

		bit = genre_bit (genre);
		if (bit == 0) {
			genres.append (genre);
			bit = genre_bit (genre);

			sql = "INSERT INTO Genres(Bit, Genre) VALUES (%d, \"%s\");".printf (bit, genre);

			rc = db.exec (sql, callback, null);
			if (rc != Sqlite.OK) {
				stderr.printf ("SQL error: %d, %s\n", rc, db.errmsg ());
				return 1;
			}
		}

		sql = "UPDATE Movies SET Genres=Genres|%d WHERE ID=%lld;".printf (bit, (int64) half_md5);
		rc = db.exec (sql, callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("SQL error: %d, %s\n", rc, db.errmsg ());
			return 1;
		}

		return 0;
	}

	int genre_bit (string genre) {
		for (int i = 0; i < genres.length (); i++) {
			if (genres.nth_data (i) == genre)
				return 1 << i;
		}
		return 0;
	}

	public int clear () {
		int rc;

		rc = db.exec ("DROP TABLE IF EXISTS Movies; CREATE TABLE Movies (ID INTEGER PRIMARY KEY, Title TEXT NOT NULL, Year INTEGER, Rating INTEGER, Genres INTEGER NOT NULL DEFAULT 0); DROP TABLE IF EXISTS Genres; CREATE TABLE Genres (Bit INTEGER PRIMARY KEY, Genre TEXT NOT NULL);", callback, null);
		if (rc != Sqlite.OK) {
			stderr.printf ("SQL error: %d, %s\n", rc, db.errmsg ());
			return 1;
		}

		return 0;
	}

	public int query (string filter, ReceiveMovieFunction receive_movie) {
		var sql = "SELECT Title, Year, Rating FROM Movies WHERE Title LIKE \"%s%%\" LIMIT 100;".printf (filter);
		Statement stmt;
		int rc;

		rc = db.prepare_v2 (sql, -1, out stmt);
		if (rc != Sqlite.OK) {
			stderr.printf ("SQL error: %d, %s\n", rc, db.errmsg ());
			return 1;
		}

		do {
			rc = stmt.step ();
			if (rc == Sqlite.ROW) {
				string title = stmt.column_text (0);
				int year = stmt.column_int (1);
				int rating = stmt.column_int (2);
				receive_movie (title, year, rating);
			}
		} while (rc == Sqlite.ROW);

		return 0;
	}
}