const clone  = require("./utils").clone;
const config = require("../config");
const mysql  = require("mysql");

var connection = mysql.createConnection( {
        host     : "localhost",
        database : "galactic_imperium",
        user     : "root",
        password : ""
    } );
connection.connect();

/** Initializes the database in the global variable _db. Doesn’t require or
 *  return anything
 */
module.exports.init = function() {
    _db = {
        players: [],
        areas: [],
        planets: [],
        species: []
    };

    _db_vars = {
        players: [],
        areas: [],
        planets: [],
        species: []
    };

    connection.query( "SELECT * FROM players", function( err, players ) {
        if ( err ) {
            throw err;
        } else {
            for ( var player in players ) {
                _db.players[players[player].login] = players[player];
            }
        }
    } );

    connection.query( "SELECT * FROM areas", function( err, areas ) {
        if ( err ) {
            throw err;
        } else {
            for ( var area in areas ) {
                _db.areas[areas[area].name] = areas[area];
            }
        }
    } );

    connection.query( "SELECT * FROM planets", function( err, planets ) {
        if ( err ) {
            throw err;
        } else {
            for ( var planet in planets ) {
                _db.planets[planets[planet].name] = planets[planet];
            }
        }
    } );

    connection.query( "SELECT * FROM species", function( err, specie ) {
        if ( err ) {
            throw err;
        } else {
            for ( var species in specie ) {
                _db.species[specie[species].name] = specie[species];
            }
        }
    } );

    console.log( "Database initialized !" );
}

/** Gets an element in a given array of the database.
 * @param array The name of the array in which to look for `id` in the
 *  database. Is a string.
 * @param id The name of the variable to look for in the database. Can be any
 *  valid key type.
 */
module.exports.get = function( array, id ) {
    if ( id ) {
        if ( !_db[array][id] ) {
            _db_vars[array][id] = [3, false];
        }

        _db_vars[array][id][0] = 3;

        return clone( _db[array][id] );
    } else {
        return clone( _db[array] );
    }
}

/** Indicates whether some data is stored in a given array and at a given key
 *  in the DB.
 * @param array Name of the array in which to look for.
 * @param id The name of the variable to look for in the array.
 */
module.exports.exists = function( array, id ) {
    if (_db[array][id]) {
        _db_vars[array][id][0] = 3;

        return true
    } else {
        return false;
    }
}

/** Exports a value in the database.
 * @param array Name of the DB array.
 * @param id Key of the DB array.
 * @param value Value to set the value of the array of key `id` to.
 */
module.exports.set = function( array, id, value ) {
    // Clone prevent to change _db content without using set.
    _db[array][id] = clone(value);

    if( !_db_vars[array][id] ) {
        _db_vars[array][id] = [];
    }

    _db_vars[array][id][0] = 3;
    _db_vars[array][id][1] = true;
}

/**
 * Write an object in his file.
 * @param array Name of the DB array.
 * @param id Key of the DB array.
 */
function write( array, id ) {
    if ( _db[array][id] ) {
        if ( _db[array][id].id ) {
            connection.query( "UPDATE " + array + " SET ? WHERE id = " + db[array][id].id, _db[array][id], function( err ) {
                if ( err ) {
                    throw err;
                } else {
                    if( _db_vars[array][id][0] !== 0 ) {
                        _db_vars[array][id][1] = false;
                    }
                }
            } );
        } else {
            connection.query( "INSERT INTO " + array + " SET ?", _db[array][id], function( err ) {
                if ( err ) {
                    throw err;
                } else {
                    if( _db_vars[array][id][0] !== 0 ) {
                        _db_vars[array][id][1] = false;
                    }
                }
            } );
        }
    }
}

/**
 * Write all data form memory to database files.
 */
module.exports.flush = function() {
    for ( var array in _db ) {
        for ( var id in _db[array] ) {
            --_db_vars[array][id][0];

            if ( _db_vars[array][id][1] ) {
                write( array, id );
            }
        }
    }
}