'use strict';

const types = require("./types");

module.exports = function createBufferReader(buffer) {
    let typeSpecs = {
        strA: {},
        strD: {},
        strFilename: {},
        int8: { length: 1 },
        sint8: { length: 1 },
        int16_LSB: { length: 2 },
        int16_MSB: { length: 2 },
        int16_LSB_MSB: { length: 4 },
        sint16_LSB: { length: 2 },
        sint16_MSB: { length: 2 },
        sint16_LSB_MSB: { length: 4 },
        int32_LSB: { length: 4 },
        int32_MSB: { length: 4 },
        int32_LSB_MSB: { length: 8 },
        sint32_LSB: { length: 4 },
        sint32_MSB: { length: 4 },
        sint32_LSB_MSB: { length: 8 },
        decDatetime: { length: 17 },
        directoryDatetime: { length: 7 }
    }

    return Object.keys(typeSpecs).reduce((methods, type) => {
        let options = typeSpecs[type];

        if (options.length == null) {
            methods[type] = function(offset, length) {
                return types[type](buffer.slice(offset, offset + length));
            }
        } else {
            methods[type] = function(offset) {
                return types[type](buffer.slice(offset, offset + options.length));
            }
        }

        return methods;
    }, {});
};