var conversions = require('./conversions');
var route = require('./route');

var convert = {};

var models = Object.keys(conversions);

function wrapRaw(fn) {
    var wrappedFn = function (args) {
        if (args === undefined || args === null) {
            return args;
        }

        if (arguments.length > 1) {
            args = Array.prototype.slice.call(arguments);
        }

        return fn(args);
    };

    // preserve .conversion property if there is one
    if ('conversion' in fn) {
        wrappedFn.conversion = fn.conversion;
    }

    return wrappedFn;
}

function wrapRounded(fn) {
    var wrappedFn = function (args) {
        if (args === undefined || args === null) {
            return args;
        }

        if (arguments.length > 1) {
            args = Array.prototype.slice.call(arguments);
        }

        var result = fn(args);

        // we're assuming the result is an array here.
        // see notice in conversions.js; don't use box types
        // in conversion functions.
        if (typeof result === 'object') {
            for (var len = result.length, i = 0; i < len; i++) {
                result[i] = Math.round(result[i]);
            }
        }

        return result;
    };

    // preserve .conversion property if there is one
    if ('conversion' in fn) {
        wrappedFn.conversion = fn.conversion;
    }

    return wrappedFn;
}

models.forEach(function (fromModel) {
    convert[fromModel] = {};

    Object.defineProperty(convert[fromModel], 'channels', {value: conversions[fromModel].channels});
    Object.defineProperty(convert[fromModel], 'labels', {value: conversions[fromModel].labels});

    var routes = route(fromModel);
    var routeModels = Object.keys(routes);

    routeModels.forEach(function (toModel) {
        var fn = routes[toModel];

        convert[fromModel][toModel] = wrapRounded(fn);
        convert[fromModel][toModel].raw = wrapRaw(fn);
    });
});

module.exports = convert;