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

const convert = {};

const models = Object.keys(conversions);

function wrapRaw(fn) {
    const wrappedFn = function (...args) {
        const arg0 = args[0];
        if (arg0 === undefined || arg0 === null) {
            return arg0;
        }

        if (arg0.length > 1) {
            args = arg0;
        }

        return fn(args);
    };

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

    return wrappedFn;
}

function wrapRounded(fn) {
    const wrappedFn = function (...args) {
        const arg0 = args[0];

        if (arg0 === undefined || arg0 === null) {
            return arg0;
        }

        if (arg0.length > 1) {
            args = arg0;
        }

        const 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 (let 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(fromModel => {
    convert[fromModel] = {};

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

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

    routeModels.forEach(toModel => {
        const fn = routes[toModel];

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

module.exports = convert;