medimatrix/arcee

var path = require("path")
var fs = require("fs")
var yaml = require("yaml")
var toml = require("toml")

var supportedExtensions = {}

function readFile(fileLocation, configType) {
    var parser = supportedExtensions[configType]

    if (parser._passFileLocation) {
        return parser(fileLocation)
    } else {
        return parser(fs.readFileSync(fileLocation).toString())
    }
}

function storeExt(store, fn) {
    return function(ext) {
        store[ext] = fn
    }
}

function addExtension(ext, fn, passFileLocation) {
    if (passFileLocation) {
        fn._passFileLocation = true
    }

    if (typeof ext === "string") {
        supportedExtensions[ext] = fn
    } else if (Array.isArray(ext)) {
        ext.forEach(storeExt(supportedExtensions, fn))
    }
}

addExtension(["yaml", "yml"], yaml.eval)
addExtension("toml", toml.parse)
addExtension("json", JSON.parse)
addExtension("js", require, true)

exports.addExtension = addExtension

exports.supportedExtensions = function() {
    return Object.keys(supportedExtensions)
}

exports.parse = function(fileLocation) {
    // Slice the returned string as it contains a dot
    var configType = path.extname(fileLocation).slice(1)

    if (exports.supportedExtensions().indexOf(configType) !== -1) {
        return readFile(fileLocation, configType)
    } else {
        throw new Error("Filetype " + configType + " not supported")
    }
}