Help me write a simple Swift function to load a string from a file

gistfile1.swift

import Foundation

struct ShowdownDataLoader {
    
    
    // So this is a simple function that should return a string from a file but it sucks.
    // if feels way to verbose and I hate all the indentation. Please show me how I might
    // be able to refactor it.
    
    // Please be additive to the GIST with your suggestion so others can see the origianl. 
    
    func loadPokemonJSONString() -> String? {
        let mainBundle = NSBundle.mainBundle()
        if let pathToJSON = mainBundle.pathForResource("pokedex", ofType: "js") {
            var stringError: NSError?
            if let jsonString = String(contentsOfFile: pathToJSON, encoding: NSUTF8StringEncoding, error: &stringError) {
                return jsonString
            } else {
                var errorMessage = "Error not returned"
                if let error = stringError {
                    errorMessage = error.localizedDescription
                }
                NSLog("Error reading String from file: \(pathToJSON) error: \(errorMessage)")
                return nil;
            }
        } else {
            NSLog("Could not find path to JSON resource")
            return nil
        }
    }
    
}

I suspect you're looking for a Swiftier solution, but I am not Swifty yet. That being said, a more generic way of refactoring is to break up the problem into more functions.

import Foundation

struct ShowdownDataLoader {

    func loadPokemonJSONString() -> String? {
        let mainBundle = NSBundle.mainBundle()
        if let pathToJSON = mainBundle.pathForResource("pokedex", ofType: "js") {
            return loadJSONFromPath(pathToJSON)
        } else {
            NSLog("Could not find path to JSON resource")
            return nil
        }
    }

    func loadJSONFromPath(pathToJSON: String) -> String? {
        var stringError: NSError?
        if let jsonString = String(contentsOfFile: pathToJSON, encoding: NSUTF8StringEncoding, error: &stringError) {
            return jsonString
        } else {
            var errorMessage = "Error not returned"
            if let error = stringError {
                errorMessage = error.localizedDescription
            }
            NSLog("Error reading String from file: \(pathToJSON) error: \(errorMessage)")
            return nil;
        }
    }
}

Thanks for the feedback. The refactor is an improvement but still doesn't feel elegant. Not sure it ever will as long as I have to call ObjC-based APIs. Thanks for taking the time to give me some feedback.