import http = require("http");
import types = require("utils/types");

// This is used for definition purposes only, it does not generate JavaScript for it.
import definition = require("image-source");

var RESOURCE_PREFIX = "res://";

export function fromResource(name: string): definition.ImageSource {
    var image = new definition.ImageSource();
    return image.loadFromResource(name) ? image : null;
}

export function fromFile(path: string): definition.ImageSource {
    var image = new definition.ImageSource();
    return image.loadFromFile(path) ? image : null;
}

export function fromData(data: any): definition.ImageSource {
    var image = new definition.ImageSource();
    return image.loadFromData(data) ? image : null;
}

export function fromNativeSource(source: any): definition.ImageSource {
    var image = new definition.ImageSource();
    return image.setNativeSource(source) ? image : null;
}

export function fromUrl(url: string): Promise<definition.ImageSource> {
    return http.getImage(url);
}

export function fromFileOrResource(path: string): definition.ImageSource {
    if (!isFileOrResourcePath(path)) {
        throw new Error("Path \"" + "\" is not a valid file or resource.");
    }

    if (path.indexOf(RESOURCE_PREFIX) === 0) {
        return fromResource(path.substr(RESOURCE_PREFIX.length));
    }
    return fromFile(path);
}

export function isFileOrResourcePath(path: string): boolean {
    if (!types.isString(path)) {
        return false;
    }

    return path.indexOf("~/") === 0 ||  // relative to AppRoot
        path.indexOf("/") === 0 ||      // absolute path
        path.indexOf(RESOURCE_PREFIX) === 0;    // resource
}