const Image = require("@11ty/eleventy-img");
const path = require("path");

function relativeToInputPath(inputPath, relativeFilePath) {
	let split = inputPath.split("/");
	split.pop();

	return path.resolve(split.join(path.sep), relativeFilePath);

}

function isFullUrl(url) {
	try {
		new URL(url);
		return true;
	} catch(e) {
		return false;
	}
}

// Only one module.exports per configuration file, please!
module.exports = function (eleventyConfig) {
  eleventyConfig.addPassthroughCopy("content/albums/**/*.mp3");

	eleventyConfig.addShortcode("image", async function (src, alt, sizes) {
    let input;
		if(isFullUrl(src)) {
			input = src;
		} else {
			input = relativeToInputPath(this.page.inputPath, src);
		}
    
		let metadata = await Image(input, {
			widths: [300, 600],
			formats: ["avif", "jpeg"],
      outputDir: path.join(eleventyConfig.dir.output, "img"),
		});

		let imageAttributes = {
			alt,
			sizes,
			loading: "lazy",
			decoding: "async",
		};

		// You bet we throw an error on a missing alt (alt="" works okay)
		return Image.generateHTML(metadata, imageAttributes);
	});
};