var fs = require("fs"), path = require("path");

var images = [];

function scanDir(dir) {

fs.readdirSync(dir).forEach(function(file) {

var full = path.resolve(dir, file), type;

if (fs.lstatSync(full).isDirectory())

return scanDir(full);

if (/\.svg$/.test(file))

type = "image/svg+xml";

else if (/\.png$/.test(file))

type = "image/png";

else if (/\.jpg$/.test(file))

type = "image/jpeg";

else

throw new Error("Unknown image type: " + full);

var local = full.slice(full.indexOf("/img/") + 1);

images.push(" <item id=\"image." + file + "\" href=\"" + local + "\" media-type=\"" + type + "\"/>");

});

}

scanDir("epub/img");

var out = fs.readFileSync("epub/content.opf.src", "utf8").replace("{{images}}", images.join("\n"));

fs.writeFileSync("epub/content.opf", out);