fun createRenders(pkg: Package, renderOutputDir: File, renderedAt: Instant): Set<Render> {
    return pkg.templates.map { renderTemplatePath ->
        val renderTemplate = renderTemplatePath.removeSuffix(".yml").let { id ->
            templatesById[id] ?: throw Exception("could not find template for id: $id")
        }
        val renderDir = renderOutputDir.resolve(renderTemplate.id)
        check(renderDir.exists() && renderDir.isDirectory)
        renderMetricTimer.tagVal(renderTemplate.mediaType.name).time {
            when (renderTemplate.mediaType) {
                RenderTemplate.MediaType.Video -> {
                    val videoFile = renderDir.listFiles().single { it.extension.equals("MP4", true) }

                    // if no thumbnail was rendered, copy the default thumbnail into the rendered directory
                    if (renderDir.listFiles().singleOrNull { it.extension.equals("JPG", true) } == null) {
                        requireNotNull(renderTemplate.defaultThumbnail) {
                            "no thumbnail was rendered and template has no default thumbnail"
                        }.copyTo(renderDir.resolve("defaultThumbnail.jpg"))
                    }
                    val thumbnail = renderDir.listFiles().single { it.extension.equals("JPG", true) }
                    Render.Video(
                        id = renderTemplate.id,
                        name = renderTemplate.name,
                        renderedAt = renderedAt,
                        videoFile = toRenderFile(videoFile, renderDir),
                        thumbnails = mapOf("1280x720" to toRenderFile(thumbnail, renderDir))
                    )
                }
                RenderTemplate.MediaType.PhotoGroup -> {
                    Render.PhotoGroup(
                        id = renderTemplate.id,
                        name = renderTemplate.name,
                        renderedAt = renderedAt,
                        localDir = renderDir.absolutePath,
                        numPhotos = renderDir.listFiles().size
                    )
                }
            }
        }
        

    }.toSet()
}