export class imageProcessador{

    constructor(
        private userRequest: Request
    ){}

    process(){

        const url = new URL(this.userRequest.url);

        const options = {
            cf: {
                image: {
                }
            }
        }

        if (url.searchParams.has("fit")) options.cf.image.fit = url.searchParams.get("fit")
        if (url.searchParams.has("width")) options.cf.image.width = url.searchParams.get("width")
        if (url.searchParams.has("height")) options.cf.image.height = url.searchParams.get("height")
        if (url.searchParams.has("quality")) options.cf.image.quality = url.searchParams.get("quality")

        const accept : string = this.userRequest.headers.get("Accept") || '';

        if (/image\/avif/.test(accept)) {
            options.cf.image.format = 'avif';
        } else if (/image\/webp/.test(accept)) {
            options.cf.image.format = 'webp';
        }

        const imageURL = url.searchParams.get("image")
        if (!imageURL) return new Response('Missing "image" value', { status: 400 })

        try {

            const { hostname, pathname } = new URL(imageURL)

            if (!/\.(jpe?g|png|gif|webp)$/i.test(pathname)) {
                return new Response('Disallowed file extension', { status: 400 })
            }

            if (hostname !== 'example.com') {
                return new Response('Must use "example.com" source images', { status: 403 })
            }
        } catch (err) {
            return new Response('Invalid "image" value', { status: 400 })
        }

        const imageRequest = new Request(imageURL, {
            headers: this.userRequest.headers
        })

        fetch(imageRequest, options)
    }
}