import { z } from "zod";

const UNSPLASH_WALLPAPERS_URL =
    "https://api.unsplash.com/topics/wallpapers/photos";

const unsplashPhotoSchema = z
    .object({
        id: z.string(),
        slug: z.string().nullish(),
        description: z.string().nullish(),
        alt_description: z.string().nullish(),
        width: z.number().int().nullish(),
        height: z.number().int().nullish(),
        color: z.string().nullish(),
        blur_hash: z.string().nullish(),
        likes: z.number().int().nullish(),
        created_at: z.string().nullish(),
        updated_at: z.string().nullish(),
        urls: z.record(z.string(), z.unknown()).nullish(),
        links: z.record(z.string(), z.unknown()).nullish(),
        user: z.record(z.string(), z.unknown()).nullish(),
    })
    .passthrough();

export type UnsplashPhoto = z.infer<typeof unsplashPhotoSchema>;

export async function fetchUnsplashWallpaperPhotos({
    page,
    perPage,
}: {
    page: number;
    perPage: number;
}) {
    const accessKey = process.env.UNSPLASH_ACCESS_KEY;

    if (!accessKey) {
        throw new Error("UNSPLASH_ACCESS_KEY is not configured.");
    }

    const url = new URL(UNSPLASH_WALLPAPERS_URL);
    url.searchParams.set("page", String(page));
    url.searchParams.set("per_page", String(perPage));

    const response = await fetch(url, {
        headers: {
            accept: "application/json",
            authorization: `Client-ID ${accessKey}`,
            "user-agent": "WalloraGallerySync/1.0",
        },
        cache: "no-store",
    });

    const contentType = response.headers.get("content-type") ?? "";
    if (!response.ok) {
        throw new Error(`Unsplash API request failed with ${response.status}.`);
    }

    if (!contentType.includes("application/json")) {
        throw new Error(
            `Unsplash returned non-JSON content: ${contentType || "unknown"}.`,
        );
    }

    const payload = await response.json();
    const parsed = z.array(unsplashPhotoSchema).safeParse(payload);

    if (!parsed.success) {
        throw new Error("Unsplash response did not match the expected array.");
    }

    return parsed.data;
}