import { client } from "$lib/server/nextcloud";
import { error } from "@sveltejs/kit";
import type { RequestHandler } from "./$types";
import mime from "mime-types";
import { env } from "$env/dynamic/private";

export const GET: RequestHandler = async ({ params, url }) => {
    const { path } = params;
    const width = url.searchParams.get("w");
    const height = url.searchParams.get("h");
    
    if (!path) {
        throw error(400, "Path is required");
    }

    try {
        let buffer: ArrayBuffer;
        let contentType: string;

        // Try both original path and hidden variant if applicable
        const pathsToTry = [path];
        if (!path.startsWith('_')) {
            pathsToTry.push(`_${path}`);
        }

        let response: Response | null = null;
        let lastError: any = null;

        for (const currentPath of pathsToTry) {
            try {
                if (width || height) {
                    // Use Nextcloud Preview API
                    const baseUrl = env.NEXTCLOUD_URL?.endsWith("/") ? env.NEXTCLOUD_URL : `${env.NEXTCLOUD_URL}/`;
                    
                    let fullPath = currentPath;
                    if (env.NEXTCLOUD_BASE_DIR) {
                        const baseDir = env.NEXTCLOUD_BASE_DIR.replace(/^\/+|\/+$/g, "");
                        fullPath = baseDir ? `${baseDir}/${currentPath}` : currentPath;
                    }

                    const isJpg = fullPath.match(/\.(jpg|jpeg)$/i);
                    const previewExtension = isJpg ? 'jpg' : 'png';
                    const previewUrl = new URL(`${baseUrl}index.php/core/preview.${previewExtension}`);
                    // Ensure leading slash for the file parameter
                    const fileParam = fullPath.startsWith('/') ? fullPath : `/${fullPath}`;
                    previewUrl.searchParams.set("file", fileParam);
                    if (width) previewUrl.searchParams.set("x", width);
                    if (height) previewUrl.searchParams.set("y", height);
                    previewUrl.searchParams.set("forceIcon", "0");

                    const auth = Buffer.from(`${env.NEXTCLOUD_USER}:${env.NEXTCLOUD_PASSWORD}`).toString("base64");
                    
                    console.log(`Fetching preview: ${previewUrl.toString()} for file: ${fullPath}`);

                    const ncResponse = await fetch(previewUrl.toString(), {
                        headers: {
                            "Authorization": `Basic ${auth}`
                        }
                    });

                    if (ncResponse.ok) {
                        buffer = await ncResponse.arrayBuffer();
                        contentType = ncResponse.headers.get("Content-Type") || "image/png";
                        
                        return new Response(buffer, {
                            headers: {
                                "Content-Type": contentType,
                                "Cache-Control": "public, max-age=86400",
                                "Vary": "Accept-Encoding"
                            }
                        });
                    } else {
                        console.warn(`Nextcloud preview failed (${ncResponse.status}) for ${fullPath}.`);
                    }
                }

                // Fetch original via WebDAV (Fallback or no resize requested)
                console.log(`Fetching original file via WebDAV: /${currentPath}`);
                const data = await client.getFileContents("/" + currentPath);
                buffer = data as ArrayBuffer;
                contentType = mime.lookup(currentPath) || "application/octet-stream";
                
                return new Response(buffer, {
                    headers: {
                        "Content-Type": contentType,
                        "Cache-Control": "public, max-age=86400",
                        "Vary": "Accept-Encoding"
                    }
                });
            } catch (e) {
                lastError = e;
                continue; // Try next path variant
            }
        }
        
        throw lastError || new Error("Asset not found");
    } catch (e) {
        console.error(`Error fetching asset from Nextcloud: ${path}`, e);
        throw error(404, "Asset not found");
    }
};