import { davError } from "@/worker/dav/http";
import { maxDavDepthInfinityNodes } from "@/worker/dav/limits";
import { parentHref } from "@/worker/dav/paths";
import { davHtmlListingResponse, type DavListingEntry } from "@/worker/dav/html-listing";
import type { SubjectRow } from "@/worker/db/d1/schema";
import type { FileDavNodeView } from "@/worker/objects/file-dav-object";
import { getFileBlob } from "@/worker/r2/blobs";
import type { AppContext } from "@/worker/types";
import { fileDavObject, resultError, type NormalizedFilesRequestPath } from "@/worker/webdav/object";
import { httpDate } from "@/worker/webdav/props";

function fileListingName(node: { name: string }, href: string): string {
  if (href === "/files/") return "Files";
  return node.name || href;
}

function fileListingEntries(nodes: FileDavNodeView[]) {
  return nodes.slice(1).map((entry): DavListingEntry => {
    const isCollection = entry.node.kind === "collection";
    return {
      href: entry.href,
      name: fileListingName(entry.node, entry.href),
      kind: isCollection ? "collection" : "file",
      size: isCollection ? null : entry.node.size,
      modifiedAtMs: entry.node.modifiedAtMs,
    };
  });
}

async function handleCollectionGetHead(c: AppContext, subject: SubjectRow, path: NormalizedFilesRequestPath) {
  const result = await fileDavObject(c.env, subject.storageId).propfind({
    subjectId: subject.id,
    storageId: subject.storageId,
    path: path.path,
    depth: "1",
    maxNodes: maxDavDepthInfinityNodes(c.env),
    nowMs: Date.now(),
  });
  if (!result.ok) return resultError(result);
  const target = result.nodes[0];
  if (!target || target.node.kind !== "collection") return davError(405, "Resource is not a collection");
  return await davHtmlListingResponse(
    c,
    {
      title: fileListingName(target.node, target.href),
      href: target.href,
      parentHref: path.path.segments.length === 0 ? "/" : parentHref(path.path),
      entries: fileListingEntries(result.nodes),
    },
    c.req.method,
  );
}

export async function handleGetHead(c: AppContext, subject: SubjectRow, path: NormalizedFilesRequestPath) {
  const result = await fileDavObject(c.env, subject.storageId).resolveFile({
    subjectId: subject.id,
    storageId: subject.storageId,
    path: path.path,
    ifMatch: c.req.header("if-match") ?? null,
    ifNoneMatch: c.req.header("if-none-match") ?? null,
    nowMs: Date.now(),
  });
  if (!result.ok && result.status === 405 && result.code === "method_not_allowed") {
    return await handleCollectionGetHead(c, subject, path);
  }
  if (!result.ok) return resultError(result);
  const object = result.blob ? await getFileBlob(c.env.FILE_BLOBS, result.blob.blobKey) : null;
  if (result.blob && !object) return davError(404, "Blob not found");
  const headers = new Headers({
    "Content-Length": String(result.node.size),
    "Content-Type": result.node.contentType ?? object?.httpMetadata?.contentType ?? "application/octet-stream",
    "Last-Modified": httpDate(result.node.modifiedAtMs),
  });
  if (result.node.etag) headers.set("ETag", result.node.etag);
  if (c.req.method === "HEAD") return new Response(null, { status: 200, headers });
  return new Response(object?.body ?? null, { status: 200, headers });
}