import { describe, expect, test } from "bun:test";
import { createHash } from "node:crypto";
import {
  parseImageReference,
  resolveRegistryDigest,
} from "../../server/registry";

describe("OCI registry digest resolution", () => {
  test("parses tags, ports, defaults, and pinned references", () => {
    expect(parseImageReference("localhost:5000/team/image:v1")).toMatchObject({
      registry: "localhost:5000",
      repository: "team/image",
      reference: "v1",
    });
    expect(
      parseImageReference("registry.example.com/team/image").reference,
    ).toBe("latest");
    const pinned = `sha256:${"a".repeat(64)}` as const;
    expect(
      parseImageReference(`registry.example.com/team/image@${pinned}`).digest,
    ).toBe(pinned);
    expect(() => parseImageReference("image:latest")).toThrow("registry host");
    expect(() =>
      parseImageReference(`registry.example.com/../image@${pinned}`),
    ).toThrow("Invalid image reference");
  });

  test("resolves an anonymous manifest using the advertised digest", async () => {
    const expected = `sha256:${"b".repeat(64)}` as const;
    const calls: Array<{ url: string; authorization: string | null }> = [];
    const fetcher = async (
      input: string | URL | Request,
      init?: RequestInit,
    ) => {
      const headers = new Headers(init?.headers);
      calls.push({
        url: String(input),
        authorization: headers.get("authorization"),
      });
      return new Response("manifest", {
        headers: { "docker-content-digest": expected },
      });
    };
    expect(
      await resolveRegistryDigest("registry.example.com/team/image:v1", {
        fetch: fetcher,
      }),
    ).toBe(expected);
    expect(calls).toEqual([
      {
        url: "https://registry.example.com/v2/team/image/manifests/v1",
        authorization: null,
      },
    ]);
  });

  test("caches successful digest resolutions with deterministic expiry and bounds", async () => {
    let now = 0;
    let calls = 0;
    const fetcher = async () => {
      calls += 1;
      return new Response("manifest", {
        headers: { "docker-content-digest": `sha256:${"d".repeat(64)}` },
      });
    };
    const options = {
      fetch: fetcher,
      cacheTtlMs: 100,
      cacheMaxEntries: 1,
      clock: () => now,
    };

    await resolveRegistryDigest("cache.example.com/team/first:v1", options);
    await resolveRegistryDigest("cache.example.com/team/first:v1", options);
    expect(calls).toBe(1);

    now = 100;
    await resolveRegistryDigest("cache.example.com/team/first:v1", options);
    expect(calls).toBe(2);

    await resolveRegistryDigest("cache.example.com/team/second:v1", options);
    await resolveRegistryDigest("cache.example.com/team/first:v1", options);
    expect(calls).toBe(4);
  });

  test("does not cache failed resolutions or share entries across credentials", async () => {
    let calls = 0;
    const failing = async () => {
      calls += 1;
      return new Response("unavailable", { status: 503 });
    };
    const options = { fetch: failing, cacheTtlMs: 1_000 };
    await expect(
      resolveRegistryDigest("failure.example.com/team/image:v1", options),
    ).rejects.toThrow("503");
    await expect(
      resolveRegistryDigest("failure.example.com/team/image:v1", options),
    ).rejects.toThrow("503");
    expect(calls).toBe(2);

    const authorizedCalls: string[] = [];
    const authorized = async (
      _input: string | URL | Request,
      init?: RequestInit,
    ) => {
      authorizedCalls.push(new Headers(init?.headers).get("authorization")!);
      return new Response("manifest", {
        headers: { "docker-content-digest": `sha256:${"e".repeat(64)}` },
      });
    };
    for (const username of ["one", "two"]) {
      await resolveRegistryDigest("credentials.example.com/team/image:v1", {
        fetch: authorized,
        credentials: { username, password: "password" },
      });
    }
    expect(authorizedCalls).toHaveLength(2);
  });

  test("resolves through a trusted internal registry origin", async () => {
    const expected = `sha256:${"c".repeat(64)}` as const;
    let requested = "";
    await expect(
      resolveRegistryDigest("registry.example.com/team/image:v1", {
        origin: "http://registry.registry.svc.cluster.local:5000/",
        insecure: true,
        fetch: async (input) => {
          requested = String(input);
          return new Response("manifest", {
            headers: { "docker-content-digest": expected },
          });
        },
      }),
    ).resolves.toBe(expected);
    expect(requested).toBe(
      "http://registry.registry.svc.cluster.local:5000/v2/team/image/manifests/v1",
    );
  });

  test("follows a standard bearer challenge and hashes a digest-less response", async () => {
    const body = '{"schemaVersion":2}';
    const expected =
      `sha256:${createHash("sha256").update(body).digest("hex")}` as const;
    const calls: Array<{ url: string; authorization: string | null }> = [];
    const fetcher = async (
      input: string | URL | Request,
      init?: RequestInit,
    ) => {
      const url = String(input);
      const authorization = new Headers(init?.headers).get("authorization");
      calls.push({ url, authorization });
      if (url.startsWith("https://auth.example/token")) {
        expect(new URL(url).searchParams.get("scope")).toBe(
          "repository:team/image:pull",
        );
        expect(authorization).toBe(
          `Basic ${Buffer.from("user:pass").toString("base64")}`,
        );
        return Response.json({ access_token: "registry-token" });
      }
      if (authorization !== "Bearer registry-token") {
        return new Response("unauthorized", {
          status: 401,
          headers: {
            "www-authenticate":
              'Bearer realm="https://auth.example/token",service="registry.example.com"',
          },
        });
      }
      return new Response(body, {
        headers: {
          "content-type": "application/vnd.oci.image.manifest.v1+json",
        },
      });
    };

    expect(
      await resolveRegistryDigest("registry.example.com/team/image:v2", {
        fetch: fetcher,
        credentials: { username: "user", password: "pass" },
      }),
    ).toBe(expected);
    expect(calls).toHaveLength(3);
    expect(calls[2]?.authorization).toBe("Bearer registry-token");
  });

  test("rejects unsupported challenges and malformed advertised digests", async () => {
    const unauthorized = async () =>
      new Response("no", {
        status: 401,
        headers: { "www-authenticate": 'Basic realm="registry"' },
      });
    await expect(
      resolveRegistryDigest("registry.example.com/team/image", {
        fetch: unauthorized,
      }),
    ).rejects.toThrow("401");

    const malformed = async () =>
      new Response("body", {
        headers: { "docker-content-digest": "sha256:bad" },
      });
    await expect(
      resolveRegistryDigest("registry.example.com/team/image", {
        fetch: malformed,
      }),
    ).rejects.toThrow("Invalid SHA-256");
  });
});