// Must stay first: see setup.ts.
import { TEST_DIR } from "./setup.ts";

import { stub } from "@std/testing/mock";
import { app } from "../main.ts";
import { db } from "../db/connection.ts";
import { createJWT, createMediaToken, hashPassword } from "../lib/jwt.ts";
import { makeSlug } from "../lib/slugify.ts";
import { canonicalizeUrl } from "../lib/canonical-url.ts";
import { clearRichContentCache } from "../services/rich-content-service.ts";
import { clearImageCache } from "../remote/image-proxy.ts";
import type { APIError, APIResponse } from "../../shared/api.ts";
import type { Role } from "../../shared/user.ts";

export { app, db, TEST_DIR };

// ── Database ─────────────────────────────────────────────────────────────────

const TABLES = [
  "dump_backlinks",
  "dump_categories",
  "playlist_dumps",
  "comment_likes",
  "comments",
  "votes",
  "follows",
  "notifications",
  "password_reset_tokens",
  "invites",
  "attachments",
  "chat_messages",
  "categories",
  "playlists",
  "dumps",
  "users",
];

/** Empties every table, the default admin included. */
export function resetDb(): void {
  db.exec("PRAGMA foreign_keys = OFF;");
  for (const table of TABLES) db.exec(`DELETE FROM ${table};`);
  db.exec("PRAGMA foreign_keys = ON;");
}

/**
 * Wraps a test body so it starts from an empty database. Usernames and emails
 * still have to be unique across the whole run where the rate limiter keys on
 * them (login, password reset), since its buckets live for the process.
 */
export function test(
  name: string,
  fn: (t: Deno.TestContext) => void | Promise<void>,
  options: Omit<Deno.TestDefinition, "name" | "fn"> = {},
): void {
  Deno.test({
    name,
    ...options,
    async fn(t) {
      resetDb();
      await fn(t);
    },
  });
}

// ── Users ────────────────────────────────────────────────────────────────────

export const PASSWORD = "correct-horse";
// scrypt is deliberately slow; hash the shared password once.
let passwordHash: Promise<string> | undefined;

let seq = 0;
/** A name no other test in this process has used. */
export function uniqueName(prefix = "user"): string {
  return `${prefix}_${++seq}_${crypto.randomUUID().slice(0, 6)}`;
}

export interface TestUser {
  id: string;
  username: string;
  email: string;
  role: Role;
  token: string;
  mediaToken: string;
  /** Authorization header for this user. */
  auth: { Authorization: string };
}

export async function createUser(
  opts: {
    username?: string;
    role?: Role;
    email?: string;
    invitedBy?: string;
    createdAt?: string;
  } = {},
): Promise<TestUser> {
  const id = crypto.randomUUID();
  const username = opts.username ?? uniqueName();
  const email = opts.email ?? `${username}@example.test`;
  const role = opts.role ?? "user";
  passwordHash ??= hashPassword(PASSWORD);
  db.prepare(
    `INSERT INTO users (id, username, password_hash, role, created_at, email, invited_by)
     VALUES (?, ?, ?, ?, ?, ?, ?);`,
  ).run(
    id,
    username,
    await passwordHash,
    role,
    opts.createdAt ?? new Date().toISOString(),
    email,
    opts.invitedBy ?? null,
  );
  const token = await createJWT({ userId: id, username, role });
  return {
    id,
    username,
    email,
    role,
    token,
    mediaToken: await createMediaToken(id),
    auth: { Authorization: `Bearer ${token}` },
  };
}

// ── Content ──────────────────────────────────────────────────────────────────

export interface InsertDumpOptions {
  userId: string;
  title?: string;
  kind?: "url" | "file";
  url?: string;
  comment?: string;
  isPrivate?: boolean;
  createdAt?: string;
  fileName?: string;
  fileMime?: string;
  /** Bytes written to the uploads directory for a file dump. */
  fileData?: Uint8Array;
  richContent?: Record<string, unknown>;
}

/**
 * Inserts a dump row directly, skipping the metadata fetch the create route
 * does. Returns its id and slug.
 */
export function insertDump(
  opts: InsertDumpOptions,
): { id: string; slug: string } {
  const id = crypto.randomUUID();
  const title = opts.title ?? "A dump";
  const slug = makeSlug(title, id);
  const kind = opts.kind ?? (opts.fileName ? "file" : "url");
  const url = kind === "url" ? (opts.url ?? `https://example.com/${id}`) : null;
  const data = opts.fileData ?? new TextEncoder().encode("hello");
  db.prepare(
    `INSERT INTO dumps (id, kind, title, slug, comment, user_id, created_at, url, url_canonical,
       rich_content, file_name, file_mime, file_size, is_private)
     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);`,
  ).run(
    id,
    kind,
    title,
    slug,
    opts.comment ?? null,
    opts.userId,
    opts.createdAt ?? new Date().toISOString(),
    url,
    url ? canonicalizeUrl(url) : null,
    opts.richContent ? JSON.stringify(opts.richContent) : null,
    kind === "file" ? (opts.fileName ?? "file.txt") : null,
    kind === "file" ? (opts.fileMime ?? "text/plain") : null,
    kind === "file" ? data.byteLength : null,
    opts.isPrivate ? 1 : 0,
  );
  if (kind === "file") {
    Deno.mkdirSync(`${TEST_DIR}/uploads/dumps`, { recursive: true });
    Deno.writeFileSync(`${TEST_DIR}/uploads/dumps/${id}`, data);
  }
  return { id, slug };
}

export function insertPlaylist(
  opts: { userId: string; title?: string; isPublic?: boolean },
): { id: string; slug: string } {
  const id = crypto.randomUUID();
  const title = opts.title ?? "A playlist";
  const slug = makeSlug(title, id);
  db.prepare(
    `INSERT INTO playlists (id, user_id, title, slug, is_public, created_at)
     VALUES (?, ?, ?, ?, ?, ?);`,
  ).run(
    id,
    opts.userId,
    title,
    slug,
    opts.isPublic === false ? 0 : 1,
    new Date().toISOString(),
  );
  return { id, slug };
}

export function insertComment(
  opts: {
    dumpId: string;
    userId: string;
    body?: string;
    parentId?: string;
    createdAt?: string;
  },
): string {
  const id = crypto.randomUUID();
  db.prepare(
    `INSERT INTO comments (id, dump_id, user_id, parent_id, body, created_at)
     VALUES (?, ?, ?, ?, ?, ?);`,
  ).run(
    id,
    opts.dumpId,
    opts.userId,
    opts.parentId ?? null,
    opts.body ?? "A comment",
    opts.createdAt ?? new Date().toISOString(),
  );
  return id;
}

export function insertCategory(
  opts: { slug: string; name?: string; position?: number },
): string {
  const id = crypto.randomUUID();
  db.prepare(
    `INSERT INTO categories (id, slug, name, position, created_at) VALUES (?, ?, ?, ?, ?);`,
  ).run(
    id,
    opts.slug,
    opts.name ?? opts.slug,
    opts.position ?? 0,
    new Date().toISOString(),
  );
  return id;
}

export function count(sql: string, ...params: (string | number)[]): number {
  return (db.prepare(sql).get(...params) as { n: number }).n;
}

// ── HTTP ─────────────────────────────────────────────────────────────────────

export const BASE_URL = "http://gerbeur.test";

export interface ApiResponse<T = unknown> {
  status: number;
  headers: Headers;
  /** The parsed body when it's JSON, null otherwise. */
  body: APIResponse<T> | null;
  bytes: Uint8Array;
  /** The body's `data`; throws if the request didn't succeed. */
  readonly data: T;
  /** The body's `error`; throws if the request didn't fail. */
  readonly error: APIError;
}

type RequestOptions = {
  auth?: { Authorization: string };
  json?: unknown;
  form?: FormData;
  headers?: Record<string, string>;
};

/**
 * Sends a request through the full middleware stack in-process — no socket.
 * `json` sends a JSON body, `form` a multipart one. `T` is what the endpoint
 * answers with in `data`.
 */
export async function request<T = unknown>(
  method: string,
  path: string,
  opts: RequestOptions = {},
): Promise<ApiResponse<T>> {
  const headers = new Headers({ ...opts.auth, ...opts.headers });
  let body: BodyInit | undefined;
  if (opts.json !== undefined) {
    headers.set("Content-Type", "application/json");
    body = JSON.stringify(opts.json);
  } else if (opts.form) {
    body = opts.form;
  }
  const res = await app.handle(
    new Request(`${BASE_URL}${path}`, { method, headers, body }),
  );
  if (!res) throw new Error(`No response for ${method} ${path}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  const text = new TextDecoder().decode(bytes);
  let parsed: APIResponse<T> | null = null;
  if ((res.headers.get("content-type") ?? "").includes("json") && text) {
    parsed = JSON.parse(text);
  }
  const what = `${method} ${path} (${res.status})`;
  return {
    status: res.status,
    headers: res.headers,
    body: parsed,
    bytes,
    get data() {
      if (!parsed?.success) {
        throw new Error(`${what} failed: ${parsed?.error.message ?? text}`);
      }
      return parsed.data;
    },
    get error() {
      if (parsed?.success !== false) {
        throw new Error(`${what} didn't fail`);
      }
      return parsed.error;
    },
  };
}

export const get = <T = unknown>(path: string, opts?: RequestOptions) =>
  request<T>("GET", path, opts);
export const post = <T = unknown>(path: string, opts?: RequestOptions) =>
  request<T>("POST", path, opts);
export const put = <T = unknown>(path: string, opts?: RequestOptions) =>
  request<T>("PUT", path, opts);
export const patch = <T = unknown>(path: string, opts?: RequestOptions) =>
  request<T>("PATCH", path, opts);
export const del = <T = unknown>(path: string, opts?: RequestOptions) =>
  request<T>("DELETE", path, opts);

// ── Files ────────────────────────────────────────────────────────────────────

/** Smallest valid PNG: a 1×1 transparent pixel. */
export const PNG: Uint8Array<ArrayBuffer> = Uint8Array.from(
  atob(
    "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==",
  ),
  (c) => c.charCodeAt(0),
);

export function formWithFile(
  bytes: Uint8Array<ArrayBuffer>,
  name = "file.png",
  type = "image/png",
  fields: Record<string, string> = {},
): FormData {
  const form = new FormData();
  form.set("file", new File([bytes], name, { type }));
  for (const [key, value] of Object.entries(fields)) form.set(key, value);
  return form;
}

// ── Network ──────────────────────────────────────────────────────────────────

/**
 * Replaces outbound fetches and DNS for the life of the returned handle
 * (`using net = stubNetwork(...)`). Every hostname resolves to a public
 * address unless `dns` says otherwise; `handler` answers every fetch.
 */
export function stubNetwork(
  handler: (url: URL, init?: RequestInit) => Response | Promise<Response>,
  dns: Record<string, string[]> = {},
): { calls: URL[] } & Disposable {
  const calls: URL[] = [];
  // A new network: metadata cached from the last one no longer describes it.
  clearRichContentCache();
  clearImageCache();
  const fetchStub = stub(
    globalThis,
    "fetch",
    (input: string | URL | Request, init?: RequestInit) => {
      const url = new URL(input instanceof Request ? input.url : input);
      calls.push(url);
      return Promise.resolve(handler(url, init));
    },
  );
  const dnsStub = stub(
    Deno,
    "resolveDns",
    ((host: string, type: string) =>
      Promise.resolve(
        dns[host] ?? (type === "A" ? ["93.184.216.34"] : []),
      )) as typeof Deno.resolveDns,
  );
  return {
    calls,
    [Symbol.dispose]() {
      fetchStub.restore();
      dnsStub.restore();
    },
  };
}

export function html(body: string, status = 200): Response {
  return new Response(body, {
    status,
    headers: { "content-type": "text/html; charset=utf-8" },
  });
}