import { cookies } from "next/headers";
import { redirect } from "next/navigation";

import { getEnv } from "@/lib/env";
import { createOpaqueToken, createStableId, sha256 } from "@/lib/password";
import {
  createAdminSessionRecord,
  createUserSessionRecord,
  deleteAdminSessionByHash,
  deleteUserSessionByHash,
  getAdminSessionByHash,
  getUserSessionByHash,
  touchAdminSession,
  touchUserSession,
} from "@/lib/store";

const ADMIN_COOKIE_NAME = "hy2_panel_admin_session";
const USER_COOKIE_NAME = "hy2_panel_user_session";

function shouldUseSecureCookies() {
  const env = getEnv();

  if (env.SESSION_COOKIE_SECURE === "true") {
    return true;
  }

  if (env.SESSION_COOKIE_SECURE === "false") {
    return false;
  }

  return new URL(env.APP_URL).protocol === "https:";
}

export async function createAdminSession(adminId: number) {
  const env = getEnv();
  const token = createOpaqueToken(32);
  const expiresAt = new Date(
    Date.now() + env.SESSION_TTL_HOURS * 60 * 60 * 1000,
  ).toISOString();

  await createAdminSessionRecord({
    id: createStableId(),
    adminId,
    sessionHash: sha256(`${env.SESSION_SECRET}:${token}`),
    expiresAt,
  });

  const cookieStore = await cookies();
  cookieStore.set(ADMIN_COOKIE_NAME, token, {
    httpOnly: true,
    sameSite: "lax",
    secure: shouldUseSecureCookies(),
    path: "/",
    expires: new Date(expiresAt),
  });
}

export async function createUserSession(userId: number) {
  const env = getEnv();
  const token = createOpaqueToken(32);
  const expiresAt = new Date(
    Date.now() + env.SESSION_TTL_HOURS * 60 * 60 * 1000,
  ).toISOString();

  await createUserSessionRecord({
    id: createStableId(),
    userId,
    sessionHash: sha256(`${env.SESSION_SECRET}:${token}`),
    expiresAt,
  });

  const cookieStore = await cookies();
  cookieStore.set(USER_COOKIE_NAME, token, {
    httpOnly: true,
    sameSite: "lax",
    secure: shouldUseSecureCookies(),
    path: "/",
    expires: new Date(expiresAt),
  });
}

export async function destroyAdminSession() {
  const cookieStore = await cookies();
  const raw = cookieStore.get(ADMIN_COOKIE_NAME)?.value;

  if (raw) {
    await deleteAdminSessionByHash(sha256(`${getEnv().SESSION_SECRET}:${raw}`));
  }

  cookieStore.delete(ADMIN_COOKIE_NAME);
}

export async function destroyUserSession() {
  const cookieStore = await cookies();
  const raw = cookieStore.get(USER_COOKIE_NAME)?.value;

  if (raw) {
    await deleteUserSessionByHash(sha256(`${getEnv().SESSION_SECRET}:${raw}`));
  }

  cookieStore.delete(USER_COOKIE_NAME);
}

export async function getAdminSession() {
  const raw = (await cookies()).get(ADMIN_COOKIE_NAME)?.value;
  if (!raw) return null;

  const session = await getAdminSessionByHash(
    sha256(`${getEnv().SESSION_SECRET}:${raw}`),
  );

  if (!session) {
    return null;
  }

  if (new Date(session.expires_at).getTime() <= Date.now()) {
    await deleteAdminSessionByHash(sha256(`${getEnv().SESSION_SECRET}:${raw}`));
    return null;
  }

  if (Date.now() - new Date(session.last_seen_at).getTime() > 5 * 60 * 1000) {
    await touchAdminSession(session.id);
  }

  return session;
}

export async function getUserSession() {
  const raw = (await cookies()).get(USER_COOKIE_NAME)?.value;
  if (!raw) return null;

  const session = await getUserSessionByHash(
    sha256(`${getEnv().SESSION_SECRET}:${raw}`),
  );

  if (!session) {
    return null;
  }

  if (new Date(session.expires_at).getTime() <= Date.now()) {
    await deleteUserSessionByHash(sha256(`${getEnv().SESSION_SECRET}:${raw}`));
    return null;
  }

  if (Date.now() - new Date(session.last_seen_at).getTime() > 5 * 60 * 1000) {
    await touchUserSession(session.id);
  }

  return session;
}

export async function requireAdminSession() {
  const session = await getAdminSession();
  if (!session) {
    redirect("/login");
  }

  return session;
}

export async function requireAdminAccess() {
  const adminSession = await getAdminSession();
  if (adminSession) {
    return {
      username: adminSession.username,
      source: "admin" as const,
    };
  }

  const userSession = await getUserSession();
  if (userSession?.is_admin) {
    return {
      username: userSession.username,
      source: "user" as const,
    };
  }

  redirect("/login");
}

export async function requireUserSession() {
  const session = await getUserSession();
  if (!session) {
    redirect("/login");
  }

  return session;
}