import { notAuthenticated } from '@roleypoly/api/utils/responses';
import {
  evaluatePermission,
  permissions as Permissions,
} from '@roleypoly/misc-utils/hasPermission';
import { SessionData, UserGuildPermissions } from '@roleypoly/types';
import { Handler, WrappedKVNamespace } from '@roleypoly/worker-utils';
import KSUID from 'ksuid';
import {
  allowedCallbackHosts,
  apiPublicURI,
  interactionsSharedKey,
  rootUsers,
} from './config';
import { Sessions } from './kv';

export const formData = (obj: Record<string, any>): string => {
  return Object.keys(obj)
    .map((key) => `${encodeURIComponent(key)}=${encodeURIComponent(obj[key])}`)
    .join('&');
};

export const respond = (obj: Record<string, any>, init: ResponseInit = {}) =>
  new Response(JSON.stringify(obj), init);

export const resolveFailures =
  (
    handleWith: () => Response,
    handler: (request: Request) => Promise<Response> | Response
  ) =>
  async (request: Request): Promise<Response> => {
    try {
      return handler(request);
    } catch (e) {
      console.error(e);
      return handleWith() || respond({ error: 'internal server error' }, { status: 500 });
    }
  };

export const parsePermissions = (
  permissions: bigint,
  owner: boolean = false
): UserGuildPermissions => {
  if (owner || evaluatePermission(permissions, Permissions.ADMINISTRATOR)) {
    return UserGuildPermissions.Admin;
  }

  if (evaluatePermission(permissions, Permissions.MANAGE_ROLES)) {
    return UserGuildPermissions.Manager;
  }

  return UserGuildPermissions.User;
};

export const getSessionID = (request: Request): { type: string; id: string } | null => {
  const sessionID = request.headers.get('authorization');
  if (!sessionID) {
    return null;
  }

  const [type, id] = sessionID.split(' ');
  if (type !== 'Bearer') {
    return null;
  }

  return { type, id };
};

export type CacheLayerOptions = {
  skipCachePull?: boolean;
};

export const cacheLayer =
  <Identity, Data>(
    kv: WrappedKVNamespace,
    keyFactory: (identity: Identity) => string,
    missHandler: (identity: Identity) => Promise<Data | null>,
    ttlSeconds?: number
  ) =>
  async (identity: Identity, options: CacheLayerOptions = {}): Promise<Data | null> => {
    const key = keyFactory(identity);

    if (!options.skipCachePull) {
      const value = await kv.get<Data>(key);
      if (value) {
        return value;
      }
    }

    const fallbackValue = await missHandler(identity);
    if (!fallbackValue) {
      return null;
    }

    await kv.put(key, fallbackValue, ttlSeconds);

    return fallbackValue;
  };

const NotAuthenticated = (extra?: string) =>
  respond(
    {
      error: extra || 'not authenticated',
    },
    { status: 403 }
  );

export const withSession =
  (wrappedHandler: (session: SessionData) => Handler): Handler =>
  async (request: Request): Promise<Response> => {
    const sessionID = getSessionID(request);
    if (!sessionID) {
      return NotAuthenticated('missing authentication');
    }

    const session = await Sessions.get<SessionData>(sessionID.id);
    if (!session) {
      return NotAuthenticated('authentication expired or not found');
    }

    return await wrappedHandler(session)(request);
  };

export const setupStateSession = async <T>(data: T): Promise<string> => {
  const stateID = (await KSUID.random()).string;

  await Sessions.put(`state_${stateID}`, { data }, 60 * 5);

  return stateID;
};

export const getStateSession = async <T>(stateID: string): Promise<T | undefined> => {
  const stateSession = await Sessions.get<{ data: T }>(`state_${stateID}`);

  return stateSession?.data;
};

export const isRoot = (userID: string): boolean => rootUsers.includes(userID);

export const onlyRootUsers = (handler: Handler): Handler =>
  withSession((session) => (request: Request) => {
    if (isRoot(session.user.id)) {
      return handler(request);
    }

    return respond(
      {
        error: 'not_found',
      },
      {
        status: 404,
      }
    );
  });

export const isAllowedCallbackHost = (host: string): boolean => {
  return (
    host === apiPublicURI ||
    allowedCallbackHosts.includes(host) ||
    allowedCallbackHosts
      .filter((callbackHost) => callbackHost.includes('*'))
      .find((wildcard) => new RegExp(wildcard.replace('*', '[a-z0-9-]+')).test(host)) !==
      null
  );
};

export const interactionsEndpoint =
  (handler: Handler): Handler =>
  async (request: Request): Promise<Response> => {
    const authHeader = request.headers.get('authorization') || '';
    if (authHeader !== `Shared ${interactionsSharedKey}`) {
      return notAuthenticated();
    }

    return handler(request);
  };