import { Application, NextFunction, Request, Response } from 'express';

export type Handle = (req: Request, res: Response, next: NextFunction) => void;
export type Authorize = (privilege: string, action?: number) => Handle;
export type MultiAuthorize<T> = (v: T[], privilege: string, action?: number) => Handle;
export type Authorizes<T> = (v: T[], privilege: string, action?: number) => Handle;
export type Check<T> = (v: T[]) => Handle;
export interface Token {
  secret: string;
  expires: number;
}
export type TokenConfig = Token;
export type TokenConf = Token;
export interface StatusError {
  status: number;
  body: string;
}
export type GetToken<P> = (req: Request, res: Response) => Promise<PayloadToken<P>>;
export interface StringToken {
  token: string;
  error?: string;
}
export interface PayloadToken<P> {
  payload?: P;
  token?: string;
  error?: string;
  end?: boolean;
}
export function handleToken<P>(res: Response, secret: string, name: string, t: StringToken, verify: (token: string, secret: string) => Promise<P>, buildErr: (err: any) => StatusError): Promise<PayloadToken<P>> {
  if (t.error) {
    res.status(401).end(t.error);
    return Promise.resolve({error: t.error, end: true});
  } else {
    return verify(t.token, secret).then(payload => {
      res.locals[name] = payload;
      return Promise.resolve({payload, token: t.token});
    }).catch(err => {
      const { status, body } = buildErr(err);
      res.status(status).end(body);
      return Promise.resolve({token: t.token, error: t.error, end: true});
    });
  }
}
export function fromCookies(req: Request, name: string): StringToken {
  if (!req.cookies) {
    return { token: '', error: `Require cookies`};
  } else {
    const token = req.cookies[name];
    if (!token) {
      return { token: '', error: `Require '${name}' in cookies`};
    } else {
      return { token };
    }
  }
}
export function fromAuthorization(req: Request, prefix: string): StringToken {
  const data = req.headers['authorization'];
    if (data) {
      if (!data.startsWith(prefix)) {
        return { token: '', error: `Authorization must start with '${prefix.trim()}'`};
      } else {
        const token = data.substr(prefix.length);
        return { token };
      }
    } else {
      return { token: '', error: `Require 'Authorization' in header`};
    }
}
export interface TokenHandler<P> {
  getToken(req: Request, res: Response): Promise<PayloadToken<P>>;
}
export class LocalsToken<P> implements TokenHandler<P> {
  token: string;
  constructor(token?: string) {
    this.token = (token ? token : 'token');
    this.getToken = this.getToken.bind(this);
  }
  getToken(req: Request, res: Response): Promise<PayloadToken<P>> {
    const payload = res.locals[this.token];
    return Promise.resolve({ payload });
  }
}
// tslint:disable-next-line:max-classes-per-file
export class CookiesToken<P> implements TokenHandler<P> {
  token: string;
  payload: string;
  buildError: (err: any) => StatusError;
  constructor(public secret: string, public verify: (token: string, secret: string) => Promise<P>, buildErr?: (err: any) => StatusError, payload?: string, token?: string) {
    this.token = (token ? token : 'token');
    this.payload = (payload ? payload : 'token');
    this.buildError = (buildErr ? buildErr : buildError);
    this.getToken = this.getToken.bind(this);
  }
  getToken(req: Request, res: Response): Promise<PayloadToken<P>> {
    const t = fromCookies(req, this.token);
    return handleToken<P>(res, this.secret, this.payload, t, this.verify, this.buildError);
  }
}
// tslint:disable-next-line:max-classes-per-file
export class AuthorizationToken<P> implements TokenHandler<P> {
  prefix: string;
  payload: string;
  buildError: (err: any) => StatusError;
  constructor(public secret: string, public verify: (token: string, secret: string) => Promise<P>, buildErr?: (err: any) => StatusError, payload?: string, prefix?: string) {
    this.prefix = (prefix ? prefix : 'Bearer ');
    this.payload = (payload ? payload : 'token');
    this.buildError = (buildErr ? buildErr : buildError);
    this.getToken = this.getToken.bind(this);
  }
  getToken(req: Request, res: Response): Promise<PayloadToken<P>> {
    const t = fromAuthorization(req, this.prefix);
    return handleToken<P>(res, this.secret, this.payload, t, this.verify, this.buildError);
  }
}
// tslint:disable-next-line:max-classes-per-file
export class TokenService<P> implements TokenHandler<P> {
  prefix: string;
  token: string;
  payload: string;
  buildError: (err: any) => StatusError;
  constructor(public secret: string, public verify: (token: string, secret: string) => Promise<P>, buildErr?: (err: any) => StatusError, payload?: string, token?: string, prefix?: string) {
    this.prefix = (prefix ? prefix : 'Bearer ');
    this.token = (token ? token : 'token');
    this.payload = (payload ? payload : 'token');
    this.buildError = (buildErr ? buildErr : buildError);
    this.getToken = this.getToken.bind(this);
  }
  getToken(req: Request, res: Response): Promise<PayloadToken<P>> {
    let t = fromCookies(req, this.token);
    if (t.error) {
      t = fromAuthorization(req, this.prefix);
    }
    return handleToken<P>(res, this.secret, this.payload, t, this.verify, this.buildError);
  }
}
export function useToken<P>(secret: string, verify: (token: string, secret: string) => Promise<P>, buildErr?: (err: any) => StatusError, cookie?: boolean, payload?: string, token?: string, prefix?: string): GetToken<P> {
  if (cookie === true) {
    return new CookiesToken(secret, verify, buildErr, payload, token).getToken;
  } else if (cookie === false) {
    return new AuthorizationToken(secret, verify, buildErr, payload, prefix).getToken;
  } else {
    return new TokenService(secret, verify, buildErr, payload, token, prefix).getToken;
  }
}
export const getToken = useToken;
// tslint:disable-next-line:max-classes-per-file
export class Handler<P> {
  prefix: string;
  token: string;
  payload: string;
  constructor(public secret: string, public verify: (token: string, secret: string) => Promise<P>, prefix?: string, token?: string, payload?: string) {
    this.prefix = (prefix ? prefix : 'Bearer ');
    this.token = (token ? token : 'token');
    this.payload = (payload ? payload : 'token');
    this.handle = this.handle.bind(this);
  }
  handle(): (req: Request, res: Response, next: NextFunction) => void {
    return (req: Request, res: Response, next: NextFunction) => {
      let t = fromCookies(req, this.token);
      if (t.error) {
        t = fromAuthorization(req, this.prefix);
      }
      if (t.error) {
        next();
      } else {
        this.verify(t.token, this.secret).then(payload => {
          res.locals[this.payload] = payload;
          next();
        }).catch(err => {
          next();
        });
      }
    };
  }
}
export const AuthorizationHandler = Handler;
// tslint:disable-next-line:max-classes-per-file
export class AuthorizationChecker<P> {
  getToken: GetToken<P>;
  constructor(gt: GetToken<P>) {
    this.getToken = gt;
    this.check = this.check.bind(this);
    this.require = this.require.bind(this);
  }
  require(): Handle {
    return (req: Request, res: Response, next: NextFunction) => {
      this.getToken(req, res).then(t => {
        if (!t.end) {
          next();
        }
      });
    };
  }
  check(): Handle {
    return this.require();
  }
}
export function exist<T>(obj: T | T[], arr: T[]): boolean {
  if (Array.isArray(obj)) {
    for (const o of obj) {
      for (const v of arr) {
        // tslint:disable-next-line:triple-equals
        if (o == v) {
          return true;
        }
      }
    }
  } else {
    for (const v of arr) {
      // tslint:disable-next-line:triple-equals
      if (obj == v) {
        return true;
      }
    }
  }
  return false;
}
// tslint:disable-next-line:max-classes-per-file
export class Checker<T, P> {
  key: string;
  getToken: GetToken<P>;
  constructor(gt: GetToken<P>, key?: string) {
    this.getToken = gt;
    this.key = (key ? key : 'id');
    this.check = this.check.bind(this);
  }
  check(v: T[]): Handle {
    return (req: Request, res: Response, next: NextFunction) => {
      this.getToken(req, res).then(t => {
        if (!t.end) {
          if (t.payload) {
            const obj = (t.payload as any)[this.key];
            if (!obj) {
              res.status(403).end('Payload must contain ' + this.key);
            } else {
              if (exist<T>(obj as any, v)) {
                next();
              } else {
                res.status(403).end('invalid ' + this.key);
              }
            }
          } else {
            res.status(403).end('Payload cannot be undefined');
          }
        }
      });
    };
  }
}
// tslint:disable-next-line:max-classes-per-file
export class MultiAuthorizer<T, P> {
  user: string;
  key: string;
  exact: boolean;
  getToken: GetToken<P>;
  buildError: (err: any) => StatusError;
  constructor(gt: GetToken<P>, public privilege: (userId: string, privilegeId: string) => Promise<number>, buildErr?: (err: any) => StatusError, key?: string, user?: string, exact?: boolean) {
    this.getToken = gt;
    this.buildError = (buildErr ? buildErr : buildError);
    this.user = (user ? user : 'id');
    this.key = (key ? key : 'userType');
    this.exact = (exact !== undefined ? exact : true);
    this.authorize = this.authorize.bind(this);
  }
  authorize(v: T[], privilege: string, action?: number): Handle {
    return (req: Request, res: Response, next: NextFunction) => {
      this.getToken(req, res).then(t => {
        if (!t.end) {
          if (t.payload) {
            const obj = (t.payload as any)[this.key];
            if (!obj) {
              res.status(403).end('Payload must contain ' + this.key);
            } else {
              if (exist<T>(obj as any, v)) {
                const userId = (t.payload as any)[this.user];
                if (!userId) {
                  res.status(403).end('Payload must contain ' + this.user);
                } else {
                  this.privilege(userId, privilege).then(p => {
                    if (p === none) {
                      res.status(403).end('no permission for ' + userId);
                    } else {
                      if (!action) {
                        next();
                      } else {
                        if (this.exact) {
                          // tslint:disable-next-line:no-bitwise
                          const sum = action & p;
                          if (sum === action) {
                            return next();
                          } else {
                            res.status(403).end('no permission');
                          }
                        } else {
                          if (p >= action) {
                            return next();
                          } else {
                            res.status(403).end('no permission');
                          }
                        }
                      }
                    }
                  }).catch(err => {
                    const { status, body } = this.buildError(err);
                    res.status(status).end(body);
                  });
                }
              } else {
                res.status(403).end('invalid ' + this.key);
              }
            }
          } else {
            res.status(401).end('Payload cannot be undefined');
          }
        }
      });
    };
  }
}
// tslint:disable-next-line:max-classes-per-file
export class Authorizer<P> {
  key: string;
  exact: boolean;
  getToken: GetToken<P>;
  buildError: (err: any) => StatusError;
  constructor(gt: GetToken<P>, public privilege: (userId: string, privilegeId: string) => Promise<number>, buildErr?: (err: any) => StatusError, exact?: boolean, key?: string) {
    this.getToken = gt;
    this.buildError = (buildErr ? buildErr : buildError);
    this.key = (key ? key : 'id');
    this.exact = (exact !== undefined ? exact : true);
    this.authorize = this.authorize.bind(this);
  }
  authorize(privilege: string, action?: number): Handle {
    return (req: Request, res: Response, next: NextFunction) => {
      this.getToken(req, res).then(t => {
        if (!t.end) {
          const payload = t.payload;
          if (payload === undefined) {
            res.status(401).end('Payload cannot be undefined');
          } else {
            const userId = (payload as any)[this.key];
            if (!userId) {
              res.status(403).end('Payload must contain ' + this.key);
            } else {
              this.privilege(userId, privilege).then(p => {
                if (p === none) {
                  res.status(403).end('no permission for ' + userId);
                } else {
                  if (!action) {
                    next();
                  } else {
                    if (this.exact) {
                      // tslint:disable-next-line:no-bitwise
                      const sum = action & p;
                      if (sum === action) {
                        return next();
                      } else {
                        res.status(403).end('no permission');
                      }
                    } else {
                      if (p >= action) {
                        return next();
                      } else {
                        res.status(403).end('no permission');
                      }
                    }
                  }
                }
              }).catch(err => {
                const { status, body } = this.buildError(err);
                res.status(status).end(body);
              });
            }
          }
        }
      });
    };
  }
}
export const none = 0;
export const read = 1;
export const write = 2;
export const approve = 4;
export const all = 2147483647;
// tslint:disable-next-line:max-classes-per-file
export class PrivilegeLoader {
  constructor(public sql: string, public query: <T>(sql: string, args?: any[]) => Promise<T[]>) {
    this.privilege = this.privilege.bind(this);
  }
  privilege(userId: string, privilegeId: string): Promise<number> {
    return this.query<any>(this.sql, [userId, privilegeId]).then(v => {
      if (!v || v.length === 0) {
        return none;
      }
      const keys = Object.keys(v[0]);
      if (keys.length === 0) {
        return all;
      }
      const k: string = keys[0];
      let permissions = 0;
      let ok = false;
      for (const p of v) {
        const x = p[k];
        if (typeof x === 'number') {
          // tslint:disable-next-line:no-bitwise
          permissions = permissions | x;
          ok = true;
        }
      }
      return (ok ? permissions : all);
    });
  }
}
export function buildError(err: any): StatusError {
  return { status: 401, body: 'Invalid token: ' + toString(err) };
}
export function toString(err: any): string {
  return (typeof err === 'string' ? err : JSON.stringify(err));
}

export function get(app: Application, path: string, authorize: Handle, handle: Handle, secure?: boolean): void {
  if (secure) {
    app.get(path, authorize, handle);
  } else {
    app.get(path, handle);
  }
}
export function post(app: Application, path: string, authorize: Handle, handle: Handle, secure?: boolean): void {
  if (secure) {
    app.post(path, authorize, handle);
  } else {
    app.post(path, handle);
  }
}
export function put(app: Application, path: string, authorize: Handle, handle: Handle, secure?: boolean): void {
  if (secure) {
    app.put(path, authorize, handle);
  } else {
    app.put(path, handle);
  }
}
export function patch(app: Application, path: string, authorize: Handle, handle: Handle, secure?: boolean): void {
  if (secure) {
    app.patch(path, authorize, handle);
  } else {
    app.patch(path, handle);
  }
}
export function del(app: Application, path: string, authorize: Handle, handle: Handle, secure?: boolean): void {
  if (secure) {
    app.delete(path, authorize, handle);
  } else {
    app.delete(path, handle);
  }
}