st2.lisp

(in-package :cl-user)

;;(ql:quickload '(:dexador :plump))

(defpackage :stocks
  (:use :cl)
  (:import-from :dexador)
  (:import-from :plump))

(in-package :stocks)

(defvar *cookie-jar* (cl-cookie:make-cookie-jar))

(defparameter ENDPOINT "https://finance.yahoo.com/quote")
(defparameter USER-AGENT "curl/7.88.1")

(defun build-url (base path)
  (concatenate 'string base "/" path "/"))

(defun stock-url (ticker)
  (build-url ENDPOINT ticker))

(defun price-tag? (elem ticker)
  (and (typep elem 'plump-dom:element)
       (string= "fin-streamer" (plump-dom:tag-name elem))
       (string= "regularMarketPrice" (plump-dom:attribute elem "data-field"))
       (string= ticker (plump-dom:attribute elem "data-symbol"))))

(defun scrape (body ticker)
  (print body)
  (let ((html (plump:parse body))
        (price nil))
    (plump:traverse
     html
     (lambda (e)
       (setf price (plump-dom:attribute e "data-value")))
     :test (lambda (elem) (price-tag? elem ticker)))
    (when price
      (read-from-string price))))

(defun fetch (url)
  (let ((retry-request (dex:retry-request 3 :interval 2)))
    (handler-bind ((dex:http-request-failed retry-request))
      (dex:get url
            ;;:cookie-jar *cookie-jar*
            :headers    `(("User-Agent" . ,USER-AGENT)
                          ("Accept"     . "*/*"))
            :verbose t))))

(defun price (ticker)
  (handler-case
      (scrape (fetch (stock-url ticker)) ticker)
    (dex:http-request-failed (e)
      (format *error-output*
              "Error: ~D for ticker: ~s"
              (dex:response-status e)
              ticker))))