(in-package #:chatikbot)

(defparameter +yahoo-url+ "https://query.yahooapis.com/v1/public/yql" "Yahoo Finance API endpoint")
(defparameter +yahoo-query+ "select Name,Rate from yahoo.finance.xchange where pair in (~{\"~A\"~^,~})")

(defparameter +brent-url+ "http://www.cmegroup.com/CmeWS/mvc/Quotes/Future/424/G")

(defvar *rate-pairs* '("USDRUB" "EURRUB" "GBPRUB"))

(defun get-rates (&optional (pairs *rate-pairs*))
  (let ((response (json-request
                   +yahoo-url+
                   :parameters (append '(("format" . "json")
                                         ("env" . "store://datatables.org/alltableswithkeys"))
                                       (list (cons "q" (format nil +yahoo-query+ pairs)))))))
    (when (aget "error" response)
      (error "Error in rates request"))
    (loop for rate in (aget "rate" (aget "results" (aget "query" response)))
       collect (cons (aget "Name" rate)
                     (read-from-string (aget "Rate" rate))))))

(defun get-brent ()
  (handler-case
      (let ((last (read-from-string
                   (aget "last" (first (aget "quotes" (json-request  +brent-url+)))))))
        (when (numberp last)
          last))
    (error (e) (log:error e))))

(defun get-serie (series name)
  (sort (loop for (time . rates) in series
           when (numberp (aget name rates))
           collect (list time (aget name rates)))
        #'> :key #'car))

(defun make-chart (series &key (usd t) (eur t) (gbp t) (brent t))
  (let ((flat (remove-if #'null (if (alexandria:circular-list-p series)
                                     (flat-circular series)
                                     series))))
    (adw-charting:with-line-chart (1200 900)
      (when usd (adw-charting:add-series "USD/RUB" (get-serie flat "USD/RUB")))
      (when eur (adw-charting:add-series "EUR/RUB" (get-serie flat "EUR/RUB")))
      (when gbp (adw-charting:add-series "GBP/RUB" (get-serie flat "GBP/RUB")))
      (when brent (adw-charting:add-series "Brent last day futures"
                                           (get-serie flat "Brent")))
      (adw-charting:set-axis
       :x "Time" :draw-gridlines-p t
       :label-formatter #'(lambda (v) (local-time:format-timestring nil (local-time:unix-to-timestamp v)
                                                               :format '((:hour 2) ":" (:min 2)))))
      (adw-charting:set-axis :y "RUB" :draw-gridlines-p t :label-formatter "~,2F")
      (adw-charting:save-file "chart.png"))))