(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))))

(defparameter +btc-e-usd-url+ "https://btc-e.com/api/2/btc_usd/ticker" "BTC-e BTC/USD ticker url")
(defun get-btc-e ()
  (handler-case
      (aget "last" (aget "ticker" (json-request +btc-e-usd-url+)))
    (error (e) (log:error e))))

(defun get-serie (series idx)
  (loop for row in series
     when (elt row idx)
     collect (list (first row) (elt row idx))))

(defun range (seq &key (key 'identity))
  (loop
     for item in seq
     for value = (funcall key item)
     minimizing value into min
     maximizing value into max
     finally (return (values min max))))

(defvar *chart-points* 800 "Data points in chart")

(defun make-chart (series names)
  (let* ((r (multiple-value-list (range series :key #'car)))
         (fmt (if (<= (- (second r) (first r))
                      (* 60 60 36))
                  '((:hour 2) ":" (:min 2))
                  '((:day 2) "." (:month 2) " " (:hour 2) ":" (:min 2)))))
    (adw-charting:with-line-chart ((+ 90 *chart-points*)
                                   (floor (* 3 *chart-points*) 4))
      (loop for serie in names
         for idx from 1
         do (adw-charting:add-series serie (get-serie series idx)))
      (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 fmt)))
      (adw-charting:set-axis :y "RUB" :draw-gridlines-p t :label-formatter "~,2F")
      (adw-charting:save-file "chart.png"))))