(defvar servall-endpoint "localhost:5555")
(defvar servall-client-buffer-name "*servall-client*")

(defun servall-api-wikipedia-search (query)
  (servall-url-fetch-json
   (concat servall-endpoint "/wikipedia/search/" query)))

(defun servall-api-ytdl-search (query cb)
  (servall-url-fetch-json-async
   (concat servall-endpoint "/ytdl/search/" query) cb))

(defun servall-api-wikipedia-org (name)
  (servall-url-fetch-json
   (concat servall-endpoint "/wikipedia/org/" name)))

(defun servall-api-wikipedia-summary (name)
  (servall-url-fetch-json
   (concat servall-endpoint "/wikipedia/summary/" name)))

(defun servall-parse-http-header (text)
  (let ((status) (fields))
    (with-temp-buffer
      (insert text)
      (goto-char (point-min))
      (re-search-forward "^HTTP.*\\([0-9]\\{3\\}\\).*$")
      (setq status (match-string 1))
      (while (re-search-forward "^\\(.*?\\): \\(.*\\)$" nil t)
        (push (cons (intern (match-string 1)) (match-string 2)) fields)))
    (list (cons 'status status) (cons 'fields fields))))

(defun servall-url-fetch-json (url &optional decompression with-header)
  (with-current-buffer (get-buffer-create servall-client-buffer-name)
    (goto-char (point-max))
    (insert "[" (current-time-string) "] Request: " url "\n"))
  (with-current-buffer (url-retrieve-synchronously url t)
    (servall-url-fetch-json-callback nil nil decompression with-header)))

(defun servall-url-fetch-json-async (url cb &optional decompression with-header)
  (with-current-buffer (get-buffer-create servall-client-buffer-name)
    (goto-char (point-max))
    (insert "[" (current-time-string) "] Request: " url "\n"))
  (url-retrieve url 'servall-url-fetch-json-callback
                (list cb decompression with-header) t))

(defun servall-url-fetch-json-callback (unused cb decompression with-header)
  (let ((header) (status) (fields) (json) (result))
    (delete-http-header)
    (setq header (servall-parse-http-header (car kill-ring))
          status (alist-get 'status header)
          fields (alist-get 'fields header))
    (with-current-buffer servall-client-buffer-name
      (insert "[" (current-time-string) "] Response: " status "\n"))
    (when decompression
      (call-process-region (point) (point-max) "gunzip" t t t)
      (goto-char (point-min)))
    (call-interactively 'delete-trailing-whitespace)
    (if (string= status "200")
        (unless (= (point) (point-max))
          (setq json (json-read-from-string
                      (decode-coding-string
                       (buffer-string) 'utf-8)))
          (setq result
                (if with-header
                    (list
                     (cons 'header fields)
                     (cons 'json json))
                  json)))
      (error "HTTP error: %s" (buffer-substring (point) (point-max))))
    (if cb (funcall cb result)
      result)))

(provide 'servall-client)