(defgroup ollama-complete nil "Ollama Code Completion." :group 'completion)

(require 'plz)

(defcustom ollama-complete-host "http://localhost:11434"
  "URL of local ollama service."
  :type 'url)

(defcustom ollama-complete-model "qwen2.5-coder:3b-instruct-q4_K_M"
  "Model to use for Fill-in-Middle completion.")

(defvar ollama-complete--options
  '(("temperature" . 0) ("top_p" . 0.5) ("num_predict" . 30)))

(defvar ollama-complete--overlay nil)

(defvar ollama-complete--overlay-buffer nil
    "Buffer in which the overlay is placed.")

(defun ollama-complete--fill-in-middle ()
  "Ask ollama to generate response for fill-in-middle prompt."
  (interactive)
  (let ((prompt
         (concat
          "<|fim_prefix|>"
          (concat
           (buffer-substring-no-properties (point-min) (point))
           (concat
            "<|fim_suffix|>"
            (concat
             (buffer-substring-no-properties (point) (point-max))
             "<|fim_middle|>"))))))
    (setq ollama-complete--overlay-buffer (current-buffer))
    (message "overlay-buffer: %s" ollama-complete--overlay-buffer)
    (plz 'post
      (concat ollama-complete-host "/api/generate")
      :body (json-encode `(("model" . "qwen2.5-coder:3b-instruct-q4_K_M")
                           ("raw" . t)
                           ("stream" . :json-false)
                           ("options" . ,ollama-complete--options)
                           ("prompt" . ,prompt)
                           ))
      :as #'json-read
      :then (lambda (alist)
              (message "Ollama: FIM Completion: %s" (alist-get 'response alist))
              (ollama-complete--make-overlay (alist-get 'response alist))))
    )
  )

(defun ollama-complete--make-overlay (string)
  "make overlay showign STRING at POS, or move existing overlay there."
  (interactive)
  (if ollama-complete--overlay-buffer
      (with-current-buffer ollama-complete--overlay-buffer
        (message "make-overlay %d \"%s\" %s" (point) string ollama-complete--overlay-buffer)
        (if ollama-complete--overlay
            (move-overlay ollama-complete--overlay (point) (point) ollama-complete--overlay-buffer)
          (setq ollama-complete--overlay (make-overlay (point) (point) ollama-complete--overlay-buffer))
          (overlay-put ollama-complete--overlay 'window (selected-window))
          (overlay-put ollama-complete--overlay
                       'after-string (propertize string 'face 'font-lock-comment-face))
          (add-text-properties 0 1 '(cursor 1) string)
          ollama-complete--overlay)))
  )

(defun ollama-complete--hide-overlay ()
  "Hide temporary completion candidate overlay."
  (interactive)
  (when ollama-complete--overlay
    (delete-overlay ollama-complete--overlay)
    (setq ollama-complete--overlay nil)
    (setq ollama-complete--overlay-buffer nil))
  )

(defun ollama-complete--insert-completion ()
  "Hide temporary completion candidate overlay."
  (interactive)
  (when ollama-complete--overlay
    (let ((completion (overlay-get ollama-complete--overlay 'after-string)))
      (set-text-properties 0 (length completion) nil completion)
        (goto-char (overlay-start ollama-complete--overlay))
        (insert (substring-no-properties completion)))
    (ollama-complete--hide-overlay)))

(provide 'ollama-complete)