(in-package :cl-tty.dialog)

(defvar *dialog-stack* nil
  "Stack of active dialogs. (list) of dialog instances.")

(defvar *toasts* nil
  "List of active toast notifications.")

(defclass dialog ()
  ((title :initarg :title :accessor dialog-title)
   (size :initarg :size :initform :medium :accessor dialog-size)
   (content :initarg :content :initform nil :accessor dialog-content)
   (on-dismiss :initarg :on-dismiss :initform nil :accessor dialog-on-dismiss)))

(defun dialog-size-pixels (size &optional (max-w 80) (max-h 24))
  (multiple-value-bind (dw dh)
      (case size
        (:small (values 40 8))
        (:medium (values 60 16))
        (:large (values 88 24))
        (t (values 60 16)))
    (values (min dw max-w) (min dh max-h))))

(defun render-dialog (dialog screen w h)
  (multiple-value-bind (dw dh) (dialog-size-pixels (dialog-size dialog) w h)
    (let ((x (floor (- w dw) 2))
          (y (floor (- h dh) 2)))
      ;; Backdrop — dim the full screen
      (dotimes (row h)
        (draw-rect screen 0 row w 1 :bg :bright-black))
      ;; Dialog panel
      (draw-border screen x y dw dh :style :single :title (dialog-title dialog))
      (when (dialog-content dialog)
        ;; Content rendering delegated to component system
        (draw-text screen (1+ x) (1+ y)
                   (format nil "~a" (dialog-content dialog))
                   :white :default)))))

(defun push-dialog (dialog)
  (push dialog *dialog-stack*)
  dialog)

(defun pop-dialog ()
  (when *dialog-stack*
    (let ((dialog (pop *dialog-stack*)))
      (when (dialog-on-dismiss dialog)
        (funcall (dialog-on-dismiss dialog)))
      dialog)))

(defun alert-dialog (title message)
  (make-instance 'dialog
    :title title
    :size :small
    :content (make-instance 'select
               :options (list (list :title "OK" :value :ok))
               :on-select (lambda (opt) (declare (ignore opt)) (pop-dialog)))
    :on-dismiss (lambda () (pop-dialog))))

(defun confirm-dialog (title message &key on-yes on-no)
  (make-instance 'dialog
    :title title
    :size :small
    :content (make-instance 'select
               :options (list (list :title "Yes" :value :yes)
                              (list :title "No" :value :no))
               :on-select (lambda (opt)
                            (pop-dialog)
                            (if (eql opt :yes)
                                (when on-yes (funcall on-yes))
                                (when on-no (funcall on-no)))))))

(defun select-dialog (title options &key on-select)
  (make-instance 'dialog
    :title title
    :size :medium
    :content (make-instance 'select
               :options options
               :on-select (lambda (opt)
                            (pop-dialog)
                            (when on-select (funcall on-select opt))))))

(defun prompt-dialog (title &key on-submit)
  (make-instance 'dialog
    :title title
    :size :small
    :content (make-instance 'text-input
               :on-submit (lambda (value)
                            (pop-dialog)
                            (when on-submit (funcall on-submit value))))))

(defclass toast ()
  ((message :initarg :message :accessor toast-message)
   (variant :initarg :variant :initform :info :accessor toast-variant)))

(defun render-toast (toast screen w)
  (let* ((msg (toast-message toast))
         (variant (toast-variant toast))
         (color (case variant
                  (:info :blue) (:success :green)
                  (:warning :yellow) (:error :red)))
         (max-w (min 60 (1- w)))
         (x (- w max-w 1))
         (text (if (> (length msg) (- max-w 2))
                   (concatenate 'string (subseq msg 0 (- max-w 5)) "...")
                   msg)))
    (draw-rect screen x 0 max-w 1 :bg color)
    (draw-text screen (1+ x) 0 text :white color :bold t)))

(defun toast (message &key (variant :info) (duration 0))
  (let ((toast (make-instance 'toast :message message :variant variant)))
    (push toast *toasts*)
    (when (plusp duration) (dismiss-toast toast))
    toast))

(defun dismiss-toast (toast)
  (setf *toasts* (remove toast *toasts*)))