(defpackage :cl-tty-framebuffer-test
  (:use :cl :fiveam :cl-tty.rendering :cl-tty.backend))
(in-package :cl-tty-framebuffer-test)

(def-suite framebuffer-suite :description "Framebuffer rendering pipeline tests")
(in-suite framebuffer-suite)

(test make-framebuffer-creates-correct-size
  (let ((fb (make-framebuffer 80 24)))
    (is (= 24 (framebuffer-height fb)))
    (is (= 80 (framebuffer-width fb)))))

(test cell-defaults-are-space
  (let ((cell (aref (make-framebuffer 10 10) 0 0)))
    (is (eql #\space (cell-char cell)))
    (is (null (cell-fg cell)))
    (is (null (cell-bg cell)))))

(test draw-text-on-fb-sets-cells
  (let ((fb (make-framebuffer-backend)))
    (draw-text fb 2 3 "abc" :red nil)
    (let ((cells (fb-framebuffer fb)))
      (is (eql #\a (cell-char (aref cells 3 2))))
      (is (eql #\b (cell-char (aref cells 3 3))))
      (is (eql #\c (cell-char (aref cells 3 4))))
      (is (eql :red (cell-fg (aref cells 3 2)))))))

(test draw-text-clips-at-bounds
  (let ((fb (make-framebuffer-backend :width 10 :height 5)))
    (draw-text fb 8 2 "hello" nil nil)
    (let ((cells (fb-framebuffer fb)))
      (is (eql #\h (cell-char (aref cells 2 8))))
      (is (eql #\e (cell-char (aref cells 2 9))))
      (is (eql #\space (cell-char (aref cells 2 0))) "out of bounds text is ignored"))))

(test diff-identical-fbs-returns-empty
  (let ((fb1 (make-framebuffer 80 24))
        (fb2 (make-framebuffer 80 24)))
    (is (null (diff-framebuffers fb1 fb2)))))

(test diff-changed-fb-returns-changes
  (let* ((fb1 (make-framebuffer 10 10))
         (fb2 (make-framebuffer 10 10)))
    (setf (aref fb2 5 5) (make-cell :char #\X :fg :red))
    (let ((changes (diff-framebuffers fb1 fb2)))
      (is (= 1 (length changes)))
      (destructuring-bind (x y cell) (first changes)
        (is (= 5 x))
        (is (= 5 y))
        (is (eql #\X (cell-char cell)))))))

(test with-scissor-clips-drawing
  (let ((fb (make-framebuffer-backend :width 20 :height 10)))
    (with-scissor (fb 5 5 3 3)
      (draw-text fb 6 6 "ABC" nil nil)
      (draw-text fb 1 1 "OUTSIDE" nil nil))
    (let ((cells (fb-framebuffer fb)))
      (is (eql #\A (cell-char (aref cells 6 6))) "inside scissor draws")
      (is (eql #\space (cell-char (aref cells 1 1))) "outside scissor is clipped"))))

(test flush-fb-copies-to-backend
  (let* ((real-be (make-simple-backend :output-stream (make-string-output-stream)))
         (fb (make-framebuffer-backend)))
    (draw-text fb 0 0 "X" :red nil)
    (let ((changed (flush-framebuffer (make-framebuffer 80 24) (fb-framebuffer fb) real-be)))
      (is (>= changed 1)))))

;; ── Frame inspection ──────────────────────────────────────────

(test fb-cell-link-url-returns-nil-for-blank-cell
  (let ((fb (make-framebuffer 10 10)))
    (is (null (fb-cell-link-url fb 5 5)))))

(test fb-cell-link-url-finds-link-url
  (let ((fb (make-framebuffer-backend)))
    (draw-text fb 0 0 "click" nil nil :link-url "https://example.com")
    (is (equal "https://example.com" (fb-cell-link-url (fb-framebuffer fb) 0 0)))
    (is (null (fb-cell-link-url (fb-framebuffer fb) 5 5)))))

(test fb-cell-link-url-out-of-bounds-returns-nil
  (let ((fb (make-framebuffer 5 5)))
    (is (null (fb-cell-link-url fb 10 10)))))

(test extract-text-single-row
  (let ((fb (make-framebuffer-backend)))
    (draw-text fb 0 0 "hello" nil nil)
    (let ((cells (fb-framebuffer fb)))
      (is (equal "hello" (extract-text cells 0 0 4 0))))))

(test extract-text-multi-row
  (let ((fb (make-framebuffer-backend)))
    (draw-text fb 0 0 "abc" nil nil)
    (draw-text fb 0 1 "def" nil nil)
    (let* ((cells (fb-framebuffer fb))
           (text (extract-text cells 0 0 2 1)))
      (is (equal "abc
def" text)))))