From ddd9bf0b2907082eeab68851af4f6344c9456724 Mon Sep 17 00:00:00 2001
From: Dimitri Lozeve <dimitri@lozeve.com>
Date: Sat, 10 Sep 2022 21:06:37 +0200
Subject: [PATCH] Add progress bars

---
 build.ss          |  1 +
 demo.ss           |  6 ++++++
 fancy/progress.ss | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 fancy/progress.ss

diff --git a/build.ss b/build.ss
index 0b6399f..c814c94 100755
--- a/build.ss
+++ b/build.ss
@@ -6,5 +6,6 @@
   '("fancy/format"
     "fancy/table"
     "fancy/rule"
+    "fancy/progress"
     "fancy/spinner")
   optimize: #t debug: 'src)
diff --git a/demo.ss b/demo.ss
index 7a228d2..8f8a507 100755
--- a/demo.ss
+++ b/demo.ss
@@ -8,6 +8,7 @@
 	:dlozeve/fancy/format
 	:dlozeve/fancy/table
 	:dlozeve/fancy/rule
+	:dlozeve/fancy/progress
 	:dlozeve/fancy/spinner)
 
 (def (main)
@@ -30,6 +31,11 @@ culpa qui officia deserunt mollit anim id est laborum."))
   (display (table-footer tab))
   (displayln)
   (displayln)
+  (def pbar (progress-bar 100 "[green]Progress: " percent: #f style: 'line))
+  (for ((i (in-range 100)))
+    (display (progress pbar (1+ i)))
+    (thread-sleep! 0.05))
+  (displayln)
   (for ((i (in-range 20)))
     (display (spinner i "[yellow]Waiting:" (format "(computing ~d/20)" (1+ i))
 		      style: 'dots))
diff --git a/fancy/progress.ss b/fancy/progress.ss
new file mode 100644
index 0000000..576db8f
--- /dev/null
+++ b/fancy/progress.ss
@@ -0,0 +1,39 @@
+(export (struct-out progress-bar)
+	progress)
+
+(import :std/misc/string
+	:std/format
+	:dlozeve/fancy/format)
+
+(def +progress-styles+
+  '((ascii  . (#\[ #\= #\> #\  #\]))
+    (line   . (#\┝ #\━ #\━ #\  #\┥))
+    (double . (#\╞ #\═ #\═ #\  #\╡))
+    (block  . (#\│ #\█ #\█ #\ #\│))
+    (halfblock . (#\╻ #\▄ #\▄ #\ #\╻))
+    (dots   . (#\⣿ #\⠶ #\⠶ #\⠀ #\⣿))))
+
+(defstruct progress-bar (total description length style percent)
+  constructor: :init!)
+
+(defmethod {:init! progress-bar}
+  (lambda (self total (description #f) length: (length 80) style: (style 'line) percent: (percent #f))
+    (struct-instance-init! self total description length style percent)))
+
+(def (progress pbar n)
+  (with ((progress-bar total description length style percent) pbar)
+    (let* ((n (min total (max 0 n)))
+	   (n-done (inexact->exact (floor (* (- length 3) (/ n total)))))
+	   (n-remaining (inexact->exact (ceiling (* (- length 3) (/ (- total n) total)))))
+	   (progress-chars (assgetq style +progress-styles+))
+	   (bar (format "~c~a~c~a~c"
+			(list-ref progress-chars 0)
+			(make-string n-done (list-ref progress-chars 1))
+			(list-ref progress-chars 2)
+			(make-string n-remaining (list-ref progress-chars 3))
+			(list-ref progress-chars 4)))
+	   (progress (if percent
+		       (format "~3,0F%" (* 100 (/ n total)))
+		       (format "(~d/~d)"  n total))))
+      (str (cursor-up 1)
+	   (parse-markup description) bar " " progress "\n"))))