tweak(flymake): patch modeline to look project-wide

config.org

@@ -1920,15 +1920,55 @@ Flymake normally uses italics for warnings, but my italics font being cursive ma
 
 #+begin_src emacs-lisp
 (custom-set-faces!
-  '(compilation-warning :slant normal :weight bold)
-  '(flymake-note-echo :underline nil :inherit compilation-info))
+  '(compilation-warning :slant unspecified :weight bold)
+  '(flymake-note-echo :inherit compilation-info))
 #+end_src
 
-And just to make sure nothing else accidentally starts running:
+**** Tooltips
 
-#+begin_src emacs-lisp :tangle packages.el
-(package! flycheck :disable t)
-(package! flyspell :disable t)
+Having an IDE-style tooltip pop up is nice, but ~flymake-popon~ is a bit ugly by default.
+
+#+begin_src emacs-lisp
+(after! flymake-popon
+  ; Widen popon
+  (setq flymake-popon-width 120)
+  ; Add visible border
+  (set-face-foreground 'flymake-popon-posframe-border (doom-color 'selection)))
+#+end_src
+
+*** Modeline
+
+In order to obtain as much information as possible about the current state of the program, I like to use Flymake's tools for project-wide diagnostics, rather than the default buffer-specific ones. Unfortunately, Doom's modeline segment for Flymake doesn't support this, so we'll have to patch it in.
+
+#+begin_src emacs-lisp
+(defpatch! doom-modeline-segments
+    (defun doom-modeline--flymake-count-errors) ()
+  "Count the number of ERRORS, grouped by level."
+  ((el-patch-swap let let*)
+   ((el-patch-add
+      (project (project-current))
+      (root (project-root project))
+      (states (--keep
+               (and (buffer-file-name it)
+                    (buffer-local-value 'flymake--state it))
+               (project-buffers project))))
+    (warning-level (warning-numeric-level :warning))
+    (note-level (warning-numeric-level :debug))
+    (note 0) (warning 0) (error 0))
+   (el-patch-wrap 2
+     (dolist (st states)
+       (maphash (lambda (_b state)
+                  (cl-loop
+                   with diags = (flymake--state-diags state)
+                   for diag in diags do
+                   (let ((severity (flymake--lookup-type-property
+                                    (flymake--diag-type diag) 'severity
+                                    (warning-numeric-level :error))))
+                     (cond ((> severity warning-level) (cl-incf error))
+                           ((> severity note-level) (cl-incf warning))
+                           (t (cl-incf note))))))
+                (el-patch-swap flymake--state st))))
+   `((note . ,note) (warning . ,warning) (error . ,error))))
 #+end_src
 
 *** Bindings