;;; dev-fkeys.el --- Developer F-key dispatchers -*- lexical-binding: t -*-

;;; Commentary:
;; Project-aware F-key block for developer workflows:
;;
;;   F4    completing-read of compile/run candidates filtered by project type
;;   C-F4  fast path: compile only (no-op on interpreted projects)
;;   M-F4  fast path: clean + rebuild (no-op on interpreted projects)
;;   S-F4  recompile (built-in)
;;   F6    completing-read of test candidates: All tests / Current file's tests
;;   C-F6  fast path: current file's tests
;;
;; F4 project-type detection runs against the projectile root and falls back
;; to \\='unknown when no marker matches. Interpreted markers are checked
;; before compiled markers, so a Python or Node project that also has a
;; Makefile for tasks classifies as interpreted.
;;
;; F6 \"All tests\" delegates to `projectile-test-project'. F6 \"Current
;; file's tests\" detects the language by extension, derives the runner
;; command (elisp via the project Makefile, Python via pytest, Go via the
;; package), and pipes through `compile' from the projectile root.
;; TypeScript / JavaScript are detected but punted for v1 — the function
;; signals a user-error rather than guessing a runner.
;;
;; M-F6 is reserved for Phase 2b (\"Run a test...\" menu entry with
;; per-language test-name discovery). Phase 2b also adds buffer-local
;; last-test memory and tree-sitter-based discovery for Python / Go /
;; TypeScript. The tree-sitter discovery uses a capture-then-filter pattern
;; (queries without `:match' / `:equal' / `:pred' predicates, with the
;; pattern filter applied in Elisp) to sidestep Emacs bug #79687 — Emacs
;; 30.2 emits unsuffixed `#match' predicates that libtree-sitter 0.26
;; rejects. The fix lives on Emacs master (commit b0143530) and is
;; targeted at Emacs 31; it has not been backported to the emacs-30
;; branch as of 2026-05-03. See Mike Olson's writeup at
;; https://mwolson.org/blog/emacs/2026-04-20-fixing-typescript-ts-mode-in-emacs-30-2/
;; for the same workaround applied to font-lock.
;;
;; F7 (coverage) is wired in coverage-core.el. F5 is reserved for the debug
;; ticket and intentionally left unbound here.

;;; Code:

(require 'cl-lib)

(declare-function projectile-compile-project "projectile" (arg))
(declare-function projectile-run-project "projectile" (arg))
(declare-function projectile-project-root "projectile" (&optional dir))
(declare-function projectile-test-project "projectile" (arg))
(declare-function recompile "compile" (&optional edit-command))

;; ---------- Project root ----------

(defun cj/--f4-project-root ()
  "Return projectile project root, or nil. Never errors.
Some projectile configurations signal an error when called outside a
known project; this wrapper degrades to nil so the F4 dispatcher routes
to the \\='unknown branch instead of crashing."
  (when (fboundp 'projectile-project-root)
    (condition-case nil
        (projectile-project-root)
      (error nil))))

;; ---------- Project-type detection ----------

(defconst cj/--f4-interpreted-markers
  '("pyproject.toml" "requirements.txt" "Pipfile" "package.json")
  "Markers that classify a project as interpreted (Run-only menu).")

(defconst cj/--f4-compiled-markers
  '("go.mod" "Cargo.toml" "CMakeLists.txt" "Makefile" "Eask")
  "Markers that classify a project as compiled (full Compile/Run/Clean menu).")

(defun cj/--f4-any-marker-p (root markers)
  "Return non-nil if any of MARKERS exists at ROOT."
  (cl-some (lambda (m) (file-exists-p (expand-file-name m root))) markers))

(defun cj/--detect-project-type (root)
  "Classify project at ROOT as \\='compiled, \\='interpreted, or \\='unknown.
Interpreted markers are checked before compiled markers, so a Python or
Node project that also has a Makefile for tasks classifies as interpreted.
Returns \\='unknown when ROOT is nil or no marker matches."
  (cond
   ((not root) 'unknown)
   ((cj/--f4-any-marker-p root cj/--f4-interpreted-markers) 'interpreted)
   ((cj/--f4-any-marker-p root cj/--f4-compiled-markers) 'compiled)
   (t 'unknown)))

;; ---------- Clean command derivation ----------

(defun cj/--f4-derive-clean-cmd (root)
  "Pick a clean shell command for the project at ROOT, or nil.
First marker matched wins. ROOT may be nil; nil and a path with no
recognized markers both return nil."
  (when root
    (cond
     ((file-exists-p (expand-file-name "go.mod" root))         "go clean ./...")
     ((file-exists-p (expand-file-name "Cargo.toml" root))     "cargo clean")
     ((file-exists-p (expand-file-name "Eask" root))           "eask clean")
     ((file-exists-p (expand-file-name "Makefile" root))       "make clean")
     ((file-exists-p (expand-file-name "CMakeLists.txt" root)) "cmake --build build --target clean"))))

;; ---------- Action handlers ----------

(defun cj/--f4-compile-and-run-impl ()
  "Run `projectile-compile-project', then `projectile-run-project' on success.
Installs a one-shot `compilation-finish-functions' hook to chain the run."
  (add-hook 'compilation-finish-functions
            (cj/--f4-make-once-hook
             (lambda () (projectile-run-project nil))))
  (projectile-compile-project nil))

(defun cj/--f4-dispatch (action)
  "Route ACTION (a symbol from `cj/--f4-candidates') to its handler.
Signals `user-error' on an unrecognized symbol or nil."
  (pcase action
    ('compile-only    (projectile-compile-project current-prefix-arg))
    ('run-only        (projectile-run-project current-prefix-arg))
    ('compile-and-run (cj/--f4-compile-and-run-impl))
    ('clean-rebuild   (cj/--f4-clean-rebuild-impl (cj/--f4-project-root)))
    ('compile-plain   (call-interactively #'compile))
    (_ (user-error "Unknown F4 action: %s" action))))

(defun cj/--f4-clean-rebuild-impl (root)
  "Run the heuristic clean for project at ROOT, then rebuild on success.
Signals `user-error' when no clean command can be derived. The rebuild
side reuses `projectile-compile-project' so the per-project compile
command (prompted-and-cached by projectile) drives the build."
  (let ((clean-cmd (cj/--f4-derive-clean-cmd root)))
    (unless clean-cmd
      (user-error "Clean + Rebuild: no clean command for this project type"))
    (add-hook 'compilation-finish-functions
              (cj/--f4-make-once-hook
               (lambda () (projectile-compile-project nil))))
    (let ((default-directory root))
      (compile clean-cmd))))

;; ---------- One-shot compilation-finish hook ----------

(defun cj/--f4-make-once-hook (then-fn)
  "Build a one-shot `compilation-finish-functions' hook that chains THEN-FN.
The returned lambda removes itself from `compilation-finish-functions' on
first invocation regardless of status, then calls THEN-FN only if the
status string starts with \"finished\" (the convention used by compile.el
for a successful compile)."
  (let (hook)
    (setq hook
          (lambda (_buf status)
            (remove-hook 'compilation-finish-functions hook)
            (when (and (stringp status)
                       (string-prefix-p "finished" status))
              (funcall then-fn))))
    hook))

;; ---------- Candidate menus ----------

(defun cj/--f4-candidates (project-type)
  "Return alist of (LABEL . ACTION) for the F4 menu given PROJECT-TYPE.
The first entry is the default, selected on RET in completing-read.
Compiled projects get the full menu, interpreted projects get Run only,
anything else (including nil and unrecognized symbols) falls through to
a single Compile entry that calls plain `compile'."
  (pcase project-type
    ('compiled    '(("Compile + Run"   . compile-and-run)
                    ("Compile"         . compile-only)
                    ("Run"             . run-only)
                    ("Clean + Rebuild" . clean-rebuild)))
    ('interpreted '(("Run"             . run-only)))
    (_            '(("Compile"         . compile-plain)))))

;; ---------- Projectile cache revert on failure ----------
;;
;; Without this, a one-off typo at projectile's prompt poisons the per-
;; project cmd cache: every subsequent invocation pre-fills the broken
;; value. The capture/finish-hook pair installed by `:around' advice on
;; the three projectile cmd-runners reverts the cache to its prior value
;; if the compile fails AND the cmd was modified. A test that fails
;; because of a real code bug (cmd unchanged) leaves the cache alone.
;; Revert state is captured before Projectile runs, then closed over by a
;; buffer-local compilation finish hook so overlapping compiles cannot
;; overwrite or consume one another's revert metadata.

(defun cj/--projectile-capture-cmd (map-symbol)
  "Capture the cached cmd at the project root in MAP-SYMBOL.
MAP-SYMBOL is the symbol of a projectile cmd-map (e.g.
`projectile-compile-cmd-map'). Return nil when the project root cannot
be resolved or MAP-SYMBOL is unbound (projectile not loaded)."
  (let ((root (cj/--f4-project-root)))
    (when (and root (boundp map-symbol))
      (let ((prior (gethash root (symbol-value map-symbol))))
        (list :map map-symbol :root root :prior prior)))))

(defun cj/--projectile-revert-state-on-fail (state status)
  "Apply projectile cache revert STATE when STATUS is a failed compile.
Reverts the cmd-map entry only when the compile failed AND the cmd was
modified from the captured prior value AND that prior was non-nil. The
unchanged-and-failed case (test fails because of a real bug) leaves the
cache alone."
  (when (and state (stringp status)
             (not (string-prefix-p "finished" status)))
    (let* ((map     (plist-get state :map))
           (root    (plist-get state :root))
           (prior   (plist-get state :prior))
           (current (and (boundp map) (gethash root (symbol-value map)))))
      (when (and root prior (boundp map)
                 (not (equal prior current)))
        (puthash root prior (symbol-value map))))))

(defun cj/--projectile-make-revert-on-fail-hook (state)
  "Return a one-shot buffer-local finish hook for projectile revert STATE."
  (let (hook)
    (setq hook
          (lambda (buf status)
            (when (buffer-live-p buf)
              (with-current-buffer buf
                (remove-hook 'compilation-finish-functions hook t)))
            (cj/--projectile-revert-state-on-fail state status)))
    hook))

(defun cj/--projectile-compilation-buffer (result)
  "Return the compilation buffer represented by RESULT, or nil."
  (cond
   ((bufferp result) result)
   ((processp result) (process-buffer result))
   (t nil)))

(defun cj/--projectile-around-revert (map-symbol orig-fn &rest args)
  "Around-advice for projectile cmd-runners.
MAP-SYMBOL identifies which cmd-map to capture (compile / test / run).
Captures the prior cached cmd, invokes ORIG-FN with ARGS, then installs a
one-shot buffer-local revert-on-failure hook on the returned compilation
buffer when possible."
  (let* ((state (cj/--projectile-capture-cmd map-symbol))
         (result (apply orig-fn args))
         (buffer (cj/--projectile-compilation-buffer result)))
    (when (and state (buffer-live-p buffer))
      (with-current-buffer buffer
        (add-hook 'compilation-finish-functions
                  (cj/--projectile-make-revert-on-fail-hook state)
                  nil t)))
    result))

(defun cj/projectile-reset-cmds ()
  "Clear projectile's cached compile/test/run cmds for the current project.
Use when projectile's auto-detected default was wrong to begin with and
you want to start fresh — the next F4 / F6 invocation will re-derive
projectile's project-type default."
  (interactive)
  (let ((root (cj/--f4-project-root)))
    (unless root
      (user-error "F-keys: no project detected"))
    (dolist (map '(projectile-compile-cmd-map
                   projectile-test-cmd-map
                   projectile-run-cmd-map))
      (when (boundp map)
        (remhash root (symbol-value map))))
    (message "Cleared projectile compile/test/run cache for %s" root)))

;; ---------- F6 language detection ----------

(defconst cj/--f6-extension-language-map
  '(("el"   . elisp)
    ("py"   . python)
    ("go"   . go)
    ("ts"   . typescript)
    ("tsx"  . typescript)
    ("js"   . javascript)
    ("jsx"  . javascript))
  "Map of file-extension string to language symbol.
Used by `cj/--f6-language-detect'.")

(defun cj/--f6-language-detect (filename)
  "Classify FILENAME's language by extension.
Returns one of \\='elisp, \\='python, \\='go, \\='typescript, \\='javascript,
or \\='unknown. Match is case-insensitive. Nil or extensionless input
returns \\='unknown."
  (if (or (null filename) (string-empty-p filename))
      'unknown
    (let ((ext (file-name-extension filename)))
      (or (and ext
               (cdr (assoc (downcase ext) cj/--f6-extension-language-map)))
          'unknown))))

;; ---------- F6 test-file detection ----------

(defun cj/--f6-buffer-is-test-file-p (filename)
  "Return non-nil if FILENAME's basename matches a test-file naming convention.
Per language: elisp basenames start with `test-'; Python basenames start
with `test_' or end with `_test.py'; Go basenames end with `_test.go';
TypeScript / JavaScript basenames contain `.test.' or `.spec.'. Files
whose extension we don't classify return nil even if their name happens
to match a generic pattern."
  (when (and filename (not (string-empty-p filename)))
    (let ((language (cj/--f6-language-detect filename))
          (base (file-name-nondirectory filename)))
      (pcase language
        ('elisp      (string-prefix-p "test-" base))
        ('python     (or (string-prefix-p "test_" base)
                         (string-suffix-p "_test.py" base)))
        ('go         (string-suffix-p "_test.go" base))
        ((or 'typescript 'javascript)
                     (or (string-match-p "\\.test\\." base)
                         (string-match-p "\\.spec\\." base)))
        (_           nil)))))

;; ---------- F6 source-stem extraction ----------

(defun cj/--f6-source-stem (filename)
  "Return the source-module stem from FILENAME, or nil for nil/empty input.
Strips directory, extension, and any test-pattern prefix or suffix.
For elisp test files like `test-foo--bar.el', drops everything from
`--' onward so the result is the source module name (`foo'). Unsupported
languages fall back to the basename without extension."
  (when (and filename (not (string-empty-p filename)))
    (let ((language (cj/--f6-language-detect filename))
          (base (file-name-base filename)))
      (pcase language
        ('elisp
         (let ((stripped (if (string-prefix-p "test-" base)
                             (substring base 5)
                           base)))
           (if (string-match "--" stripped)
               (substring stripped 0 (match-beginning 0))
             stripped)))
        ('python
         (cond
          ((string-prefix-p "test_" base) (substring base 5))
          ((string-suffix-p "_test" base) (substring base 0 -5))
          (t base)))
        ('go
         (if (string-suffix-p "_test" base)
             (substring base 0 -5)
           base))
        (_ base)))))

;; ---------- F6 test-runner command builder ----------

(defconst cj/--f6-shell-safe-argument-regexp "\\`[[:alnum:]_./=+@%:,^-]+\\'"
  "Regexp matching shell arguments safe to interpolate unchanged.")

(defun cj/--f6-shell-quote-argument (argument)
  "Quote ARGUMENT for shell command interpolation when needed.
Simple file paths and test regexes are returned unchanged so existing
F6 command strings stay readable. Arguments containing whitespace or
shell-significant characters are escaped with `shell-quote-argument'."
  (if (string-match-p cj/--f6-shell-safe-argument-regexp argument)
      argument
    (shell-quote-argument argument)))

(defun cj/--f6-test-runner-cmd-for (language is-test-file rel-path stem rel-dir)
  "Return shell command to run tests for the given primitives, or nil.
LANGUAGE is the language symbol; IS-TEST-FILE is non-nil when the file
itself is a test file; REL-PATH and REL-DIR are the path and directory
relative to project root; STEM is the source-module stem.

For elisp test files the command runs only that file via
`make test-file FILE='. For elisp source files it picks up the matching
tests by name regex via `make test-name TEST=^test-<stem>-'. Python
source files map to `pytest tests/test_<stem>.py'; Python test files run
the file directly. Go runs the package containing the file.
TypeScript / JavaScript and unknown languages return nil."
  (pcase language
    ('elisp
     (if is-test-file
         ;; The project Makefile prepends `tests/' to FILE, so pass the
         ;; basename only — passing the rel-path produces `tests/tests/...'.
         (format "make test-file FILE=%s"
                 (cj/--f6-shell-quote-argument
                  (file-name-nondirectory rel-path)))
       (format "make test-name TEST=%s"
               (cj/--f6-shell-quote-argument
                (format "^test-%s-" stem)))))
    ('python
     (if is-test-file
         (format "pytest %s" (cj/--f6-shell-quote-argument rel-path))
       (format "pytest %s"
               (cj/--f6-shell-quote-argument
                (format "tests/test_%s.py" stem)))))
    ('go
     (format "go test %s"
             (cj/--f6-shell-quote-argument
              (if (string-empty-p rel-dir)
                  "./"
                (format "./%s" rel-dir)))))
    (_ nil)))

;; ---------- F6 current-file orchestrator ----------

(defun cj/--f6-current-file-tests-impl (file project-root)
  "Run the tests for FILE within PROJECT-ROOT.
Detects language, derives the runner command via
`cj/--f6-test-runner-cmd-for', and invokes `compile' with
`default-directory' bound to PROJECT-ROOT. Signals `user-error' for nil
inputs or files in languages without a runner."
  (unless file
    (user-error "F6: no file backing this buffer"))
  (unless project-root
    (user-error "F6: no project detected"))
  (let* ((language (cj/--f6-language-detect file))
         (rel-path (file-relative-name file project-root))
         (rel-dir  (file-relative-name (file-name-directory file) project-root))
         (rel-dir  (cond
                    ((string= rel-dir "./") "")
                    ((string-suffix-p "/" rel-dir)
                     (substring rel-dir 0 -1))
                    (t rel-dir)))
         (stem     (cj/--f6-source-stem file))
         (is-test  (cj/--f6-buffer-is-test-file-p file))
         (cmd      (cj/--f6-test-runner-cmd-for
                    language is-test rel-path stem rel-dir)))
    (unless cmd
      (user-error "F6: no test runner for %s files" language))
    (let ((default-directory project-root))
      (compile cmd))))

;; ---------- Interactive wrappers ----------

(defun cj/f4-compile-and-run ()
  "Project-aware F4 dispatcher.
Prompts via `completing-read' with a candidate set filtered by project
type (compiled / interpreted / unknown), then dispatches the chosen
label's action."
  (interactive)
  (let* ((root (cj/--f4-project-root))
         (project-type (cj/--detect-project-type root))
         (candidates (cj/--f4-candidates project-type))
         (default (caar candidates))
         (label (completing-read
                 (format "F4 (%s): " project-type)
                 (mapcar #'car candidates) nil t nil nil default))
         (action (cdr (assoc label candidates))))
    (cj/--f4-dispatch action)))

(defun cj/f4-compile-only ()
  "C-F4 fast path: compile only.
Compiled projects run `projectile-compile-project'. Interpreted projects
get a no-op message. Outside any project, falls back to interactive
`compile'."
  (interactive)
  (let* ((root (cj/--f4-project-root))
         (project-type (cj/--detect-project-type root)))
    (pcase project-type
      ('compiled    (projectile-compile-project current-prefix-arg))
      ('interpreted (message "C-F4: not a compiled language"))
      (_            (call-interactively #'compile)))))

(defun cj/f6-test-runner ()
  "F6 top-level test menu.
Prompts via `completing-read' between \"All tests\" (delegates to
`projectile-test-project') and \"Current file's tests\" (delegates to
`cj/--f6-current-file-tests-impl')."
  (interactive)
  (let* ((candidates '("All tests" "Current file's tests"))
         (label (completing-read "F6: " candidates nil t nil nil (car candidates))))
    (pcase label
      ("All tests" (projectile-test-project current-prefix-arg))
      ("Current file's tests"
       (cj/--f6-current-file-tests-impl
        (buffer-file-name) (cj/--f4-project-root))))))

(defun cj/f6-current-file-tests ()
  "C-F6 fast path: run tests for the current buffer's file.
Resolves `buffer-file-name' and projectile root, then delegates to
`cj/--f6-current-file-tests-impl'."
  (interactive)
  (cj/--f6-current-file-tests-impl
   (buffer-file-name) (cj/--f4-project-root)))

(defun cj/f4-clean-rebuild ()
  "M-F4 fast path: clean + rebuild.
Compiled projects run the heuristic clean + projectile-compile-project
chain. Interpreted projects and unrecognized projects get a no-op
message."
  (interactive)
  (let* ((root (cj/--f4-project-root))
         (project-type (cj/--detect-project-type root)))
    (pcase project-type
      ('compiled    (cj/--f4-clean-rebuild-impl root))
      ('interpreted (message "M-F4: not a compiled language"))
      (_            (message "M-F4: no project detected")))))

;; ---------- Projectile advice ----------

(defun cj/--projectile-compile-around-revert (orig-fn &rest args)
  "Around advice for `projectile-compile-project' command-cache revert."
  (apply #'cj/--projectile-around-revert
         'projectile-compile-cmd-map orig-fn args))

(defun cj/--projectile-test-around-revert (orig-fn &rest args)
  "Around advice for `projectile-test-project' command-cache revert."
  (apply #'cj/--projectile-around-revert
         'projectile-test-cmd-map orig-fn args))

(defun cj/--projectile-run-around-revert (orig-fn &rest args)
  "Around advice for `projectile-run-project' command-cache revert."
  (apply #'cj/--projectile-around-revert
         'projectile-run-cmd-map orig-fn args))

(defconst cj/--projectile-revert-advice-specs
  '((projectile-compile-project . cj/--projectile-compile-around-revert)
    (projectile-test-project    . cj/--projectile-test-around-revert)
    (projectile-run-project     . cj/--projectile-run-around-revert))
  "Projectile command runners and their command-cache revert advice.")

(defun cj/--projectile-install-revert-advice ()
  "Install Projectile command-cache revert advice when Projectile is available."
  (dolist (spec cj/--projectile-revert-advice-specs)
    (let ((target (car spec))
          (advice (cdr spec)))
      (when (and (fboundp target)
                 (not (advice-member-p advice target)))
        (advice-add target :around advice)))))

(defun cj/--projectile-register-revert-advice ()
  "Install Projectile revert advice now, or after Projectile loads."
  (if (featurep 'projectile)
      (cj/--projectile-install-revert-advice)
    (eval-after-load 'projectile
      (list 'cj/--projectile-install-revert-advice))))

(cj/--projectile-register-revert-advice)

;; ---------- Bindings ----------

(eval-when-compile (defvar cj/custom-keymap)) ;; defined in keybindings.el

;; Skip the binding if cj/custom-keymap isn't loaded yet (e.g. when this
;; module is required directly in batch tests).
(when (boundp 'cj/custom-keymap)
  (keymap-set cj/custom-keymap "P" #'cj/projectile-reset-cmds))

(keymap-global-set "<f4>"   #'cj/f4-compile-and-run)
(keymap-global-set "C-<f4>" #'cj/f4-compile-only)
(keymap-global-set "M-<f4>" #'cj/f4-clean-rebuild)
(keymap-global-set "S-<f4>" #'recompile)
(keymap-global-set "<f6>"   #'cj/f6-test-runner)
(keymap-global-set "C-<f6>" #'cj/f6-current-file-tests)
;; M-<f6> reserved for Phase 2b ("Run a test..." with last-test memory).

(provide 'dev-fkeys)
;;; dev-fkeys.el ends here.