;;; init.el --- Minimal Emacs: built-ins + evil + consult -*- lexical-binding: t; -*-
;; Learning: F1 k KEY, F1 f FUNCTION, F1 v VARIABLE,
;;           F1 m (modes), F1 b (bindings).
;;           C-h works too, except in normal/motion state where it moves
;;           to the window on the left.
;;; Code:

;;;; 1. Emac setup, files, packages and paths
(let ((bin (expand-file-name "~/.local/bin")))
  (add-to-list 'exec-path bin)
  (setenv "PATH" (concat bin path-separator (getenv "PATH"))))

;; all the emacs runtime files live in var/.
;; early-init.el redirects eln-cache and elpa. 
(defvar my/var (locate-user-emacs-file "var/"))
(make-directory (concat my/var "transient/") t)
(setq savehist-file              (concat my/var "history")
      save-place-file            (concat my/var "places.eld")
      recentf-save-file          (concat my/var "recentf.eld")
      project-list-file          (concat my/var "projects.eld")
      transient-history-file     (concat my/var "transient/history.el")
      transient-levels-file      (concat my/var "transient/levels.el")
      transient-values-file      (concat my/var "transient/values.el"))

;; Custom output goes to its own file, not here.
(setq custom-file (expand-file-name "var/custom.el" user-emacs-directory))
(load custom-file 'noerror 'nomessage)

;; No session manager save: stops the empty session.* files.
(add-hook 'emacs-save-session-functions #'always)

;; Package GNU, NonGNU are built in melpa additional lowest priority.
(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
(setq package-archive-priorities '(("gnu" . 3) ("nongnu" . 2) ("melpa" . 1)))
(package-initialize)

(require 'use-package)
(setq use-package-always-ensure t)

;;;; 2. Ui settings, theme setup and fonts
(add-to-list 'default-frame-alist '(fullscreen . maximized))
(menu-bar-mode -1)
(tool-bar-mode -1)
(scroll-bar-mode -1)
(blink-cursor-mode -1)

(setq inhibit-startup-screen t
      initial-scratch-message nil
      ring-bell-function #'ignore
      use-short-answers t
      scroll-conservatively 101
      scroll-margin 15)

(setq-default indent-tabs-mode nil
              tab-width 4)

(global-hl-line-mode 1)
(global-display-line-numbers-mode 1)
(pixel-scroll-precision-mode 1)
(column-number-mode 1)
(electric-pair-mode 1)
(which-key-mode 1)

(add-to-list 'warning-suppress-types '(files))
(use-package jbeans-theme
  :config
  (load-theme 'jbeans t))

(set-face-attribute 'default nil :family "JetBrainsMono Nerd Font" :height 120)
(setq-default line-spacing '(4 . 4))

;; set mode line at the top of each window
(setq-default header-line-format mode-line-format mode-line-format nil)
(set-face-attribute 'header-line nil :inherit 'mode-line :background "#131313")

;; Command launcher.
(keymap-global-set "C-S-p" #'execute-extended-command)

;; Escape behaves like C-g
(keymap-global-set "<escape>" #'keyboard-quit)
(keymap-set minibuffer-local-map "<escape>" #'abort-minibuffers)

;;;; 3. Files
(setq make-backup-files nil
      auto-save-default nil
      auto-save-list-file-prefix nil
      create-lockfiles nil
      confirm-kill-processes nil
      vc-follow-symlinks t)

(save-place-mode 1)
(savehist-mode 1)
(recentf-mode 1)
(global-auto-revert-mode 1)

;;;; 4. Completion
;; C-n/C-p navigates up and down, section 5 stops evil from overrriding
(use-package vertico
  :init
  (vertico-mode 1)
  :custom
  (vertico-count 15))

(setq completion-styles '(basic partial-completion flex)
      completion-ignore-case t
      read-buffer-completion-ignore-case t
      read-file-name-completion-ignore-case t
      completions-format 'one-column
      isearch-lazy-count t
      xref-search-program 'ripgrep)

(use-package vertico-posframe
  :after vertico
  :custom
  (vertico-posframe-poshandler #'posframe-poshandler-frame-center)
  :config
  (vertico-posframe-mode 1))

;;;; 5. Evil
(defvar evil-mode-buffers nil)

(defun my/insert-tab ()
  "Insert a literal tab character."
  (interactive)
  (insert "\t"))

(use-package evil
  :init
  (setq evil-want-C-u-scroll t
        evil-undo-system 'undo-redo
        evil-want-keybinding nil)

  :config
  (evil-mode 1)

  (evil-define-key 'insert 'global
    (kbd "TAB")   #'my/insert-tab
    (kbd "<tab>") #'my/insert-tab
    ;; complete using the buffer's completion sources.
    (kbd "C-SPC") #'completion-at-point
    (kbd "C-@")   #'completion-at-point)

  ;; C-p, C-f and C-b are assigned to Consult below.
  (evil-define-key '(normal motion) 'global
    (kbd "C-e") #'dired-jump))

(use-package evil-collection
  :after evil
  :custom
  ;; Don't add its global [b ]b [e ]e ... bindings.
  (evil-collection-want-unimpaired-p nil)
  :config
  (evil-collection-init '(info)))

;; Minibuffer. Vertico 
(with-eval-after-load 'vertico
  (evil-define-key '(insert normal) vertico-map
    (kbd "C-n")   #'vertico-next
    (kbd "C-p")   #'vertico-previous
    (kbd "TAB")   #'vertico-insert
    (kbd "<tab>") #'vertico-insert))

(evil-define-key '(insert normal) minibuffer-local-map
  (kbd "<escape>") #'abort-minibuffers)

;; Window navigation (normal/motion state): Ctrl+hjkl move, Ctrl+` closes.
(evil-define-key '(normal motion) 'global
  (kbd "C-h") #'windmove-left
  (kbd "C-j") #'windmove-down
  (kbd "C-k") #'windmove-up
  (kbd "C-l") #'windmove-right
  (kbd "C-q") #'delete-window)

;; Result buffers: hjkl motions and RET to jump to a result.
(dolist (m '(occur-mode grep-mode xref--xref-buffer-mode))
  (evil-set-initial-state m 'motion))

(with-eval-after-load 'compile
  (evil-define-key 'motion compilation-mode-map
    (kbd "RET") #'compile-goto-error))

(with-eval-after-load 'grep
  (evil-define-key 'motion grep-mode-map
    (kbd "RET") #'compile-goto-error))

(with-eval-after-load 'replace
  (evil-define-key 'motion occur-mode-map
    (kbd "RET") #'occur-mode-goto-occurrence))

(with-eval-after-load 'xref
  (evil-define-key 'motion xref--xref-buffer-mode-map
    (kbd "RET") #'xref-goto-xref))

;;;; 6. Consult
;; Requires the external `fd` and `rg` executables. Both honour .ignore files,
;; so keep excludes (node_modules, elpa, ...) in ~/.ignore or per-project .ignore.
;; Searches start at the project root when there is one, else the current directory.
(use-package consult
  :config
  ;; Hide noise from the buffer picker.
  (dolist (re '("\\`\\*scratch\\*\\'"
                "\\`\\*Messages\\*\\'"
                "\\`\\*Warnings\\*\\'"
                "\\`\\*xref\\*\\'"))
    (add-to-list 'consult-buffer-filter re))

  ;; Don't re-run the preview on every keystroke while typing a search.
  (consult-customize consult-ripgrep
                     :preview-key '(:debounce 0.4 any)))

;; Bind immediately, without waiting for consult to load.
(evil-define-key '(normal motion) 'global
  (kbd "C-p") #'consult-fd
  (kbd "C-f") #'consult-ripgrep
  (kbd "C-b") #'consult-buffer)

;;;; 7. Dired
(setq dired-dwim-target t
      dired-kill-when-opening-new-dired-buffer t
      dired-listing-switches "-agho --group-directories-first"
      dired-recursive-copies 'always
      delete-by-moving-to-trash t)

(with-eval-after-load 'dired
  (evil-set-initial-state 'dired-mode 'motion)

  (evil-define-key 'motion dired-mode-map
    "h"         #'dired-up-directory
    "l"         #'dired-find-file
    (kbd "RET") #'dired-find-file))

;;;; 8. Build
(setq compile-command "./build.sh"
      compilation-read-command nil
      compilation-ask-about-save nil
      compilation-scroll-output t)

(add-hook 'compilation-filter-hook #'ansi-color-compilation-filter)

;; Compilation buffer always at the bottom, full frame width.
(add-to-list 'display-buffer-alist
             '((derived-mode . compilation-mode)
               (display-buffer-reuse-window display-buffer-at-bottom)
               (window-height . 0.45)))

;; C-c C-c builds from the project root.
;; C-c b asks first: the prompt is pre-filled with ./build.sh, so type the args after it.
(defun my/project-compile-prompt ()
  "Run `project-compile', prompting to edit the command."
  (interactive)
  (let ((compilation-read-command t))
    (call-interactively #'project-compile)))

(keymap-global-set "C-c C-c" #'project-compile)
(keymap-global-set "C-c b"   #'my/project-compile-prompt)

;; Focus the compilation window when a build starts.
(add-hook 'compilation-start-hook
          (lambda (proc)
            (when-let* ((win (get-buffer-window (process-buffer proc))))
              (select-window win))))

;;;; 9. Modules - additional functionality outside of the core init.el
;; Magit and the :git command live in modules/git.el.
(load (locate-user-emacs-file "modules/git.el") nil 'nomessage)
;; Setup for dev languages, modes, lsp and lsp keybinds.
(load (locate-user-emacs-file "modules/development.el") nil 'nomessage)

;;; init.el ends here