init.el

;;; init.el --- Main Configuration -*- lexical-binding: t; -*-

;;; ------------------------------------------------------------------
;;; 1. PACKAGE MANAGEMENT
;;; ------------------------------------------------------------------
(require 'package)
(setq package-archives '(("melpa" . "https://melpa.org/packages/")
                         ("gnu"   . "https://elpa.gnu.org/packages/")))

(package-initialize)

;; Install and configure use-package (The modern way to manage plugins)
(unless (package-installed-p 'use-package)
  (package-refresh-contents)
  (package-install 'use-package))
(require 'use-package)
(setq use-package-always-ensure t) ; Automatically install packages

;;; ------------------------------------------------------------------
;;; 2. BASIC EDITOR SETTINGS & VISUALS
;;; ------------------------------------------------------------------
(setq inhibit-startup-message t)
(global-display-line-numbers-mode) ; Show line numbers globally
(setq make-backup-files nil)        ; Stop creating auto-backup files (~ files)

;; THEME: Set a robust, high-contrast theme
(use-package doom-themes
  :config
  ;; Load a dark theme, which provides good contrast for highlighting
  (load-theme 'doom-one t))

;;; ------------------------------------------------------------------
;;; 3. SCALA LSP SETUP (Metals Integration)
;;; ------------------------------------------------------------------

;; SCALA-MODE: Basic syntax highlighting
(use-package scala-mode
  :interpreter ("scala" . scala-mode))

;; SBT-MODE: Interaction with the build tool
(use-package sbt-mode
  :commands sbt-start sbt-command)

;; LSP-MODE: The core Language Server Client
(use-package lsp-mode
  :hook
  ;; Activate LSP features when opening a Scala file
  (scala-mode . lsp)
  :init
  (setq lsp-keymap-prefix "C-c l") ; Set a prefix for LSP commands
  ;; Optimization
  (setq gc-cons-threshold 100000000)
  (setq read-process-output-max (* 1024 1024))
  :commands lsp)

;; LSP-METALS: Scala-specific extensions for lsp-mode
(use-package lsp-metals
  :config
  ;; FIX: Explicitly set the path to the Metals binary installed by Coursier
  (setq lsp-metals-server-path "~/.local/share/coursier/bin/metals")
  (setq lsp-metals-treeview-show-when-views-received t))

;; AUTO-COMPLETION (Presents the list of available methods/functions)
(use-package company
  :hook (scala-mode . company-mode)
  :config
  (setq company-minimum-prefix-length 1)
  (setq company-idle-delay 0.0))

;; ERROR CHECKING (Red squiggly lines / Diagnostics)
(use-package flycheck
  :init (global-flycheck-mode))

;; LSP-UI: Popups for documentation and definitions
(use-package lsp-ui
  :config
  (setq lsp-ui-doc-enable t)
  (setq lsp-ui-doc-position 'top))

;;; ------------------------------------------------------------------
;;; 4. CUSTOM COLOR OVERRIDES (To match his specific request)
;;; ------------------------------------------------------------------

;; Emacs uses 'font-lock' for syntax highlighting.
;; We manually override the colors to meet the 'keywords yellow, functions red' request.
(custom-set-faces
  ;; Keywords (like 'def', 'val', 'class') in Yellow
  '(font-lock-keyword-face ((t (:foreground "yellow"))))
  ;; Function/Method names in Red
  '(font-lock-function-name-face ((t (:foreground "red")))))