;;; -*- lexical-binding: t; -*-
;;; slang-lsp.el --- Major mode for Slang shader files

;; Author: Michael Ghaben <michaelghaben@gmail.com>
;; Version: 0.0.3
;; Package-Requires: ((emacs "28.1") (eglot "1.19"))
;; Keywords: slang shaders vulkan opengl spir-v

;;; Commentary:
;;  This package provides a major mode for Slang shader files.

;;; Code:
(require 'cc-mode)
(require 'font-lock)

(defgroup slang nil
  "Major mode for Slang shader files."
  :group 'language
  :prefix "slang-")

(defcustom slang-indent-offset 4
  "Indentation offset for Slang code."
  :type 'integer
  :group 'slang)

;; Syntax table
(defvar slang-mode-syntax-table
  (let ((table (make-syntax-table)))
    ;; C-style comments
    (modify-syntax-entry ?/ ". 124b" table)
    (modify-syntax-entry ?* ". 23" table)
    (modify-syntax-entry ?\n "> b" table)
    
    ;; Strings
    (modify-syntax-entry ?\" "\"" table)
    (modify-syntax-entry ?\' "\"" table)
    
    ;; Operators and punctuation
    (modify-syntax-entry ?+ "." table)
    (modify-syntax-entry ?- "." table)
    (modify-syntax-entry ?% "." table)
    (modify-syntax-entry ?< "." table)
    (modify-syntax-entry ?> "." table)
    (modify-syntax-entry ?& "." table)
    (modify-syntax-entry ?| "." table)
    (modify-syntax-entry ?= "." table)
    (modify-syntax-entry ?! "." table)
    
    ;; Underscore as word constituent
    (modify-syntax-entry ?_ "w" table)
    
    table)
  "Syntax table for Slang mode.")

;; Font lock keywords - comprehensive Slang language support
(defconst slang-font-lock-keywords
  (list
   ;; Preprocessor directives
   '("^[ \t]*#.*$" . 'font-lock-preprocessor-face)
   
   ;; Attributes (shader annotations)
   '("\\[\\([^]]+\\)\\]" . 'font-lock-preprocessor-face)
   
   ;; Keywords - core language
   `(,(regexp-opt '("break" "case" "continue" "default" "do" "else" "for" 
                    "if" "return" "switch" "while" "goto"
                    "const" "static" "uniform" "varying" "in" "out" "inout"
                    "public" "private" "internal" "extern"
                    "true" "false" "null" "none")
                  'words)
     . 'font-lock-keyword-face)
   
   ;; Keywords - Slang-specific
   `(,(regexp-opt '("interface" "struct" "enum" "class" "namespace" "module"
                    "import" "export" "using" "typealias" "associatedtype"
                    "extension" "where" "let" "var" "property" "subscript"
                    "init" "__init" "deinit" "__deinit" "this" "This" "Self"
                    "super" "throws" "try" "catch" "finally"
                    "is" "as" "sizeof" "alignof" "offsetof"
                    "expand" "each" "repeat" "unroll" "loop"
                    "target" "version" "profile" "stage" "binding"
                    "set" "get" "implements" "extends")
                  'words)
     . 'font-lock-keyword-face)
   
   ;; Storage class keywords  
   `(,(regexp-opt '("typedef" "register" "auto" "volatile" "inline"
                    "virtual" "abstract" "override" "final" "sealed")
                  'words)
     . 'font-lock-keyword-face)
   
   ;; Built-in scalar types
   `(,(regexp-opt '("void" "bool" "int" "uint" "float" "double" "half"
                    "int8_t" "uint8_t" "int16_t" "uint16_t" 
                    "int32_t" "uint32_t" "int64_t" "uint64_t"
                    "float16_t" "float32_t" "float64_t"
                    "string" "StringLiteral")
                  'words)
     . 'font-lock-type-face)
   
   ;; Vector and matrix types
   '("\\b\\(bool\\|int\\|uint\\|float\\|double\\|half\\)\\([1-4]\\)\\b" . 'font-lock-type-face)
   '("\\b\\(bool\\|int\\|uint\\|float\\|double\\|half\\)\\([1-4]\\)x\\([1-4]\\)\\b" . 'font-lock-type-face)
   
   ;; Texture and buffer types
   `(,(regexp-opt '("Texture1D" "Texture2D" "Texture3D" "TextureCube"
                    "Texture1DArray" "Texture2DArray" "TextureCubeArray"
                    "Texture2DMS" "Texture2DMSArray"
                    "RWTexture1D" "RWTexture2D" "RWTexture3D"
                    "RWTexture1DArray" "RWTexture2DArray"
                    "Buffer" "RWBuffer" "StructuredBuffer" "RWStructuredBuffer"
                    "ByteAddressBuffer" "RWByteAddressBuffer"
                    "ConstantBuffer" "TextureBuffer" "RWTextureBuffer"
                    "AppendStructuredBuffer" "ConsumeStructuredBuffer"
                    "SamplerState" "SamplerComparisonState"
                    "RasterizerOrderedBuffer" "RasterizerOrderedStructuredBuffer"
                    "RasterizerOrderedTexture1D" "RasterizerOrderedTexture2D"
                    "RasterizerOrderedTexture3D")
                  'words)
     . 'font-lock-type-face)
   
   ;; Built-in interfaces
   `(,(regexp-opt '("IArithmetic" "ILogical" "IComparable" "IFloat"
                    "IInteger" "ISigned" "IUnsigned" "INumeric"
                    "IDifferentiable" "ITexture" "IResource")
                  'words)
     . 'font-lock-type-face)
   
   ;; HLSL semantics and system values
   `(,(regexp-opt '("SV_Position" "SV_Target" "SV_Depth" "SV_Coverage"
                    "SV_VertexID" "SV_InstanceID" "SV_PrimitiveID"
                    "SV_DispatchThreadID" "SV_GroupID" "SV_GroupThreadID"
                    "SV_GroupIndex" "SV_DomainLocation" "SV_InsideTessFactor"
                    "SV_TessFactor" "SV_OutputControlPointID" "SV_GSInstanceID"
                    "POSITION" "NORMAL" "TANGENT" "BINORMAL" "COLOR"
                    "TEXCOORD0" "TEXCOORD1" "TEXCOORD2" "TEXCOORD3"
                    "TEXCOORD4" "TEXCOORD5" "TEXCOORD6" "TEXCOORD7"
                    "BLENDWEIGHT" "BLENDINDICES" "PSIZE" "FOG")
                  'words)
     . 'font-lock-constant-face)
   
   ;; Boolean constants
   `(,(regexp-opt '("true" "false") 'words) . 'font-lock-constant-face)
   
   ;; Built-in mathematical functions
   `(,(regexp-opt '("abs" "acos" "all" "any" "asin" "atan" "atan2"
                    "ceil" "clamp" "cos" "cosh" "cross" "degrees"
                    "determinant" "distance" "dot" "exp" "exp2"
                    "faceforward" "floor" "fmod" "frac" "frexp"
                    "fwidth" "ldexp" "length" "lerp" "log" "log2"
                    "log10" "max" "min" "modf" "mul" "normalize"
                    "pow" "radians" "reflect" "refract" "round"
                    "rsqrt" "saturate" "sign" "sin" "sincos" "sinh"
                    "smoothstep" "sqrt" "step" "tan" "tanh" "transpose"
                    "trunc" "ddx" "ddy" "ddx_coarse" "ddy_coarse"
                    "ddx_fine" "ddy_fine" "tex1D" "tex2D" "tex3D"
                    "texCUBE" "noise" "clip" "discard" "lit")
                  'words)
     . 'font-lock-builtin-face)
   
   ;; Shader function intrinsics
   `(,(regexp-opt '("Sample" "SampleLevel" "SampleBias" "SampleCmp"
                    "SampleCmpLevelZero" "SampleGrad" "Load" "Store"
                    "GetDimensions" "CalculateLevelOfDetail"
                    "CalculateLevelOfDetailUnclamped"
                    "Gather" "GatherRed" "GatherGreen" "GatherBlue"
                    "GatherAlpha" "GatherCmp" "GatherCmpRed"
                    "GatherCmpGreen" "GatherCmpBlue" "GatherCmpAlpha"
                    "GroupMemoryBarrier" "GroupMemoryBarrierWithGroupSync"
                    "DeviceMemoryBarrier" "DeviceMemoryBarrierWithGroupSync"
                    "AllMemoryBarrier" "AllMemoryBarrierWithGroupSync"
                    "InterlockedAdd" "InterlockedAnd" "InterlockedCompareExchange"
                    "InterlockedCompareStore" "InterlockedExchange"
                    "InterlockedMax" "InterlockedMin" "InterlockedOr"
                    "InterlockedXor" "WaveActiveAllEqual" "WaveActiveBallot"
                    "WaveActiveCountBits" "WaveGetLaneCount" "WaveGetLaneIndex"
                    "WaveIsFirstLane" "WaveActiveAnyTrue" "WaveActiveAllTrue"
                    "WaveActiveSum" "WaveActiveProduct" "WaveActiveMin"
                    "WaveActiveMax" "WaveActiveBitAnd" "WaveActiveBitOr"
                    "WaveActiveBitXor" "WavePrefixCountBits" "WavePrefixSum"
                    "WavePrefixProduct" "WaveQuadReadAcrossX" "WaveQuadReadAcrossY"
                    "WaveQuadReadAcrossDiagonal" "WaveQuadSwapX" "WaveQuadSwapY"
                    "WaveReadLaneAt" "WaveReadLaneFirst")
                  'words)
     . 'font-lock-builtin-face)
   
   ;; Number literals
   '("\\b[0-9]+\\(\\.[0-9]+\\)?\\([eE][-+]?[0-9]+\\)?[fFhHlLuU]*\\b" . 'font-lock-constant-face)
   '("\\b0[xX][0-9a-fA-F]+[uUlL]*\\b" . 'font-lock-constant-face)
   
   ;; String literals
   '("\"\\([^\"\\\\]\\|\\\\.\\)*\"" . 'font-lock-string-face)
   '("'\\([^'\\\\]\\|\\\\.\\)*'" . 'font-lock-string-face)
   
   ;; Function definitions
   '("\\b\\([a-zA-Z_][a-zA-Z0-9_]*\\)\\s-*(" (1 'font-lock-function-name-face))
   
   ;; Type names (capitalized identifiers)
   '("\\b[A-Z][a-zA-Z0-9_]*\\b" . 'font-lock-type-face)
   )
  "Font lock keywords for Slang mode.")

;; Imenu support
(defvar slang-imenu-generic-expression
  '(("Functions" "^\\s-*\\([a-zA-Z_][a-zA-Z0-9_<>]*\\)\\s-+\\([a-zA-Z_][a-zA-Z0-9_]*\\)\\s-*(" 2)
    ("Structs" "^\\s-*struct\\s-+\\([a-zA-Z_][a-zA-Z0-9_]*\\)" 1)
    ("Interfaces" "^\\s-*interface\\s-+\\([a-zA-Z_][a-zA-Z0-9_]*\\)" 1)
    ("Enums" "^\\s-*enum\\s-+\\([a-zA-Z_][a-zA-Z0-9_]*\\)" 1)
    ("Classes" "^\\s-*class\\s-+\\([a-zA-Z_][a-zA-Z0-9_]*\\)" 1))
  "Imenu generic expression for Slang mode.")

;; Indentation function
(defun slang-indent-line ()
  "Indent current line as Slang code."
  (interactive)
  (c-indent-line))

;; Electric brace function
(defun slang-electric-brace (arg)
  "Insert a brace and indent properly."
  (interactive "P")
  (self-insert-command (prefix-numeric-value arg))
  (when (and (not arg)
             (eolp)
             (save-excursion
               (skip-chars-backward " \t")
               (bolp)))
    (c-indent-line)))

;; Keymap
(defvar slang-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "{" 'slang-electric-brace)
    (define-key map "}" 'slang-electric-brace)
    (define-key map (kbd "C-c C-c") 'comment-region)
    (define-key map (kbd "C-c C-u") 'uncomment-region)
    map)
  "Keymap for Slang mode.")

;; Mode menu
(easy-menu-define slang-mode-menu slang-mode-map
  "Menu for Slang mode."
  '("Slang"
    ["Comment Region" comment-region (mark)]
    ["Uncomment Region" uncomment-region (mark)]
    "---"
    ["Indent Line" slang-indent-line t]
    ["Indent Region" indent-region (mark)]
    "---"
    ["Customize Slang" (customize-group 'slang) t]))

;;;###autoload
(define-derived-mode slang-mode c-mode "Slang"
  "Major mode for editing Slang shader files."
  :syntax-table slang-mode-syntax-table
  :group 'slang
  
  ;; Font lock
  (setq font-lock-defaults '(slang-font-lock-keywords nil nil nil nil))
  
  ;; Comments
  (setq comment-start "// "
        comment-end ""
        comment-start-skip "\\(//+\\|/\\*+\\)\\s *"
        comment-end-skip "\\s *\\(\\s>\\|\\*+/\\)")
  
  ;; Indentation
  (setq c-basic-offset slang-indent-offset
        tab-width slang-indent-offset
        indent-tabs-mode nil)
  
  ;; Case sensitivity
  (setq case-fold-search nil)
  
  ;; Imenu
  (setq imenu-generic-expression slang-imenu-generic-expression)
  
  ;; Compilation support
  (when (boundp 'compilation-error-regexp-alist)
    (set (make-local-variable 'compilation-error-regexp-alist)
         '(("^\\([^:]+\\):\\([0-9]+\\):" 1 2))))
  
  ;; Run mode hooks
  (run-mode-hooks 'slang-mode-hook))

;; File associations
;;;###autoload
(add-to-list 'auto-mode-alist '("\\.slang\\'" . slang-mode))
;;;###autoload
(add-to-list 'auto-mode-alist '("\\.sl\\'" . slang-mode))
;;;###autoload
(add-to-list 'auto-mode-alist '("\\.slangh\\'" . slang-mode))

(provide 'slang-mode)

;;; slang-mode.el ends here