" Vim syntax file
" Language:    HCL
" Maintainer:  Gregory Anders
" Upstream:    https://github.com/hashivim/vim-terraform
" Last Change: 2024-09-03

if exists('b:current_syntax')
  finish
endif

syn iskeyword a-z,A-Z,48-57,_,-

syn case match

" A block is introduced by a type, some number of labels - which are either
" strings or identifiers - and an opening curly brace.  Match the type.
syn match hclBlockType /^\s*\zs\K\k*\ze\s\+\(\("\K\k*"\|\K\k*\)\s\+\)*{/

" An attribute name is an identifier followed by an equals sign.
syn match hclAttributeAssignment /\(\K\k*\.\)*\K\k*\s\+=\s/ contains=hclAttributeName
syn match hclAttributeName /\<\K\k*\>/ contained

syn keyword hclValueBool true false

syn keyword hclTodo         contained TODO FIXME XXX BUG
syn region  hclComment      start="/\*" end="\*/" contains=hclTodo,@Spell
syn region  hclComment      start="#" end="$" contains=hclTodo,@Spell
syn region  hclComment      start="//" end="$" contains=hclTodo,@Spell

""" misc.
syn match hclValueDec      "\<[0-9]\+\([kKmMgG]b\?\)\?\>"
syn match hclValueHexaDec  "\<0x[0-9a-f]\+\([kKmMgG]b\?\)\?\>"
syn match hclBraces        "[\[\]]"

""" skip \" and \\ in strings.
syn region hclValueString   start=/"/ skip=/\\\\\|\\"/ end=/"/ contains=hclStringInterp
syn region hclStringInterp  matchgroup=hclBraces start=/\(^\|[^$]\)\$\zs{/ end=/}/ contained contains=ALLBUT,hclAttributeName
syn region hclHereDocText   start=/<<-\?\z([a-z0-9A-Z]\+\)/ end=/^\s*\z1/ contains=hclStringInterp

"" Functions.
syn match hclFunction "[a-z0-9]\+(\@="

""" HCL2
syn keyword hclRepeat         for in
syn keyword hclConditional    if
syn keyword hclValueNull      null

" enable block folding
syn region hclBlockBody matchgroup=hclBraces start="{" end="}" fold transparent

hi def link hclComment           Comment
hi def link hclTodo              Todo
hi def link hclBraces            Delimiter
hi def link hclAttributeName     Identifier
hi def link hclBlockType         Type
hi def link hclValueBool         Boolean
hi def link hclValueDec          Number
hi def link hclValueHexaDec      Number
hi def link hclValueString       String
hi def link hclHereDocText       String
hi def link hclFunction          Function
hi def link hclRepeat            Repeat
hi def link hclConditional       Conditional
hi def link hclValueNull         Constant

let b:current_syntax = 'hcl'