" syntax/vimwiki.vim — default highlight groups for nuwiki.
"
" Two responsibilities:
"   1. Default `@vimwiki*` highlight groups for the LSP semantic tokens
"      (SPEC §11 P7). Loaded eagerly so the very first hover/highlight
"      cycle after server startup already has colours.
"   2. A small regex-based fallback so static highlighting works on
"      buffers where the LSP isn't running yet.
"
" The `@group.modifier` group names are Neovim's Tree-sitter convention
" — plain Vim rejects `@` and `.` with W18, so the LSP-token defaults
" are gated behind `has('nvim')`. The static fallback below works
" everywhere.

if exists('b:current_syntax')
  finish
endif

" ===== Semantic-token defaults (Neovim only — uses TS-style @group names) =====

if has('nvim')
  " Headings — level modifiers map to progressively softer accents.
  highlight default link @vimwikiHeading              Title
  highlight default link @vimwikiHeading.level1       Title
  highlight default link @vimwikiHeading.level2       Function
  highlight default link @vimwikiHeading.level3       Identifier
  highlight default link @vimwikiHeading.level4       Type
  highlight default link @vimwikiHeading.level5       Constant
  highlight default link @vimwikiHeading.level6       PreProc
  highlight default link @vimwikiHeading.centered     Title

  " Inline text styling.
  " Use @markup.* (nvim 0.9+ treesitter standard groups, defined by all
  " colorschemes) instead of markdownBold/Italic which only exist when the
  " markdown treesitter parser is loaded — never the case in a vimwiki buffer.
  highlight default link @vimwikiBold                 @markup.strong
  highlight default link @vimwikiItalic               @markup.italic
  highlight default link @vimwikiBoldItalic           @markup.strong
  highlight default link @vimwikiStrikethrough        @markup.strikethrough
  highlight default link @vimwikiSuperscript          Special
  highlight default link @vimwikiSubscript            Special

  " Code + math.
  highlight default link @vimwikiCode                 @markup.raw.inline
  highlight default link @vimwikiCodeBlock            @markup.raw.block
  highlight default link @vimwikiMath                 Number
  highlight default link @vimwikiMathBlock            Number

  " Links + transclusions.
  highlight default link @vimwikiWikilink             @markup.link
  highlight default link @vimwikiExternalLink         @markup.link.url
  highlight default link @vimwikiUrl                  @markup.link.url
  highlight default link @vimwikiTransclusion         Identifier

  " Misc.
  highlight default link @vimwikiKeyword              Todo
  highlight default link @vimwikiColor                Constant
  highlight default link @vimwikiComment              Comment
  highlight default link @vimwikiDefinitionTerm       Statement
endif

" ===== Static fallback (no LSP required) =====

syntax case match

" One match per heading level so colorschemes can style each differently.
" Each pattern requires whitespace immediately after the equals run, which
" makes the levels mutually exclusive (`==` won't match `===`).
syntax match nuwikiHeading1      /^\s*=\s.\{-}\s=\s*$/
syntax match nuwikiHeading2      /^\s*==\s.\{-}\s==\s*$/
syntax match nuwikiHeading3      /^\s*===\s.\{-}\s===\s*$/
syntax match nuwikiHeading4      /^\s*====\s.\{-}\s====\s*$/
syntax match nuwikiHeading5      /^\s*=====\s.\{-}\s=====\s*$/
syntax match nuwikiHeading6      /^\s*======\s.\{-}\s======\s*$/
syntax match nuwikiHorizontal   /^-\{4,}\s*$/
syntax match nuwikiCommentLine  /^%%.*$/
syntax region nuwikiCommentBlock start=/^%%+/ end=/+%%/ keepend
syntax region nuwikiPreformatted matchgroup=nuwikiPreDelim start=/^\s*{{{/ end=/^\s*}}}\s*$/ keepend
syntax region nuwikiMathBlock    start=/^{{\$/ end=/^}}\$/ keepend
syntax match nuwikiPlaceholder  /^%\(title\|nohtml\|template\|date\)\>.*$/

syntax match nuwikiBold         /\*[^*]\+\*/ contains=nuwikiBoldDelim
syntax match nuwikiBoldDelim    /\*/ contained conceal

syntax match nuwikiItalic       /\<_[^_]\+_\>/ contains=nuwikiItalicDelim
syntax match nuwikiItalicDelim  /_/ contained conceal

syntax match nuwikiCode         /`[^`]\+`/ contains=nuwikiCodeDelim
syntax match nuwikiCodeDelim    /`/ contained conceal

syntax match nuwikiMathInline   /\$[^$]\+\$/
" Two keyword groups so the editor can colour them like the HTML export:
" attention/pending (red) vs resolved/in-progress (green).
syntax match nuwikiKeywordAttn  /\<\(TODO\|FIXME\|XXX\|STOPPED\)\>/
syntax match nuwikiKeywordDone  /\<\(DONE\|FIXED\|STARTED\)\>/

" Wikilink conceal: hide [[ / ]], and for [[target|desc]] hide target|.
syntax region nuwikiWikilink start=/\[\[/ end=/\]\]/ keepend contains=nuwikiWikilinkBracket,nuwikiWikilinkTarget
syntax match nuwikiWikilinkBracket /\[\[/ contained conceal
syntax match nuwikiWikilinkBracket /\]\]/ contained conceal
syntax match nuwikiWikilinkTarget  /[^|\]]*|/ contained conceal

syntax region nuwikiTransclusion start=/{{[^{]/ end=/}}/ keepend
syntax match nuwikiUrl          /\<\(https\?\|ftp\|mailto\|file\):\/\?\/\?\S\+/

" Heading levels map to progressively softer accents — matches the Neovim
" semantic-token mapping above so static fallback and LSP-driven highlights
" agree. Colorschemes that don't differentiate Title vs Function vs etc.
" will still show all six as the same colour, but most do.
highlight default link nuwikiHeading1       Title
highlight default link nuwikiHeading2       Function
highlight default link nuwikiHeading3       Identifier
highlight default link nuwikiHeading4       Type
highlight default link nuwikiHeading5       Constant
highlight default link nuwikiHeading6       PreProc
highlight default link nuwikiHorizontal     Comment
highlight default link nuwikiCommentLine    Comment
highlight default link nuwikiCommentBlock   Comment
highlight default link nuwikiPreformatted   String
highlight default link nuwikiPreDelim       Comment
highlight default link nuwikiMathBlock      Number
highlight default link nuwikiPlaceholder    PreProc
" Bold / Italic use explicit attributes so they work in plain Vim too (no
" dependency on the 'Bold' / 'Italic' groups which are Neovim-only).
highlight default nuwikiBold      gui=bold        cterm=bold        term=bold
highlight default nuwikiItalic    gui=italic      cterm=italic      term=italic
highlight default link nuwikiCode           String
highlight default link nuwikiMathInline     Number
" Explicit colours (not a `Todo` link) so the red/green split is visible in any
" colorscheme. Matches the HTML export: TODO/FIXME/XXX red, DONE/FIXED/STARTED
" green.
highlight default nuwikiKeywordAttn gui=bold cterm=bold term=bold guifg=#F44747 ctermfg=203
highlight default nuwikiKeywordDone gui=bold cterm=bold term=bold guifg=#2EA043 ctermfg=35
highlight default link nuwikiWikilink       Underlined
highlight default link nuwikiTransclusion   Identifier
highlight default link nuwikiUrl            Underlined

" ===== Nested syntax for code blocks =====
"
" Highlight `{{{lang … }}}` fences with the embedded language's syntax, like
" vimwiki's automatic nested syntaxes. We scan the buffer for the languages
" actually used, `:syntax include` each one under a cluster, then define a
" contained region per language. Defined *after* nuwikiPreformatted so the
" language regions win for tagged fences (Vim gives later items priority),
" while bare `{{{` / `{{{class="…"` fences fall back to nuwikiPreformatted.

" Labels that don't match a Vim filetype name 1:1.
let s:nuwiki_nested_aliases = {
      \ 'bash': 'sh', 'shell': 'sh', 'zsh': 'sh', 'console': 'sh',
      \ 'js': 'javascript', 'ts': 'typescript', 'py': 'python',
      \ 'rs': 'rust', 'yml': 'yaml', 'md': 'markdown', 'c++': 'cpp',
      \ }

" The language label of a fence line: the first whitespace-separated token
" after `{{{` that isn't a `key=val` attribute (mirrors the Rust lexer).
function! s:nuwiki_fence_label(line) abort
  let l:after = matchstr(a:line, '^\s*{{{\zs.*$')
  for l:tok in split(l:after, '\s\+')
    if l:tok !~# '='
      return l:tok
    endif
  endfor
  return ''
endfunction

function! s:nuwiki_setup_nested() abort
  let l:included = {}
  let l:defined = {}
  for l:lnum in range(1, line('$'))
    let l:line = getline(l:lnum)
    if l:line !~# '^\s*{{{'
      continue
    endif
    let l:label = s:nuwiki_fence_label(l:line)
    if l:label ==# '' || has_key(l:defined, l:label)
      continue
    endif
    let l:defined[l:label] = 1
    let l:ft = get(s:nuwiki_nested_aliases, tolower(l:label), tolower(l:label))
    let l:cluster = 'nuwikiNested_' . substitute(l:ft, '[^a-zA-Z0-9]', '_', 'g')
    if !has_key(l:included, l:cluster)
      if exists('b:current_syntax')
        unlet b:current_syntax
      endif
      try
        execute 'syntax include @' . l:cluster . ' syntax/' . l:ft . '.vim'
      catch
        " No syntax file for this language — leave it to nuwikiPreformatted.
        continue
      endtry
      if exists('b:current_syntax')
        unlet b:current_syntax
      endif
      let l:included[l:cluster] = 1
    endif
    let l:region = 'nuwikiNestedRegion_' . substitute(l:label, '[^a-zA-Z0-9]', '_', 'g')
    execute 'syntax region ' . l:region
          \ . ' matchgroup=nuwikiPreDelim'
          \ . ' start=/^\s*{{{\s*' . escape(l:label, '/\.*$^~[]') . '\>.*$/'
          \ . ' end=/^\s*}}}\s*$/'
          \ . ' contains=@' . l:cluster
          \ . ' keepend'
  endfor
endfunction

call s:nuwiki_setup_nested()

let b:current_syntax = 'vimwiki'