" Vim indent file
" Language: YAML
" Maintainer: Nikolai Pavlov <[email protected]>

" Only load this indent file when no other was loaded.
if exists('b:did_indent')
finish
endif

let s:save_cpo = &cpo
set cpo&vim

let b:did_indent = 1

setlocal indentexpr=GetYAMLIndent(v:lnum)
setlocal indentkeys=!^F,o,O,0#,0},0],<:>,-
setlocal nosmartindent

let b:undo_indent = 'setlocal indentexpr< indentkeys< smartindent<'

" Only define the function once.
if exists('*GetYAMLIndent')
finish
endif

if exists('*shiftwidth')
let s:shiftwidth = function('shiftwidth')
else
function s:shiftwidth()
return &shiftwidth
endfunction
endif

function s:FindPrevLessIndentedLine(lnum, ...)
let prevlnum = prevnonblank(a:lnum-1)
let curindent = a:0 ? a:1 : indent(a:lnum)
while prevlnum
\&& indent(prevlnum) >= curindent
\&& getline(prevlnum) !~# '^\s*#'
let prevlnum = prevnonblank(prevlnum-1)
endwhile
return prevlnum
endfunction

function s:FindPrevLEIndentedLineMatchingRegex(lnum, regex)
let plilnum = s:FindPrevLessIndentedLine(a:lnum, indent(a:lnum)+1)
while plilnum && getline(plilnum) !~# a:regex
let plilnum = s:FindPrevLessIndentedLine(plilnum)
endwhile
return plilnum
endfunction

let s:mapkeyregex='\v^\s*%(\''%([^'']|'''')*\'''.
\ '|\"%([^"\\]|\\.)*\"'.
\ '|%(%(\:\ )@!.)*)\:%(\ |$)'
let s:liststartregex='\v^\s*%(\-%(\ |$))'

function GetYAMLIndent(lnum)
if a:lnum == 1 || !prevnonblank(a:lnum-1)
return 0
endif

let prevlnum = prevnonblank(a:lnum-1)
let previndent = indent(prevlnum)

let line = getline(a:lnum)
if line =~# '^\s*#' && getline(a:lnum-1) =~# '^\s*#'
" Comment blocks should have identical indent
return previndent
elseif line =~# '^\s*[\]}]'
" Lines containing only closing braces should have previous indent
return indent(s:FindPrevLessIndentedLine(a:lnum))
endif

" Ignore comment lines when calculating indent
while getline(prevlnum) =~# '^\s*#'
let prevlnum = prevnonblank(prevlnum-1)
if !prevlnum
return previndent
endif
endwhile

let prevline = getline(prevlnum)
let previndent = indent(prevlnum)

" Any examples below assume that shiftwidth=2
if prevline =~# '\v[{[:]$|[:-]\ [|>][+\-]?%(\s+\#.*|\s*)$'
" Mapping key:
" nested mapping: ...
"
" - {
" key: [
" list value
" ]
" }
"
" - |-
" Block scalar without indentation indicator
return previndent+s:shiftwidth()
elseif prevline =~# '\v[:-]\ [|>]%(\d+[+\-]?|[+\-]?\d+)%(\#.*|\s*)$'
" - |+2
" block scalar with indentation indicator
"#^^ indent+2, not indent+shiftwidth
return previndent + str2nr(matchstr(prevline,
\'\v([:-]\ [|>])@<=[+\-]?\d+%([+\-]?%(\s+\#.*|\s*)$)@='))
elseif prevline =~# '\v\"%([^"\\]|\\.)*\\$'
" "Multiline string \
" with escaped end"
let qidx = match(prevline, '\v\"%([^"\\]|\\.)*\\')
return virtcol([prevlnum, qidx+1])
elseif line =~# s:liststartregex
" List line should have indent equal to previous list line unless it was
" caught by one of the previous rules
return indent(s:FindPrevLEIndentedLineMatchingRegex(a:lnum,
\ s:liststartregex))
elseif line =~# s:mapkeyregex
" Same for line containing mapping key
return indent(s:FindPrevLEIndentedLineMatchingRegex(a:lnum,
\ s:mapkeyregex))
elseif prevline =~# '^\s*- '
" - List with
" multiline scalar
return previndent+2
elseif prevline =~# s:mapkeyregex
" Mapping with: value
" that is multiline scalar
return previndent+s:shiftwidth()
endif
return previndent
endfunction

let &cpo = s:save_cpo