" vim: et sw=2 sts=2

scriptencoding utf-8

" Init: values {{{1
if !exists('g:signify_diffoptions')
  let g:signify_diffoptions = {}
endif

let s:difftool = get(g:, 'signify_difftool', 'diff')

if executable(s:difftool)
  let s:vcs_dict = {
        \ 'git':      'git',
        \ 'hg':       'hg',
        \ 'svn':      'svn',
        \ 'darcs':    'darcs',
        \ 'bzr':      'bzr',
        \ 'fossil':   'fossil',
        \ 'cvs':      'cvs',
        \ 'rcs':      'rcsdiff',
        \ 'accurev':  'accurev',
        \ 'perforce': 'p4'
        \ }
else
  echomsg 'signify: No diff tool found -> no support for svn, darcs, bzr, fossil.'
  let s:vcs_dict = {
        \ 'git':      'git',
        \ 'hg':       'hg',
        \ 'cvs':      'cvs',
        \ 'rcs':      'rcsdiff',
        \ 'accurev':  'accurev',
        \ 'perforce': 'p4'
        \ }
endif

let s:vcs_list = get(g:, 'signify_vcs_list', [])
if empty(s:vcs_list)
  let s:vcs_list = keys(filter(s:vcs_dict, 'executable(v:val)'))
endif

" Function: #detect {{{1
function! sy#repo#detect() abort
  let dir = fnamemodify(b:sy.path, ':h')

  let vcs_list = s:vcs_list
  " Simple cache. If there is a registered VCS-controlled file in this
  " directory already, assume that this file is probably controlled by
  " the same VCS. Thus we shuffle that VCS to the top of our copy of
  " s:vcs_list, so we don't affect the preference order of s:vcs_list.
  if has_key(g:sy_cache, dir)
    let vcs_list = [g:sy_cache[dir]] + filter(copy(s:vcs_list), 'v:val != "'. g:sy_cache[dir] .'"')
  endif

  let s:info = {
        \ 'chdir':    haslocaldir() ? 'lcd' : 'cd',
        \ 'cwd':      getcwd(),
        \ 'dir':      fnamemodify(b:sy.path, ':p:h'),
        \ 'path':     s:escape(b:sy.path),
        \ 'file':     s:escape(fnamemodify(b:sy.path, ':t')),
        \ 'difftool': s:escape(s:difftool),
        \ 'devnull':  s:devnull(),
        \ }

  for type in vcs_list
    let [istype, diff] = sy#repo#get_diff_{type}()
    if istype
      return [ diff, type ]
    endif
  endfor

  return [ '', 'unknown' ]
endfunction

" Function: #get_diff_git {{{1
function! sy#repo#get_diff_git() abort
  let diff = s:run('git diff --no-color --no-ext-diff -U0 -- %f',
        \ s:info.file, 1)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_hg {{{1
function! sy#repo#get_diff_hg() abort
  let diff = s:run('hg diff --config extensions.color=! --config defaults.diff= --nodates -U0 -- %f',
        \ s:info.path, 1)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_svn {{{1
function! sy#repo#get_diff_svn() abort
  let diff = s:run('svn diff --diff-cmd %d -x -U0 -- %f',
        \ s:info.path, 0)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_bzr {{{1
function! sy#repo#get_diff_bzr() abort
  let diff = s:run('bzr diff --using %d --diff-options=-U0 -- %f',
        \ s:info.path, 0)
  return (v:shell_error =~ '[012]') ? [1, diff] : [0, '']
endfunction

" Function: #get_diff_darcs {{{1
function! sy#repo#get_diff_darcs() abort
  let diff = s:run('darcs diff --no-pause-for-gui --diff-command="%d -U0 %1 %2" -- %f',
        \ s:info.path, 1)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_fossil {{{1
function! sy#repo#get_diff_fossil() abort
  let diff = s:run('fossil set diff-command "%d -U 0" && fossil diff --unified -c 0 -- %f',
        \ s:info.path, 1)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_cvs {{{1
function! sy#repo#get_diff_cvs() abort
  let diff = s:run('cvs diff -U0 -- %f', s:info.file, 1)
  return ((v:shell_error == 1) && (diff =~ '+++')) ? [1, diff] : [0, '']
endfunction

" Function: #get_diff_rcs {{{1
function! sy#repo#get_diff_rcs() abort
  let diff = s:run('rcsdiff -U0 %f 2>/dev/null', s:info.path, 0)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_accurev {{{1
function! sy#repo#get_diff_accurev() abort
  let diff = s:run('accurev diff %f -- -U0', s:info.file, 1)
  return (v:shell_error != 1) ? [0, ''] : [1, diff]
endfunction

" Function: #get_diff_perforce {{{1
function! sy#repo#get_diff_perforce() abort
  let diff = s:run('p4 info 2>&1 >%n && env P4DIFF=diff p4 diff -dU0 %f',
        \ s:info.path, 0)
  return v:shell_error ? [0, ''] : [1, diff]
endfunction

" Function: #get_stats {{{1
function! sy#repo#get_stats() abort
  if !exists('b:sy') || !has_key(b:sy, 'stats')
    return [-1, -1, -1]
  endif

  return b:sy.stats
endfunction

" Function: s:devnull {{{1
function! s:devnull() abort
  return has('win32') || has ('win64') ? 'NUL' : '/dev/null'
endfunction

" Function: s:escape {{{1
function! s:escape(path) abort
  if exists('+shellslash')
    let old_ssl = &shellslash
    if fnamemodify(&shell, ':t') == 'cmd.exe'
      set noshellslash
    else
      set shellslash
    endif
  endif

  let path = shellescape(a:path)

  if exists('old_ssl')
    let &shellslash = old_ssl
  endif

  return path
endfunction

" Function: s:run {{{1
function! s:run(cmd, path, do_switch_dir) abort
  let cmd = substitute(a:cmd, '%f', a:path,          '')
  let cmd = substitute(cmd,   '%d', s:info.difftool, '')
  let cmd = substitute(cmd,   '%n', s:info.devnull,  '')

  if a:do_switch_dir
    try
      execute s:info.chdir fnameescape(s:info.dir)
      let ret = system(cmd)
    finally
      execute s:info.chdir fnameescape(s:info.cwd)
    endtry
    return ret
  endif

  return system(cmd)
endfunction