-- Copyright 2006-2013 gwash. See LICENSE.
-- Archlinux PKGBUILD LPeg lexer.

local l = require('lexer')
local token, word_match = l.token, l.word_match
local P, R, S = lpeg.P, lpeg.R, lpeg.S

local M = {_NAME = 'pkgbuild'}

-- Whitespace.
local ws = token(l.WHITESPACE, l.space^1)

-- Comments.
local comment = token(l.COMMENT, '#' * l.nonnewline^0)

-- Strings.
local sq_str = l.delimited_range("'", false, true)
local dq_str = l.delimited_range('"')
local ex_str = l.delimited_range('`')
local heredoc = '<<' * P(function(input, index)
  local s, e, _, delimiter =
    input:find('(["\']?)([%a_][%w_]*)%1[\n\r\f;]+', index)
  if s == index and delimiter then
    local _, e = input:find('[\n\r\f]+'..delimiter, e)
    return e and e + 1 or #input + 1
  end
end)
local string = token(l.STRING, sq_str + dq_str + ex_str + heredoc)

-- Numbers.
local number = token(l.NUMBER, l.float + l.integer)

-- Keywords.
local keyword = token(l.KEYWORD, word_match({
  'patch', 'cd', 'make', 'patch', 'mkdir', 'cp', 'sed', 'install', 'rm',
  'if', 'then', 'elif', 'else', 'fi', 'case', 'in', 'esac', 'while', 'for',
  'do', 'done', 'continue', 'local', 'return', 'git', 'svn', 'co', 'clone',
  'gconf-merge-schema', 'msg', 'echo', 'ln',
  -- Operators.
  '-a', '-b', '-c', '-d', '-e', '-f', '-g', '-h', '-k', '-p', '-r', '-s', '-t',
  '-u', '-w', '-x', '-O', '-G', '-L', '-S', '-N', '-nt', '-ot', '-ef', '-o',
  '-z', '-n', '-eq', '-ne', '-lt', '-le', '-gt', '-ge', '-Np', '-i'
}, '-'))

-- Functions.
local func = token(l.FUNCTION, word_match{
  'build',
  'check',
  'package',
  'pkgver',
  'prepare'
} * '()')

-- Constants.
local constant = token(l.CONSTANT, word_match{
  -- We do *not* list pkgver, srcdir and startdir here.
  -- These are defined by makepkg but user should not alter them.
  'arch',
  'backup',
  'changelog',
  'checkdepends',
  'conflicts',
  'depends',
  'epoch',
  'groups',
  'install',
  'license',
  'makedepends',
  'md5sums',
  'noextract',
  'optdepends',
  'options',
  'pkgbase',
  'pkgdesc',
  'pkgname',
  'pkgrel',
  'pkgver',
  'provides',
  'replaces',
  'sha1sums',
  'sha256sums',
  'sha384sums',
  'sha512sums',
  'source',
  'url',
  'validpgpkeys'
})

-- Identifiers.
local identifier = token(l.IDENTIFIER, l.word)

-- Variables.
local variable = token(l.VARIABLE,
                       '$' * (S('!#?*@$') +
                       l.delimited_range('()', true, true) +
                       l.delimited_range('[]', true, true) +
                       l.delimited_range('{}', true, true) +
                       l.delimited_range('`', true, true) +
                       l.digit^1 + l.word))

-- Operators.
local operator = token(l.OPERATOR, S('=!<>+-/*^~.,:;?()[]{}'))

M._rules = {
  {'whitespace', ws},
  {'comment', comment},
  {'string', string},
  {'number', number},
  {'keyword', keyword},
  {'function', func},
  {'constant', constant},
  {'identifier', identifier},
  {'variable', variable},
  {'operator', operator},
}

M._foldsymbols = {
  _patterns = {'[%(%){}]', '#'},
  [l.OPERATOR] = {['('] = 1, [')'] = -1, ['{'] = 1, ['}'] = -1},
  [l.COMMENT] = {['#'] = l.fold_line_comments('#')}
}

return M