-- Copyright 2006-2010 Mitchell Foral mitchell<att>caladbolg.net. See LICENSE.
-- CSS LPeg lexer

module(..., package.seeall)
local P, R, S, V = lpeg.P, lpeg.R, lpeg.S, lpeg.V

local ws = token('css_whitespace', space^1)

-- comments
local comment = token('comment', '/*' * (any - '*/')^0 * P('*/')^-1)

local word_char = alnum + S('_-')
local identifier = alpha^1 * word_char^0

-- at rules
local at_rule = word_match(word_list{
  'import', 'media', 'page', 'font-face', 'charset'
})
local at_rule_arg = word_match(word_list{
  'all', 'aural', 'braille', 'embossed', 'handheld', 'print',
  'projection', 'screen', 'tty', 'tv'
})
local at_rule = token('at_rule', '@' * at_rule * (space * at_rule_arg)^-1)

-- strings
local sq_str = delimited_range("'", '\\', true)
local dq_str = delimited_range('"', '\\', true)
local string = token('string', sq_str + dq_str)

local colon = token('operator', ':')
local semicolon = token('operator', ';')
local comma = token('operator', ',')
local obrace = token('operator', '{')
local cbrace = token('operator', '}')

-- selectors
local attribute = '[' * word_char^1 * (S('|~')^-1 * '=' * (identifier + sq_str + dq_str))^-1 * ']'
local class_id_selector = identifier^-1 * S('.#') * identifier
local selector = '*' * space + (class_id_selector + identifier + '*') * attribute^-1
local pseudoclass = word_match(word_list{
  'first-letter', 'first-line', 'link', 'active', 'visited',
  'first-child', 'focus', 'hover', 'lang', 'before', 'after',
  'left', 'right', 'first'
})
selector = token('css_selector', selector * (space * selector)^0) *
  (token('css_selector', ':' * pseudoclass) + token('default', ':' * word_char^1))^-1
selector = selector * (ws^0 * (comma + token('css_selector', S('>+*'))) * ws^0 * selector)^0

-- css properties and values
local css1_property = word_match(word_list{
  'color', 'background-color', 'background-image',
  'background-repeat', 'background-attachment',
  'background-position', 'background', 'font-family', 'font-style',
  'font-variant', 'font-weight', 'font-size', 'font',
  'word-spacing', 'letter-spacing', 'text-decoration',
  'vertical-align', 'text-transform', 'text-align', 'text-indent',
  'line-height', 'margin-top', 'margin-right', 'margin-bottom',
  'margin-left', 'margin', 'padding-top', 'padding-right',
  'padding-bottom', 'padding-left', 'padding', 'border-top-width',
  'border-right-width', 'border-bottom-width', 'border-left-width',
  'border-width', 'border-top', 'border-right', 'border-bottom',
  'border-left', 'border', 'border-color', 'border-style', 'width',
  'height', 'float', 'clear', 'display', 'white-space',
  'list-style-type', 'list-style-image', 'list-style-position',
  'list-style'
}, '-')
local css1_value = word_match(word_list{
  'auto', 'none', 'normal', 'italic', 'oblique', 'small-caps',
  'bold', 'bolder', 'lighter', 'xx-small', 'x-small', 'small',
  'medium', 'large', 'x-large', 'xx-large', 'larger', 'smaller',
  'transparent', 'repeat', 'repeat-x', 'repeat-y', 'no-repeat',
  'scroll', 'fixed', 'top', 'bottom', 'left', 'center', 'right',
  'justify', 'both', 'underline', 'overline', 'line-through',
  'blink', 'baseline', 'sub', 'super', 'text-top', 'middle',
  'text-bottom', 'capitalize', 'uppercase', 'lowercase', 'thin',
  'medium', 'thick', 'dotted', 'dashed', 'solid', 'double',
  'groove', 'ridge', 'inset', 'outset', 'block', 'inline',
  'list-item', 'pre', 'no-wrap', 'inside', 'outside', 'disc',
  'circle', 'square', 'decimal', 'lower-roman', 'upper-roman',
  'lower-alpha', 'upper-alpha', 'aqua', 'black', 'blue', 'fuchsia',
  'gray', 'green', 'lime', 'maroon', 'navy', 'olive', 'purple',
  'red', 'silver', 'teal', 'white', 'yellow'
}, '-')
local css2_property = word_match(word_list{
  'border-top-color', 'border-right-color', 'border-bottom-color',
  'border-left-color', 'border-color', 'border-top-style',
  'border-right-style', 'border-bottom-style', 'border-left-style',
  'border-style', 'top', 'right', 'bottom', 'left', 'position',
  'z-index', 'direction', 'unicode-bidi', 'min-width', 'max-width',
  'min-height', 'max-height', 'overflow', 'clip', 'visibility',
  'content', 'quotes', 'counter-reset', 'counter-increment',
  'marker-offset', 'size', 'marks', 'page-break-before',
  'page-break-after', 'page-break-inside', 'page', 'orphans',
  'widows', 'font-stretch', 'font-size-adjust', 'unicode-range',
  'units-per-em', 'src', 'panose-1', 'stemv', 'stemh', 'slope',
  'cap-height', 'x-height', 'ascent', 'descent', 'widths', 'bbox',
  'definition-src', 'baseline', 'centerline', 'mathline',
  'topline', 'text-shadow', 'caption-side', 'table-layout',
  'border-collapse', 'border-spacing', 'empty-cells',
  'speak-header', 'cursor', 'outline', 'outline-width',
  'outline-style', 'outline-color', 'volume', 'speak',
  'pause-before', 'pause-after', 'pause', 'cue-before',
  'cue-after', 'cue', 'play-during', 'azimuth', 'elevation',
  'speech-rate', 'voice-family', 'pitch', 'pitch-range', 'stress',
  'richness', 'speak-punctuation', 'speak-numeral'
}, '-')
local css2_value = word_match(word_list{
  'inherit', 'run-in', 'compact', 'marker', 'table',
  'inline-table', 'table-row-group', 'table-header-group',
  'table-footer-group', 'table-row', 'table-column-group',
  'table-column', 'table-cell', 'table-caption', 'static',
  'relative', 'absolute', 'fixed', 'ltr', 'rtl', 'embed',
  'bidi-override', 'visible', 'hidden', 'scroll', 'collapse',
  'open-quote', 'close-quote', 'no-open-quote', 'no-close-quote',
  'decimal-leading-zero', 'lower-greek', 'lower-latin',
  'upper-latin', 'hebrew', 'armenian', 'georgian',
  'cjk-ideographic', 'hiragana', 'katakana', 'hiragana-iroha',
  'katakana-iroha', 'landscape', 'portrait', 'crop', 'cross',
  'always', 'avoid', 'wider', 'narrower', 'ultra-condensed',
  'extra-condensed', 'condensed', 'semi-condensed',
  'semi-expanded', 'expanded', 'extra-expanded', 'ultra-expanded',
  'caption', 'icon', 'menu', 'message-box', 'small-caption',
  'status-bar', 'separate', 'show', 'hide', 'once', 'crosshair',
  'default', 'pointer', 'move', 'text', 'wait', 'help', 'e-resize',
  'ne-resize', 'nw-resize', 'n-resize', 'se-resize', 'sw-resize',
  's-resize', 'w-resize', 'ActiveBorder', 'ActiveCaption',
  'AppWorkspace', 'Background', 'ButtonFace', 'ButtonHighlight',
  'ButtonShadow', 'InactiveCaptionText', 'ButtonText',
  'CaptionText', 'GrayText', 'Highlight', 'HighlightText',
  'InactiveBorder', 'InactiveCaption', 'InfoBackground',
  'InfoText', 'Menu', 'MenuText', 'Scrollbar', 'ThreeDDarkShadow',
  'ThreeDFace', 'ThreeDHighlight', 'ThreeDLightShadow',
  'ThreeDShadow', 'Window', 'WindowFrame', 'WindowText', 'silent',
  'x-soft', 'soft', 'medium', 'loud', 'x-loud', 'spell-out', 'mix',
  'left-side', 'far-left', 'center-left', 'center-right',
  'far-right', 'right-side', 'behind', 'leftwards', 'rightwards',
  'below', 'level', 'above', 'higher', 'lower', 'x-slow', 'slow',
  'medium', 'fast', 'x-fast', 'faster', 'slower', 'male', 'female',
  'child', 'x-low', 'low', 'high', 'x-high', 'code', 'digits',
  'continous'
}, '-')
local property = token('keyword', css1_property + css2_property)
local value = token('css_value', css1_value + css2_value)
local keyword = property + value

-- colors, units, numbers, and urls
local hexcolor = token('css_color', '#' * xdigit * xdigit * xdigit* (xdigit * xdigit * xdigit)^-1)
local rgbunit = (digit^1 * P('%')^-1)
local rgbcolor = token('css_color', 'rgb(' * rgbunit * ',' * rgbunit * ',' * rgbunit * ')')
local color = hexcolor + rgbcolor
local unit = word_match(word_list{
  'pt', 'mm', 'cm', 'pc', 'in', 'px', 'em', 'ex', 'deg',
  'rad', 'grad', 'ms', 's', 'Hz', 'kHz'
})
unit = token('css_unit', unit + '%')
local css_float = digit^0 * '.' * digit^1 + digit^1 * '.' * digit^0 + digit^1
local number = token('number', S('+-')^-1 * css_float) * unit^-1
local url = token('css_url', 'url' * ('(' * (sq_str + dq_str) * ')' + delimited_range('()', '\\', true)))

-- declaration block
local block_default_char = token('default', (any - '}')^0) -- used to keep block colored properly
local property_value = value + string + number + color + url + token('default', word_char^1)
local property_values = { property_value * (ws * property_value)^0 * (ws^0 * comma * ws^0 * V(1))^0 }
local declaration_value = colon * ws^0 * property_values * ws^0 * (semicolon + block_default_char)
local declaration_property = property * ws^0
local declaration = (declaration_property * (declaration_value + block_default_char)) + comment + block_default_char
local declaration_block = obrace * ws^0 * declaration * (ws * declaration)^0 * ws^0 * cbrace^-1

local css_element = selector * ws^0 * declaration_block^-1

function LoadTokens()
  local css = css
  add_token(css, 'css_whitespace', ws)
  add_token(css, 'comment', comment)
  add_token(css, 'css_at_rule', at_rule)
  add_token(css, 'string', string)
  add_token(css, 'css_element', css_element)
  add_token(css, 'any_char', any_char)

  -- embedding CSS in another language
  if hypertext then
    local html = hypertext
    local tag = html.TokenPatterns.tag
    local case_insensitive = html.case_insensitive_tags
    -- search for something of the form <style type="text/css">
    local style_element = word_match(word_list{'style'}, nil, case_insensitive_tags)
    start_token = #(P('<') * style_element *
      P(function(input, index)
        if input:find('[^>]+type%s*=%s*(["\'])text/css%1') then return index end
      end)) * tag -- color tag normally, and tag passes for start_token
    end_token = #(P('</') * style_element * ws^0 * P('>')) * tag -- </style>
    css.TokenPatterns.any_char = token('css_default', any - end_token)
    make_embeddable(css, html, start_token, end_token)
  end
end

function LoadStyles()
  add_style('css_whitespace', style_nothing)
  add_style('css_default', style_nothing)
  add_style('css_at_rule', style_predefinition)
  add_style('css_selector', style_definition)
  add_style('css_value', style_nothing..{ bold = true })
  add_style('css_unit', style_number)
  add_style('css_color', style_number)
  add_style('css_url', style_string)
end