# Module:Chessboard

local p = {}  

local cfg, nrows, ncols  

local function innerboard(args, size, rev)  
pattern = cfg.pattern or '%w%w'  
local root = mw.html.create('div')  
root:addClass('chess-board')  
:css('position', 'relative')  
:wikitext(cfg.image_board(size))  

for trow = 1,nrows do  
local row = rev and trow or ( 1 + nrows - trow )  
for tcol = 1,ncols do  
local col = rev and ( 1 + ncols - tcol ) or tcol  
local piece = args[ncols * ( nrows - row ) + col + 2] or ''  
if piece:match( pattern ) then  
local img = cfg.image_square(piece:match(pattern), row, col, size )  
root:tag('div')  
:css('position', 'absolute')  
:css('z-index', '3')  
:css('top', tostring(( trow - 1 ) * size) .. 'px')  
:css('', tostring(( tcol - 1 ) * size) .. 'px')  
:css('width', size .. 'px')  
:css('height', size .. 'px')  
:wikitext(img)  
end  
end  
end  

return tostring(root)  
end  

function chessboard(args, size, rev, letters, numbers, header, footer, align, clear)  
function letters_row( rev, num_lt, num_rt )  
local letters = cfg.letters  
local root = mw.html.create('')  
if num_lt then  
root:tag('td')  
:css('vertical-align', 'inherit')  
:css('padding', '0')  
end  
for k = 1,ncols do  
root:tag('td')  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:css('text-align', '')  
:css('height', '')  
:css('width', size .. 'px')  
:wikitext(rev and letters[1+ncols-k] or letters[k])  
end  
if num_rt then  
root:tag('td')  
:css('vertical-align', 'inherit')  
:css('padding', '0')  
end  
return tostring(root)  
end  

local letters_tp = letters:match( 'both' ) or letters:match( 'top' )  
local letters_bt = letters:match( 'both' ) or letters:match( 'bottom' )  
local numbers_lt = numbers:match( 'both' ) or numbers:match( '' )  
local numbers_rt = numbers:match( 'both' ) or numbers:match( '' )  
local width = ncols * size + 2  
if ( numbers_lt ) then width = width + 18 end  
if ( numbers_rt ) then width = width + 18 end  

local root = mw.html.create('div')  
:addClass('')  
:addClass('noviewer')  
:addClass(align)  
if( header and header ~= '' ) then  
root:tag('div'):addClass(''):css('line-height', '130%'):css('margin', '0 auto'):css('max-width', (width + ncols) .. 'px'):wikitext(header)  
end  
local div = root:tag('div')  
:addClass('thumbinner')  
:css('width', width .. 'px')  
local b = div:tag('table')  
:attr('cellpadding', '0')  
:attr('cellspacing', '0')  
:css('background', 'white')  
:css('font-size', '88%')  
:css('' , ' #c8ccd1 solid')  
:css('padding', '0')  
:css('margin', 'auto')  

if ( letters_tp ) then  
b:tag('tr')  
:css('vertical-align', 'middle')  
:wikitext(letters_row( rev, numbers_lt, numbers_rt ))  
end  
local tablerow = b:tag('tr'):css('vertical-align','middle')  
if ( numbers_lt ) then  
tablerow:tag('td')  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:css('text-align', '')  
:css('width', '')  
:css('height', size .. 'px')  
:wikitext(rev and 1 or nrows)  
end  
local td = tablerow:tag('td')  
:attr('colspan', ncols)  
:attr('rowspan', nrows)  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:wikitext(innerboard(args, size, rev))  

if ( numbers_rt ) then  
tablerow:tag('td')  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:css('text-align', '')  
:css('width', '')  
:css('height', size .. 'px')  
:wikitext(rev and 1 or nrows)  
end  
if ( numbers_lt or numbers_rt ) then  
for trow = 2, nrows do  
local idx = rev and trow or ( 1 + nrows - trow )  
tablerow = b:tag('tr')  
:css('vertical-align', 'middle')  
if ( numbers_lt ) then  
tablerow:tag('td')  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:css('text-align', '')  
:css('height', size .. 'px')  
:wikitext(idx)  
end  
if ( numbers_rt ) then  
tablerow:tag('td')  
:css('padding', '0')  
:css('vertical-align', 'inherit')  
:css('text-align', '')  
:css('height', size .. 'px')  
:wikitext(idx)  
end  
end  
end  
if ( letters_bt ) then  
b:tag('tr')  
:css('vertical-align', 'middle')  
:wikitext(letters_row( rev, numbers_lt, numbers_rt ))  
end  

if (footer and footer ~= '') then  
div:tag('div')  
:addClass('thumbcaption')  
:wikitext(footer)  
end  

return tostring(root)  
end  

function convertFenToArgs( fen )  
-- converts FEN notation to 64 entry array of positions, offset by 2  
local res = { ' ', ' ' }  
-- Loop over rows, which are delimited by /  
for srow in string.gmatch( "/" .. fen, "/%w+" ) do  
-- Loop over all letters and numbers in the row  
for piece in srow:gmatch( "%w" ) do  
if piece:match( "%d" ) then -- if a digit  
for k=1,piece do  
table.insert(res,' ')  
end  
else -- not a digit  
local color = piece:match( '%u' ) and 'l' or 'd'  
piece = piece:lower  
table.insert( res, piece .. color )  
end  
end  
end  

return res  
end  

function convertArgsToFen( args, offset )  
function nullOrWhitespace( s ) return not s or s:match( '^%s*(.-)%s*$' ) == '' end  
function piece( s )  
return nullOrWhitespace( s ) and 1  
or s:gsub( '%s*(%a)(%a)%s*', function( a, b ) return b == 'l' and a:upper or a end )  
end  

local res = ''  
offset = offset or 0  
for row = 1, 8 do  
for file = 1, 8 do  
res = res .. piece( args[8*(row - 1) + file + offset] )  
end  
if row < 8 then res = res .. '/' end  
end  
return mw.ustring.gsub(res, '1+', function( s ) return #s end )  
end  

function p.board  
local args = .args  
local pargs = :getParent.args  
local style = args.style or pargs.style or 'Chess'  
cfg = require('Module:Chessboard/' .. style)  
nrows, ncols = cfg.dims  

local size = args.size or pargs.size or '26'  
local reverse = ( args.reverse or pargs.reverse or '' ):lower == "true"  
local letters = ( args.letters or pargs.letters or 'both' ):lower  
local numbers = ( args.numbers or pargs.numbers or 'both' ):lower  
local header = args[2] or pargs[2] or ''  
local footer = args[nrows*ncols + 3] or pargs[nrows*ncols + 3] or ''  
local align = ( args[1] or pargs[1] or 'tright' ):lower  
local clear = args.clear or pargs.clear or ( align:match('tright') and * ) or *  
local fen = args.fen or pargs.fen  

size = mw.ustring.match( size, '[%d]+' ) or '26' -- remove px from size  
if (fen) then  
align = args.align or pargs.align or 'tright'  
clear = args.clear or pargs.clear or ( align:match('tright') and * ) or *  
header = args.header or pargs.header or ''  
footer = args.footer or pargs.footer or ''  
return chessboard( convertFenToArgs( fen ), size, reverse, letters, numbers, header, footer, align, clear )  
end  
if args[3] then  
return chessboard(args, size, reverse, letters, numbers, header, footer, align, clear)  
else  
return chessboard(pargs, size, reverse, letters, numbers, header, footer, align, clear)  
end  
end  

function p.fen2ascii  
---
local b = convertFenToArgs( .args.fen )  
local res = '|=\n'  
local offset = 2  
for row = 1,8 do  
local n = (9 - row)  
res = res .. n .. ' |' ..  
table.concat(b, '|', 8*(row-1) + 1 + offset, 8*(row-1) + 8 + offset) .. '|=\n'  
end  
res = mw.ustring.gsub( res,'\| \|', '| |' )  
res = mw.ustring.gsub( res,'\| \|', '| |' )  
return res .. ' a b c d e f g h'  
end  

function p.ascii2fen  
---
return convertArgsToFen( .args, .args.offset or 1 )  
end  

return p