almost done with chess app

It's still not very legible.

chesstv.tlv

@@ -4,9 +4,92 @@ window = curses.stdscr()
 -- animation-based app
 window:nodelay(true)
 lines, cols = window:getmaxyx()]==],
+  current_game = [==[current_game = {}]==],
+  piece_glyph = [==[
+piece_glyph = {
+  K = 0x2654,
+  Q = 0x2655,
+  R = 0x2656,
+  B = 0x2657,
+  N = 0x2658,
+  P = 0x2659,
+  k = 0x265a,
+  q = 0x265b,
+  r = 0x265c,
+  b = 0x265d,
+  n = 0x265e,
+  p = 0x265f,
+}]==],
+  top_player = [==[
+function top_player(current_game)
+  if current_game.players[1].color ~= current_game.orientation then
+    return current_game.players[1]
+  end
+  return current_game.players[2]
+end]==],
+  bottom_player = [==[
+function bottom_player(current_game)
+  if current_game.players[1].color == current_game.orientation then
+    return current_game.players[1]
+  end
+  return current_game.players[2]
+end]==],
+  render_player = [==[
+function render_player(y, x, player)
+  curses.mvaddstr(y, x, player.user.name)
+  curses.addstr(" · ")
+  curses.addstr(tostring(player.rating))
+end]==],
+  render_square = [==[
+function render_square(current_game, rank, file)
+  if (rank+file)%2 == 1 then
+    curses.attrset(curses.A_REVERSE)
+  end
+  curses.mvaddstr(rank*3,   file*5, "     ")
+  curses.mvaddstr(rank*3+1, file*5, "     ")
+  curses.mvaddstr(rank*3+2, file*5, "     ")
+  curses.attrset(curses.A_NORMAL)
+end]==],
+  render_fen_rank = [==[
+function render_fen_rank(rank, fen_rank)
+  local file = 1
+  for x in fen_rank:gmatch(".") do
+    if x:match("%d") then
+      file = file + tonumber(x)
+    else  -- if x ~= nil then
+      if (rank+file)%2 == 1 then
+        curses.attrset(curses.A_REVERSE)
+      end
+      curses.mvaddstr(rank*3+1, file*5+2, utf8(piece_glyph[x]))
+      curses.attrset(curses.A_NORMAL)
+      file = file + 1
+    end
+  end
+end]==],
+  render_board = [==[
+function render_board(current_game)
+  render_player(2, 5, top_player(current_game))
+  for rank=1,8 do
+    for file=1,8 do
+      render_square(current_game, rank, file)
+    end
+    render_fen_rank(rank, current_game.fen_rank[rank])
+  end
+  render_player(27, 5, bottom_player(current_game))
+end]==],
   render = [==[
 function render(chunk)
-  curses.mvaddstr(5, 5, chunk)
+  local o = json.decode(chunk)
+  if o.t == "featured" then
+    current_game = o.d
+  else
+    current_game.fen = o.d.fen
+    current_game.wc = o.d.wc
+    current_game.bc = o.d.bc
+    -- todo: o.d.lm to highlight the last move?
+  end
+  current_game.fen_rank = split(current_game.fen, "%w+")
+  render_board(current_game)
   curses.refresh()
 end]==],
   main = [==[
@@ -23,7 +106,33 @@ function main()
            end,
   }
   http.request(request)
-  curses.getch()
+end]==],
+  utf8 = [==[
+-- https://stackoverflow.com/questions/7983574/how-to-write-a-unicode-symbol-in-lua
+function utf8(decimal)
+  local bytemarkers = { {0x7FF,192}, {0xFFFF,224}, {0x1FFFFF,240} }
+  if decimal<128 then return string.char(decimal) end
+  local charbytes = {}
+  for bytes,vals in ipairs(bytemarkers) do
+    if decimal<=vals[1] then
+      for b=bytes+1,2,-1 do
+        local mod = decimal%64
+        decimal = (decimal-mod)/64
+        charbytes[b] = string.char(128+mod)
+      end
+      charbytes[1] = string.char(vals[2]+decimal)
+      break
+    end
+  end
+  return table.concat(charbytes)
+end]==],
+  split = [==[
+function split(s, pat)
+  result = {}
+  for x in s:gmatch(pat) do
+    table.insert(result, x)
+  end
+  return result
 end]==],
   dump = [==[
 -- https://stackoverflow.com/questions/9168058/how-to-dump-a-table-to-console