1 files changed, 252 insertions, 0 deletions
diff --git a/lib/chessh/ssh/client/board/renderer.ex b/lib/chessh/ssh/client/board/renderer.ex
new file mode 100644
index 0000000..fa8648f
--- /dev/null
+++ b/lib/chessh/ssh/client/board/renderer.ex
@@ -0,0 +1,252 @@
+defmodule Chessh.SSH.Client.Board.Renderer do
+  alias IO.ANSI
+  alias Chessh.Utils
+  alias Chessh.SSH.Client.Board
+  require Logger
+
+  @chess_board_height 8
+  @chess_board_width 8
+
+  @tile_width 7
+  @tile_height 4
+
+  @from_select_background ANSI.light_blue_background()
+  @to_select_background ANSI.blue_background()
+  @dark_piece_color ANSI.light_red()
+  @light_piece_color ANSI.light_magenta()
+
+  def chess_board_height(), do: @chess_board_height
+  def chess_board_width(), do: @chess_board_width
+  def to_select_background(), do: @to_select_background
+  def from_select_background(), do: @from_select_background
+
+  def to_chess_coord({y, x})
+      when x >= 0 and x < @chess_board_width and y >= 0 and y < @chess_board_height do
+    "#{List.to_string([?a + x])}#{@chess_board_height - y}"
+  end
+
+  def render_board_state(fen, %Board.State{
+        width: _width,
+        height: _height,
+        highlighted: highlighted,
+        flipped: flipped
+      }) do
+    board =
+      draw_board(
+        fen,
+        {@tile_width, @tile_height},
+        highlighted,
+        flipped
+      )
+
+    [ANSI.home()] ++
+      Enum.map(
+        Enum.zip(1..length(board), board),
+        fn {i, line} ->
+          [ANSI.cursor(i, 0), line]
+        end
+      )
+  end
+
+  defp tileIsLight(row, col) do
+    rem(row, 2) == rem(col, 2)
+  end
+
+  defp piece_type(char) do
+    case String.capitalize(char) do
+      "P" -> "pawn"
+      "N" -> "knight"
+      "R" -> "rook"
+      "B" -> "bishop"
+      "K" -> "king"
+      "Q" -> "queen"
+      _ -> nil
+    end
+  end
+
+  defp skip_cols_or_place_piece_reduce(char, {curr_column, data}, rowI) do
+    case Integer.parse(char) do
+      {skip, ""} ->
+        {curr_column + skip, data}
+
+      _ ->
+        case piece_type(char) do
+          nil ->
+            {curr_column, data}
+
+          type ->
+            shade = if(char == String.capitalize(char), do: "light", else: "dark")
+
+            {curr_column + 1,
+             Map.put(
+               data,
+               "#{rowI}, #{curr_column}",
+               {shade, type}
+             )}
+        end
+    end
+  end
+
+  defp make_coordinate_to_piece_art_map(fen) do
+    rows =
+      String.split(fen, " ")
+      |> List.first()
+      |> String.split("/")
+
+    Enum.zip(rows, 0..(length(rows) - 1))
+    |> Enum.map(fn {row, rowI} ->
+      {@chess_board_height, pieces_per_row} =
+        Enum.reduce(
+          String.split(row, ""),
+          {0, %{}},
+          &skip_cols_or_place_piece_reduce(&1, &2, rowI)
+        )
+
+      pieces_per_row
+    end)
+    |> Enum.reduce(%{}, fn pieces_map_for_this_row, acc ->
+      Map.merge(acc, pieces_map_for_this_row)
+    end)
+  end
+
+  defp draw_board(
+         fen,
+         {tile_width, tile_height} = tile_dims,
+         highlights,
+         flipped
+       ) do
+    coordinate_to_piece = make_coordinate_to_piece_art_map(fen)
+    board = make_board(tile_dims)
+
+    (Enum.zip_with([board, 0..(length(board) - 1)], fn [row_str, row] ->
+       curr_y = div(row, tile_height)
+
+       %{row_chars: row_chars} =
+         Enum.reduce(
+           Enum.zip(String.graphemes(row_str), 0..(String.length(row_str) - 1)),
+           %{current_color: ANSI.black(), row_chars: []},
+           fn {char, col}, %{current_color: current_color, row_chars: row_chars} = row_state ->
+             curr_x = div(col, tile_width)
+
+             key =
+               "#{if !flipped, do: curr_y, else: @chess_board_height - curr_y - 1}, #{if !flipped, do: curr_x, else: @chess_board_width - curr_x - 1}"
+
+             relative_to_tile_col = col - curr_x * tile_width
+
+             prefix =
+               if relative_to_tile_col == 0 do
+                 case Map.fetch(highlights, {curr_y, curr_x}) do
+                   {:ok, color} ->
+                     color
+
+                   _ ->
+                     ANSI.default_background()
+                 end
+               end
+
+             {color, row_chars} =
+               case Map.fetch(coordinate_to_piece, key) do
+                 {:ok, {shade, type}} ->
+                   piece = Utils.ascii_chars()["pieces"][shade][type]
+                   piece_line = Enum.at(piece, row - curr_y * tile_height)
+                   pad_left_right = div(tile_width - String.length(piece_line), 2)
+
+                   if relative_to_tile_col >= pad_left_right &&
+                        relative_to_tile_col < tile_width - pad_left_right do
+                     piece_char = String.at(piece_line, relative_to_tile_col - pad_left_right)
+                     new_char = if piece_char == " ", do: char, else: piece_char
+
+                     color =
+                       if piece_char == " ",
+                         do: ANSI.default_color(),
+                         else:
+                           if(shade == "dark", do: @dark_piece_color, else: @light_piece_color)
+
+                     if color != current_color do
+                       {color, row_chars ++ [prefix, color, new_char]}
+                     else
+                       {current_color, row_chars ++ [prefix, new_char]}
+                     end
+                   else
+                     {ANSI.default_color(), row_chars ++ [prefix, ANSI.default_color(), char]}
+                   end
+
+                 _ ->
+                   if ANSI.default_color() != current_color do
+                     {ANSI.default_color(), row_chars ++ [prefix, ANSI.default_color(), char]}
+                   else
+                     {current_color, row_chars ++ [prefix, char]}
+                   end
+               end
+
+             %{
+               row_state
+               | current_color: color,
+                 row_chars: row_chars
+             }
+           end
+         )
+
+       curr_num =
+         Utils.ascii_chars()["numbers"][
+           Integer.to_string(if flipped, do: curr_y + 1, else: @chess_board_height - curr_y)
+         ]
+
+       curr_num_line_no = rem(row, @tile_height)
+
+       Enum.join(
+         [
+           String.pad_trailing(
+             if(curr_num_line_no < length(curr_num),
+               do: Enum.at(curr_num, curr_num_line_no),
+               else: ""
+             ),
+             @tile_width
+           )
+         ] ++ row_chars,
+         ""
+       )
+     end) ++ column_coords(flipped))
+    |> Enum.map(fn row_line -> "#{ANSI.default_background()}#{row_line}" end)
+  end
+
+  defp column_coords(flipped) do
+    Enum.map(0..(@tile_height - 1), fn row ->
+      String.duplicate(" ", @tile_width) <>
+        (Enum.map(
+           if(!flipped, do: 0..(@chess_board_width - 1), else: (@chess_board_width - 1)..0),
+           fn col ->
+             curr_letter = Utils.ascii_chars()["letters"][List.to_string([?a + col])]
+             curr_letter_line_no = rem(row, @tile_height)
+
+             curr_line =
+               if(curr_letter_line_no < length(curr_letter),
+                 do: Enum.at(curr_letter, curr_letter_line_no),
+                 else: ""
+               )
+
+             center_prefix_len = div(@tile_width - String.length(curr_line), 2)
+
+             String.pad_trailing(
+               String.duplicate(" ", center_prefix_len) <> curr_line,
+               @tile_width
+             )
+           end
+         )
+         |> Enum.join(""))
+    end)
+  end
+
+  defp make_board({tile_width, tile_height}) do
+    rows =
+      Enum.map(0..(@chess_board_height - 1), fn row ->
+        Enum.map(0..(@chess_board_width - 1), fn col ->
+          if(tileIsLight(row, col), do: '▊', else: ' ')
+          |> List.duplicate(tile_width)
+        end)
+        |> Enum.join("")
+      end)
+
+    Enum.flat_map(rows, fn row -> Enum.map(1..tile_height, fn _ -> row end) end)
+  end
+end