From bff9fd0a6ae8b1f034e4d20007b442957539e7ec Mon Sep 17 00:00:00 2001
From: Simponic <loganhunt@simponic.xyz>
Date: Wed, 4 Jan 2023 20:43:32 -0700
Subject: [PATCH] Well it's drawing *something*

---
 lib/chessh/ssh/screens/board.ex | 101 +++++++++++++++++++++++++++++++-
 priv/ascii_chars.json           |   4 +-
 2 files changed, 101 insertions(+), 4 deletions(-)

diff --git a/lib/chessh/ssh/screens/board.ex b/lib/chessh/ssh/screens/board.ex
index c95049f..9b18295 100644
--- a/lib/chessh/ssh/screens/board.ex
+++ b/lib/chessh/ssh/screens/board.ex
@@ -11,12 +11,109 @@ defmodule Chessh.SSH.Client.Board do
 
   use Chessh.SSH.Client.Screen
 
+  @chess_board_height 8
+  @chess_board_width 8
+
+  def tileIsLight(row, col) do
+    rem(row, 2) == rem(col, 2)
+  end
+
+  def piece_type(char) do
+    case String.capitalize(char) do
+      "P" -> "pawn"
+      "N" -> "knight"
+      "R" -> "rook"
+      "B" -> "bishop"
+      "K" -> "king"
+      "Q" -> "queen"
+      _ -> nil
+    end
+  end
+
+  def make_board({tile_width, tile_height}) do
+    rows =
+      Enum.map(0..(@chess_board_height - 1), fn i ->
+        Enum.map(0..(@chess_board_width - 1), fn j ->
+          List.duplicate(if(tileIsLight(i, j), do: ' ', else: '#'), tile_width)
+        end)
+      end)
+
+    Enum.flat_map(rows, fn row -> Enum.map(1..tile_height, fn _ -> row end) end)
+  end
+
+  def make_board(fen, {tile_width, tile_height} = tile_dims) do
+    rows =
+      String.split(fen, " ")
+      |> List.first()
+      |> String.split("/")
+
+    coordinate_to_piece =
+      Enum.zip(rows, 0..(length(rows) - 1))
+      |> Enum.map(fn {row, rowI} ->
+        {@chess_board_height, pieces_per_row} =
+          Enum.reduce(
+            String.split(row, ""),
+            {0, %{}},
+            fn char, {curr_column, data} ->
+              case Integer.parse(char) do
+                {skip, ""} ->
+                  {curr_column + skip, data}
+
+                _ ->
+                  case piece_type(char) do
+                    nil ->
+                      {curr_column, data}
+
+                    type ->
+                      {curr_column + 1,
+                       Map.put(
+                         data,
+                         "#{rowI}, #{curr_column}",
+                         @ascii_chars["pieces"][
+                           if(char != String.capitalize(char), do: "light", else: "dark")
+                         ][type]
+                       )}
+                  end
+              end
+            end
+          )
+
+        pieces_per_row
+      end)
+      |> Enum.reduce(%{}, fn pieces_map_for_this_row, acc ->
+        Map.merge(acc, pieces_map_for_this_row)
+      end)
+
+    board = make_board(tile_dims)
+
+    Enum.zip_with([board, 1..length(board)], fn [row, rowI] ->
+      curr_y = div(rowI, tile_height)
+
+      Enum.zip_with([row, 1..length(row)], fn [char, col] ->
+        curr_x = div(col, tile_width)
+        key = "#{rowI}, #{col}"
+
+        if Map.has_key?(coordinate_to_piece, key) do
+          piece_char =
+            Map.fetch!(coordinate_to_piece, key)
+            |> Enum.at(rowI - curr_y * tile_height)
+            |> String.at(col - curr_x * tile_width)
+
+          if piece_char == " ", do: String.Chars.to_string(char), else: piece_char
+        else
+          char
+        end
+      end)
+      |> Enum.join("")
+    end)
+  end
+
   def render(%Client.State{} = _state) do
-    knight = @ascii_chars["pieces"]["white"]["knight"]
+    board = make_board("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1", {9, 5})
 
     [ANSI.home()] ++
       Enum.map(
-        Enum.zip(0..(length(knight) - 1), knight),
+        Enum.zip(0..(length(board) - 1), board),
         fn {i, line} ->
           [ANSI.cursor(i, 0), line]
         end
diff --git a/priv/ascii_chars.json b/priv/ascii_chars.json
index e50be22..58a7cb0 100644
--- a/priv/ascii_chars.json
+++ b/priv/ascii_chars.json
@@ -94,7 +94,7 @@
     ]
   },
   "pieces": {
-    "white": {
+    "light": {
       "rook": [
         "         ",
         "  [`'`'] ",
@@ -137,7 +137,7 @@
         "         "
       ]
     },
-    "black": {
+    "dark": {
       "rook": [
         "         ",
         "  [`'`'] ",