content: package org.allaymc.api.item.recipe;
  
  import lombok.Getter;
  import org.allaymc.api.item.ItemStack;
  import org.allaymc.api.item.recipe.descriptor.ItemDescriptor;
  import org.allaymc.api.item.recipe.input.CraftingRecipeInput;
  import org.allaymc.api.item.recipe.input.RecipeInput;
  import org.allaymc.api.utils.identifier.Identifier;
  
  import java.util.Arrays;
  import java.util.List;
  import java.util.Map;
  
  import static org.allaymc.api.item.type.ItemTypes.AIR;
  
  /**
   * Represents a shaped recipe.
   *
   * @author daoge_cmd
   */
  @Getter
  public class ShapedRecipe extends Recipe {
  
      /**
       * The character that represents an empty key in the pattern.
       */
      public static final char EMPTY_KEY_CHAR = ' ';
      protected static final ItemStack[][] EMPTY_ITEM_STACK_ARRAY = new ItemStack[0][0];
  
      protected Map<Character, ItemDescriptor> keys;
      protected char[][] pattern;
  
      public ShapedRecipe(Identifier identifier, ItemStack[] outputs, int priority, char[][] pattern, Map<Character, ItemDescriptor> keys) {
          super(identifier, outputs, priority);
          this.pattern = pattern;
          this.keys = keys;
      }
  
      @Override
      public boolean match(RecipeInput input) {
          if (!(input instanceof CraftingRecipeInput(ItemStack[][] items))) return false;
  
          var inputs = removeUselessRowAndColumn(items);
          // Empty input isn't allowed
          if (inputs.length == 0 ||
              inputs.length > pattern.length ||
              inputs[0].length > pattern[0].length) {
              return false;
          }
  
          for (int i = 0, patternLength = pattern.length; i < patternLength; i++) {
              var row = pattern[i];
              for (int j = 0, rowLength = row.length; j < rowLength; j++) {
                  var key = row[j];
                  var item = inputs[i][j];
                  if (key == EMPTY_KEY_CHAR) {
                      if (!item.getItemType().equals(AIR)) {
                          return false;
                      }
                  } else {
                      var descriptor = keys.get(key);
                      if (!descriptor.match(item)) {
                          return false;
                      }
                  }
              }
          }
  
          return true;
      }
  
      // @formatter:off
      /**
       * Remove useless row and column。
       *
       * @param inputs <pre>
       *               {@code
       *               [o, o, x]    [x, o, o]
       *               [o, o, x] or [x, o, o] or etc...
       *               [x, x, x]    [x, x, x]
       *               }
       *               </pre>
       *
       * @return <pre>
       *     {@code
       *     [o, o]
       *     [o, o]
       *     }
       * </pre>
       */
      // @formatter:on
      protected ItemStack[][] removeUselessRowAndColumn(ItemStack[][] inputs) {
          int
                  startRow = 0,
                  endRow = inputs.length - 1;
          for (int row = 0; row < inputs.length; row++) {
              if (notAllEmptyRow(inputs[row])) {
                  startRow = row;
                  break;
              }
  
              // If all are air, return empty array directly
              if (row == inputs.length - 1) return EMPTY_ITEM_STACK_ARRAY;
          }
  
          for (int row = inputs.length - 1; row >= 0; row--) {
              if (notAllEmptyRow(inputs[row])) {
                  endRow = row;
                  break;
              }
          }
  
          int
                  startColumn = 0,
                  endColumn = inputs[0].length - 1;
          for (int column = 0; column < inputs[0].length; column++) {
              if (notAllEmptyColumn(inputs, column)) {
                  startColumn = column;
                  break;
              }
          }
  
          for (int column = inputs[0].length - 1; column >= 0; column--) {
              if (notAllEmptyColumn(inputs, column)) {
                  endColumn = column;
                  break;
              }
          }
  
          if (startRow == 0 && endRow == inputs.length - 1 &&
              startColumn == 0 && endColumn == inputs[0].length - 1
          ) return inputs;
  
          var result = new ItemStack[endRow - startRow + 1][endColumn - startColumn + 1];
          for (int row = startRow; row <= endRow; row++) {
              if (endColumn + 1 - startColumn >= 0)
                  System.arraycopy(inputs[row], startColumn, result[row - startRow], 0, endColumn + 1 - startColumn);
          }
  
          return result;
      }
  
      protected boolean notAllEmptyRow(ItemStack[] inputs) {
          return Arrays.stream(inputs).anyMatch(item -> item.getItemType() != AIR);
      }
  
      protected boolean notAllEmptyColumn(ItemStack[][] inputs, int column) {
          return Arrays.stream(inputs).anyMatch(row -> row[column].getItemType() != AIR);
      }
  
      public interface PatternHelper {
          static char[][] build(
                  char a, char b, char c,
                  char d, char e, char f,
                  char g, char h, char i
          ) {
              return new char[][]{
                      {a, b, c},
                      {d, e, f},
                      {g, h, i}
              };
          }
  
          static char[][] build(
                  char a, char b,
                  char c, char d
          ) {
              return new char[][]{
                      {a, b},
                      {c, d}
              };
          }
  
          static char[][] build(char a) {
              return new char[][]{{a}};
          }
  
          static char[][] build(String l1, String l2, String l3) {
              return new char[][]{
                      l1.toCharArray(),
                      l2.toCharArray(),
                      l3.toCharArray()
              };
          }
  
          static char[][] build(String l1, String l2) {
              return new char[][]{
                      l1.toCharArray(),
                      l2.toCharArray()
              };
          }
  
          static char[][] build(List<String> stringList) {
              var commonLength = stringList.getFirst().length();
              var pattern = new char[stringList.size()][commonLength];
              for (int row = 0; row < stringList.size(); row++) {
                  var line = stringList.get(row);
                  if (line.length() != commonLength)
                      throw new IllegalArgumentException("All row in pattern must have the same length");
  
                  var charArray = line.toCharArray();
                  System.arraycopy(charArray, 0, pattern[row], 0, charArray.length);
              }
  
              return pattern;
          }
      }
  }
  