package net.minecraft.commands.functions;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableList.Builder;
import java.util.List;

public record StringTemplate(List<String> segments, List<String> variables) {
	public static StringTemplate fromString(final String input) {
		Builder<String> segments = ImmutableList.builder();
		Builder<String> variables = ImmutableList.builder();
		int length = input.length();
		int start = 0;
		int index = input.indexOf(36);

		while (index != -1) {
			if (index != length - 1 && input.charAt(index + 1) == '(') {
				segments.add(input.substring(start, index));
				int variableEnd = input.indexOf(41, index + 1);
				if (variableEnd == -1) {
					throw new IllegalArgumentException("Unterminated macro variable");
				}

				String variable = input.substring(index + 2, variableEnd);
				if (!isValidVariableName(variable)) {
					throw new IllegalArgumentException("Invalid macro variable name '" + variable + "'");
				}

				variables.add(variable);
				start = variableEnd + 1;
				index = input.indexOf(36, start);
			} else {
				index = input.indexOf(36, index + 1);
			}
		}

		if (start == 0) {
			throw new IllegalArgumentException("No variables in macro");
		} else {
			if (start != length) {
				segments.add(input.substring(start));
			}

			return new StringTemplate(segments.build(), variables.build());
		}
	}

	public static boolean isValidVariableName(final String variable) {
		for (int i = 0; i < variable.length(); i++) {
			char character = variable.charAt(i);
			if (!Character.isLetterOrDigit(character) && character != '_') {
				return false;
			}
		}

		return true;
	}

	public String substitute(final List<String> arguments) {
		StringBuilder builder = new StringBuilder();

		for (int i = 0; i < this.variables.size(); i++) {
			builder.append((String)this.segments.get(i)).append((String)arguments.get(i));
			CommandFunction.checkCommandLineLength(builder);
		}

		if (this.segments.size() > this.variables.size()) {
			builder.append((String)this.segments.getLast());
		}

		CommandFunction.checkCommandLineLength(builder);
		return builder.toString();
	}
}