#include "CodegenDecl.hpp"

#include <Utils.hpp>

static EnumValuePattern NextPattern(EnumValuePattern val) {
	return (EnumValuePattern)(val + 1);
}

EnumValuePattern DeclEnum::CalcPattern() const {
	if (elements.empty()) return EVP_Continuous;

	auto pattern = EVP_Continuous;
restart:
	auto lastVal = elements[0].value;
	for (size_t i = 1; i < elements.size(); ++i) {
		auto currVal = elements[i].value;
		switch (pattern) {
			case EVP_Continuous: {
				bool satisfy = lastVal + 1 == currVal;
				if (!satisfy) {
					pattern = NextPattern(pattern);
					goto restart;
				}
			} break;

			case EVP_Bits: {
				bool satisfy = (lastVal << 1) == currVal;
				if (!satisfy) {
					pattern = NextPattern(pattern);
					goto restart;
				}
			} break;

			// A random pattern can match anything
			case EVP_Random:
			case EVP_COUNT: break;
		}
		lastVal = currVal;
	}

	return pattern;
}

void DeclEnum::CalcPatternIfNecessary() {
	if (pattern == EVP_COUNT) {
		CalcPattern();
	}
}