package protocol

// Match the input against the magic string pattern.
//
//   - '?' matches any single character
//   - '*' matches zero or more characters
//   - '\' escapes special characters ('?', '*', '\')
//   - all other characters must match exactly
//
// Returns true if all magic bytes are matched, even if the input has extra bytes.
func Match(magic string, input []byte) bool {
	if len(magic) == 0 {
		return true
	}
	return match(magic, input, 0, 0)
}

// match is a recursive helper function that implements the matching logic
func match(magic string, input []byte, magicIndex, inputIndex int) bool {
	// If we've reached the end of magic string, we've successfully matched all magic bytes
	// It doesn't matter if there are extra bytes in the input
	if magicIndex == len(magic) {
		return true
	}

	// Handle escape character
	if magic[magicIndex] == '\\' {
		// Check if there's a next character in magic
		if magicIndex+1 >= len(magic) {
			// Backslash at end of magic string - treat as literal backslash
			if inputIndex >= len(input) || input[inputIndex] != '\\' {
				return false
			}
			return match(magic, input, magicIndex+1, inputIndex+1)
		}

		// Escape the next character - we need to match it literally
		escapedChar := magic[magicIndex+1]
		if inputIndex >= len(input) || input[inputIndex] != escapedChar {
			return false
		}
		// Skip both the backslash and the escaped character in magic, move one in input
		return match(magic, input, magicIndex+2, inputIndex+1)
	}

	// If we've reached the end of input but not magic string
	if inputIndex == len(input) {
		// If we have '*' at the current position, it can match zero characters
		if magic[magicIndex] == '*' {
			return match(magic, input, magicIndex+1, inputIndex)
		}
		return false
	}

	// Handle '*' character - matches zero or more characters
	if magic[magicIndex] == '*' {
		// Try matching zero characters
		if match(magic, input, magicIndex+1, inputIndex) {
			return true
		}
		// Try matching one or more characters
		if inputIndex < len(input) && match(magic, input, magicIndex, inputIndex+1) {
			return true
		}
		return false
	}

	// Handle '?' character - matches any single character
	if magic[magicIndex] == '?' {
		return match(magic, input, magicIndex+1, inputIndex+1)
	}

	// Handle exact character match
	if magic[magicIndex] == input[inputIndex] {
		return match(magic, input, magicIndex+1, inputIndex+1)
	}

	// No match found
	return false
}