export function parseCommandArgs(argsString: string): string[] {
	const args: string[] = [];
	let current = "";
	let inQuote: string | null = null;

	for (let i = 0; i < argsString.length; i++) {
		const char = argsString[i];

		if (inQuote) {
			if (char === inQuote) {
				inQuote = null;
			} else {
				current += char;
			}
		} else if (char === '"' || char === "'") {
			inQuote = char;
		} else if (char === " " || char === "\t") {
			if (current) {
				args.push(current);
				current = "";
			}
		} else {
			current += char;
		}
	}

	if (current) {
		args.push(current);
	}

	return args;
}

/**
 * Substitute argument placeholders in template content
 * Supports $1, $2, ... for positional args, $@ and $ARGUMENTS for all args
 *
 * Note: Replacement happens on the template string only. Argument values
 * containing patterns like $1, $@, or $ARGUMENTS are NOT recursively substituted.
 */
export function substituteArgs(content: string, args: string[]): string {
	let result = content;

	// Replace $1, $2, etc. with positional args FIRST (before wildcards)
	// This prevents wildcard replacement values containing $<digit> patterns from being re-substituted
	result = result.replace(/\$(\d+)/g, (_, num) => {
		const index = parseInt(num, 10) - 1;
		return args[index] ?? "";
	});

	result = result.replace(/\$@\[(\d+)(?::(\d*)?)?\]/g, (_, startRaw: string, lengthRaw?: string) => {
		const start = Number.parseInt(startRaw, 10);
		if (!Number.isFinite(start) || start < 1) return "";
		const startIndex = start - 1;
		if (startIndex >= args.length) return "";

		if (lengthRaw === undefined || lengthRaw === "") {
			return args.slice(startIndex).join(" ");
		}

		const length = Number.parseInt(lengthRaw, 10);
		if (!Number.isFinite(length) || length <= 0) return "";
		return args.slice(startIndex, startIndex + length).join(" ");
	});

	// Pre-compute all args joined (optimization)
	const allArgs = args.join(" ");

	// Replace $ARGUMENTS with all args joined (new syntax, aligns with Claude, Codex, OpenCode)
	result = result.replaceAll("$ARGUMENTS", allArgs);

	// Replace $@ with all args joined (existing syntax)
	result = result.replaceAll("$@", allArgs);

	return result;
}