/* 
 * tabcompletion.cpp
 * Tab completion module
 * Copyright (c) 2026 Daniel Hammer
 */ 

#include <montauk/string.h>
#include <montauk/syscall.h>

#define RD_MAX 128

/*
	Does the file path end with .elf? 
*/
bool is_executable(const char* path) {
	size_t len = montauk::slen(path);

	if (path[len - 1] == 'f' &&
		path[len - 2] == 'l' &&
		path[len - 3] == 'e' && 
		path[len - 4] == '.')
	{
		return true;
	}

	return false;
}

/*
	i.e., "shell.elf" => "shell"
*/
const char* strip_elf_extension(const char* path) {
	size_t len = montauk::slen(path);

	char* p = (char* ) path;
	p[len - 4] = '\0';

	return (const char*)p;
}

int get_completions(		// returns no. of results 
		char*	string, 	// String to match/complete
		char**	array, 		// Array of strings containing completions
		int	arrayMax
	) {
	
	const char* names[RD_MAX] 	= { };

	int n = montauk::readdir("0:/os", names, RD_MAX);
	int r = 0;

	for (int i = 0; i < n; i++) {
		/*
			Shift by 3 characters (names[i] + 3):
				"os/shell.elf" => "shell.elf"

			This is somewhat of a workaround. 
		*/
		if (montauk::starts_with(names[i] + 3, (const char*)string)) {
			if (r > arrayMax)
				break;

			if (!is_executable(names[i]))
				continue;

			char* p = (char *)names[i] + 3;
			strip_elf_extension(p);

			array[r] = (char *)p;
			r++;
		} 
	}

	return r;
}