--[[
crypto.lua - Cryptographic functions powered by Go
]]--

-- ======================================================================
-- HASHING FUNCTIONS
-- ======================================================================

-- Generate hash digest using various algorithms
-- Algorithms: md5, sha1, sha256, sha512
-- Formats: hex (default), binary
function hash(data, algorithm, format)
	if type(data) ~= "string" then
		error("hash: data must be a string", 2)
	end
	
	algorithm = algorithm or "sha256"
	format = format or "hex"
	
	return __crypto_hash(data, algorithm, format)
end

function md5(data, format)
	return hash(data, "md5", format)
end

function sha1(data, format)
	return hash(data, "sha1", format)
end

function sha256(data, format)
	return hash(data, "sha256", format)
end

function sha512(data, format)
	return hash(data, "sha512", format)
end

-- ======================================================================
-- HMAC FUNCTIONS
-- ======================================================================

-- Generate HMAC using various algorithms
-- Algorithms: md5, sha1, sha256, sha512
-- Formats: hex (default), binary
function hmac(data, key, algorithm, format)
	if type(data) ~= "string" then
		error("hmac: data must be a string", 2)
	end
	
	if type(key) ~= "string" then
		error("hmac: key must be a string", 2)
	end
	
	algorithm = algorithm or "sha256"
	format = format or "hex"
	
	return __crypto_hmac(data, key, algorithm, format)
end

function hmac_md5(data, key, format)
	return hmac(data, key, "md5", format)
end

function hmac_sha1(data, key, format)
	return hmac(data, key, "sha1", format)
end

function hmac_sha256(data, key, format)
	return hmac(data, key, "sha256", format)
end

function hmac_sha512(data, key, format)
	return hmac(data, key, "sha512", format)
end

-- ======================================================================
-- RANDOM FUNCTIONS
-- ======================================================================

-- Generate random bytes
-- Formats: binary (default), hex
function random_bytes(length, secure, format)
	if type(length) ~= "number" or length <= 0 then
		error("random_bytes: length must be positive", 2)
	end
	
	secure = secure ~= false -- Default to secure
	format = format or "binary"
	
	return __crypto_random_bytes(length, secure, format)
end

-- Generate random integer in range [min, max]
function random_int(min, max, secure)
	if type(min) ~= "number" or type(max) ~= "number" then
		error("random_int: min and max must be numbers", 2)
	end
	
	if max <= min then
		error("random_int: max must be greater than min", 2)
	end
	
	secure = secure ~= false -- Default to secure
	
	return __crypto_random_int(min, max, secure)
end

-- Generate random string of specified length
function random_string(length, charset, secure)
	if type(length) ~= "number" or length <= 0 then
		error("random_string: length must be positive", 2)
	end
	
	secure = secure ~= false -- Default to secure
	
	-- Default character set: alphanumeric
	charset = charset or "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
	
	if type(charset) ~= "string" or #charset == 0 then
		error("random_string: charset must be non-empty", 2)
	end
	
	local result = ""
	local charset_length = #charset
	
	for i = 1, length do
		local index = random_int(1, charset_length, secure)
		result = result .. charset:sub(index, index)
	end
	
	return result
end

-- ======================================================================
-- UUID FUNCTIONS
-- ======================================================================

-- Generate random UUID (v4)
function uuid()
	return __crypto_uuid()
end