--[[
Lua wrapper for OpenCC.

--]]

local ffi = require("ffi")
local opencc = ffi.load("/usr/lib64/libopencc.so.2")

-- Define C API bindings
ffi.cdef[[
    typedef void* opencc_t;
    opencc_t opencc_open(const char* configFileName);
    opencc_t opencc_open_w(const wchar_t* configFileName);
    int opencc_close(opencc_t opencc);
    size_t opencc_convert_utf8_to_buffer(opencc_t opencc, const char* input, size_t length, char* output);
    char* opencc_convert_utf8(opencc_t opencc, const char* input, size_t length);
    void opencc_convert_utf8_free(char* str);
    const char* opencc_error(void);
]]

local _M = {}

--[[
Function to convert input string according to given configuration.

Parameters:
@input: input string, cannot be null
@config: opencc configuration file, can be "t2s.json", "s2t.json" or custom file path.

Returns:
the converted string
--]]
function _M.convert(input, config)
    local opencc_instance = opencc.opencc_open(config)
    local cd = opencc.opencc_convert_utf8(opencc_instance, input, -1)
    local ret = ffi.string(cd)
    opencc.opencc_convert_utf8_free(cd)
    opencc.opencc_close(opencc_instance)
    return ret
end

return _M