'use strict';

/**
 * Module dependencies.
 */

const ref = require('ref-napi');
const assert = require('assert');
const debug = require('debug')('ffi:ffi');
const Struct = require('ref-struct-di')(ref);
const bindings = require('./bindings');

/**
 * Export some of the properties from the "bindings" file.
 */

['FFI_TYPES',
 'FFI_OK', 'FFI_BAD_TYPEDEF', 'FFI_BAD_ABI',
 'FFI_DEFAULT_ABI', 'FFI_FIRST_ABI', 'FFI_LAST_ABI', 'FFI_SYSV', 'FFI_UNIX64',
 'FFI_WIN64', 'FFI_VFP', 'FFI_STDCALL', 'FFI_THISCALL', 'FFI_FASTCALL',
 'RTLD_LAZY', 'RTLD_NOW', 'RTLD_LOCAL', 'RTLD_GLOBAL', 'RTLD_NOLOAD',
 'RTLD_NODELETE', 'RTLD_FIRST', 'RTLD_NEXT', 'RTLD_DEFAULT', 'RTLD_SELF',
 'RTLD_MAIN_ONLY', 'FFI_MS_CDECL'].forEach(prop => {
  if (!bindings.hasOwnProperty(prop)) {
    return debug('skipping exporting of non-existant property', prop);
  }
  const desc = Object.getOwnPropertyDescriptor(bindings, prop);
  Object.defineProperty(exports, prop, desc);
});

/**
 * Set the `ffi_type` property on the built-in types.
 */

Object.keys(bindings.FFI_TYPES).forEach(name => {
  const type = bindings.FFI_TYPES[name];
  type.name = name;
  if (name === 'pointer')
    return; // there is no "pointer" type...
  ref.types[name].ffi_type = type;
});

// make `size_t` use the "ffi_type_pointer"
ref.types.size_t.ffi_type = bindings.FFI_TYPES.pointer;

// make `Utf8String` use "ffi_type_pointer"
const CString = ref.types.CString || ref.types.Utf8String;
CString.ffi_type = bindings.FFI_TYPES.pointer;

// make `Object` use the "ffi_type_pointer"
ref.types.Object.ffi_type = bindings.FFI_TYPES.pointer;

// libffi is weird when it comes to long data types (defaults to 64-bit),
// so we emulate here, since some platforms have 32-bit longs and some
// platforms have 64-bit longs.
switch (ref.sizeof.long) {
  case 4:
    ref.types.ulong.ffi_type = bindings.FFI_TYPES.uint32;
    ref.types.long.ffi_type = bindings.FFI_TYPES.int32;
    break;
  case 8:
    ref.types.ulong.ffi_type = bindings.FFI_TYPES.uint64;
    ref.types.long.ffi_type = bindings.FFI_TYPES.int64;
    break;
  default:
    throw new Error('unsupported "long" size: ' + ref.sizeof.long);
}

/**
 * Alias the "ref" types onto ffi's exports, for convenience...
 */

exports.types = ref.types;

// Include our other modules
exports.version = bindings.version;
exports.CIF = require('./cif');
exports.CIF_var = require('./cif_var');
exports.Function = require('./function');
exports.ForeignFunction = require('./foreign_function');
exports.VariadicForeignFunction = require('./foreign_function_var');
exports.DynamicLibrary = require('./dynamic_library');
exports.Library = require('./library');
exports.Callback = require('./callback');
exports.errno = require('./errno');
exports.ffiType = require('./type');

// the shared library extension for this platform
exports.LIB_EXT = exports.Library.EXT;

// the FFI_TYPE struct definition
exports.FFI_TYPE = exports.ffiType.FFI_TYPE;