/**
 * Locale.d
 * Information of a locale.
 * Author: knt.roh
 * License: Public Domain
 */
module java.nonstandard.locale;

import java.lang.String;
import java.lang.util : implMissing;

version(Tango){
    private import tango.text.locale.Core;
} else { // Phobos
    private import std.conv;
    private import std.exception;
}
version (Windows) {
    private import std.c.string;
    private import std.c.windows.windows;
    private bool W_VERSION;
    static this() {
        W_VERSION = GetVersion < 0x80000000;
    }
    private extern (Windows) {
        enum LCID : DWORD {
            /// The default locale for the user or process.
            LOCALE_USER_DEFAULT     = 0x0400,
        }
        enum LCTYPE : DWORD {
            /// ISO639 language name.
            LOCALE_SISO639LANGNAME  = 0x0059,
            /// ISO3166 country name.
            LOCALE_SISO3166CTRYNAME = 0x005A
        }
        /// Retrieves information about a locale specified by identifier.
        /// See_Also: GetLocaleInfo Function (Windows)
        ///           (http://msdn.microsoft.com/en-us/library/dd318101%28VS.85%29.aspx)
        INT GetLocaleInfoW(
            LCID Locale,
            LCTYPE LCType,
            LPWSTR lpLCData,
            INT cchData
        );
        /// ditto
        INT GetLocaleInfoA(
            LCID Locale,
            LCTYPE LCType,
            LPCSTR lpLCData,
            INT cchData
        );
    }
    /// A purpose of this templete is switch of W or A in Windows.
    private String caltureNameImpl(Char, alias GetLocalInfo)() {
        INT len;
        Char[] res;
        Char[] buf;
        len = GetLocalInfo(LCID.LOCALE_USER_DEFAULT,
            LCTYPE.LOCALE_SISO639LANGNAME, null, 0);
        enforce(len, new Exception("LOCALE_SISO639LANGNAME (len)", __FILE__, __LINE__));
        buf.length = len;
        len = GetLocalInfo(LCID.LOCALE_USER_DEFAULT,
            LCTYPE.LOCALE_SISO639LANGNAME, buf.ptr, buf.length);
        enforce(len, new Exception("LOCALE_SISO639LANGNAME", __FILE__, __LINE__));
        res ~= buf[0 .. len - 1];
        res ~= "-";
        len = GetLocalInfo(LCID.LOCALE_USER_DEFAULT,
            LCTYPE.LOCALE_SISO3166CTRYNAME, null, 0);
        enforce(len, new Exception("LOCALE_SISO3166CTRYNAME (len)", __FILE__, __LINE__));
        buf.length = len;
        len = GetLocalInfo(LCID.LOCALE_USER_DEFAULT,
            LCTYPE.LOCALE_SISO3166CTRYNAME, buf.ptr, buf.length);
        enforce(len, new Exception("LOCALE_SISO3166CTRYNAME", __FILE__, __LINE__));
        res ~= buf[0 .. len - 1];
        return to!(String)(res);
    }
} else version (Posix) {
    private import std.process : getenv;
    private import std.string : indexOf, replace;
}

/// Get a omitted calture name. for example: "en-US"
String caltureName() {
    version(Tango){
        return Culture.current.name;
    } else { // Phobos
        version (Windows) {
            if (W_VERSION) {
                return caltureNameImpl!(wchar, GetLocaleInfoW)();
            } else {
                return caltureNameImpl!(char, GetLocaleInfoA)();
            }
        } else version (Posix) {
            // LC_ALL is override to settings of all category.
            // This is undefined in almost case.
            String res = .getenv("LC_ALL");
            if (!res || !res.length) {
                // LANG is basic Locale setting.
                // A settings of each category override this. 
                res = .getenv("LANG");
            }
            int dot = .indexOf(res, '.');
            if (dot != -1) res = res[0 .. dot];
            return .replace(res, "_", "-");
        } else {
            implMissing(__FILE__, __LINE__);
            return "";
        }
    }
}