/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "apr_private.h"
#include "apr_arch_misc.h"
#include "apr_arch_file_io.h"
#include "assert.h"
#include "apr_lib.h"
#include "tchar.h"

APR_DECLARE_DATA apr_oslevel_e apr_os_level = APR_WIN_UNK;

apr_status_t apr_get_oslevel(apr_oslevel_e *level)
{
    if (apr_os_level == APR_WIN_UNK) 
    {
        OSVERSIONINFOEXW oslev;
        oslev.dwOSVersionInfoSize = sizeof(oslev);
        if (!GetVersionExW((OSVERSIONINFOW*) &oslev)) {
            return apr_get_os_error();
        }

        if (oslev.dwPlatformId == VER_PLATFORM_WIN32_NT) 
        {
            unsigned int servpack = oslev.wServicePackMajor;

            if (oslev.dwMajorVersion < 3) {
                apr_os_level = APR_WIN_UNSUP;
            }
            else if (oslev.dwMajorVersion == 3) {
                if (oslev.dwMajorVersion < 50) {
                    apr_os_level = APR_WIN_UNSUP;
                }
                else if (oslev.dwMajorVersion == 50) {
                    apr_os_level = APR_WIN_NT_3_5;
                }
                else {
                    apr_os_level = APR_WIN_NT_3_51;
                }
            }
            else if (oslev.dwMajorVersion == 4) {
                if (servpack < 2)
                    apr_os_level = APR_WIN_NT_4;
                else if (servpack <= 2)
                    apr_os_level = APR_WIN_NT_4_SP2;
                else if (servpack <= 3)
                    apr_os_level = APR_WIN_NT_4_SP3;
                else if (servpack <= 4)
                    apr_os_level = APR_WIN_NT_4_SP4;
                else if (servpack <= 5)
                    apr_os_level = APR_WIN_NT_4_SP5;
                else 
                    apr_os_level = APR_WIN_NT_4_SP6;
            }
            else if (oslev.dwMajorVersion == 5) {
                if (oslev.dwMinorVersion == 0) {
                    if (servpack == 0)
                        apr_os_level = APR_WIN_2000;
                    else if (servpack == 1)
                        apr_os_level = APR_WIN_2000_SP1;
                    else
                        apr_os_level = APR_WIN_2000_SP2;
                }
                else if (oslev.dwMinorVersion == 2) {
                    apr_os_level = APR_WIN_2003;
                }
                else {
                    if (servpack < 1)
                        apr_os_level = APR_WIN_XP;
                    else if (servpack == 1)
                        apr_os_level = APR_WIN_XP_SP1;
                    else
                        apr_os_level = APR_WIN_XP_SP2;
                }
            }
            else if (oslev.dwMajorVersion == 6) {
                if (oslev.dwMinorVersion == 0)
                    apr_os_level = APR_WIN_VISTA;
                else if (oslev.dwMinorVersion == 1) {
                    if (servpack < 1)
                        apr_os_level = APR_WIN_7;
                    else
                        apr_os_level = APR_WIN_7_SP1;
                }
                else if (oslev.dwMinorVersion == 2)
                    apr_os_level = APR_WIN_8;
                else
                    apr_os_level = APR_WIN_8_1;
            }
            else {
                apr_os_level = APR_WIN_10;
            }
        }
#ifndef WINNT
        else if (oslev.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {
            TCHAR *prevision;
            if (prevision = oslev.szCSDVersion) {
                while (*prevision && !apr_isupper(*prevision)) {
                     prevision++;
                }
            }
            else prevision = _T("");

            if (oslev.dwMinorVersion < 10) {
                if (*prevision < _T('C'))
                    apr_os_level = APR_WIN_95;
                else
                    apr_os_level = APR_WIN_95_OSR2;
            }
            else if (oslev.dwMinorVersion < 90) {
                if (*prevision < _T('A'))
                    apr_os_level = APR_WIN_98;
                else
                    apr_os_level = APR_WIN_98_SE;
            }
            else {
                apr_os_level = APR_WIN_ME;
            }
        }
#endif
#ifdef _WIN32_WCE
        else if (oslev.dwPlatformId == VER_PLATFORM_WIN32_CE) 
        {
            if (oslev.dwMajorVersion < 3) {
                apr_os_level = APR_WIN_UNSUP;
            }
            else {
                apr_os_level = APR_WIN_CE_3;
            }
        }
#endif
        else {
            apr_os_level = APR_WIN_UNSUP;
        }
    }

    *level = apr_os_level;

    if (apr_os_level <= APR_WIN_UNSUP) {
        return APR_EGENERAL;
    }

    return APR_SUCCESS;
}


/* This is the helper code to resolve late bound entry points 
 * missing from one or more releases of the Win32 API
 */

typedef struct win32_late_dll_t {
    const char *dll_name;
    volatile HMODULE dll_handle;
} win32_late_dll_t;

static win32_late_dll_t late_dll[DLL_defined] = {
    {"kernel32", INVALID_HANDLE_VALUE},
    {"advapi32", INVALID_HANDLE_VALUE},
    {"mswsock", INVALID_HANDLE_VALUE},
    {"ws2_32", INVALID_HANDLE_VALUE},
    {"shell32", INVALID_HANDLE_VALUE},
    {"ntdll.dll", INVALID_HANDLE_VALUE},
    {"Iphplapi", INVALID_HANDLE_VALUE}
};

FARPROC apr_load_dll_func(apr_dlltoken_e fnLib, char* fnName, int ordinal)
{
    win32_late_dll_t *dll = &late_dll[fnLib];
    HMODULE cached_dll_handle;

    /* Pointer sized reads are atomic on Windows. */
    cached_dll_handle = dll->dll_handle;
    if (cached_dll_handle == INVALID_HANDLE_VALUE) {
        HMODULE dll_handle = NULL;

        dll_handle = LoadLibrary(dll->dll_name);

        cached_dll_handle = InterlockedCompareExchangePointer(&dll->dll_handle,
                                                              dll_handle,
                                                              INVALID_HANDLE_VALUE);
        if (cached_dll_handle == INVALID_HANDLE_VALUE) {
            cached_dll_handle = dll_handle;
        }
        else if (dll_handle) {
            /* Other thread won the race: release our library handle. */
            FreeLibrary(dll_handle);
        }
    }

    if (!cached_dll_handle) {
        return NULL;
    }

#if defined(_WIN32_WCE)
    if (ordinal)
        return GetProcAddressA(cached_dll_handle,
                               (const char *) (apr_ssize_t)ordinal);
    else
        return GetProcAddressA(cached_dll_handle, fnName);
#else
    if (ordinal)
        return GetProcAddress(cached_dll_handle,
                              (const char *) (apr_ssize_t)ordinal);
    else
        return GetProcAddress(cached_dll_handle, fnName);
#endif
}

/* Declared in include/arch/win32/apr_dbg_win32_handles.h
 */
APR_DECLARE_NONSTD(HANDLE) apr_dbg_log(char* fn, HANDLE ha, char* fl, int ln, 
                                       int nh, /* HANDLE hv, char *dsc */...)
{
    static DWORD tlsid = 0xFFFFFFFF;
    static HANDLE fh = NULL;
    static long ctr = 0;
    static CRITICAL_SECTION cs;
    long seq;
    DWORD wrote;
    char *sbuf;
    
    seq = (InterlockedIncrement)(&ctr);

    if (tlsid == 0xFFFFFFFF) {
        tlsid = (TlsAlloc)();
    }

    sbuf = (TlsGetValue)(tlsid);
    if (!fh || !sbuf) {
        sbuf = (malloc)(1024);
        (TlsSetValue)(tlsid, sbuf);
        sbuf[1023] = '\0';
        if (!fh) {
            (GetModuleFileNameA)(NULL, sbuf, 250);
            sprintf(strchr(sbuf, '\0'), ".%u",
                    (unsigned int)(GetCurrentProcessId)());
            fh = (CreateFileA)(sbuf, GENERIC_WRITE, 0, NULL, 
                            CREATE_ALWAYS, 0, NULL);
            (InitializeCriticalSection)(&cs);
        }
    }

    if (!nh) {
        (sprintf)(sbuf, "%p %08x %08x %s() %s:%d\n",
                  ha, (unsigned int)seq, (unsigned int)GetCurrentThreadId(),
                  fn, fl, ln);
        (EnterCriticalSection)(&cs);
        (WriteFile)(fh, sbuf, (DWORD)strlen(sbuf), &wrote, NULL);
        (LeaveCriticalSection)(&cs);
    } 
    else {
        va_list a;
        va_start(a,nh);
        (EnterCriticalSection)(&cs);
        do {
            HANDLE *hv = va_arg(a, HANDLE*);
            char *dsc = va_arg(a, char*);
            if (strcmp(dsc, "Signaled") == 0) {
                if ((apr_ssize_t)ha >= STATUS_WAIT_0 
                       && (apr_ssize_t)ha < STATUS_ABANDONED_WAIT_0) {
                    hv += (apr_ssize_t)ha;
                }
                else if ((apr_ssize_t)ha >= STATUS_ABANDONED_WAIT_0
                            && (apr_ssize_t)ha < STATUS_USER_APC) {
                    hv += (apr_ssize_t)ha - STATUS_ABANDONED_WAIT_0;
                    dsc = "Abandoned";
                }
                else if ((apr_ssize_t)ha == WAIT_TIMEOUT) {
                    dsc = "Timed Out";
                }
            }
            (sprintf)(sbuf, "%p %08x %08x %s(%s) %s:%d\n",
                      *hv, (unsigned int)seq,
                      (unsigned int)GetCurrentThreadId(), 
                      fn, dsc, fl, ln);
            (WriteFile)(fh, sbuf, (DWORD)strlen(sbuf), &wrote, NULL);
        } while (--nh);
        (LeaveCriticalSection)(&cs);
        va_end(a);
    }
    return ha;
}
