/*

 * Posix-esque support routines for PhysicsFS.

 *

 * Please see the file LICENSE.txt in the source's root directory.

 *

 *  This file written by Ryan C. Gordon.

 */

/* !!! FIXME: check for EINTR? */

#define __PHYSICSFS_INTERNAL__

#include "physfs_platforms.h"

#ifdef PHYSFS_PLATFORM_POSIX

#include <unistd.h>

#include <ctype.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <pwd.h>

#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#if ((!defined PHYSFS_NO_THREAD_SUPPORT) && (!defined PHYSFS_PLATFORM_BEOS))

#include <pthread.h>

#endif

#include "physfs_internal.h"

static PHYSFS_ErrorCode errcodeFromErrnoError(const int err)

{

    switch (err)

    {

        case 0: return PHYSFS_ERR_OK;

        case EACCES: return PHYSFS_ERR_PERMISSION;

        case EPERM: return PHYSFS_ERR_PERMISSION;

        case EDQUOT: return PHYSFS_ERR_NO_SPACE;

        case EIO: return PHYSFS_ERR_IO;

        case ELOOP: return PHYSFS_ERR_SYMLINK_LOOP;

        case EMLINK: return PHYSFS_ERR_NO_SPACE;

        case ENAMETOOLONG: return PHYSFS_ERR_BAD_FILENAME;

        case ENOENT: return PHYSFS_ERR_NOT_FOUND;

        case ENOSPC: return PHYSFS_ERR_NO_SPACE;

        case ENOTDIR: return PHYSFS_ERR_NOT_FOUND;

        case EISDIR: return PHYSFS_ERR_NOT_A_FILE;

        case EROFS: return PHYSFS_ERR_READ_ONLY;

        case ETXTBSY: return PHYSFS_ERR_BUSY;

        case EBUSY: return PHYSFS_ERR_BUSY;

        case ENOMEM: return PHYSFS_ERR_OUT_OF_MEMORY;

        case ENOTEMPTY: return PHYSFS_ERR_DIR_NOT_EMPTY;

        default: return PHYSFS_ERR_OS_ERROR;

    } /* switch */

} /* errcodeFromErrnoError */

static inline PHYSFS_ErrorCode errcodeFromErrno(void)

{

    return errcodeFromErrnoError(errno);

} /* errcodeFromErrno */

static char *getUserDirByUID(void)

{

    uid_t uid = getuid();

    struct passwd *pw;

    char *retval = NULL;

    pw = getpwuid(uid);

    if ((pw != NULL) && (pw->pw_dir != NULL) && (*pw->pw_dir != '\0'))

    {

        const size_t dlen = strlen(pw->pw_dir);

        const size_t add_dirsep = (pw->pw_dir[dlen-1] != '/') ? 1 : 0;

        retval = (char *) allocator.Malloc(dlen + 1 + add_dirsep);

        if (retval != NULL)

        {

            strcpy(retval, pw->pw_dir);

            if (add_dirsep)

            {

                retval[dlen] = '/';

                retval[dlen+1] = '\0';

            } /* if */

        } /* if */

    } /* if */

    return retval;

} /* getUserDirByUID */

char *__PHYSFS_platformCalcUserDir(void)

{

    char *retval = NULL;

    char *envr = getenv("HOME");

    /* if the environment variable was set, make sure it's really a dir. */

    if (envr != NULL)

    {

        struct stat statbuf;

        if ((stat(envr, &statbuf) != -1) && (S_ISDIR(statbuf.st_mode)))

        {

            const size_t envrlen = strlen(envr);

            const size_t add_dirsep = (envr[envrlen-1] != '/') ? 1 : 0;

            retval = allocator.Malloc(envrlen + 1 + add_dirsep);

            if (retval)

            {

                strcpy(retval, envr);

                if (add_dirsep)

                {

                    retval[envrlen] = '/';

                    retval[envrlen+1] = '\0';

                } /* if */

            } /* if */

        } /* if */

    } /* if */

    if (retval == NULL)

        retval = getUserDirByUID();

    return retval;

} /* __PHYSFS_platformCalcUserDir */

void __PHYSFS_platformEnumerateFiles(const char *dirname,

                                     PHYSFS_EnumFilesCallback callback,

                                     const char *origdir,

                                     void *callbackdata)

{

    DIR *dir;

    struct dirent *ent;

    char *buf = NULL;

    errno = 0;

    dir = opendir(dirname);

    if (dir == NULL)

    {

        allocator.Free(buf);

        return;

    } /* if */

    while ((ent = readdir(dir)) != NULL)

    {

        if (strcmp(ent->d_name, ".") == 0)

            continue;

        else if (strcmp(ent->d_name, "..") == 0)

            continue;

        callback(callbackdata, origdir, ent->d_name);

    } /* while */

    allocator.Free(buf);

    closedir(dir);

} /* __PHYSFS_platformEnumerateFiles */

int __PHYSFS_platformMkDir(const char *path)

{

    const int rc = mkdir(path, S_IRWXU);

    BAIL_IF_MACRO(rc == -1, errcodeFromErrno(), 0);

    return 1;

} /* __PHYSFS_platformMkDir */

static void *doOpen(const char *filename, int mode)

{

    const int appending = (mode & O_APPEND);

    int fd;

    int *retval;

    errno = 0;

    /* O_APPEND doesn't actually behave as we'd like. */

    mode &= ~O_APPEND;

    fd = open(filename, mode, S_IRUSR | S_IWUSR);

    BAIL_IF_MACRO(fd < 0, errcodeFromErrno(), NULL);

    if (appending)

    {

        if (lseek(fd, 0, SEEK_END) < 0)

        {

            const int err = errno;

            close(fd);

            BAIL_MACRO(errcodeFromErrnoError(err), NULL);

        } /* if */

    } /* if */

    retval = (int *) allocator.Malloc(sizeof (int));

    if (!retval)

    {

        close(fd);

        BAIL_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    } /* if */

    *retval = fd;

    return ((void *) retval);

} /* doOpen */

void *__PHYSFS_platformOpenRead(const char *filename)

{

    return doOpen(filename, O_RDONLY);

} /* __PHYSFS_platformOpenRead */

void *__PHYSFS_platformOpenWrite(const char *filename)

{

    return doOpen(filename, O_WRONLY | O_CREAT | O_TRUNC);

} /* __PHYSFS_platformOpenWrite */

void *__PHYSFS_platformOpenAppend(const char *filename)

{

    return doOpen(filename, O_WRONLY | O_CREAT | O_APPEND);

} /* __PHYSFS_platformOpenAppend */

PHYSFS_sint64 __PHYSFS_platformRead(void *opaque, void *buffer,

                                    PHYSFS_uint64 len)

{

    const int fd = *((int *) opaque);

    ssize_t rc = 0;

    if (!__PHYSFS_ui64FitsAddressSpace(len))

        BAIL_MACRO(PHYSFS_ERR_INVALID_ARGUMENT, -1);

    rc = read(fd, buffer, (size_t) len);

    BAIL_IF_MACRO(rc == -1, errcodeFromErrno(), -1);

    assert(rc >= 0);

    assert(rc <= len);

    return (PHYSFS_sint64) rc;

} /* __PHYSFS_platformRead */

PHYSFS_sint64 __PHYSFS_platformWrite(void *opaque, const void *buffer,

                                     PHYSFS_uint64 len)

{

    const int fd = *((int *) opaque);

    ssize_t rc = 0;

    if (!__PHYSFS_ui64FitsAddressSpace(len))

        BAIL_MACRO(PHYSFS_ERR_INVALID_ARGUMENT, -1);

    rc = write(fd, (void *) buffer, (size_t) len);

    BAIL_IF_MACRO(rc == -1, errcodeFromErrno(), rc);

    assert(rc >= 0);

    assert(rc <= len);

    return (PHYSFS_sint64) rc;

} /* __PHYSFS_platformWrite */

int __PHYSFS_platformSeek(void *opaque, PHYSFS_uint64 pos)

{

    const int fd = *((int *) opaque);

    const int rc = lseek(fd, (off_t) pos, SEEK_SET);

    BAIL_IF_MACRO(rc == -1, errcodeFromErrno(), 0);

    return 1;

} /* __PHYSFS_platformSeek */

PHYSFS_sint64 __PHYSFS_platformTell(void *opaque)

{

    const int fd = *((int *) opaque);

    PHYSFS_sint64 retval;

    retval = (PHYSFS_sint64) lseek(fd, 0, SEEK_CUR);

    BAIL_IF_MACRO(retval == -1, errcodeFromErrno(), -1);

    return retval;

} /* __PHYSFS_platformTell */

PHYSFS_sint64 __PHYSFS_platformFileLength(void *opaque)

{

    const int fd = *((int *) opaque);

    struct stat statbuf;

    BAIL_IF_MACRO(fstat(fd, &statbuf) == -1, errcodeFromErrno(), -1);

    return ((PHYSFS_sint64) statbuf.st_size);

} /* __PHYSFS_platformFileLength */

int __PHYSFS_platformFlush(void *opaque)

{

    const int fd = *((int *) opaque);

    if ((fcntl(fd, F_GETFL) & O_ACCMODE) != O_RDONLY)

        BAIL_IF_MACRO(fsync(fd) == -1, errcodeFromErrno(), 0);

    return 1;

} /* __PHYSFS_platformFlush */

void __PHYSFS_platformClose(void *opaque)

{

    const int fd = *((int *) opaque);

    (void) close(fd);  /* we don't check this. You should have used flush! */

    allocator.Free(opaque);

} /* __PHYSFS_platformClose */

int __PHYSFS_platformDelete(const char *path)

{

    BAIL_IF_MACRO(remove(path) == -1, errcodeFromErrno(), 0);

    return 1;

} /* __PHYSFS_platformDelete */

int __PHYSFS_platformStat(const char *filename, PHYSFS_Stat *st)

{

    struct stat statbuf;

    BAIL_IF_MACRO(lstat(filename, &statbuf) == -1, errcodeFromErrno(), 0);

    if (S_ISREG(statbuf.st_mode))

    {

        st->filetype = PHYSFS_FILETYPE_REGULAR;

        st->filesize = statbuf.st_size;

    } /* if */

    else if(S_ISDIR(statbuf.st_mode))

    {

        st->filetype = PHYSFS_FILETYPE_DIRECTORY;

        st->filesize = 0;

    } /* else if */

    else if(S_ISLNK(statbuf.st_mode))

    {

        st->filetype = PHYSFS_FILETYPE_SYMLINK;

        st->filesize = 0;

    } /* else if */

    else

    {

        st->filetype = PHYSFS_FILETYPE_OTHER;

        st->filesize = statbuf.st_size;

    } /* else */

    st->modtime = statbuf.st_mtime;

    st->createtime = statbuf.st_ctime;

    st->accesstime = statbuf.st_atime;

    /* !!! FIXME: maybe we should just report full permissions? */

    st->readonly = access(filename, W_OK);

    return 1;

} /* __PHYSFS_platformStat */

#ifndef PHYSFS_PLATFORM_BEOS  /* BeOS has its own code in platform_beos.cpp */

#if (defined PHYSFS_NO_THREAD_SUPPORT)

void *__PHYSFS_platformGetThreadID(void) { return ((void *) 0x0001); }

void *__PHYSFS_platformCreateMutex(void) { return ((void *) 0x0001); }

void __PHYSFS_platformDestroyMutex(void *mutex) {}

int __PHYSFS_platformGrabMutex(void *mutex) { return 1; }

void __PHYSFS_platformReleaseMutex(void *mutex) {}

#else

typedef struct

{

    pthread_mutex_t mutex;

    pthread_t owner;

    PHYSFS_uint32 count;

} PthreadMutex;

void *__PHYSFS_platformGetThreadID(void)

{

    return ( (void *) ((size_t) pthread_self()) );

} /* __PHYSFS_platformGetThreadID */

void *__PHYSFS_platformCreateMutex(void)

{

    int rc;

    PthreadMutex *m = (PthreadMutex *) allocator.Malloc(sizeof (PthreadMutex));

    BAIL_IF_MACRO(!m, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    rc = pthread_mutex_init(&m->mutex, NULL);

    if (rc != 0)

    {

        allocator.Free(m);

        BAIL_MACRO(PHYSFS_ERR_OS_ERROR, NULL);

    } /* if */

    m->count = 0;

    m->owner = (pthread_t) 0xDEADBEEF;

    return ((void *) m);

} /* __PHYSFS_platformCreateMutex */

void __PHYSFS_platformDestroyMutex(void *mutex)

{

    PthreadMutex *m = (PthreadMutex *) mutex;

    /* Destroying a locked mutex is a bug, but we'll try to be helpful. */

    if ((m->owner == pthread_self()) && (m->count > 0))

        pthread_mutex_unlock(&m->mutex);

    pthread_mutex_destroy(&m->mutex);

    allocator.Free(m);

} /* __PHYSFS_platformDestroyMutex */

int __PHYSFS_platformGrabMutex(void *mutex)

{

    PthreadMutex *m = (PthreadMutex *) mutex;

    pthread_t tid = pthread_self();

    if (m->owner != tid)

    {

        if (pthread_mutex_lock(&m->mutex) != 0)

            return 0;

        m->owner = tid;

    } /* if */

    m->count++;

    return 1;

} /* __PHYSFS_platformGrabMutex */

void __PHYSFS_platformReleaseMutex(void *mutex)

{

    PthreadMutex *m = (PthreadMutex *) mutex;

    assert(m->owner == pthread_self());  /* catch programming errors. */

    assert(m->count > 0);  /* catch programming errors. */

    if (m->owner == pthread_self())

    {

        if (--m->count == 0)

        {

            m->owner = (pthread_t) 0xDEADBEEF;

            pthread_mutex_unlock(&m->mutex);

        } /* if */

    } /* if */

} /* __PHYSFS_platformReleaseMutex */

#endif /* !PHYSFS_NO_THREAD_SUPPORT */

#endif /* !PHYSFS_PLATFORM_BEOS */

#endif  /* PHYSFS_PLATFORM_POSIX */

/* end of posix.c ... */