#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "generic.h"

#if defined WORDS_BIGENDIAN
#if defined HAVE_BYTESWAP_H
#include <byteswap.h>
#else
inline Uint16 bswap_16(Uint16 w) {
    return (w >> 8) | (w << 8);
}

inline Uint32 bswap_32(Uint32 w) {
    return (w >> 24) | ((w >> 8) & 0x0000ff00) | ((w << 8) & 0x00ff0000) | (w << 24);
}
#endif
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#else
#include <io.h>
#endif

#include "Handle.h"
#include "gettext.h"

enum {
    DEFLATE,
    INFLATE
};

Handle::Handle(const Handle & nh) : itell(0), h(nh.h >= 0 ? dup(nh.h) : nh.h), closed(nh.closed), nonblock(nh.closed), zfile(0), z(0)
{
#ifdef DEBUG
    std::cerr << "Duplication of handle " << nh.h << " to " << h << std::endl;
#endif
    if ((h >= 0) && (nh.z)) {
	SetZ(nh.z);
    }
}

Handle::~Handle() {
#ifdef DEBUG
    std::cerr << "Destroying handle " << h << std::endl;
#endif
    close();
}

Handle::Handle(int nh) : h(nh), closed(false), nonblock(false), zfile(0), z(0)
{
#ifdef DEBUG
    std::cerr << "Initialising handle " << h << std::endl;
#endif
}

int Handle::GetHandle() {
    return h;
}

int Handle::GetHandle() const {
    return h;
}

ssize_t Handle::write(const void *cbuf, size_t count) throw (GeneralException) {
    ssize_t r, tr = 0;
    bool done, full = false;
    const char * buf = (const char *)cbuf;
    

    do {
	done = true;
	errno = 0;
        if ((r = uwrite(buf, count)) < 0) {
    	    if ((!errno) || (errno == EAGAIN) || (errno == EINTR)) {
		// Avant de déclarer une erreur, on vérifie si ce n'est pas un
		// problème lié au fait qu'il n'y a plus de place libre. Cela peut
		// arriver si l'on agit sur un pipe ou un handle. Nous
		// attendons encore une fois avant de déclarer l'erreur,
		// grace au drapeau full.
		if (full) {
		    throw IOException(GetName(), IO_WRITE, count);
		} else {
		    done = false;
		    full = true;
		    if (nonblock) {
#ifdef DEBUG
			std::cerr << "write: throwing IOAgain for handle " << GetName() << std::endl;
#endif
			throw IOAgain();
		    } else {
#ifdef HAVE_SLEEP
			sleep(1);
#endif
		    }
		}
	    } else {
		throw IOException(GetName(), IO_WRITE, count);
	    }
	} else if (((size_t) r) != count) {
	    if (nonblock) {
		return r;
	    }
	    full = done = false;
	    buf += r;
	    tr += r;
	}
    } while (!done);

    return r + tr;
}

ssize_t Handle::read(void *buf, size_t count) throw (GeneralException) {
    ssize_t r;

#ifdef FULLDEBUG
    std::cerr << "read: reading " << count << " bytes from handle " << GetHandle() << std::endl;
#endif
    
    errno = 0;
    while ((r = uread(buf, count)) < 0) {
	if ((!errno) || (errno == EAGAIN) || (errno == EINTR)) {
	    // Avant de déclarer une erreur, on vérifie si ce n'est pas un
	    // problème lié au fait qu'il n'y a plus d'octets.
	    if (nonblock) {
#ifdef DEBUG
		std::cerr << "read: throwing IOAgain for handle " << GetName() << std::endl;
#endif
		throw IOAgain();
	    }
	} else {
	    throw IOException(GetName(), IO_READ, count);
	}
    }
    
    if (!r) {
	close();
    }

    return r;
}

bool Handle::IsClosed(void) const {
    return closed;
}

bool Handle::IsNonBlock(void) const {
    return nonblock;
}

void Handle::SetNonBlock(void) {
#ifdef HAVE_FCNTL
    if ((h >= 0) || !nonblock) {
	fcntl(h, F_SETFL, O_NONBLOCK);
    }
    nonblock = true;
#endif
}

Handle & operator<<(Handle & h, const String & s) {
    const char * p;
    
    p = s.to_charp();
    h.write(p, strlen(p));
    
    return h;
}

Handle & operator>>(Handle & h, String & s) {
    char t[BUFSIZ];
    int i = 0, r;
    
    while ((r = h.read(&(t[i]), 1)) && (i != (BUFSIZ - 1))) {
	// Il y a souvent des \r\n dans les sockets par exemple,
	// ou bien en lisant des fichiers au format MS-DOS. On
	// ignore le \r pour ne garder que le \n, standard sous Unix.
	if (t[i] == '\r') {
	    continue;
	}
	if (t[i] == '\n') {
	    break;
	} else {
	    i++;
	}
    }
    
    t[i] = '\0';
    s = t;
    return h;
}

void Handle::close() throw (GeneralException) {
    if (IsClosed()) {
	return;
    }
    
    Flush();
    
    if (h >= 0) {
	if (z >= 10) {
	    int err;
	    if (c == DEFLATE) {
		err = deflateEnd(&zstrm);
		if (err != Z_OK) {
		    throw (String(_("Error during deflateEnd: ")) + zstrm.msg);
		}
	    } else {
		err = inflateEnd(&zstrm);
		if (err != Z_OK) {
		    throw (String(_("Error during inflateEnd: ")) + zstrm.msg);
		}
	    }
	    err = ::close(h);
	    if (err) {
		throw GeneralException(String(_("Error during (zstream) close: ")) + strerror(errno));
	    }
	} else if (z) {
#ifdef DEBUG
	    std::cerr << "Performing gzclose on handle " << h << std::endl;
#endif
	    int err = gzclose(zfile);
#ifdef DEBUG
	    std::cerr << "gzclose returned " << err << std::endl;
#endif
	    if (err) {
		if (err == Z_ERRNO) {
		    throw GeneralException(String(_("Error during close: ")) + strerror(errno));
		} else {
		    throw GeneralException(String(_("Error in zlib during gzclose: ")) + gzerror(zfile, &err));
		}
	    }
	} else {
	    int err = ::close(h);
	    if (err) {
		throw GeneralException(String(_("Error during close: ")) + strerror(errno));
	    }
	}
    }
    
    h = -1;
    
    closed = 1;
}

bool Handle::CanRead(void) const {
    return false;
}

bool Handle::CanWrite(void) const {
    return false;
}

String Handle::GetName(void) const {
    return _("Bare Handle - should not happend");
}

ssize_t Handle::GetSize(void) const {
    return -1;
}

time_t Handle::GetModif(void) const {
    return -1;
}

bool Handle::CanWatch(void) const {
    return true;
}

int Handle::Dup() const {
    return dup(h);
}

void Handle::SetZ(int az) throw (GeneralException) {
    if (z) {
	throw GeneralException(_("Can't SetZ a Handle twice."));
    }
    if (h < 0) {
	throw GeneralException(_("Can't SetZ a virtual Handle."));
    }
    if (az >= 10) {
#ifdef DEBUG
	std::cerr << "Setting up zstream using inflate/deflate...\n";
#endif
	int err;
	zstrm.zalloc = Z_NULL;
	zstrm.zfree = Z_NULL;
	if (CanWrite()) {
	    c = DEFLATE;
	    err = deflateInit(&zstrm, az - 10);
	    if (err != Z_OK) {
		throw GeneralException(String(_("Error in deflateInit: ")) + zstrm.msg);
	    }
	} else {
	    c = INFLATE;
	    zstrm.next_in = 0;
	    zstrm.avail_in = 0;
	    err = inflateInit(&zstrm);
	    if (err != Z_OK) {
		throw GeneralException(String(_("Error in inflateInit: ")) + zstrm.msg);
	    }
	}
    } else if (az) {
	char format[4];
	int index = 0;
	if (CanRead()) {
	    format[index++] = 'r';
	}
	if (CanWrite()) {
	    format[index++] = 'w';
	}
	format[index++] = (char) (az + '0');
	format[index] = 0;
#ifdef FULLDEBUG
	std::cerr << "Performing gzdopen on handle " << h << " with mode \"" << format << "\"\n";
#endif
	if (!(zfile = gzdopen(h, format))) {
	    throw GeneralException(_("Was not able to gzdopen."));
	}
	z = az;
    }
}

ssize_t Handle::uwrite(const void * buf, size_t count) throw (GeneralException) {
    if (z >= 10) {
    } else if (z) {
#ifdef FULLDEBUG
	std::cerr << "Performing gzwrite of " << count << " byte for handle " << h << std::endl;
#endif
#ifdef HAVE_WD_ZLIB
	int err = gzwrite(zfile, buf, count);
#else
	int err = gzwrite(zfile, (char *) buf, count);
#endif
	if (err == 0) {
	    const char * m = gzerror(zfile, &err);
	    if (err == Z_ERRNO) {
		return -1;
	    } else {
		throw GeneralException(String(_("Error in zlib during gzwrite: ")) + m);
	    }
	}
	itell += err;
	return err;
    } else {
	itell += count = ::write(h, buf, count);
	return count;
    }
}

ssize_t Handle::uread(void * buf, size_t count) {
    if (z >= 10) {
    } if (z) {
#ifdef DEBUG
	std::cerr << "Performing gzread of " << count << " byte for handle " << h << std::endl;
#endif
	int err = gzread(zfile, buf, count);
	if (err == -1) {
	    gzerror(zfile, &err);
	    if (err == Z_ERRNO) {
		return -1;
	    } else {
		return 0;
	    }
	}
	itell += err;
	return err;
    } else {
	itell += count = ::read(h, buf, count);
	return count;
    }
}

off_t Handle::tell() const {
    if (z) {
	return gztell(zfile);
    } else {
	return itell;
    }
}

bool Handle::CanSeek() const {
    return 0;
}

off_t Handle::seek(off_t offset, int whence) throw(GeneralException) {
    if (z) {
	 return itell = gzseek(zfile, offset, whence); 
    } else {
	throw IOGeneral("Handle " + GetName() + " can't seek");
    }
}

Uint8 Handle::readU8() {
    Uint8 r;
    read(&r, 1);
    return r;
}

Uint16 Handle::readU16() {
    Uint16 r;
    read(&r, 2);
#ifdef WORDS_BIGENDIAN
    return bswap_16(r);
#else
    return r;
#endif
}

Uint32 Handle::readU32() {
    Uint32 r;
    read(&r, 4);
#ifdef WORDS_BIGENDIAN
    return bswap_32(r);
#else
    return r;
#endif
}

void Handle::writeU8(Uint8 v) {
    write(&v, 1);
}

void Handle::writeU16(Uint16 v) {
#ifdef WORDS_BIGENDIAN
    Uint16 t = bswap_16(v);
    write(&t, 2);
#else
    write(&v, 2);
#endif
}

void Handle::writeU32(Uint32 v) {
#ifdef WORDS_BIGENDIAN
    Uint32 t = bswap_32(v);
    write(&t, 4);
#else
    write(&v, 4);
#endif
}

void copy(Handle * s, Handle * d, ssize_t size) {
    long i;
    unsigned char c;
    long r;
    
    for (i = 0; (i < size) || (size < 0); i++) {
	r = s->read(&c, 1);
	if (r == 0) {
	    break;
	}
	d->write(&c, 1);
    }
}

void Handle::Flush() {
    if (h < 0)
	return;
    if (z >= 10) {
	
    } else if (z) {
	gzflush(&z, Z_FULL_FLUSH);
    } else {
#ifdef HAVE_FSYNC
	fsync(h);
#endif
    }
}