/*
 *  Baltisot
 *  Copyright (C) 1999-2008 Nicolas "Pixel" Noble
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

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

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

#include "Input.h"
#include "Exceptions.h"
#include "gettext.h"
#include "Atomic.h"

#ifndef S_ISREG
#define S_ISREG(x) 1
#endif

#ifdef WORDS_BIGENDIAN
#define BUILTIN_SIG 0x4e504151
#else
#define BUILTIN_SIG 0x5141504e
#endif

/*

 NPAQ file format
 ================

off|siz|description
---+---+-----------
 0 | 4 | Magic: NPAQ
 4 | X | Index
4+X| Y | Files

Index:
It's composed of entries. Each entries have the same format:

off|siz|description
---+---+-----------
 0 | 1 | name size = n
 1 | n | file name
1+n| 4 | file size
5+n| 1 | type --> 0 = file / 1 = directory

If it's a directory, it means the following entries belongs to this directory.
If n = 0, there is nothing else afterward (no filesize nor type) and it
means the end of the current directory. The end of the root directory
means the end of the index.

Files:
Each file are gzipped. They are all concatenated after the index. They
all start with a four bytes length which correspond to the unpacked size.
The size in the index corresponds to the size of the gzipped result plus
those 4 bytes.

*/

static Input::openresults_t gresults;

int Input::nb_input = 0;

Input::Input(const String & no) throw (GeneralException) :
    Handle(no.strlen() ? wrapopen(no, &gresults) : dup(0)),
    n(no) {

#ifdef DEBUG    
    printm(M_BARE, String(_("Opening file")) + no + _("Input at %p\n"), this);
#endif

    if (GetHandle() < 0) {
#ifdef DEBUG    
	printm(M_BARE, "Got handle: %i opening file " + no + "\n", GetHandle());
#endif
	throw IOGeneral(String(_("Error opening file ")) + no + _(" for reading: ") + strerror(errno));
    }
    
    Atomic::Increment(&nb_input);
    
    results = gresults;
    
    fromarchive = false;
    if (results.name == "") {
#ifndef __MIPSEL__
	struct stat s;
	fstat(GetHandle(), &s);
	date_modif = s.st_mtime;
#endif

#ifdef __linux__
	if (S_ISREG(s.st_mode))
#endif
#if 0 && defined (_WIN32) && !defined (NO_HFILE)
        if (hFile) {
            GetFileSize(hFile, (LPDWORD)&size);
        } else
#endif
        {
    	    size = seek(0, SEEK_END);
    	    seek(0, SEEK_SET);
        }
    } else {
#ifdef DEBUG
	printm(M_INFO, String(_("Opening file in archive, position ")) + results.ptr + "\n");
#endif
	size = results.size;
	seek(results.ptr, SEEK_SET);
	size = readU32();
	date_modif = 0;
	SetZ();
	fromarchive = true;
        itell = 0;
    }
}

bool Input::CanSeek() const {
#ifdef __MIPSEL__
    return true;
#else
    struct stat s;
    
    fstat(GetHandle(), &s);

    return S_ISREG(s.st_mode);
#endif
}

off_t Input::seek(off_t offset, int whence) throw (GeneralException) {
    if (!fromarchive) {
	if ((itell = lseek(GetHandle(), offset, whence)) < 0) {
	    throw IOGeneral(String(_("Error seeking file ")) + GetName() + _(": ") + strerror(errno));
	}
#ifdef PARANOID_SEEK
	if (itell != lseek(GetHandle(), 0, SEEK_CUR)) {
	    throw IOGeneral(String(_("Error seeking file ")) + GetName() + _(": the position does not match"));
	}
#endif
	return itell;
    } else {
	return Handle::seek(offset, whence);
    }
}

int Input::wrapopen(const String & fname, openresults_t * results) {
#ifdef DEBUG
    printm(M_INFO, _("Wrap-opening ") + fname + "\n");
#endif
    if (fname[0] != '/') {
	Archive * t;
	t = Archive::inarchive(fname);
	if (t) {
#ifdef DEBUG
	    printm(M_BARE, _("Trying to open the file in archive, since it seems to be here\n"));
#endif
            hFile = 0;
#if defined (_WIN32) && !defined (NO_HFILE)
//	    hFile = t->GetHandle()->GetHFile();
#endif
	    return t->open(fname, results);
	}
    }
    results->name = "";
    hFile = 0;
#if !defined (_WIN32) || defined (NO_HFILE)
    return open(fname.to_charp(), O_RDONLY
#ifdef _WIN32
        | O_BINARY
#endif
#ifdef O_LARGEFILE
        | O_LARGEFILE
#endif
        );
#else
    hFile = CreateFile(fname.to_charp(), GENERIC_READ, FILE_SHARE_WRITE | FILE_SHARE_READ, 0, OPEN_EXISTING, 0, 0);
    return _open_osfhandle((INT_PTR) hFile, O_RDONLY | O_BINARY);
#endif
}

void Input::SetZ(int l) throw(GeneralException) {
    if (!fromarchive) {
	Handle::SetZ(l);
	size = -1;
    }
}

#ifdef HOOK_STDS
Stdin_t Stdin;
#endif

Archive * Archive::header = 0;
iLock Archive::lock;

Archive::Archive(const String & fname, int atype) :
  name(fname), archive(new Input(fname)), type(atype) {
      create();
}

Archive::Archive(Handle * hand, int atype) :
  name(hand->GetName()), archive(hand), type(atype) {
      create();
}

#ifdef _MSC_VER
#pragma pack(1)
#endif

struct PEsection_t {
    char name[8];
    Uint32 VSize, VAdd, SizeOf, Pointer, PTRelocs, PTLNs;
    Uint16 NR, NLN;
    Uint32 Chars;
} PACKED;

struct elf_header_t {
    union {
        Uint8 raw[16];
        struct e_ident_t {
            Uint8 ei_magic[4];
            Uint8 ei_class;
            Uint8 ei_data;
            Uint8 ei_version;
        } cook;
    } e_ident;
    Uint16 e_type;
    Uint16 e_machine;
    Uint32 e_version;
    Uint32 e_entry;
    Uint32 e_phoff;
    Uint32 e_shoff;
    Uint32 e_flags;
    Uint16 e_ehsize;
    Uint16 e_phentsize;
    Uint16 e_phnum;
    Uint16 e_shentsize;
    Uint16 e_shnum;
    Uint16 e_shstrndx;
} PACKED;

struct elf_section_t {
    Uint32 sh_name, sh_type, sh_flags, sh_addr, sh_offset, sh_size;
    Uint32 sh_link, sh_info, sh_addralign, sh_entsize;
} PACKED;

void Archive::create() throw (GeneralException) {
    char buffer[1024];
    int len;
    Uint32 sig, ptr, maxptr = 0, startptr;
    Uint16 sections;
    PEsection_t PEsection;
    size_t size;
    FileTree * p = &filetree, * t;
    String ifname;
    int i;
    
    switch(type) {
    case ARCHIVE_EXECUTABLE:
	startptr = archive->tell();
	sig = archive->readU32();
	archive->seek(-4, SEEK_CUR);
	if ((sig & 0xffff) == 0x5a4d) { /* MZ */
	    archive->seek(60, SEEK_CUR);
	    sig = archive->readU32();
	    archive->seek(sig - 64, SEEK_CUR);
	    sig = archive->readU32();
	    if (sig != 0x4550)
		throw GeneralException(_("Archive: file is not a PE."));
	    archive->seek(2, SEEK_CUR);
	    sections = archive->readU16();
	    archive->seek(240, SEEK_CUR);
	    for (i = 0; i < sections; i++) {
		archive->read(&PEsection, sizeof(PEsection));
#ifdef DEBUG
                printm(M_INFO, "Section: %s\n", PEsection.name);
#endif
		ptr = PEsection.Pointer + PEsection.SizeOf;
		if (ptr > maxptr)
		    maxptr = ptr;
	    }
	    archive->seek(startptr - archive->tell() + maxptr, SEEK_CUR);
	} else if (sig == 0x464c457f) { /* ELF */
	    elf_header_t head;
	    elf_section_t sec;
	    int cur_end, max_end = 0;
	    int i;

	    archive->read(&head, sizeof(head));
	    archive->seek(startptr + head.e_shoff);
	    
	    for (i = 0; i < head.e_shnum; i++) {
		archive->read(&sec, sizeof(elf_section_t));
		archive->seek(head.e_shentsize - sizeof(elf_section_t), SEEK_CUR);
		if (sec.sh_type == 8)
		    continue;
		cur_end = sec.sh_offset + sec.sh_size;
		if (cur_end > max_end)
		    max_end = cur_end;
	    }
	    archive->seek(startptr + max_end);
	}
    case ARCHIVE_BUILTIN:
	memset(buffer, 0, 4);
	archive->read(buffer, 4);
	if (*((Uint32 *)buffer) != BUILTIN_SIG)
	    throw GeneralException(_("Archive: not in built-in format."));
	    
        lock.lock();
	while (p) {
	    archive->read(buffer, 1);
	    len = *buffer;
	    if (len) {
		archive->read(buffer, len);
		buffer[len] = 0;
		ifname = buffer;
		size = archive->readU32();
		archive->read(buffer, 1);
#ifdef DEBUG
		printm(M_BARE, _("Adding file `") + ifname + _("' to node `") + p->name + "'\n");
#endif
		t = new FileTree(ifname, size, buffer[0], p);
		if (buffer[0])
		    p = t;
	    } else {
		p = p->Father();
	    }
	}
	filetree.compute_ptrs(archive->tell());
        lock.unlock();
	break;
    default:
	throw GeneralException(_("Archive: unsupported archive format."));
    }
    
    do {
        next = header;
    } while (!Atomic::CmpXChgBool(&header, this, next));
}

Archive * Archive::inarchive(const String & fname) {
    Archive * p;
    for (p = header; p; p = p->next) {
#ifdef DEBUG
	printm(M_BARE, _("Looking for file `") + fname + _("' in archive ") + p->name + "\n");
#endif
	if (p->inarchivein(fname)) {
#ifdef DEBUG
	    printm(M_BARE, _("File `") + fname + _("' found in archive ") + p->name + "\n");
#endif
	    return p;
	}
    }
    return 0;
}

int Archive::open(const String & fname, Input::openresults_t * results) {
    return openin(fname, results);
}

bool Archive::inarchivein(const String & fname) {
    lock.lock();
    Archive::FileTree * p = filetree.Child();
    ssize_t pos;
    String name = fname;
    String reste;
    
    while((name != "") && p) {
	pos = name.strchr('/');
	if (pos >= 0) {
	    reste = name.extract(0, pos - 1);
	    name = name.extract(pos + 1);
	} else {
	    reste = name;
	    name = "";
	}
#ifdef DEBUG
	printm(M_BARE, _("Checking against node `") + p->name + "'\n");
#endif
	while (p) {
	    if (p->name == reste) {
		if (name != "")
		    p = p->Child();
		break;
	    } else {
		p = p->Next();
	    }
	}
    }
    lock.unlock();
    
    return p != 0;
}

int Archive::openin(const String & fname, Input::openresults_t * results) throw (GeneralException) {
    lock.lock();
    Archive::FileTree * p = filetree.Child();
    ssize_t pos;
    String name = fname;
    String reste;
    
    while((name != "") && p) {
	pos = name.strchr('/');
	if (pos >= 0) {
	    reste = name.extract(0, pos - 1);
	    name = name.extract(pos + 1);
	} else {
	    reste = name;
	    name = "";
	}
	
	while (p) {
	    if (p->name == reste) {
		if (name != "")
		    p = p->Child();
		break;
	    } else {
		p = p->Next();
	    }
	}
    }
    lock.unlock();
    
    if (!p)
	throw IOGeneral(_("File `") + fname + _("' not in archive ") + this->name);
    
    if (p->Child())
	throw IOGeneral(_("File `") + fname + _("' in archive ") + this->name + _(" is a directory - can't open."));

    results->name = p->name;
    results->ptr = p->ptr;
    results->size = p->size;
    results->type = p->type;
    return archive->Dup();
}

Archive::FileTree::FileTree(const String & fname, size_t fsize, int ftype, Archive::FileTree * fFather) :
  name(fname), type(ftype), size(fsize), next(0), prev(0), father(fFather), child(0) {
    if (father) {
	if (father->child) {
	    FileTree * p;
	    for (p = father->child; p->next; p = p->next);
	    p->next = this;
	    prev = p;
	} else {
#ifdef DEBUG
	    std::cerr << _("Adding `") << fname << _("' as first child of node `") << father->name << "'\n";
#endif
	    father->child = this;
	}
    }
}

void Archive::FileTree::touched() {
    if (father)
	father->touched();
    else
	compute_ptrs(ptr);
}

int Archive::FileTree::compute_ptrs(size_t cptr) {
    ptr = cptr;
    
#ifdef DEBUG
    std::cerr << _("Computed pointer for `") << name << "' = " << ptr << std::endl;
    if (child)
	std::cerr << _("Node has child\n");
    else
	std::cerr << _("Node is ") << size << _(" bytes large.\n");
#endif

    if (child) {
	FileTree * p;
	size = 0;
	for (p = child; p; p = p->next) {
	    size = p->compute_ptrs(ptr + size) - ptr;
	}
    }
    
    return size + ptr;
}