#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"

#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;

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

#ifdef DEBUG    
    fprintf(stderr, _("Opening file %s, Input at %p\n"), no.to_charp(), this);
#endif

    if (GetHandle() < 0) {
	throw IOGeneral(String(_("Error opening file ")) + no + _(" for reading: ") + strerror(errno));
    }
    
    results = gresults;
    
    fromarchive = false;
    if (results.name == "") {
	struct stat s;
	fstat(GetHandle(), &s);
	date_modif = s.st_mtime;

	if (S_ISREG(s.st_mode)) {
	    size = seek(0, SEEK_END);
	    seek(0, SEEK_SET);
	}
    } else {
#ifdef DEBUG
	std::cerr << _("Opening file in archive, position ") << results.ptr << std::endl;
#endif
	size = results.size;
	seek(results.ptr, SEEK_SET);
	size = readU32();
	date_modif = 0;
	SetZ();
	fromarchive = true;
    }
}

Input::Input(const Input & i) : Handle(i), n(i.n), size(i.size), date_modif(i.date_modif) {
}

bool Input::CanWrite() const {
    return 0;
}

bool Input::CanRead() const {
    return 1;
}

bool Input::CanSeek() const {
    struct stat s;
    
    fstat(GetHandle(), &s);

    return S_ISREG(s.st_mode);
}

String Input::GetName() const {
    return n;
}

ssize_t Input::GetSize() const {
    return size;
}

time_t Input::GetModif() const {
    return date_modif;
}

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
    std::cerr << _("Wrap-opening ") << fname << std::endl;
#endif
    if (fname[0] != '/') {
	bool t;
	t = Archive::inarchive(fname);
	if (t) {
#ifdef DEBUG
	    std::cerr << _("Trying to open the file in archive, since it seems to be here\n");
#endif
	    return Archive::open(fname, results);
	}
    }
    results->name = "";
    return open(fname.to_charp(), O_RDONLY);
}

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

Stdin_t::Stdin_t() { }

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

String Stdin_t::GetName() const {
    return "Stdin";
}

#ifdef HOOK_STDS
Stdin_t Stdin;
#endif

Archive * Archive::header = 0;

Archive::Archive(const String & fname, int atype) throw (GeneralException) :
  name(fname), archive(fname), type(atype) {
    char buffer[1024];
    int len;
    size_t size;
    FileTree * p = &filetree, * t;
    String ifname;

    switch(type) {
    case ARCHIVE_BUILTIN:
	archive.read(buffer, 4);
	if (*((Uint32 *)buffer) != BUILTIN_SIG)
	    throw GeneralException(_("Archive: not in built-in format."));
	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
		std::cerr << _("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());
	break;
    default:
	throw GeneralException(_("Archive: unsupported archive format."));
    }

    next = header;
    prev = 0;
    header = this;
    if (next)
	next->prev = this;

}

Archive::~Archive() {
    if (prev)
	prev->next = next;
    if (next)
	next->prev = prev;
    if (header == this)
	header = next;
}

bool Archive::inarchive(const String & fname) {
    Archive * p;
    for (p = header; p; p = p->next) {
#ifdef DEBUG
	std::cerr << _("Looking for file `") << fname << _("' in archive ") << p->name << std::endl;
#endif
	if (p->inarchivein(fname)) {
#ifdef DEBUG
	    std::cerr << _("File `") << fname << _("' found in archive ") << p->name << std::endl;
#endif
	    return true;
	}
    }
    return false;
}

int Archive::open(const String & fname, Input::openresults_t * results) throw (GeneralException) {
    Archive * p;

    for (p = header; p; p = p->next) {
	bool t;
	t = p->inarchive(fname);
	if (t)
	    return p->openin(fname, results);
    }
    throw IOGeneral(_("File `") + fname + _("' not found in archive collection."));
}

bool Archive::inarchivein(const String & fname) {
    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
	std::cerr << _("Checking against node `") << p->name << "'\n";
#endif
	while (p) {
	    if (p->name == reste) {
		if (name != "")
		    p = p->Child();
		break;
	    } else {
		p = p->Next();
	    }
	}
    }
    
    return p != 0;
}

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

Archive::FileTree::~FileTree() {
    if (child)
	delete child;
    if (next)
	next->prev = prev;
    if (prev)
	prev->next = next;
    if (father) {
	if (father->child == this)
	    father->child = next;
	father->touched();
    }
}

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;
}

Archive::FileTree * Archive::FileTree::Father() {
    return father;
}

Archive::FileTree * Archive::FileTree::Child() {
    return child;
}

Archive::FileTree * Archive::FileTree::Next() {
    return next;
}

Archive::FileTree * Archive::FileTree::Prev() {
    return prev;
}