/*
 * Copyright (C) 2005 Casper S. Hornstrup
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifdef _MSC_VER
#pragma warning ( disable : 4786 )
#endif//_MSC_VER

#ifdef WIN32
    #include <direct.h>
    #include <io.h>
#else
    #include <sys/stat.h>
    #include <unistd.h>

    // Some hosts don't define PATH_MAX in unistd.h
    #if !defined(PATH_MAX)
        #include <limits.h>
    #endif

    #define MAX_PATH PATH_MAX
#endif

#include <assert.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "xml.h"
#include "ssprintf.h"

#ifndef MAX_PATH
#define MAX_PATH _MAX_PATH
#endif

using std::string;
using std::vector;

#ifdef WIN32
#define getcwd _getcwd
#endif//WIN32

static const char* WS = " \t\r\n";
static const char* WSEQ = " =\t\r\n";

string working_directory;

std::vector<char> vectorize(const std::string &str)
{
    std::vector<char> result( str.size() + 1 );
    strcpy( &result[0], str.c_str() );
    return result;
}

void vectappend(std::vector<char> &strvec, const char *str)
{
    if (*str) { strvec[strlen(&strvec[0])] = *str; str++; }
    while (*str)
    {
        strvec.push_back(*str);
    str++;
    }
    strvec.push_back(0);
}

void vectappend(std::vector<char> &strvec, const std::string &str)
{
    vectappend(strvec, str.c_str());
}

void vectappend(std::vector<char> &strvec, char ch)
{
    strvec[strlen(&strvec[0])] = ch;
    strvec.push_back(0);
}

XMLException::XMLException (
    const std::string& location,
    const char* format, ... )
{
    va_list args;
    va_start ( args, format );
    SetExceptionV ( location, format, args );
    va_end ( args );
}

void XMLException::SetExceptionV ( const std::string& location, const char* format, va_list args )
{
    _e = location + ": " + ssvprintf(format,args);
}

void XMLException::SetException ( const std::string& location, const char* format, ... )
{
    va_list args;
    va_start ( args, format );
    SetExceptionV ( location, format, args );
    va_end ( args );
}

XMLIncludes::~XMLIncludes()
{
    for ( size_t i = 0; i < this->size(); i++ )
        delete (*this)[i];
}

void
InitWorkingDirectory()
{
    // store the current directory for path calculations
    working_directory.resize ( MAX_PATH );
    working_directory[0] = 0;
    getcwd ( &working_directory[0], working_directory.size() );
    working_directory.resize ( strlen ( working_directory.c_str() ) );
}

#ifdef _MSC_VER
unsigned __int64
#else
unsigned long long
#endif
filelen ( FILE* f )
{
#ifdef WIN32
    return _filelengthi64 ( _fileno(f) );
#else
# if defined(__FreeBSD__) || defined(__APPLE__) || defined(__CYGWIN__)
    struct stat file_stat;
    if ( fstat(fileno(f), &file_stat) != 0 )
# else
    struct stat64 file_stat;
    if ( fstat64(fileno(f), &file_stat) != 0 )
# endif // __FreeBSD__
        return 0;
    return file_stat.st_size;
#endif // WIN32
}

Path::Path()
{
    if ( !working_directory.size() )
        InitWorkingDirectory();
    string s ( working_directory );
    const char* p = strtok ( &s[0], "/\\" );
    while ( p )
    {
        if ( *p )
            path.push_back ( p );
        p = strtok ( NULL, "/\\" );
    }
}

Path::Path ( const Path& cwd, const string& file )
{
    string s ( cwd.Fixup ( file, false ) );
    const char* p = strtok ( &s[0], "/\\" );
    while ( p )
    {
        if ( *p )
            path.push_back ( p );
        p = strtok ( NULL, "/\\" );
    }
}

string
Path::Fixup ( const string& file, bool include_filename ) const
{
    if ( strchr ( "/\\", file[0] )
#ifdef WIN32
        // this squirreliness is b/c win32 has drive letters and *nix doesn't...
        || file[1] == ':'
#endif//WIN32
        )
    {
        return file;
    }
    vector<string> pathtmp ( path );
    vector<char> tmp = vectorize( file );
    const char* prev = strtok ( &tmp[0], "/\\" );
    const char* p = strtok ( NULL, "/\\" );
    while ( p )
    {
        if ( !strcmp ( prev, "." ) )
            ; // do nothing
        else if ( !strcmp ( prev, ".." ) )
        {
            // this squirreliness is b/c win32 has drive letters and *nix doesn't...
#ifdef WIN32
            if ( pathtmp.size() > 1 )
#else
            if ( pathtmp.size() )
#endif
                pathtmp.resize ( pathtmp.size() - 1 );
        }
        else
            pathtmp.push_back ( prev );
        prev = p;
        p = strtok ( NULL, "/\\" );
    }
    if ( include_filename )
        pathtmp.push_back ( prev );

    // reuse tmp variable to return recombined path
    tmp = vectorize("");
    for ( size_t i = 0; i < pathtmp.size(); i++ )
    {
        // this squirreliness is b/c win32 has drive letters and *nix doesn't...
#ifdef WIN32
        if ( i ) vectappend(tmp, "/");
#else
        vectappend(tmp, "/");
#endif
        vectappend(tmp, pathtmp[i]);
    }
    return &tmp[0];
}

string
Path::RelativeFromWorkingDirectory ()
{
    string out = "";
    for ( size_t i = 0; i < path.size(); i++ )
    {
        out += "/" + path[i];
    }
    return RelativeFromWorkingDirectory ( out );
}

string
Path::RelativeFromWorkingDirectory ( const string& path )
{
    return Path::RelativeFromDirectory ( path, working_directory );
}

string
Path::RelativeFromDirectory (
    const string& path,
    const string& base_directory )
{
    vector<string> vbase, vpath, vout;
    Path::Split ( vbase, base_directory, true );
    Path::Split ( vpath, path, true );
#ifdef WIN32
    // this squirreliness is b/c win32 has drive letters and *nix doesn't...
    // not possible to do relative across different drive letters
    {
        char path_driveletter = (path[1] == ':') ? toupper(path[0]) : 0;
        char base_driveletter = (base_directory[1] == ':') ? toupper(base_directory[0]) : 0;
        if ( path_driveletter != base_driveletter )
            return path;
    }
#endif
    size_t i = 0;
    while ( i < vbase.size() && i < vpath.size() && vbase[i] == vpath[i] )
        ++i;

    // did we go through all of the path?
    if ( vbase.size() == vpath.size() && i == vpath.size() )
        return ".";

    if ( i < vbase.size() )
    {
        // path goes above our base directory, we will need some ..'s
        for ( size_t j = i; j < vbase.size(); j++ )
            vout.push_back ( ".." );
    }

    while ( i < vpath.size() )
        vout.push_back ( vpath[i++] );

    // now merge vout into a string again
    string out = vout[0];
    for ( i = 1; i < vout.size(); i++ )
    {
        out += "/" + vout[i];
    }
    return out;
}

void
Path::Split (
    vector<string>& out,
    const string& path,
    bool include_last )
{
    string s ( path );
    const char* prev = strtok ( &s[0], "/\\" );
    const char* p = strtok ( NULL, "/\\" );
    out.resize ( 0 );
    while ( p )
    {
        if ( strcmp ( prev, "." ) )
            out.push_back ( prev );
        prev = p;
        p = strtok ( NULL, "/\\" );
    }
    if ( include_last && strcmp ( prev, "." ) )
        out.push_back ( prev );
    // special-case where path only has "."
    // don't move this check up higher as it might miss
    // some funny paths...
    if ( !out.size() && !strcmp ( prev, "." ) )
        out.push_back ( "." );
}

XMLFile::XMLFile()
{
}

void
XMLFile::close()
{
    _buf.resize(0);
    _p = _end = NULL;
}

bool
XMLFile::open ( const string& filename_ )
{
    close();
    FILE* f = fopen ( filename_.c_str(), "rb" );
    if ( !f )
        return false;
    unsigned long len = (unsigned long)filelen(f);
    _buf.resize ( len );
    fread ( &_buf[0], 1, len, f );
    fclose ( f );
    _p = _buf.c_str();
    _end = _p + len;
    _filename = filename_;
    next_token();
    return true;
}

// next_token() moves the pointer to next token, which may be
// an xml element or a text element, basically it's a glorified
// skipspace, normally the user of this class won't need to call
// this function
void
XMLFile::next_token()
{
    _p += strspn ( _p, WS );
}

bool
XMLFile::next_is_text()
{
    return *_p != '<';
}

bool
XMLFile::more_tokens ()
{
    return _p != _end;
}

// get_token() is used to return a token, and move the pointer
// past the token
bool
XMLFile::get_token ( string& token )
{
    const char* tokend;
    if ( !strncmp ( _p, "<!--", 4 ) )
    {
        tokend = strstr ( _p, "-->" );
        if ( !tokend )
            tokend = _end;
        else
            tokend += 3;
    }
    else if ( !strncmp ( _p, "<?", 2 ) )
    {
        tokend = strstr ( _p, "?>" );
        if ( !tokend )
            tokend = _end;
        else
            tokend += 2;
    }
    else if ( *_p == '<' )
    {
        tokend = strchr ( _p, '>' );
        if ( !tokend )
            tokend = _end;
        else
            ++tokend;
    }
    else
    {
        tokend = strchr ( _p, '<' );
        if ( !tokend )
            tokend = _end;
        while ( tokend > _p && isspace(tokend[-1]) )
            --tokend;
    }
    if ( tokend == _p )
        return false;
    token = string ( _p, tokend-_p );
    _p = tokend;
    next_token();
    return true;
}

bool
XMLFile::get_token ( string& token, string& location )
{
    location = Location();
    return get_token ( token );
}

string
XMLFile::Location() const
{
    int line = 1;
    const char* p = strchr ( _buf.c_str(), '\n' );
    while ( p && p < _p )
    {
        ++line;
        p = strchr ( p+1, '\n' );
    }
    return ssprintf ( "%s(%i)",_filename.c_str(), line );
}

XMLAttribute::XMLAttribute()
{
}

XMLAttribute::XMLAttribute(
    const string& name_,
    const string& value_ )
    : name(name_), value(value_)
{
}

XMLAttribute::XMLAttribute ( const XMLAttribute& src )
    : name(src.name), value(src.value)
{

}

XMLAttribute& XMLAttribute::operator = ( const XMLAttribute& src )
{
    name = src.name;
    value = src.value;
    return *this;
}

XMLElement::XMLElement (
    XMLFile* xmlFile,
    const string& location )
    : xmlFile ( xmlFile ),
      location ( location ),
      parentElement ( NULL )
{
}

XMLElement::~XMLElement()
{
    size_t i;
    for ( i = 0; i < attributes.size(); i++ )
        delete attributes[i];
    for ( i = 0; i < subElements.size(); i++ )
        delete subElements[i];
}

void
XMLElement::AddSubElement ( XMLElement* e )
{
    subElements.push_back ( e );
    e->parentElement = this;
}

// Parse()
// This function takes a single xml tag ( i.e. beginning with '<' and
// ending with '>', and parses out it's tag name and constituent
// attributes.
// Return Value: returns true if you need to look for a </tag> for
// the one it just parsed...
bool
XMLElement::Parse (
    const string& token,
    bool& end_tag )
{
    const char* p = token.c_str();
    assert ( *p == '<' );
    ++p;
    p += strspn ( p, WS );

    // check if this is a comment
    if ( !strncmp ( p, "!--", 3 ) )
    {
        name = "!--";
        end_tag = false;
        return false; // never look for end tag to a comment
    }

    end_tag = ( *p == '/' );
    if ( end_tag )
    {
        ++p;
        p += strspn ( p, WS );
    }
    const char* end = strpbrk ( p, WS );
    if ( !end )
    {
        end = strpbrk ( p, "/>" );
        assert ( end );
    }
    name = string ( p, end-p );
    p = end;
    p += strspn ( p, WS );
    while ( *p != '>' && *p != '/' )
    {
        end = strpbrk ( p, WSEQ );
        if ( !end )
        {
            end = strpbrk ( p, "/>" );
            assert ( end );
        }
        string attribute ( p, end-p ), value;
        p = end;
        p += strspn ( p, WS );
        if ( *p == '=' )
        {
            ++p;
            p += strspn ( p, WS );
            char quote = 0;
            if ( strchr ( "\"'", *p ) )
            {
                quote = *p++;
                end = strchr ( p, quote );
            }
            else
            {
                end = strpbrk ( p, WS );
            }
            if ( !end )
            {
                end = strchr ( p, '>' );
                assert(end);
                if ( end[-1] == '/' )
                    end--;
            }
            value = string ( p, end-p );
            p = end;
            if ( quote && *p == quote )
                p++;
            p += strspn ( p, WS );
        }
        else if ( name[0] != '!' )
        {
            throw XMLSyntaxErrorException (
                location,
                "attributes must have values" );
        }
        attributes.push_back ( new XMLAttribute ( attribute, value ) );
    }
    return !( *p == '/' ) && !end_tag;
}

XMLAttribute*
XMLElement::GetAttribute (
    const string& attribute,
    bool required )
{
    // this would be faster with a tree-based container, but our attribute
    // lists are likely to stay so short as to not be an issue.
    for ( size_t i = 0; i < attributes.size(); i++ )
    {
        if ( attribute == attributes[i]->name )
            return attributes[i];
    }
    if ( required )
    {
        throw XMLRequiredAttributeNotFoundException (
            location,
            attribute,
            name );
    }
    return NULL;
}

const XMLAttribute*
XMLElement::GetAttribute (
    const string& attribute,
    bool required ) const
{
    // this would be faster with a tree-based container, but our attribute
    // lists are likely to stay so short as to not be an issue.
    for ( size_t i = 0; i < attributes.size(); i++ )
    {
        if ( attribute == attributes[i]->name )
            return attributes[i];
    }
    if ( required )
    {
        throw XMLRequiredAttributeNotFoundException (
            location,
            attribute,
            name );
    }
    return NULL;
}

int
XMLElement::FindElement ( const std::string& type, int prev ) const
{
    int done = subElements.size();
    while ( ++prev < done )
    {
        XMLElement* e = subElements[prev];
        if ( e->name == type )
            return prev;
    }
    return -1;
}

int
XMLElement::GetElements (
    const std::string& type,
    std::vector<XMLElement*>& v )
{
    int find = FindElement ( type );
    v.resize ( 0 );
    while ( find != -1 )
    {
        v.push_back ( subElements[find] );
        find = FindElement ( type, find );
    }
    return v.size();
}

int
XMLElement::GetElements (
    const std::string& type,
    std::vector<const XMLElement*>& v ) const
{
    int find = FindElement ( type );
    v.resize ( 0 );
    while ( find != -1 )
    {
        v.push_back ( subElements[find] );
        find = FindElement ( type, find );
    }
    return v.size();
}

// XMLParse()
// This function reads a "token" from the file loaded in XMLFile
// if it finds a tag that is non-singular, it parses sub-elements and/or
// inner text into the XMLElement that it is building to return.
// Return Value: an XMLElement allocated via the new operator that contains
// it's parsed data. Keep calling this function until it returns NULL
// (no more data)
XMLElement*
XMLParse (
    XMLFile& f,
    XMLIncludes* includes,
    const Path& path,
    bool* pend_tag = NULL )
{
    string token, location;
    if ( !f.get_token(token,location) )
        return NULL;
    bool end_tag, is_include = false;

    while
    (
        token[0] != '<'
        || !strncmp ( token.c_str (), "<!--", 4 )
        || !strncmp ( token.c_str (), "<?", 2 )
    )
    {
        if ( token[0] != '<' )
        {
            throw XMLSyntaxErrorException (
                location,
                "expecting xml tag, not '%s'",
                token.c_str () );
        }
        if ( !f.get_token ( token, location ) )
            return NULL;
    }

    XMLElement* e = new XMLElement (
        &f,
        location );
    bool bNeedEnd = e->Parse ( token, end_tag );

    if ( e->name == "xi:include" && includes )
    {
        XMLAttribute* att;
        att = e->GetAttribute ( "href", true );
        assert ( att );
        string includeFile ( path.Fixup ( att->value, true ) );
        string topIncludeFile (
            Path::RelativeFromWorkingDirectory ( includeFile ) );
        includes->push_back (
            new XMLInclude ( e, path, topIncludeFile ) );
        is_include = true;
    }

    if ( !bNeedEnd )
    {
        if ( pend_tag )
            *pend_tag = end_tag;
        else if ( end_tag )
        {
            delete e;
            throw XMLSyntaxErrorException (
                location,
                "end tag '%s' not expected",
                token.c_str() );
            return NULL;
        }
        return e;
    }
    bool bThisMixingErrorReported = false;
    while ( f.more_tokens () )
    {
        if ( f.next_is_text () )
        {
            if ( !f.get_token ( token, location ) || token.size () == 0 )
            {
                throw XMLInvalidBuildFileException (
                    location,
                    "internal tool error - get_token() failed when more_tokens() returned true" );
                break;
            }
            if ( e->subElements.size() && !bThisMixingErrorReported )
            {
                throw XMLSyntaxErrorException (
                    location,
                    "mixing of inner text with sub elements" );
                bThisMixingErrorReported = true;
            }
            if ( strchr ( token.c_str (), '>' ) )
            {
                throw XMLSyntaxErrorException (
                    location,
                    "invalid symbol '>'" );
            }
            if ( e->value.size() > 0 )
            {
                throw XMLSyntaxErrorException (
                    location,
                    "multiple instances of inner text" );
                e->value += " " + token;
            }
            else
                e->value = token;
        }
        else
        {
            XMLElement* e2 = XMLParse (
                f, is_include ? NULL : includes, path, &end_tag );
            if ( !e2 )
            {
                string e_location = e->location;
                string e_name = e->name;
                delete e;
                throw XMLInvalidBuildFileException (
                    e_location,
                    "end of file found looking for end tag: </%s>",
                    e_name.c_str() );
                break;
            }
            if ( end_tag )
            {
                if ( e->name != e2->name )
                {
                    string e2_location = e2->location;
                    string e_name = e->name;
                    string e2_name = e2->name;
                    delete e;
                    delete e2;
                    throw XMLSyntaxErrorException (
                        e2_location,
                        "end tag name mismatch - found </%s> but was expecting </%s>",
                        e2_name.c_str(),
                        e_name.c_str() );
                    break;
                }
                delete e2;
                break;
            }
            if ( e->value.size () > 0 && !bThisMixingErrorReported )
            {
                string e_location = e->location;
                delete e;
                throw XMLSyntaxErrorException (
                    e_location,
                    "mixing of inner text with sub elements" );
                bThisMixingErrorReported = true;
            }
            e->AddSubElement ( e2 );
        }
    }
    return e;
}

void
XMLReadFile (
    XMLFile& f,
    XMLElement& head,
    XMLIncludes& includes,
    const Path& path )
{
    for ( ;; )
    {
        XMLElement* e = XMLParse ( f, &includes, path );
        if ( !e )
            return;
        head.AddSubElement ( e );
    }
}

XMLElement*
XMLLoadInclude (
    XMLInclude& include,
    XMLIncludes& includes )
{
    XMLAttribute* att;
    att = include.e->GetAttribute("href", true);
    assert(att);

    string file ( include.path.Fixup(att->value, true) );
    string top_file ( Path::RelativeFromWorkingDirectory ( file ) );
    include.e->attributes.push_back ( new XMLAttribute ( "top_href", top_file ) );
    XMLFile* fInc = new XMLFile();
    if ( !fInc->open ( file ) )
    {
        include.fileExists = false;
        // look for xi:fallback element
        for ( size_t i = 0; i < include.e->subElements.size (); i++ )
        {
            XMLElement* e2 = include.e->subElements[i];
            if ( e2->name == "xi:fallback" )
            {
                // now look for xi:include below...
                for ( i = 0; i < e2->subElements.size (); i++ )
                {
                    XMLElement* e3 = e2->subElements[i];
                    if ( e3->name == "xi:include" )
                    {
                        att = e3->GetAttribute ( "href", true );
                        assert ( att );
                        string includeFile (
                            include.path.Fixup ( att->value, true ) );
                        string topIncludeFile (
                            Path::RelativeFromWorkingDirectory ( includeFile ) );
                        XMLInclude* fallbackInclude =
                            new XMLInclude ( e3, include.path, topIncludeFile );

                        XMLElement* value = XMLLoadInclude (*fallbackInclude, includes );
                        delete fallbackInclude;
                        return value;
                    }
                }
                throw XMLInvalidBuildFileException (
                    e2->location,
                    "<xi:fallback> must have a <xi:include> sub-element" );
                return NULL;
            }
        }
        return NULL;
    }
    else
    {
        include.fileExists = true;
        XMLElement* new_e = new XMLElement (
            fInc,
            include.e->location );
        new_e->name = "xi:included";
        Path path2 ( include.path, att->value );
        XMLReadFile ( *fInc, *new_e, includes, path2 );
        return new_e;
    }
}

XMLElement*
XMLLoadFile (
    const string& filename,
    const Path& path,
    XMLIncludes& includes )
{
    XMLFile* f = new XMLFile();

    if ( !f->open ( filename ) )
    {
        delete f;
        throw XMLFileNotFoundException ( "(virtual)", filename );
        return NULL;
    }

    XMLElement* head = new XMLElement ( f, "(virtual)" );

    XMLReadFile ( *f, *head, includes, path );

    for ( size_t i = 0; i < includes.size (); i++ )
    {
        XMLElement* e = includes[i]->e;
        XMLElement* e2 = XMLLoadInclude ( *includes[i], includes );
        if ( !e2 )
        {
            throw XMLFileNotFoundException (
                f->Location(),
                e->GetAttribute ( "top_href", true )->value );
        }
        XMLElement* parent = e->parentElement;
        XMLElement** parent_container = NULL;
        if ( !parent )
        {
            string location = e->location;
            delete e;
            delete f;
            throw XMLException ( location, "internal tool error: xi:include doesn't have a parent" );
            return NULL;
        }
        for ( size_t j = 0; j < parent->subElements.size (); j++ )
        {
            if ( parent->subElements[j] == e )
            {
                parent_container = &parent->subElements[j];
                break;
            }
        }
        if ( !parent_container )
        {
            string location = e->location;
            delete e;
            delete f;
            throw XMLException ( location, "internal tool error: couldn't find xi:include in parent's sub-elements" );
            return NULL;
        }
        // replace inclusion tree with the imported tree
        e2->parentElement = e->parentElement;
        e2->name = e->name;
        e2->attributes = e->attributes;
        *parent_container = e2;
        e->attributes.resize ( 0 );
        delete e;
    }
    delete f;
    return head;
}

XMLElement*
XMLLoadFile ( const string& filename )
{
    Path path;
    XMLIncludes includes;
    return XMLLoadFile ( filename, path, includes );
}