#include "bu/json.h"
#include "bu/staticmembuf.h"
#include "bu/membuf.h"

#include "bu/sio.h"

#include <stdlib.h>

#define next( txt ) readChar( c, sInput, "Unexpected end of stream while reading " txt "." )

Bu::Json::Json() :
    eType( Null )
{
}

Bu::Json::Json( const Bu::UtfString &sValue ) :
    eType( String ),
    uDat( sValue.get() )
{
}

Bu::Json::Json( const Bu::String &sValue ) :
    eType( String ),
    uDat( sValue )
{
}

Bu::Json::Json( const char *sValue ) :
    eType( String ),
    uDat( sValue )
{
}

Bu::Json::Json( double dValue ) :
    eType( Number ),
    uDat( dValue )
{
}

Bu::Json::Json( bool bValue ) :
    eType( Boolean ),
    uDat( bValue )
{
}

Bu::Json::Json( Type eType ) :
    eType( eType )
{
    switch( eType )
    {
        case Object:
            uDat.pObject = new JsonHash();
            break;

        case Array:
            uDat.pArray = new JsonList();
            break;

        case String:
            uDat.pString = new Bu::String();
            break;

        case Number:
        case Boolean:
        case Null:
        case Invalid:
            uDat.pObject = NULL;
            break;
    }
}

Bu::Json::Json( Bu::Stream &sInput ) :
    eType( Invalid )
{
    parse( sInput );
}

Bu::Json::Json( char &c, Bu::Stream &sInput ) :
    eType( Invalid )
{
    parse( c, sInput );
}

Bu::Json::~Json()
{
    reset();
}

Bu::Json::Type Bu::Json::getType() const
{
    return eType;
}

Bu::String Bu::Json::getString() const
{
    if( eType != String )
        throw Bu::ExceptionBase(
            "String requested from non-string json object."
            );

    return *uDat.pString;
}

double Bu::Json::getNumber() const
{
    if( eType != Number )
        throw Bu::ExceptionBase(
            "Number requested from non-number json object."
            );

    return uDat.dNumber;
}

bool Bu::Json::getBoolean() const
{
    if( eType != Boolean )
        throw Bu::ExceptionBase(
            "Boolean requested from non-boolean json object."
            );

    return uDat.bBoolean;
}

bool Bu::Json::isNull() const
{
    return eType == Null;
}

Bu::Json *Bu::Json::operator[]( const Bu::String &sKey ) const
{
    if( eType != Object )
        throw Bu::ExceptionBase(
            "Object entry requested from non-object json object."
            );

    return uDat.pObject->get( sKey );

}

int Bu::Json::getSize() const
{
    if( eType == Object )
        return uDat.pObject->getSize();
    else if( eType == Array )
        return uDat.pArray->getSize();
    else if( eType == String )
        return uDat.pString->getSize();
    else
        throw Bu::ExceptionBase(
            "Size requseted from json type that doesn't support it."
            );
}

Bu::Json::iterator Bu::Json::begin()
{
    return uDat.pArray->begin();
}

Bu::Json::const_iterator Bu::Json::begin() const
{
    return uDat.pArray->begin();
}

Bu::Json::iterator Bu::Json::end()
{
    return uDat.pArray->end();
}

Bu::Json::const_iterator Bu::Json::end() const
{
    return uDat.pArray->end();
}

bool Bu::Json::has( const Bu::String &sKey ) const
{
    return uDat.pObject->has( sKey );
}

void Bu::Json::insert( const Bu::String &sKey, Bu::Json *pObj )
{
    uDat.pObject->insert( sKey, pObj );
}

void Bu::Json::append( Bu::Json *pObj )
{
    uDat.pArray->append( pObj );
}

void Bu::Json::parse( Bu::Stream &sInput )
{
    reset();

    char c;
    next("json");

    parse( c, sInput );
}

void Bu::Json::parse( const Bu::String &sInput )
{
    Bu::StaticMemBuf mb( sInput.getStr(), sInput.getSize() );
    parse( mb );
}

void Bu::Json::parse( char &c, Bu::Stream &sInput )
{
    while( c == ' ' || c == '\t' || c == '\r' || c == '\n' )
    {
        next( "json" );
    }
    if( c == '"' )
    {
        // String
        parseString( c, sInput );
    }
    else if( c == '{' )
    {
        // Object
        parseObject( c, sInput );
    }
    else if( c == '[' )
    {
        // Array
        parseArray( c, sInput );
    }
    else if( c == '-' || (c >= '0' && c <= '9') )
    {
        // Number -- apparently they can't start with a period
        parseNumber( c, sInput );
    }
    else if( c == 't' || c == 'f' || c == 'n' )
    {
        // True / false / null
        parseLiteral( c, sInput );
    }
    else
    {
        throw Bu::ExceptionBase("Invalid characters in json stream.");
    }
}

void Bu::Json::reset()
{
    switch( eType )
    {
        case Object:
            for( JsonHash::iterator i = uDat.pObject->begin(); i; i++ )
            {
                delete i.getValue();
            }
            delete uDat.pObject;
            break;

        case Array:
            for( JsonList::iterator i = uDat.pArray->begin(); i; i++ )
            {
                delete *i;
            }
            delete uDat.pArray;
            break;

        case String:
            delete uDat.pString;
            break;

        case Invalid:
        case Number:
        case Boolean:
        case Null:
            break;
    }
    uDat.pObject = NULL;
}

void Bu::Json::write( Bu::Stream &sOutput ) const
{
    switch( eType )
    {
        case Invalid:
            throw Bu::ExceptionBase("Invalid type in json");
            break;

        case Object:
            {
                sOutput.write("{", 1 );
                bool bFirst = true;
                for( JsonHash::iterator i = uDat.pObject->begin(); i; i++ )
                {
                    if( bFirst == true )
                        bFirst = false;
                    else
                        sOutput.write(",");
                    writeStr( i.getKey(), sOutput );
                    sOutput.write(":", 1 );
                    (*i)->write( sOutput );
                }
                sOutput.write("}", 1 );
            }
            break;

        case Array:
            {
                sOutput.write("[", 1);
                bool bFirst = true;
                for( JsonList::iterator i = uDat.pArray->begin(); i; i++ )
                {
                    if( bFirst == true )
                        bFirst = false;
                    else
                        sOutput.write(",", 1 );
                    (*i)->write( sOutput );
                }
                sOutput.write("]", 1);
            }
            break;

        case String:
            writeStr( *uDat.pString, sOutput );
            break;

        case Number:
            sOutput.write(Bu::String("%1").arg( uDat.dNumber ));
            break;

        case Boolean:
            if( uDat.bBoolean )
                sOutput.write("true", 4 );
            else
                sOutput.write("false", 5 );
            break;

        case Null:
            sOutput.write("null", 4 );
            break;
    }
}

void Bu::Json::writeStable( Bu::Stream &sOutput ) const
{
    if( eType == Object )
    {
        sOutput.write("{", 1 );
        bool bFirst = true;
        Bu::List<Bu::String> lKey = uDat.pObject->getKeys();
        lKey.sort();
        for( Bu::List<Bu::String>::iterator i = lKey.begin(); i; i++ )
        {
            if( bFirst == true )
                bFirst = false;
            else
                sOutput.write(",");
            writeStr( *i, sOutput );
            sOutput.write(":", 1 );
            uDat.pObject->get( *i )->write( sOutput );
        }
        sOutput.write("}", 1 );
    }
    else
    {
        write( sOutput );
    }
}

Bu::String Bu::Json::toString() const
{
    Bu::MemBuf mb;
    write( mb );
    return mb.getString();
}

Bu::String Bu::Json::toStringStable() const
{
    Bu::MemBuf mb;
    writeStable( mb );
    return mb.getString();
}

void Bu::Json::parseString( char &c, Bu::Stream &sInput, Bu::String &sOut )
{
    skipWs( c, sInput );
    bool bEscape = false;
    for(;;)
    {
        next( "string" );
        if( bEscape )
        {
            switch( c )
            {
                case '"':
                case '\\':
                case '/':
                    sOut += c;
                    break;

                case 'b':
                    sOut += '\b';
                    break;

                case 'f':
                    sOut += '\f';
                    break;

                case 'n':
                    sOut += '\n';
                    break;

                case 'r':
                    sOut += '\r';
                    break;

                case 't':
                    sOut += '\t';
                    break;

                case 'u':
                    // Not implimented yet, followed by four hex diigts
                    break;

                default:
                    throw Bu::ExceptionBase(
                        "Invalid escape sequence encountered in string."
                        );
                    break;
            }
            bEscape = false;
        }
        else
        {
            if( c == '\\' )
                bEscape = true;
            if( c == '"' )
            {
                readChar( c, sInput );
                break;
            }
            sOut += c;
        }
    }
}

void Bu::Json::parseString( char &c, Bu::Stream &sInput )
{
    eType = String;
    uDat.pString = new Bu::String();
    parseString( c, sInput, *uDat.pString );
}

void Bu::Json::parseObject( char &c, Bu::Stream &sInput )
{
    skipWs( c, sInput );
    eType = Object;
    uDat.pObject = new JsonHash();

    next( "object" );
    for(;;)
    {
        Bu::String sKey;
        parseString( c, sInput, sKey );
        skipWs( c, sInput );
        if( c != ':' )
        {
            throw Bu::ExceptionBase(
                "Invalid json, expected colon after key in object."
                );
        }
        next("object");
        uDat.pObject->insert( sKey, new Json( c, sInput ) );
        skipWs( c, sInput );
        if( c == '}' )
        {
            readChar( c, sInput );
            break;
        }
        else if( c == ',' )
            next( "object" );
        else
            throw Bu::ExceptionBase(
                "Invalid json, expected comma or } after value in object."
                );
    }
}

void Bu::Json::parseArray( char &c, Bu::Stream &sInput )
{
    skipWs( c, sInput );

    eType = Array;
    uDat.pArray = new JsonList();

    next("array");

    for(;;)
    {
        uDat.pArray->append( new Json( c, sInput ) );
        skipWs( c, sInput );
        if( c == ']' )
        {
            readChar( c, sInput );
            break;
        }
        else if( c == ',' )
        {
            next("array");
            continue;
        }
        else
        {
            throw Bu::ExceptionBase(
                "Invalid json, expected comma or ] after value in array."
                );
        }
    }
}

void Bu::Json::parseNumber( char &c, Bu::Stream &sInput )
{
    skipWs( c, sInput );

    Bu::String sBuf;
    if( c == '-' )
    {
        sBuf += c;
        next( "number" );
    }
    bool bIntPart = true;
    do
    {
        if( c >= '0' && c <= '9' )
            sBuf += c;
        else if( c == '.' && bIntPart == true )
        {
            bIntPart = false;
            sBuf += c;
        }
        else if( c == ' ' || c == '\t' || c == '\n' || c == '\r' ||
                 c == '}' || c == ']' || c == ',' )
        {
            break;
        }
        else
        {
            throw Bu::ExceptionBase("Invalid character in number.");
        }
    } while( readChar( c, sInput ) );

    eType = Number;
    uDat.dNumber = atof( sBuf.getStr() );
}

void Bu::Json::parseLiteral( char &c, Bu::Stream &sInput )
{
    skipWs( c, sInput );

    Bu::String s;
    do
    {
        if( isWs( c ) || c == ',' || c == '}' || c == ']' )
            break;
        else
            s += c;
    } while( readChar( c, sInput ) );

    if( s == "true" )
    {
        eType = Boolean;
        uDat.bBoolean = true;
    }
    else if( s == "false" )
    {
        eType = Boolean;
        uDat.bBoolean = false;
    }
    else if( s == "null" )
    {
        eType = Null;
        uDat.pObject = NULL;
    }
    else
    {
        throw Bu::ExceptionBase("Invalid literal token found.");
    }
}

bool Bu::Json::readChar( char &c, Bu::Stream &sInput )
{
    if( sInput.read( &c, 1 ) == 0 )
        return false;
    return true;
}

void Bu::Json::readChar( char &c, Bu::Stream &sInput, const char *sSection )
{
    if( sInput.read( &c, 1 ) == 0 )
    {
        throw Bu::ExceptionBase( sSection );
    }
}

bool Bu::Json::isWs( char c )
{
    return c == ' ' || c == '\t' || c == '\r' || c == '\n';
}

void Bu::Json::skipWs( char &c, Bu::Stream &sInput )
{
    while( isWs( c ) )
    {
        next("whitespace");
    }
}

void Bu::Json::writeStr( const Bu::String &sStr, Bu::Stream &sOutput ) const
{
    sOutput.write("\"", 1 );
    for( Bu::String::const_iterator i = sStr.begin(); i; i++ )
    {
        switch( *i )
        {
            case '"':
                sOutput.write("\\\"", 2 );
                break;

            case '\\':
                sOutput.write("\\\\", 2 );
                break;

            case '/':
                sOutput.write("\\/", 2 );
                break;

            case '\b':
                sOutput.write("\\b", 2 );
                break;

            case '\f':
                sOutput.write("\\f", 2 );
                break;

            case '\n':
                sOutput.write("\\n", 2 );
                break;

            case '\r':
                sOutput.write("\\r", 2 );
                break;

            case '\t':
                sOutput.write("\\t", 2 );
                break;

            default:
                sOutput.write( &(*i), 1 );
        }
    }
    sOutput.write("\"", 1 );
}