/*
 * ConfigCore.cpp
 *
 *  Created on: 5 Mar 2017
 *      Author: wentzelc
 */

// redA Libraries
#include "ConfigCore.h"

// Standard C/C++ Libraries
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>

//---------------------------------------------------------------------------

CConfigCore::CConfigCore()
{
    // Parameter tree
    FirstParam = NULL;

    // File Operation
    InputFile       = NULL;
    BufLen          = 500;
    Buffer          = NULL;
    BufEnd          = NULL;

    // Parsing operation
    BufPos          = NULL;
    LineMark        = NULL;
    LineNo          = 0;
    Error           = false;
    ErrorText[0]    = 0;
}
//---------------------------------------------------------------------------

CConfigCore::~CConfigCore()
{
    // Destroy Params
    while (FirstParam)
        DestroyParam( &FirstParam );
}
//---------------------------------------------------------------------------

bool  CConfigCore::DestroyParam( TConfigParam ** Param )
{
    TConfigParam    * NextParam;

    // Valdate
    if (!Param || !*Param)
        return false;

    // Get next param in list
    NextParam = (*Param)->Next;

    // Destroy
    if ((*Param)->Name)
        free( (*Param)->Name );
    if ((*Param)->Value)
        free( (*Param)->Value );

    free( *Param );

    // Restore list integrity
    *Param = NextParam;

    return true;
}
//---------------------------------------------------------------------------

bool  CConfigCore::DeleteParam( const char * Name )
{
    TConfigParam    ** Param;

    // Check if exists
    if (!(Param = GetParamPtr( Name )))
        return false;

    // Destory
    DestroyParam( Param );
    return true;
}
//---------------------------------------------------------------------------

bool  CConfigCore::DeleteAll()
{
    while (FirstParam)
        DestroyParam( &FirstParam );
    return true;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParam( TConfigParam * Param, EJSONtype Type, const char * Value, const int Len )
{
    // Clear previous value
    if (Param->Value != NULL) {
        free( Param->Value );
    }

    // Set type
    Param->Type = Type;

    // Set new value
    if (Type == jtNull) {
        Param->Len   = 0;
        Param->Value = NULL;
    }
    else {
        Param->Len = (Len == -1)? strlen(Value) : Len;
        Param->Value = (char *)malloc( sizeof(Param->Len+1) );
        memcpy( Param->Value, Value, Param->Len+1 );
        Param->Value[Param->Len] = 0;
    }

    return true;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParamStr( const char * Name, const char * Value, const int Len )
{
    TConfigParam    * Param;

    // Create new param if it doesn't exist
    Param = FindCreateParam( Name );
    SetParam( Param, jtString, Value, Len );

    return true;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParamInt( const char * Name, const long Value )
{
    TConfigParam    * Param    = NULL;
    char            ValueStr[50];

    // Create new param if it doesn't exist
    Param = FindCreateParam( Name );
    sprintf( ValueStr, "%ld", Value );
    SetParam( Param, jtInt, ValueStr, -1 );

    return false;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParamFloat( const char * Name, const double Value )
{
    TConfigParam    * Param    = NULL;
    char            ValueStr[50];

    // Create new param if it doesn't exist
    Param = FindCreateParam( Name );
    sprintf( ValueStr, "%lf", Value );
    SetParam( Param, jtFloat, ValueStr, -1 );
    return false;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParamBool( const char * Name, const bool Value )
{
    TConfigParam    * Param    = NULL;

    // Create new param if it doesn't exist
    Param = FindCreateParam( Name );
    SetParam( Param, jtBool, ((Value == 0)? "false" : "true"), -1 );
    return false;
}
//---------------------------------------------------------------------------

bool  CConfigCore::SetParamNull( const char * Name )
{
    TConfigParam    * Param    = NULL;

    // Create new param if it doesn't exist
    Param = FindCreateParam( Name );
    SetParam( Param, jtNull, NULL, -1 );
    return false;
}
//---------------------------------------------------------------------------

const EJSONtype CConfigCore::GetParamType( const char * Name )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name ))) {
        return Param->Type;
    }
    else {
        return jtNull;
    }
}
//---------------------------------------------------------------------------

const char * CConfigCore::GetParamStr( const char * Name, const char * Default )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name )) && (Param->Type == jtString)) {
        return Param->Value;
    }
    else {
        return Default;
    }
}
//---------------------------------------------------------------------------

const char * CConfigCore::GetParamStr( const char * Name, int &Len, const char * Default )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name )) && (Param->Type == jtString)) {
        Len = Param->Len;
        return Param->Value;
    }
    else {
        Len = strlen( Default );
        return Default;
    }
}
//---------------------------------------------------------------------------

const long  CConfigCore::GetParamInt( const char * Name, long Default )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name )) && (Param->Type == jtInt)) {
        return strtol( Param->Value, NULL, 10 );
    }
    else {
        return Default;
    }
}
//---------------------------------------------------------------------------

const double  CConfigCore::GetParamFloat( const char * Name, double Default )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name )) && (Param->Type == jtFloat)) {
        return strtod( Param->Value, NULL );
    }
    else {
        return Default;
    }
}
//---------------------------------------------------------------------------

const bool  CConfigCore::GetParamBool( const char * Name, bool Default )
{
    TConfigParam *  Param;

    if ((Param = GetParam( Name )) && (Param->Type == jtBool)) {
        return ((!strcasecmp( Param->Value, "true" ))? true : false );
    }
    else {
        return Default;
    }
}
//---------------------------------------------------------------------------

bool CConfigCore::LoadFile( const char * FilePath, int pBufLen )
{
    TConfigParam    * Object         = NULL;

    // Validate
    if (!FilePath || !FilePath[0])
        return false;

    // Open file
    if (!(InputFile = fopen( FilePath, "r" )))
        return false;

    // Load Buffer
    CreateBuffer( pBufLen );
    if (!FillBuffer()) {
        Error = true;
        sprintf( ErrorText, "Could not read from file" );
        FreeBuffer();
        return false;
    }

    // Reset values
    LineNo  = 1;
    Error   = false;

    // Create Root object
    DeleteAll();
    Object = FindCreateParam( "root" );

    // Parse Root Object
    SkipWhiteSpace();
    if (!ParseObject( Object )) {
        if (!Error) {
            Error = true;
            sprintf( ErrorText, "First entry in file must be an Object on line %d:%ld", LineNo, BufPos-LineMark );
        }
        FreeBuffer();
        return false;
    }

    // Ensure remainder of file is empty
    SkipWhiteSpace();
    if (*BufPos != 0) {
        Error = true;
        sprintf( ErrorText, "No content expected after Root object on line %d:%ld", LineNo, BufPos-LineMark );
        FreeBuffer();
        return false;
    }

    // Success
    FreeBuffer();
    return true;
}
//---------------------------------------------------------------------------

bool CConfigCore::CreateBuffer( int pBufLen )
{
    // Validate
    if (!pBufLen)
        return false;

    // Create buffer
    BufLen = pBufLen;
    Buffer = (char*)malloc( BufLen+1 );

    // Reset markers
    BufEnd = Buffer;
    BufPos = Buffer;
    LineMark = Buffer;

    return true;
}
//---------------------------------------------------------------------------

bool CConfigCore::FillBuffer()
{
    int             BufCount        = 0;

    // Read from file
    BufCount = fread( Buffer, 1, 500, InputFile );
    if (BufCount < 1) {
        return false;
    }

    // Update Markers
    BufEnd += BufCount;
    BufPos = Buffer;
    LineMark = Buffer;

    return true;
}
//---------------------------------------------------------------------------

void CConfigCore::FreeBuffer()
{
    // Destroy buffer
    if (Buffer) {
        free( Buffer );
        Buffer = NULL;
    }
    BufLen = 0;
}
//---------------------------------------------------------------------------

bool CConfigCore::ParseObject( TConfigParam * Object )
{
    TConfigParam    * Param         = NULL;
    char            * ParamName     = NULL;
    int             Len             = 0;

    // Clear Values
    Error = false;

    // Check for start of Object
    if (*BufPos != '{') {
        return false;
    }
    BufPos++;

    while (true)
    {
        // Look for Param Name
        SkipWhiteSpace();
        if (*BufPos == 0) {
            Error = true;
            sprintf( ErrorText, "Expect quoted key name on line %d:%ld", LineNo, BufPos-LineMark );
        }
        else if (!ParseString( &ParamName, &Len )) {
            if (!Error) {
                Error = true;
                sprintf( ErrorText, "Expect quoted key name on line %d:%ld", LineNo, BufPos-LineMark );
            }
            return false;
        }
        else if (!Len) {
            Error = true;
            sprintf( ErrorText, "Empty parameter name on line %d:%ld", LineNo, BufPos-LineMark );
            return false;
        }

        // Create parameter
        Param = FindCreateParam( ParamName );

        // Check for delimiter
        SkipWhiteSpace();
        if (*BufPos != ':') {
            Error = true;
            sprintf( ErrorText, "Expected ':' delimiter on line %d:%ld", LineNo, BufPos-LineMark );
            return false;
        }
        BufPos++;

        // Get Value
        SkipWhiteSpace();
        if (!ParseObject( Param ) &&
            !Error &&
            !ParseString( &Param->Value, &Param->Len, &Param->Type ) &&
            !Error &&
            !ParsePrimitive(  &Param->Value, &Param->Len, &Param->Type  )) {
            return false;
        }

        // Check if more parameters to follow
        SkipWhiteSpace();
        if (*BufPos != ',') {
            // No more parameters
            break;
        }
        BufPos++;
    }

    // Expect end of object
    if (*BufPos != '}') {
        Error = true;
        sprintf( ErrorText, "Closing brace for object '}' expected on line %d:%ld", LineNo, BufPos-LineMark );
        return false;
    }
    BufPos++;

    // success
    return true;
}
//---------------------------------------------------------------------------

bool CConfigCore::ParseString( char ** Value, int *pLen, EJSONtype *pType )
{
    char    * Mark;
    char    * EndMark;
    int     Len;

    // Clear value
    Error   = false;
    *Value  = NULL;
    Len     = 0;

    // Check for opening quote
    if (*BufPos != '"') {
        return false;
    }

    // Mark start of quote
    Mark = BufPos;
    BufPos++;

    // Check for closing quote
    while ((BufPos = strpbrk( BufPos, "\"/\\\n\t\b\f\n\r" )))
    {
        if (*BufPos == '"') {
            // End of string found
            BufPos++;
            break;
        }
        else if (!*BufPos) {
            Error = true;
            sprintf( ErrorText, "Expect closing '\"' for string on line %d:%ld", LineNo, Mark-LineMark );
            return false;
        }
        else if (*BufPos == '\\') {
            if (*(BufPos+1) == 'u') {
                for (EndMark = BufPos+2; EndMark < BufPos+6; EndMark++) {
                    if (!isxdigit( *EndMark )) {
                        Error = true;
                        sprintf( ErrorText, "Expect 4-digit hex value for escape value on line %d:%ld", LineNo, Mark-LineMark );
                        return false;
                    }
                }
                BufPos += 6;
            }
            else if (strchr( "bfnrt/\\\"", *(BufPos+1) )) {
                BufPos += 2;
            }
            else {
                Error = true;
                sprintf( ErrorText, "Invalid escape sequence on line %d:%ld", LineNo, Mark-LineMark );
                return false;
            }
        }
        else {
            Error = true;
            sprintf( ErrorText, "Un-escaped special character in string on line %d:%ld", LineNo, BufPos-LineMark );
            return false;
        }
    }

    // Validate size of Param name
    Len = BufPos-Mark-2;

    // Create Return value pointer
    *Value = (char*)malloc( Len+1 );
    memcpy( *Value, Mark+1, Len );
    (*Value)[Len] = 0;

    // Set other parameters
    if (pType)
        *pType = jtString;
    if (pLen)
        *pLen = Len;

    // Success
    return true;
}
//---------------------------------------------------------------------------

bool CConfigCore::ParsePrimitive( char ** Value, int * pLen, EJSONtype * pType )
{
    char    * Mark;
    char    * EndMark;
    int     Len;

    // Clear value
    Error   = false;
    *Value  = NULL;
    Len     = 0;

    // Mark start of value
    Mark    = BufPos;

    // Get end of value
    while ((*BufPos != 0) && !isspace(*BufPos) && (*BufPos != ',')) {
        BufPos++;
    }

    // Check length of value
    Len = BufPos - Mark;
    if (!Len) {
        Error = true;
        sprintf( ErrorText, "Missing param value on line %d:%ld", LineNo, Mark-LineMark );
        return false;
    }

    // Check for primitive values
    if ((Len == 4) && !strncasecmp( Mark, "null", 4 )) {
        if (pType)
            *pType = jtNull;
        if (pLen)
            *pLen = Len;
        *Value = (char*)malloc( 5 );
        strcpy( *Value, "null" );
    }
    else if ((Len == 4) && !strncasecmp( Mark, "true", 4 )) {
        if (pType)
            *pType = jtBool;
        if (pLen)
            *pLen = Len;
        *Value = (char*)malloc( 5 );
        strcpy( *Value, "true" );
    }
    else if ((Len == 5) && !strncasecmp( Mark, "false", 5 )) {
        if (pType)
            *pType = jtBool;
        if (pLen)
            *pLen = Len;
        *Value = (char*)malloc( 6 );
        strcpy( *Value, "false" );
    }
    else {
        // Try conversion to int
        strtol( Mark, &EndMark, 10 );
        if (EndMark == BufPos) {
            if (pType)
                *pType = jtInt;
            if (pLen)
                *pLen = Len;
            *Value = (char*)malloc( Len+1 );
            memcpy( *Value, Mark, Len );
            *Value[Len] = 0;
        }
        else {
            // Try conversion to float
            strtod( Mark, &EndMark );
            if (EndMark == BufPos) {
                if (pType)
                    *pType = jtFloat;
                if (pLen)
                    *pLen = Len;
                *Value = (char*)malloc( Len+1 );
                memcpy( *Value, Mark, Len );
                *Value[Len] = 0;
            }
            else {
                Error = true;
                sprintf( ErrorText, "Invalid primitive param value on line %d:%ld", LineNo, Mark-LineMark );
                return false;
            }
        }
    }

    // Success
    return true;
}
//---------------------------------------------------------------------------

bool CConfigCore::SaveFile( const char * FilePath, const int ValueTab )
{
    FILE            * OutputFile    = NULL;
    TConfigParam    * Param;
    int             SpacerLen;
    char            Spacer[50];

    // Validate
    if (!FilePath || !FilePath[0])
        return false;

    // Open file
    if (!(OutputFile = fopen( FilePath, "w" )))
        return false;

    // Save parameters
    for (Param = FirstParam; Param != NULL; (Param = Param->Next))
    {
        // Write parameter name
        fprintf( OutputFile, "\"%s\":", Param->Name );

        // Create fixed offset for values
        SpacerLen = ValueTab - (strlen(Param->Name) + 3);
        if (SpacerLen > 0) {
            memset( Spacer, ' ', SpacerLen );
            Spacer[SpacerLen] = 0;
            fwrite( Spacer, 1, SpacerLen, OutputFile );
        }

        switch (Param->Type)
        {
            case jtNull :
                fprintf( OutputFile, "%s,\n", "null" );
                break;

            case jtBool :
            case jtInt :
            case jtFloat :
                fprintf( OutputFile, "%s,\n", Param->Value );
                break;

            case jtString :
                fprintf( OutputFile, "\"%s\",\n", Param->Value );
                break;

            case jtArray :
                fprintf( OutputFile, "[],\n" );
                break;

            case jtObject :
                fprintf( OutputFile, "{},\n" );
                break;
        }
    }

    // Close file
    fclose( OutputFile );
    return false;
}
//---------------------------------------------------------------------------