/*
Copyright (C) 2004-2008 Christian Wieninger

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
Or, point your browser to http://www.gnu.org/licenses/old-licenses/gpl-2.0.html

The author can be reached at cwieninger@gmx.de

The project's page is at http://winni.vdr-developer.org/epgsearch
*/

#include <algorithm>
#include "uservars.h"
#include "epgsearchcats.h"
#include "epgsearchtools.h"
#include "log.h"

cUserVars UserVars;

string cPlugconfdirVar::dir = "";

// cUserVar

cUserVar::cUserVar()
{
   oldEvent = NULL;
}

string cUserVar::Evaluate(const cEvent* e, bool escapeStrings)
{
  if (oldEvent && oldEvent == e && oldescapeStrings == escapeStrings)
    return oldResult;
   usedVars.clear();
   string result;
   if (IsShellCmd())
      result = EvaluateShellCmd(e);
   else if (IsCondExpr())
      result = EvaluateCondExpr(e);
   else
      result = EvaluateCompExpr(e);
   oldResult = result;
   oldEvent = e;
   oldescapeStrings = escapeStrings;

   // avoid double dir separators
   int pos = 0;
   while((pos = result.find("~~")) >= 0)
      result.replace(pos, 2, "~"); 

   return result;
}

string cUserVar::EvaluateShellCmd(const cEvent* e)
{
   if (!varparser.cmd) return "";
   string cmdArgs;
   if (varparser.cmdArgs != "")
   {
      string args = varparser.cmdArgs;
      varparser.compExpr = args; //handle the args as composed expr	
      cmdArgs = EvaluateCompExpr(e, true);
   }
   const char* res = varparser.cmd->Execute(cmdArgs.c_str());
   string result = res?res:"";
   int crPos = 0; // remove any CR
   while((crPos = result.find("\n")) >= 0)
      result.replace(crPos, 1, ""); 
    
   return result;
}

string cUserVar::EvaluateCondExpr(const cEvent* e, bool escapeStrings)
{
   string condresult = "";
   cVarExpr leftExp(varparser.condEqLeft);
   string resLeft = leftExp.Evaluate(e);
   cVarExpr rightExp(varparser.condEqRight);
   string resRight = rightExp.Evaluate(e);
   if (varparser.condOp == condEq && resLeft == resRight)  condresult = "1"; // assign any value
   if (varparser.condOp == condNeq && resLeft != resRight) condresult = "1"; // assign any value
    
   cUserVar* condVarTrue = UserVars.GetFromName(varparser.condvarTrue);
   cUserVar* condVarFalse = UserVars.GetFromName(varparser.condvarFalse);
   if (!condVarTrue || !condVarFalse) return "";

   if (!AddDepVar(condVarTrue)) return "";
   if (!AddDepVar(condVarFalse)) return "";

   if (condresult != "")
   {
     LogFile.Log(3, "using case 'true'");
     return condVarTrue->Evaluate(e, escapeStrings);
   }
   else
   {
     LogFile.Log(3, "using case 'false'");
     return condVarFalse->Evaluate(e, escapeStrings);
   }
}

string cUserVar::EvaluateCompExpr(const cEvent* e, bool escapeStrings)
{
   string expr = varparser.compExpr;
   if (expr.find('%') == string::npos) return expr;

   // handle internal vars like title and subtitle
   expr = EvaluateInternalVars(expr, e, escapeStrings);

   // replace ext. EPG variables
   expr = EvaluateExtEPGVars(expr, e, escapeStrings);

   // replace other user vars
   expr = EvaluateUserVars(expr, e, escapeStrings);

   return expr;
}

string cUserVar::EvaluateInternalVars(const string& Expr, const cEvent* e, bool escapeStrings)
{
   string expr = Expr;
   if (expr.find('%') == string::npos) return expr;

   std::map<string, cInternalVar*>::iterator it;
   for (it = UserVars.internalVars.begin(); it != UserVars.internalVars.end(); it++) 
   {
      string varName = (it->second)->Name();
      int varPos = 0;
      while((varPos = FindIgnoreCase(expr, varName)) >= 0)
      {
         usedVars.insert(it->second); 
         expr.replace(varPos, varName.size(), (it->second)->Evaluate(e, escapeStrings));
      }
   }
   return expr;
}

string cUserVar::EvaluateExtEPGVars(const string& Expr, const cEvent* e, bool escapeStrings)
{
   string expr = Expr;
   if (expr.find('%') == string::npos) return expr;

   std::map<string, cExtEPGVar*>::iterator evar;
   for (evar = UserVars.extEPGVars.begin(); evar != UserVars.extEPGVars.end(); evar++) 
   {
      string varName = evar->second->Name();
      int varPos = 0;
      while((varPos = FindIgnoreCase(expr, varName)) >= 0)
      {
         expr.replace(varPos, varName.size(), evar->second->Evaluate(e, escapeStrings));
         usedVars.insert(evar->second); 		
      }
   }
   return expr;
}

string cUserVar::EvaluateUserVars(const string& Expr, const cEvent* e, bool escapeStrings)
{
   string expr = Expr;
   if (expr.find('%') == string::npos) return expr;

   std::set<cUserVar*>::iterator it;
   for (it = UserVars.userVars.begin(); it != UserVars.userVars.end(); it++) 
   {
      string varName = (*it)->Name();
      int varPos = 0;
      while((varPos = FindIgnoreCase(expr, varName)) >= 0)
      {
         if (!AddDepVar(*it)) return "";
         expr.replace(varPos, varName.size(), (*it)->Evaluate(e, escapeStrings));
      }
   }
   return expr;
}

string cUserVar::EvaluateInternalTimerVars(const string& Expr, const cTimer* t)
{
   string expr = Expr;
   if (expr.find('%') == string::npos) return expr;

   std::map<string, cTimerVar*>::iterator tvar;
   for (tvar = UserVars.internalTimerVars.begin(); tvar != UserVars.internalTimerVars.end(); tvar++) 
   {
      string varName = tvar->second->Name();
      int varPos = 0;
      while((varPos = FindIgnoreCase(expr, varName)) >= 0)
      {
         expr.replace(varPos, varName.size(), tvar->second->Evaluate(t));
      }
   }
   return expr;
}

string cUserVar::EvaluateInternalSearchVars(const string& Expr, const cSearchExt* s)
{
   string expr = Expr;
   if (expr.find('%') == string::npos) return expr;

   std::map<string, cSearchVar*>::iterator svar;
   for (svar = UserVars.internalSearchVars.begin(); svar != UserVars.internalSearchVars.end(); svar++) 
   {
      string varName = svar->second->Name();
      int varPos = 0;
      while((varPos = FindIgnoreCase(expr, varName)) >= 0)
      {
         expr.replace(varPos, varName.size(), svar->second->Evaluate(s));
      }
   }
   return expr;
}

bool cUserVar::DependsOnVar(const string& varName)
{
   string VarName = Strip(varName);
   cUserVar* var = UserVars.GetFromName(VarName);
   if (!var) return false;
   return DependsOnVar(var);
}

bool cUserVar::DependsOnVar(cUserVar* var)
{
   if (!var) return false;
   if (usedVars.find(var) != usedVars.end()) return true;
   std::set<cUserVar*>::iterator it;
   for (it = usedVars.begin(); it != usedVars.end(); it++) 
      if ((*it)->DependsOnVar(var))
         return true;
   return false;
}

bool cUserVar::AddDepVar(cUserVar* var)
{
   if (var == this || var->DependsOnVar(this))
   {
      LogFile.eSysLog("ERROR - found cylic reference to var '%s' in var '%s'", var->Name().c_str(), Name().c_str());
      return false;
   }
   usedVars.insert(var); 		    
   return true;
}

void cUserVar::ResetCache()
{
   oldEvent = NULL;
   oldResult = "";
}

// cUserVarLine
bool cUserVarLine::Parse(char *s)
{
   if (s && s[0] == '#')
      return true;
   char *p = strchr(s, '=');
   if (p) 
   {
      cUserVar* userVar = new cUserVar;
      if (userVar->varparser.Parse(s))
      {
	cUserVar* oldVar = UserVars.GetFromName(userVar->Name(), false);
	if (oldVar) // allow redefintion of existing vars
	  {
	    LogFile.Log(1, "variable '%s' gets overwritten", oldVar->Name().c_str());
	    UserVars.userVars.erase(oldVar);
	    delete oldVar;
	  }
	UserVars.userVars.insert(userVar);
	return true;
      }
   }
   return false;
}

// cUserVars
cUserVar* cUserVars::GetFromName(const string& varName, bool log)
{
   string VarName = Strip(varName);
   std::transform(VarName.begin(), VarName.end(), VarName.begin(), tolower);
    
   std::map<string, cInternalVar*>::iterator ivar = internalVars.find(VarName);
   if (ivar != internalVars.end()) 
      return ivar->second;

   std::set<cUserVar*>::iterator uvar;
   for (uvar = userVars.begin(); uvar != userVars.end(); uvar++) 
      if (EqualsNoCase((*uvar)->Name(), VarName))
         return (*uvar);

   std::map<string, cExtEPGVar*>::iterator evar = extEPGVars.find(VarName);
   if (evar != extEPGVars.end()) 
      return evar->second;

   if (log)
     LogFile.eSysLog("var '%s' not defined!", VarName.c_str());
   return NULL;
}

// cVarExpr
string cVarExpr::Evaluate(const cEvent* e)
{
   // create a dummy user var
   cUserVar var;
   if (!var.varparser.ParseExp(expr))
      return "";

   LogFile.Log(3, "start evaluating expression '%s'", expr.c_str());
   string result = var.Evaluate(e);
   LogFile.Log(3, "stop evaluating expression '%s' - result: '%s'", expr.c_str(), result.c_str());
   usedVars = var.usedVars;
   return result;
}

string cVarExpr::Evaluate(const cTimer* t)
{
   // create a dummy user var
   cUserVar var;
   if (!var.varparser.ParseExp(expr))
      return "";

   usedVars = var.usedVars;
   return var.EvaluateInternalTimerVars(expr, t);
}

string cVarExpr::Evaluate(const cSearchExt* s)
{
   // create a dummy user var
   cUserVar var;
   if (!var.varparser.ParseExp(expr))
      return "";

   usedVars = var.usedVars;
   return var.EvaluateInternalSearchVars(expr, s);
}

bool cVarExpr::DependsOnVar(const string& varName, const cEvent* e)
{
   string VarName = Strip(varName);
   if (FindIgnoreCase(expr, VarName) >= 0)
      return true;
   // create a dummy user var
   cUserVar var;
   var.varparser.varName = expr;
   if (!var.varparser.ParseExp(expr))
      return false;
   var.Evaluate(e);
   return var.DependsOnVar(VarName);
}
