//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#ifndef _AST_H_
#define _AST_H_

class ExprEvalState;
class Namespace;
class SimObject;
class SimGroup;
class CodeStream;

/// Enable this #define if you are seeing the message "precompile size mismatch" in the console.
/// This will help track down which node type is causing the error. It could be
/// due to incorrect compiler optimization.
//#define DEBUG_AST_NODES

enum TypeReq
{
   TypeReqNone,
   TypeReqUInt,
   TypeReqFloat,
   TypeReqString,
   TypeReqVar
};

/// Representation of a node for the scripting language parser.
///
/// When the scripting language is evaluated, it is turned from a string representation,
/// into a parse tree, thence into byte code, which is ultimately interpreted by the VM.
///
/// This is the base class for the nodes in the parse tree. There are a great many subclasses,
/// each representing a different language construct.
struct StmtNode
{
   StmtNode *next;   ///< Next entry in parse tree.

   StmtNode();
   virtual ~StmtNode() {}
   
   /// @name next Accessors
   /// @{

   ///
   void append(StmtNode *next);
   StmtNode *getNext() const { return next; }

   /// @}

   /// @name Debug Info
   /// @{

   StringTableEntry dbgFileName; ///< Name of file this node is associated with.
   S32 dbgLineNumber;            ///< Line number this node is associated with.
#ifdef DEBUG_AST_NODES
   virtual String dbgStmtType() const = 0;
#endif
   /// @}

   /// @name Breaking
   /// @{

   void addBreakLine(CodeStream &codeStream);
   /// @}

   /// @name Compilation
   /// @{

   virtual U32 compileStmt(CodeStream &codeStream, U32 ip) = 0;
   virtual void setPackage(StringTableEntry packageName);
   /// @}
};

/// Helper macro
#ifndef DEBUG_AST_NODES
#  define DBG_STMT_TYPE(s) virtual String dbgStmtType() const { return String(#s); }
#else
#  define DBG_STMT_TYPE(s) 
#endif

struct BreakStmtNode : StmtNode
{
   static BreakStmtNode *alloc( S32 lineNumber );

   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(BreakStmtNode);
};

struct ContinueStmtNode : StmtNode
{
   static ContinueStmtNode *alloc( S32 lineNumber );
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(ContinueStmtNode);
};

/// A mathematical expression.
struct ExprNode : StmtNode
{
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);

   virtual U32 compile(CodeStream &codeStream, U32 ip, TypeReq type) = 0;
   virtual TypeReq getPreferredType() = 0;
};

struct ReturnStmtNode : StmtNode
{
   ExprNode *expr;

   static ReturnStmtNode *alloc( S32 lineNumber, ExprNode *expr );
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(ReturnStmtNode);
};

struct IfStmtNode : StmtNode
{
   ExprNode *testExpr;
   StmtNode *ifBlock, *elseBlock;
   U32 endifOffset;
   U32 elseOffset;
   bool integer;
   bool propagate;

   static IfStmtNode *alloc( S32 lineNumber, ExprNode *testExpr, StmtNode *ifBlock, StmtNode *elseBlock, bool propagateThrough );
   void propagateSwitchExpr(ExprNode *left, bool string);
   ExprNode *getSwitchOR(ExprNode *left, ExprNode *list, bool string);
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(IfStmtNode);
};

struct LoopStmtNode : StmtNode
{
   ExprNode *testExpr;
   ExprNode *initExpr;
   ExprNode *endLoopExpr;
   StmtNode *loopBlock;
   bool isDoLoop;
   U32 breakOffset;
   U32 continueOffset;
   U32 loopBlockStartOffset;
   bool integer;

   static LoopStmtNode *alloc( S32 lineNumber, ExprNode *testExpr, ExprNode *initExpr, ExprNode *endLoopExpr, StmtNode *loopBlock, bool isDoLoop );
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(LoopStmtNode);
};

/// A "foreach" statement.
struct IterStmtNode : StmtNode
{
   /// Local variable name to use for the container element.
   StringTableEntry varName;
   
   /// Expression evaluating to a SimSet object.
   ExprNode* containerExpr;
   
   /// The statement body.
   StmtNode* body;
   
   /// If true, this is a 'foreach$'.
   bool isStringIter;
   
   /// Bytecode size of body statement.  Set by precompileStmt.
   U32 bodySize;
   
   static IterStmtNode* alloc( S32 lineNumber, StringTableEntry varName, ExprNode* containerExpr, StmtNode* body, bool isStringIter );
   
   U32 compileStmt( CodeStream &codeStream, U32 ip );
};

/// A binary mathematical expression (ie, left op right).
struct BinaryExprNode : ExprNode
{
   S32 op;
   ExprNode *left;
   ExprNode *right;
};

struct FloatBinaryExprNode : BinaryExprNode
{
   static FloatBinaryExprNode *alloc( S32 lineNumber, S32 op, ExprNode *left, ExprNode *right );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(FloatBinaryExprNode);
};

struct ConditionalExprNode : ExprNode
{
   ExprNode *testExpr;
   ExprNode *trueExpr;
   ExprNode *falseExpr;
   bool integer;
   static ConditionalExprNode *alloc( S32 lineNumber, ExprNode *testExpr, ExprNode *trueExpr, ExprNode *falseExpr );
   
   virtual U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   virtual TypeReq getPreferredType();
   DBG_STMT_TYPE(ConditionalExprNode);
};

struct IntBinaryExprNode : BinaryExprNode
{
   TypeReq subType;
   U32 operand;

   static IntBinaryExprNode *alloc( S32 lineNumber, S32 op, ExprNode *left, ExprNode *right );

   void getSubTypeOperand();
   
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(IntBinaryExprNode);
};

struct StreqExprNode : BinaryExprNode
{
   bool eq;
   static StreqExprNode *alloc( S32 lineNumber, ExprNode *left, ExprNode *right, bool eq );
   
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(StreqExprNode);
};

struct StrcatExprNode : BinaryExprNode
{
   S32 appendChar;
   static StrcatExprNode *alloc( S32 lineNumber, ExprNode *left, ExprNode *right, S32 appendChar );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(StrcatExprNode);
};

struct CommaCatExprNode : BinaryExprNode
{
   static CommaCatExprNode *alloc( S32 lineNumber, ExprNode *left, ExprNode *right );

  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(CommaCatExprNode);
};

struct IntUnaryExprNode : ExprNode
{
   S32 op;
   ExprNode *expr;
   bool integer;

   static IntUnaryExprNode *alloc( S32 lineNumber, S32 op, ExprNode *expr );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(IntUnaryExprNode);
};

struct FloatUnaryExprNode : ExprNode
{
   S32 op;
   ExprNode *expr;

   static FloatUnaryExprNode *alloc( S32 lineNumber, S32 op, ExprNode *expr );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(FloatUnaryExprNode);
};

struct VarNode : ExprNode
{
   StringTableEntry varName;
   ExprNode *arrayIndex;

   static VarNode *alloc( S32 lineNumber, StringTableEntry varName, ExprNode *arrayIndex );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(VarNode);
};

struct IntNode : ExprNode
{
   S32 value;
   U32 index; // if it's converted to float/string

   static IntNode *alloc( S32 lineNumber, S32 value );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(IntNode);
};

struct FloatNode : ExprNode
{
   F64 value;
   U32 index;

   static FloatNode *alloc( S32 lineNumber, F64 value );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(FloatNode);
};

struct StrConstNode : ExprNode
{
   char *str;
   F64 fVal;
   U32 index;
   bool tag;
   bool doc; // Specifies that this string is a documentation block.

   static StrConstNode *alloc( S32 lineNumber, char *str, bool tag, bool doc = false );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(StrConstNode);
};

struct ConstantNode : ExprNode
{
   StringTableEntry value;
   F64 fVal;
   U32 index;

   static ConstantNode *alloc( S32 lineNumber, StringTableEntry value );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(ConstantNode);
};

struct AssignExprNode : ExprNode
{
   StringTableEntry varName;
   ExprNode *expr;
   ExprNode *arrayIndex;
   TypeReq subType;

   static AssignExprNode *alloc( S32 lineNumber, StringTableEntry varName, ExprNode *arrayIndex, ExprNode *expr );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(AssignExprNode);
};

struct AssignDecl
{
   S32 lineNumber;
   S32 token;
   ExprNode *expr;
   bool integer;
};

struct AssignOpExprNode : ExprNode
{
   StringTableEntry varName;
   ExprNode *expr;
   ExprNode *arrayIndex;
   S32 op;
   U32 operand;
   TypeReq subType;

   static AssignOpExprNode *alloc( S32 lineNumber, StringTableEntry varName, ExprNode *arrayIndex, ExprNode *expr, S32 op );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(AssignOpExprNode);
};

struct TTagSetStmtNode : StmtNode
{
   StringTableEntry tag;
   ExprNode *valueExpr;
   ExprNode *stringExpr;

   static TTagSetStmtNode *alloc( S32 lineNumber, StringTableEntry tag, ExprNode *valueExpr, ExprNode *stringExpr );
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   DBG_STMT_TYPE(TTagSetStmtNode);
};

struct TTagDerefNode : ExprNode
{
   ExprNode *expr;

   static TTagDerefNode *alloc( S32 lineNumber, ExprNode *expr );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(TTagDerefNode);
};

struct TTagExprNode : ExprNode
{
   StringTableEntry tag;

   static TTagExprNode *alloc( S32 lineNumber, StringTableEntry tag );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(TTagExprNode);
};

struct FuncCallExprNode : ExprNode
{
   StringTableEntry funcName;
   StringTableEntry nameSpace;
   ExprNode *args;
   U32 callType;
   enum {
      FunctionCall,
      MethodCall,
      ParentCall
   };

   static FuncCallExprNode *alloc( S32 lineNumber, StringTableEntry funcName, StringTableEntry nameSpace, ExprNode *args, bool dot );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(FuncCallExprNode);
};

struct AssertCallExprNode : ExprNode
{
   ExprNode *testExpr;
   const char *message;
   U32 messageIndex;

   static AssertCallExprNode *alloc( S32 lineNumber, ExprNode *testExpr, const char *message );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(AssertCallExprNode);
};

struct SlotDecl
{
   S32              lineNumber;
   ExprNode         *object;
   StringTableEntry slotName;
   ExprNode         *array;
};

struct SlotAccessNode : ExprNode
{
   ExprNode *objectExpr, *arrayExpr;
   StringTableEntry slotName;

   static SlotAccessNode *alloc( S32 lineNumber, ExprNode *objectExpr, ExprNode *arrayExpr, StringTableEntry slotName );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(SlotAccessNode);
};

struct InternalSlotDecl
{
   S32              lineNumber;
   ExprNode         *object;
   ExprNode         *slotExpr;
   bool             recurse;
};

struct InternalSlotAccessNode : ExprNode
{
   ExprNode *objectExpr, *slotExpr;
   bool recurse;

   static InternalSlotAccessNode *alloc( S32 lineNumber, ExprNode *objectExpr, ExprNode *slotExpr, bool recurse );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(InternalSlotAccessNode);
};

struct SlotAssignNode : ExprNode
{
   ExprNode *objectExpr, *arrayExpr;
   StringTableEntry slotName;
   ExprNode *valueExpr;
   U32 typeID;

   static SlotAssignNode *alloc( S32 lineNumber, ExprNode *objectExpr, ExprNode *arrayExpr, StringTableEntry slotName, ExprNode *valueExpr, U32 typeID = -1 );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(SlotAssignNode);
};

struct SlotAssignOpNode : ExprNode
{
   ExprNode *objectExpr, *arrayExpr;
   StringTableEntry slotName;
   S32 op;
   ExprNode *valueExpr;
   U32 operand;
   TypeReq subType;

   static SlotAssignOpNode *alloc( S32 lineNumber, ExprNode *objectExpr, StringTableEntry slotName, ExprNode *arrayExpr, S32 op, ExprNode *valueExpr );
  
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(SlotAssignOpNode);
};

struct ObjectDeclNode : ExprNode
{
   ExprNode *classNameExpr;
   StringTableEntry parentObject;
   ExprNode *objectNameExpr;
   ExprNode *argList;
   SlotAssignNode *slotDecls;
   ObjectDeclNode *subObjects;
   bool isDatablock;
   U32 failOffset;
   bool isClassNameInternal;
   bool isSingleton;

   static ObjectDeclNode *alloc( S32 lineNumber, ExprNode *classNameExpr, ExprNode *objectNameExpr, ExprNode *argList, StringTableEntry parentObject, SlotAssignNode *slotDecls, ObjectDeclNode *subObjects, bool isDatablock, bool classNameInternal, bool isSingleton );
  
   U32 precompileSubObject(bool);
   U32 compile(CodeStream &codeStream, U32 ip, TypeReq type);
   U32 compileSubObject(CodeStream &codeStream, U32 ip, bool);
   TypeReq getPreferredType();
   DBG_STMT_TYPE(ObjectDeclNode);
};

struct ObjectBlockDecl
{
   SlotAssignNode *slots;
   ObjectDeclNode *decls;
};

struct FunctionDeclStmtNode : StmtNode
{
   StringTableEntry fnName;
   VarNode *args;
   StmtNode *stmts;
   StringTableEntry nameSpace;
   StringTableEntry package;
   U32 endOffset;
   U32 argc;

   static FunctionDeclStmtNode *alloc( S32 lineNumber, StringTableEntry fnName, StringTableEntry nameSpace, VarNode *args, StmtNode *stmts );
   
   U32 compileStmt(CodeStream &codeStream, U32 ip);
   void setPackage(StringTableEntry packageName);
   DBG_STMT_TYPE(FunctionDeclStmtNode);
};

extern StmtNode *gStatementList;
extern StmtNode *gAnonFunctionList;
extern U32 gAnonFunctionID;
extern ExprEvalState gEvalState;

#endif