#ifndef NCTREF_AST_H
#define NCTREF_AST_H

#include"types.h"
#include"lexer.h"
#include"vartable.h"

// VISITORS APPEAR IN varify_change_usedefs,ast_expr_is_equal,ast_stmt_is_after,
// dumben_chunk, cg_go, loop_second_pass AND OTHERS
//
// THEY ***MUST*** BE CHANGED ACCORDINGLY IF AST IS ALTERED

#pragma pack(push, 1)

#ifdef __GNUC__
#define ENUMPAK __attribute__((packed))
#else
#define ENUMPAK
#endif

typedef enum ENUMPAK {
	AST_CHUNK,
	AST_STMT_DECL,
	AST_TYPE_IDENTIFIER,
	AST_EXPR_PRIMITIVE,
	AST_STMT_IF,
	AST_EXPR_BINARY_OP,
	AST_EXPR_VAR,
	AST_TYPE_POINTER,
	AST_EXPR_UNARY_OP,
	AST_STMT_LOOP,
	AST_STMT_BREAK,
	AST_STMT_CONTINUE,
	AST_EXPR_CALL,
	AST_STMT_EXPR,
	AST_STMT_ASSIGN,
	AST_STMT_EXT_ALIGN,
	AST_EXPR_STRING_LITERAL,
	AST_EXPR_CAST,
	AST_EXPR_ARRAY,
	AST_STMT_EXT_ORG,
	AST_STMT_EXT_SECTION,
} ASTKind;

typedef enum ENUMPAK {
	BINOP_ADD = 0,
	BINOP_SUB = 1,
	BINOP_BITWISE_AND = 2,
	BINOP_BITWISE_OR = 3,
	BINOP_BITWISE_XOR = 4,
	BINOP_SIMPLES = 5,
	BINOP_MUL = 5,
	BINOP_DIV = 6,
	
	BINOP_EQUAL = 7,
	BINOP_NEQUAL = 8,
	
	BINOP_WTF = 999,
} BinaryOp;

static inline int binop_is_comparison(BinaryOp op) {
	return op == BINOP_EQUAL || op == BINOP_NEQUAL;
}

static inline BinaryOp binop_comp_opposite(BinaryOp op) {
	if(op == BINOP_EQUAL) {
		return BINOP_NEQUAL;
	} else if(op == BINOP_NEQUAL) {
		return BINOP_EQUAL;
	}
	return BINOP_WTF;
}

typedef enum ENUMPAK {
	UNOP_DEREF = 0,
	UNOP_NEGATE = 1,
	UNOP_BITWISE_NOT = 2,
	UNOP_REF = 3,
} UnaryOp;

union AST;

typedef struct {
	ASTKind nodeKind;
	Type *type;
} ASTExpr;

typedef struct {
	ASTExpr;
	
	int val;
} ASTExprPrimitive;

typedef struct {
	ASTExpr;
	
	union AST *operands[2];
	BinaryOp operator;
} ASTExprBinaryOp;

typedef struct {
	ASTExpr;
	
	UnaryOp operator;
	union AST *operand;
} ASTExprUnaryOp;

typedef struct {
	ASTExpr;
	
	VarTableEntry *thing;
} ASTExprVar;

typedef struct {
	ASTExpr;
	
	union AST *what;
	
	union AST **args;
} ASTExprCall;

typedef struct {
	ASTExpr;
	
	size_t length;
	char *data;
} ASTExprStringLiteral;

typedef struct {
	ASTKind nodeKind;
	
	size_t size;
} ASTType;

typedef struct {
	ASTType;
	
	Token identifier;
} ASTTypeIdentifier;

typedef struct {
	ASTType;
	
	union AST *child;
	int levels;
} ASTTypePointer;

typedef struct {
	ASTKind nodeKind;
	union AST *next;
} ASTStmt;

typedef struct {
	ASTStmt;
	
	VarTableEntry *thing;
	
	union AST *expression;
} ASTStmtDecl;

typedef struct {
	ASTKind nodeKind;
	
	/* Flattened variable array for global register allocation */
	size_t varCount;
	VarTableEntry **vars;
	
	union AST *statementFirst;
	union AST *statementLast;
} ASTChunk;

typedef struct {
	ASTStmt;
	
	union AST *expression;
	
	union AST *then;
} ASTStmtIf;

typedef struct {
	ASTStmt;
	
	union AST *body;
} ASTStmtLoop;

typedef struct {
	ASTStmt;
} ASTStmtBreak;

typedef struct {
	ASTStmt;
} ASTStmtContinue;

typedef struct {
	ASTStmt;
	
	union AST *expr;
} ASTStmtExpr;

typedef struct {
	ASTStmt;
	
	union AST *what;
	union AST *to;
} ASTStmtAssign;

typedef struct {
	ASTStmt;
	
	int val;
} ASTStmtExtAlign;

typedef struct {
	ASTExpr;
	
	union AST *what;
	Type *to;
	
	char reinterpretation; /* 1 = as, 0 = to */
} ASTExprCast;

typedef struct {
	ASTExpr;
	
	union AST **items;
} ASTExprArray;

typedef struct {
	ASTStmt;
	
	size_t val;
} ASTStmtExtOrg;

typedef struct {
	ASTStmt;
	
	Token name;
} ASTStmtExtSection;

typedef union AST {
	ASTKind nodeKind;
	
	ASTChunk chunk;
	ASTStmt statement;
	ASTStmtDecl stmtDecl;
	ASTStmtIf stmtIf;
	ASTStmtLoop stmtLoop;
	ASTStmtBreak stmtBreak;
	ASTStmtContinue stmtContinue;
	ASTStmtExpr stmtExpr;
	ASTStmtAssign stmtAssign;
	ASTExpr expression;
	ASTExprPrimitive exprPrim;
	ASTExprBinaryOp exprBinOp;
	ASTExprUnaryOp exprUnOp;
	ASTExprVar exprVar;
	ASTExprCall exprCall;
	ASTStmtExtAlign stmtExtAlign;
	ASTExprStringLiteral exprStrLit;
	ASTExprCast exprCast;
	ASTExprArray exprArray;
	ASTStmtExtOrg stmtExtOrg;
	ASTStmtExtSection stmtExtSection;
} AST;

#pragma pack(pop)

AST *ast_expression_optimize(AST*);
int ast_expression_equal(AST*, AST*);

int ast_stmt_is_after(const AST *chunk, const AST *s1, const AST *s2);

#endif