#ifndef ACC_AST_H
#define ACC_AST_H

#include <stdio.h>
#include <stdint.h>
#include "vtype.h"
#include "util/linklist.h"

// AST operation types
enum {
	A_ASSIGN,
	A_NEG, A_ADD, A_SUB, A_MUL, A_DIV,
	A_EQ, A_NE, A_LT, A_GT, A_LE, A_GE,
	A_LNOT, A_LAND, A_LOR,
	A_BNOT,
	A_LIT_I32, A_LIT_I64,
	A_VAR,
	A_BLOCK,
	A_PRINT, A_IF, A_WHILE,
	A_RETURN,
	A_SOUL // what?
};

extern const char *ast_opname[31];

// AST structure field shared by all types 
// llist_node *n	: linklist header
// struct VType type	: value type
// int op		: node operation
#define ACC_ASTnode_SHARED_FIELDS	\
	struct llist_node n;		\
	struct VType type;		\
	int op;

// AST structure (common)
struct ASTnode {
	ACC_ASTnode_SHARED_FIELDS 
};

// AST binary operation node
struct ASTbinnode {
	ACC_ASTnode_SHARED_FIELDS 
	struct ASTnode *left;
	struct ASTnode *right;
};

// AST if statement node
struct ASTifnode {
	ACC_ASTnode_SHARED_FIELDS 
	struct ASTnode *left;	// condition true branch
	struct ASTnode *right;	// condition false branch
	struct ASTnode *cond;
};

// AST unary operation node
struct ASTunnode {
	ACC_ASTnode_SHARED_FIELDS 
	struct ASTnode *left;
};

// AST block node
struct ASTblocknode {
	ACC_ASTnode_SHARED_FIELDS 
	struct linklist st; // statements linklist
};

// AST integer literal (32bit) node
struct ASTi32node {
	ACC_ASTnode_SHARED_FIELDS 
	int32_t val;
};

// AST integer literal (64bit) node
struct ASTi64node {
	ACC_ASTnode_SHARED_FIELDS 
	int64_t val;
};

// AST assign literal node
struct ASTassignnode {
	ACC_ASTnode_SHARED_FIELDS 
	struct ASTnode* left;
	struct ASTnode* right;
};

// AST variable value node
struct ASTvarnode {
	ACC_ASTnode_SHARED_FIELDS 
	int id;
};

// A function with its AST root.
// TODO: parameters
struct Afunction {
	struct llist_node n;	// linklist header
	char *name;		// function name
	struct ASTnode *rt;	// AST root
	struct VType ret_type;	// return type
};

struct Afunction* Afunction_new();

struct ASTnode* ASTbinnode_new(int op, struct ASTnode *left, struct ASTnode *right);
struct ASTnode* ASTi32node_new(int32_t x);
struct ASTnode* ASTi64node_new(int64_t x);
struct ASTnode* ASTunnode_new(int op, struct ASTnode *c, int line);
struct ASTnode* ASTblocknode_new();
struct ASTnode* ASTvarnode_new(int id);
struct ASTnode* ASTassignnode_new(int op, struct ASTnode *left, struct ASTnode *right);
struct ASTnode* ASTifnode_new(struct ASTnode *left, struct ASTnode *right, struct ASTnode *cond);

void ASTnode_print(FILE *Outfile, struct ASTnode *rt);
void Afunction_print(FILE *Outfile, struct Afunction *f);

void Afunction_free(struct Afunction *f);
void ASTnode_free(struct ASTnode *x);

// Parse source into AST.
struct Afunction* Afunction_from_source(const char *filename);

#endif