#ifndef IR_H
#define IR_H

#include "utils.h"
#include "parser.h"

struct _ir_node;
struct _basic_block;

struct symbol_def {
	struct _ir_node *node;
	bool is_lvalue;
};

typedef struct { char *key; struct symbol_def *value; } symbol_table;

// Basic block for CFG representation
typedef struct _basic_block {
	int id;
	struct _ir_node *control;        // Control node that starts this block (region, loop, proj, start)
	struct _ir_node **nodes;         // Scheduled nodes in this block (stb_ds array)
	struct _basic_block **preds;     // Predecessor blocks (stb_ds array)
	struct _basic_block **succs;     // Successor blocks (stb_ds array)
	struct _basic_block *idom;       // Immediate dominator
	struct _basic_block **dom_children; // Children in dominator tree (stb_ds array)
	int dom_depth;                   // Depth in dominator tree
	int loop_depth;                  // Loop nesting depth (for GCM optimization)
	bool visited;                    // For graph traversals
} basic_block;

// Function representation after GCM
typedef struct {
	char *name;
	basic_block *entry;              // Entry block
	basic_block **blocks;            // All blocks in RPO order (stb_ds array)
	int block_count;
} ir_function;

typedef enum {
	OC_START,
	OC_ADD,
	OC_SUB,
	OC_MUL,
	OC_DIV,
	OC_MOD,
	OC_BAND,
	OC_BOR,
	OC_BXOR,
	OC_NEG,
	OC_EQ,
	OC_NEQ,
	OC_LT,
	OC_GT,
	OC_LE,
	OC_GE,
	OC_AND,
	OC_OR,

	OC_CONST_INT,
	OC_CONST_FLOAT,
	OC_VOID,

	OC_FRAME_PTR,
	OC_ADDR,

	OC_STORE,
	OC_LOAD,
	
	OC_REGION,
	OC_PHI,

	OC_IF,
	OC_PROJ,
	OC_LOOP,

	OC_CALL,

	OC_STOP,
	OC_RETURN,

	OC_SCOPE,
} opcode;

typedef struct _ir_node {
	opcode code;
	usize id;
	struct _ir_node **in;
	struct _ir_node **out;
	union {
		i64 const_int;
		f64 const_float;
		symbol_table **symbol_tables;
		char *start_name;
		char *call_name;
	} data;
	// GCM scheduling fields
	struct _basic_block *early;      // Earliest legal block
	struct _basic_block *late;       // Latest legal block
	struct _basic_block *block;      // Final scheduled block
	bool pinned;                     // True if node must stay in its block (control nodes, phi, etc.)
	bool scheduled;                  // True if already scheduled
} ir_node;

void ir_build(ast_node *ast);

// Global Code Motion and Scheduling
ir_function *gcm_schedule(ir_node *func_start);
void gcm_print_scheduled(ir_function *func);

#endif