#include "chunk.h"
#include "memory.h"
#include "value.h"

void initChunk( Chunk* chunk ) {
	chunk->capacity = 0;
	chunk->count = 0;
	chunk->bDebug = true;
	chunk->code = NULL;
	chunk->lines = NULL;
	initValueArray( &chunk->constants );
}

void freeChunk( Chunk* chunk ) {
	FREE_ARRAY( uint8_t, chunk->code, chunk->capacity );
	FREE_ARRAY( uint16_t, chunk->lines, chunk->capacity );
	freeValueArray( &chunk->constants );
	initChunk( chunk );
}

void writeChunk( Chunk* chunk, uint8_t byte, uint16_t line ) {
	if ( chunk->capacity < chunk->count + 1 ) {
		int oldCap = chunk->capacity;
		chunk->capacity = GROW_CAPACITY( oldCap );
		chunk->code = GROW_ARRAY( chunk->code, uint8_t, oldCap, chunk->capacity );
		if ( chunk->bDebug ) {
			chunk->lines = GROW_ARRAY( chunk->lines, uint16_t, oldCap, chunk->capacity );
		}
	}

	chunk->code[chunk->count] = byte;
	if ( chunk->bDebug )
		chunk->lines[chunk->count] = line;
	chunk->count++;
}

// unsigned 16bit write
void writeChunk16( Chunk* chunk, uint16_t word, uint16_t line ) {
	writeChunk( chunk, word & 255, line );
	writeChunk( chunk, word >> 8, line );
}
// unsigned 16bit read
uint16_t readChunk16( Chunk* chunk, int offset ) {
	uint16_t val = chunk->code[offset];
	return ((val) | (chunk->code[offset + 1] << 8));
}

uint16_t addConstant( Chunk* chunk, Value val ) {
	writeValueArray( &chunk->constants, val );
	return chunk->constants.count - 1;
}

// high level for adding and writing a chunk constant
void writeConstant( Chunk* chunk, Value val, uint16_t line ) {
	uint16_t cont = addConstant( chunk, val );
	// more than 256 constants, use 16bit operand
	if ( cont > 255 ) {
		writeChunk( chunk, OP_CONSTANT_LONG, line );
		writeChunk16( chunk, cont, line );
	} else {
		writeChunk( chunk, OP_CONSTANT, line );
		writeChunk( chunk, cont, line );
	}
}