#include "tetris.h"

void grid_set(bitgrid_t* grid, int x, int y, bool value){
    if(x < 0 || x >= TOTAL_WIDTH || y < 0 || y >= TOTAL_HEIGHT) return;
    
    int bitIndex = y * TOTAL_WIDTH + x;
    int wordIndex = bitIndex / 32;
    int bitPosition = bitIndex % 32;
    
    if(value){
        grid->bits[wordIndex] |= (1U << bitPosition);
    } else {
        grid->bits[wordIndex] &= ~(1U << bitPosition);
    }
}

void grid_get(bitgrid_t* grid, int x, int y, bool* value) {
    if(x < 0 || x >= TOTAL_WIDTH || y < 0 || y >= TOTAL_HEIGHT) {
        *value = false;
        return;
    }

    int bitIndex = y * TOTAL_WIDTH + x;
    int wordIndex = bitIndex / 32;
    int bitPosition = bitIndex % 32;
    
    *value = (grid->bits[wordIndex] & (1U << bitPosition)) != 0;
}

bool grid_equals(bitgrid_t* a, bitgrid_t* b){
    for(int i = 0; i < GRID_WORDS; i++){
        if(a->bits[i] != b->bits[i]){
            return false;
        }
    }
    return true;
}

bitgrid_t grid_copy(bitgrid_t* src){
    bitgrid_t result;
    for(int i = 0; i < GRID_WORDS; i++){
        result.bits[i] = src->bits[i];
    }
    return result;
}

void bitgrid_bitwise_and(bitgrid_t* dest, bitgrid_t* a, bitgrid_t* b){
    for(int i = 0; i < GRID_WORDS; i++){
        dest->bits[i] = a->bits[i] & b->bits[i];
    }
}

void bitgrid_bitwise_or(bitgrid_t* dest, bitgrid_t* a, bitgrid_t* b){
    for(int i = 0; i < GRID_WORDS; i++){
        dest->bits[i] = a->bits[i] | b->bits[i];
    }
}

void bitgrid_bitwise_xor(bitgrid_t* dest, bitgrid_t* a, bitgrid_t* b){
    for(int i = 0; i < GRID_WORDS; i++){
        dest->bits[i] = a->bits[i] ^ b->bits[i];
    }
}

void bitgrid_bitwise_not(bitgrid_t* dest, bitgrid_t* src){
    for(int i = 0; i < GRID_WORDS; i++){
        dest->bits[i] = ~(src->bits[i]);
    }
}

void bitgrid_bitwise_shift_left(bitgrid_t* dest, bitgrid_t* src, int shift){
    if(shift < 0) return; // Invalid shift
    if(shift == 0){
        *dest = *src;
        return;
    }
    
    int totalBits = TOTAL_WIDTH * TOTAL_HEIGHT;
    if(shift >= totalBits){
        for(int i = 0; i < GRID_WORDS; i++){
            dest->bits[i] = 0;
        }
        return;
    }

    int wordShift = shift / 32;
    int bitShift = shift % 32;

    for(int i = GRID_WORDS - 1; i >= 0; i--){
        uint32_t upper = (i - wordShift - 1 >= 0 && bitShift != 0) ? (src->bits[i - wordShift - 1] >> (32 - bitShift)) : 0;
        uint32_t lower = (i - wordShift >= 0) ? (src->bits[i - wordShift] << bitShift) : 0;
        dest->bits[i] = upper | lower;
    }
}

void bitgrid_bitwise_shift_right(bitgrid_t* dest, bitgrid_t* src, int shift){
    if(shift < 0) return; // Invalid shift
    if(shift == 0){
        *dest = *src;
        return;
    }
    
    int totalBits = TOTAL_WIDTH * TOTAL_HEIGHT;
    if(shift >= totalBits){
        for(int i = 0; i < GRID_WORDS; i++){
            dest->bits[i] = 0;
        }
        return;
    }

    int wordShift = shift / 32;
    int bitShift = shift % 32;

    for(int i = 0; i < GRID_WORDS; i++){
        uint32_t lower = (i + wordShift + 1 < GRID_WORDS && bitShift != 0) ? (src->bits[i + wordShift + 1] << (32 - bitShift)) : 0;
        uint32_t upper = (i + wordShift < GRID_WORDS) ? (src->bits[i + wordShift] >> bitShift) : 0;
        dest->bits[i] = upper | lower;
    }
}