/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "shared-bindings/displayio/Bitmap.h"

#include <string.h>

#include "py/runtime.h"

void common_hal_displayio_bitmap_construct(displayio_bitmap_t *self, uint32_t width,
 uint32_t height, uint32_t bits_per_value) {
 uint32_t row_width = width * bits_per_value;
 // align to size_t
 uint8_t align_bits = 8 * sizeof(size_t);
 if (row_width % align_bits != 0) {
 self->stride = (row_width / align_bits + 1);
 } else {
 self->stride = row_width / align_bits;
 }
 self->width = width;
 self->height = height;
 self->data = m_malloc(self->stride * height * sizeof(size_t), false);
 self->read_only = false;
 self->bits_per_value = bits_per_value;

 if (bits_per_value > 8 && bits_per_value != 16 && bits_per_value != 32) {
 mp_raise_NotImplementedError(translate("Invalid bits per value"));
 }

 // Division and modulus can be slow because it has to handle any integer. We know bits_per_value
 // is a power of two. We divide and mod by bits_per_value to compute the offset into the byte
 // array. So, we can the offset computation to simplify to a shift for division and mask for mod.

 self->x_shift = 0; // Used to divide the index by the number of pixels per word. Its used in a
 // shift which effectively divides by 2 ** x_shift.
 uint32_t power_of_two = 1;
 while (power_of_two < align_bits / bits_per_value ) {
 self->x_shift++;
 power_of_two <<= 1;
 }
 self->x_mask = (1 << self->x_shift) - 1; // Used as a modulus on the x value
 self->bitmask = (1 << bits_per_value) - 1;

 self->dirty_area.x1 = 0;
 self->dirty_area.x2 = width;
 self->dirty_area.y1 = 0;
 self->dirty_area.y2 = height;
}

uint16_t common_hal_displayio_bitmap_get_height(displayio_bitmap_t *self) {
 return self->height;
}

uint16_t common_hal_displayio_bitmap_get_width(displayio_bitmap_t *self) {
 return self->width;
}

uint32_t common_hal_displayio_bitmap_get_bits_per_value(displayio_bitmap_t *self) {
 return self->bits_per_value;
}

uint32_t common_hal_displayio_bitmap_get_pixel(displayio_bitmap_t *self, int16_t x, int16_t y) {
 if (x >= self->width || x < 0 || y >= self->height || y < 0) {
 return 0;
 }
 int32_t row_start = y * self->stride;
 uint32_t bytes_per_value = self->bits_per_value / 8;
 if (bytes_per_value < 1) {
 size_t word = self->data[row_start + (x >> self->x_shift)];

 return (word >> (sizeof(size_t) * 8 - ((x & self->x_mask) + 1) * self->bits_per_value)) & self->bitmask;
 } else {
 size_t* row = self->data + row_start;
 if (bytes_per_value == 1) {
 return ((uint8_t*) row)[x];
 } else if (bytes_per_value == 2) {
 return ((uint16_t*) row)[x];
 } else if (bytes_per_value == 4) {
 return ((uint32_t*) row)[x];
 }
 }
 return 0;
}

void common_hal_displayio_bitmap_set_pixel(displayio_bitmap_t *self, int16_t x, int16_t y, uint32_t value) {
 if (self->read_only) {
 mp_raise_RuntimeError(translate("Read-only object"));
 }
 // Update the dirty area.
 if (self->dirty_area.x1 == self->dirty_area.x2) {
 self->dirty_area.x1 = x;
 self->dirty_area.x2 = x + 1;
 self->dirty_area.y1 = y;
 self->dirty_area.y2 = y + 1;
 } else {
 if (x < self->dirty_area.x1) {
 self->dirty_area.x1 = x;
 } else if (x >= self->dirty_area.x2) {
 self->dirty_area.x2 = x + 1;
 }
 if (y < self->dirty_area.y1) {
 self->dirty_area.y1 = y;
 } else if (y >= self->dirty_area.y2) {
 self->dirty_area.y2 = y + 1;
 }
 }

 // Update our data
 int32_t row_start = y * self->stride;
 uint32_t bytes_per_value = self->bits_per_value / 8;
 if (bytes_per_value < 1) {
 uint32_t bit_position = (sizeof(size_t) * 8 - ((x & self->x_mask) + 1) * self->bits_per_value);
 uint32_t index = row_start + (x >> self->x_shift);
 uint32_t word = self->data[index];
 word &= ~(self->bitmask << bit_position);
 word |= (value & self->bitmask) << bit_position;
 self->data[index] = word;
 } else {
 size_t* row = self->data + row_start;
 if (bytes_per_value == 1) {
 ((uint8_t*) row)[x] = value;
 } else if (bytes_per_value == 2) {
 ((uint16_t*) row)[x] = value;
 } else if (bytes_per_value == 4) {
 ((uint32_t*) row)[x] = value;
 }
 }
}

displayio_area_t* displayio_bitmap_get_refresh_areas(displayio_bitmap_t *self, displayio_area_t* tail) {
 if (self->dirty_area.x1 == self->dirty_area.x2) {
 return tail;
 }
 self->dirty_area.next = tail;
 return &self->dirty_area;
}

void displayio_bitmap_finish_refresh(displayio_bitmap_t *self) {
 self->dirty_area.x1 = 0;
 self->dirty_area.x2 = 0;
}

void common_hal_displayio_bitmap_fill(displayio_bitmap_t *self, uint32_t value) {
 if (self->read_only) {
 mp_raise_RuntimeError(translate("Read-only object"));
 }
 // Update the dirty area.
 self->dirty_area.x1 = 0;
 self->dirty_area.x2 = self->width;
 self->dirty_area.y1 = 0;
 self->dirty_area.y2 = self->height;

 // build the packed word
 uint32_t word = 0;
 for (uint8_t i=0; i<32 / self->bits_per_value; i++) {
 word |= (value & self->bitmask) << (32 - ((i+1)*self->bits_per_value));
 }
 // copy it in
 for (uint32_t i=0; i<self->stride * self->height; i++) {
 self->data[i] = word;
 }
}