/*
 * 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/TileGrid.h"

#include "shared-bindings/displayio/Bitmap.h"
#include "shared-bindings/displayio/ColorConverter.h"
#include "shared-bindings/displayio/OnDiskBitmap.h"
#include "shared-bindings/displayio/Palette.h"
#include "shared-bindings/displayio/Shape.h"

void common_hal_displayio_tilegrid_construct(displayio_tilegrid_t *self, mp_obj_t bitmap,
        uint16_t bitmap_width_in_tiles,
        mp_obj_t pixel_shader, uint16_t width, uint16_t height,
        uint16_t tile_width, uint16_t tile_height, uint16_t x, uint16_t y, uint8_t default_tile) {
    uint32_t total_tiles = width * height;
    // Sprites will only have one tile so save a little memory by inlining values in the pointer.
    uint8_t inline_tiles = sizeof(uint8_t*);
    if (total_tiles <= inline_tiles) {
        self->tiles = 0;
        // Pack values into the pointer since there are only a few.
        for (uint32_t i = 0; i < inline_tiles; i++) {
            ((uint8_t*) &self->tiles)[i] = default_tile;
        }
        self->inline_tiles = true;
    } else {
        self->tiles = (uint8_t*) m_malloc(total_tiles, false);
        for (uint32_t i = 0; i < total_tiles; i++) {
            self->tiles[i] = default_tile;
        }
        self->inline_tiles = false;
    }
    self->bitmap_width_in_tiles = bitmap_width_in_tiles;
    self->width_in_tiles = width;
    self->height_in_tiles = height;
    self->x = x;
    self->y = y;
    self->pixel_width = width * tile_width;
    self->pixel_height = height * tile_height;
    self->tile_width = tile_width;
    self->tile_height = tile_height;
    self->bitmap = bitmap;
    self->pixel_shader = pixel_shader;
    self->in_group = false;
    self->first_draw = true;
    self->flip_x = false;
    self->flip_y = false;
    self->transpose_xy = false;
}

bool displayio_tilegrid_get_previous_area(displayio_tilegrid_t *self, displayio_area_t* area) {
    if (self->first_draw) {
        return false;
    }
    displayio_area_copy(&self->previous_area, area);
    return true;
}

void _update_current_x(displayio_tilegrid_t *self) {
    int16_t width;
    if (self->transpose_xy) {
        width = self->pixel_height;
    } else {
        width = self->pixel_width;
    }
    if (self->absolute_transform->transpose_xy) {
        self->current_area.y1 = self->absolute_transform->y + self->absolute_transform->dy * self->x;
        self->current_area.y2 = self->absolute_transform->y + self->absolute_transform->dy * (self->x + width);
        if (self->current_area.y2 < self->current_area.y1) {
            int16_t temp = self->current_area.y2;
            self->current_area.y2 = self->current_area.y1;
            self->current_area.y1 = temp;
        }
    } else {
        self->current_area.x1 = self->absolute_transform->x + self->absolute_transform->dx * self->x;
        self->current_area.x2 = self->absolute_transform->x + self->absolute_transform->dx * (self->x + width);
        if (self->current_area.x2 < self->current_area.x1) {
            int16_t temp = self->current_area.x2;
            self->current_area.x2 = self->current_area.x1;
            self->current_area.x1 = temp;
        }
    }
}

void _update_current_y(displayio_tilegrid_t *self) {
    int16_t height;
    if (self->transpose_xy) {
        height = self->pixel_width;
    } else {
        height = self->pixel_height;
    }
    if (self->absolute_transform->transpose_xy) {
        self->current_area.x1 = self->absolute_transform->x + self->absolute_transform->dx * self->y;
        self->current_area.x2 = self->absolute_transform->x + self->absolute_transform->dx * (self->y + height);
        if (self->current_area.x2 < self->current_area.x1) {
            int16_t temp = self->current_area.x2;
            self->current_area.x2 = self->current_area.x1;
            self->current_area.x1 = temp;
        }
    } else {
        self->current_area.y1 = self->absolute_transform->y + self->absolute_transform->dy * self->y;
        self->current_area.y2 = self->absolute_transform->y + self->absolute_transform->dy * (self->y + height);
        if (self->current_area.y2 < self->current_area.y1) {
            int16_t temp = self->current_area.y2;
            self->current_area.y2 = self->current_area.y1;
            self->current_area.y1 = temp;
        }
    }
}

void displayio_tilegrid_update_transform(displayio_tilegrid_t *self,
                                         const displayio_buffer_transform_t* absolute_transform) {
    self->in_group = absolute_transform != NULL;
    self->absolute_transform = absolute_transform;
    if (absolute_transform != NULL) {
        self->moved = !self->first_draw;

        _update_current_x(self);
        _update_current_y(self);
    } else {
        self->first_draw = true;
    }
}

mp_int_t common_hal_displayio_tilegrid_get_x(displayio_tilegrid_t *self) {
    return self->x;
}
void common_hal_displayio_tilegrid_set_x(displayio_tilegrid_t *self, mp_int_t x) {
    if (self->x == x) {
        return;
    }

    self->moved = !self->first_draw;

    self->x = x;
    if (self->absolute_transform != NULL) {
        _update_current_x(self);
    }
}
mp_int_t common_hal_displayio_tilegrid_get_y(displayio_tilegrid_t *self) {
    return self->y;
}

void common_hal_displayio_tilegrid_set_y(displayio_tilegrid_t *self, mp_int_t y) {
    if (self->y == y) {
        return;
    }
    self->moved = !self->first_draw;
    self->y = y;
    if (self->absolute_transform != NULL) {
        _update_current_y(self);
    }
}

mp_obj_t common_hal_displayio_tilegrid_get_pixel_shader(displayio_tilegrid_t *self) {
    return self->pixel_shader;
}

void common_hal_displayio_tilegrid_set_pixel_shader(displayio_tilegrid_t *self, mp_obj_t pixel_shader) {
    self->pixel_shader = pixel_shader;
    self->full_change = true;
}

uint16_t common_hal_displayio_tilegrid_get_width(displayio_tilegrid_t *self) {
    return self->width_in_tiles;
}

uint16_t common_hal_displayio_tilegrid_get_height(displayio_tilegrid_t *self) {
    return self->height_in_tiles;
}

uint8_t common_hal_displayio_tilegrid_get_tile(displayio_tilegrid_t *self, uint16_t x, uint16_t y) {
    uint8_t* tiles = self->tiles;
    if (self->inline_tiles) {
        tiles = (uint8_t*) &self->tiles;
    }
    if (tiles == NULL) {
        return 0;
    }
    return tiles[y * self->width_in_tiles + x];
}

void common_hal_displayio_tilegrid_set_tile(displayio_tilegrid_t *self, uint16_t x, uint16_t y, uint8_t tile_index) {
    uint8_t* tiles = self->tiles;
    if (self->inline_tiles) {
        tiles = (uint8_t*) &self->tiles;
    }
    if (tiles == NULL) {
        return;
    }
    tiles[y * self->width_in_tiles + x] = tile_index;
    displayio_area_t temp_area;
    displayio_area_t* tile_area;
    if (!self->partial_change) {
        tile_area = &self->dirty_area;
    } else {
        tile_area = &temp_area;
    }
    tile_area->x1 = x * self->tile_width;
    tile_area->x2 = tile_area->x1 + self->tile_width;
    tile_area->y1 = y * self->tile_height;
    tile_area->y2 = tile_area->y1 + self->tile_height;
    if (self->partial_change) {
        displayio_area_expand(&self->dirty_area, &temp_area);
    }

    self->partial_change = true;
}

bool common_hal_displayio_tilegrid_get_flip_x(displayio_tilegrid_t *self) {
    return self->flip_x;
}

void common_hal_displayio_tilegrid_set_flip_x(displayio_tilegrid_t *self, bool flip_x) {
    if (self->flip_x == flip_x) {
        return;
    }
    self->flip_x = flip_x;
    self->full_change = true;
}

bool common_hal_displayio_tilegrid_get_flip_y(displayio_tilegrid_t *self) {
    return self->flip_y;
}

void common_hal_displayio_tilegrid_set_flip_y(displayio_tilegrid_t *self, bool flip_y) {
    if (self->flip_y == flip_y) {
        return;
    }
    self->flip_y = flip_y;
    self->full_change = true;
}

bool common_hal_displayio_tilegrid_get_transpose_xy(displayio_tilegrid_t *self) {
    return self->transpose_xy;
}

void common_hal_displayio_tilegrid_set_transpose_xy(displayio_tilegrid_t *self, bool transpose_xy) {
    if (self->transpose_xy == transpose_xy) {
        return;
    }
    self->transpose_xy = transpose_xy;

    // Square TileGrids do not change dimensions when transposed.
    if (self->pixel_width == self->pixel_height) {
        self->full_change = true;
        return;
    }

    _update_current_x(self);
    _update_current_y(self);

    self->moved = true;
}

void common_hal_displayio_tilegrid_set_top_left(displayio_tilegrid_t *self, uint16_t x, uint16_t y) {
    self->top_left_x = x;
    self->top_left_y = y;
    self->full_change = true;
}

bool displayio_tilegrid_fill_area(displayio_tilegrid_t *self, const displayio_area_t* area, uint32_t* mask, uint32_t *buffer) {
    // If no tiles are present we have no impact.
    uint8_t* tiles = self->tiles;
    if (self->inline_tiles) {
        tiles = (uint8_t*) &self->tiles;
    }
    if (tiles == NULL) {
        return false;
    }

    displayio_area_t overlap;
    if (!displayio_area_compute_overlap(area, &self->current_area, &overlap)) {
        return false;
    }

    int16_t x_stride = 1;
    int16_t y_stride = displayio_area_width(area);

    bool flip_x = self->flip_x;
    bool flip_y = self->flip_y;
    if (self->transpose_xy != self->absolute_transform->transpose_xy) {
        bool temp_flip = flip_x;
        flip_x = flip_y;
        flip_y = temp_flip;
    }

    // How many pixels are outside of our area between us and the start of the row.
    uint16_t start = 0;
    if ((self->absolute_transform->dx < 0) != flip_x) {
        start += (area->x2 - area->x1 - 1) * x_stride;
        x_stride *= -1;
    }
    if ((self->absolute_transform->dy < 0) != flip_y) {
        start += (area->y2 - area->y1 - 1) * y_stride;
        y_stride *= -1;
    }

    // Track if this layer finishes filling in the given area. We can ignore any remaining
    // layers at that point.
    bool full_coverage = displayio_area_equal(area, &overlap);

    // TODO(tannewt): Skip coverage tracking if all pixels outside the overlap have already been
    // set and our palette is all opaque.

    // TODO(tannewt): Check to see if the pixel_shader has any transparency. If it doesn't then we
    // can either return full coverage or bulk update the mask.
    displayio_area_t transformed;
    displayio_area_transform_within(flip_x != (self->absolute_transform->dx < 0), flip_y != (self->absolute_transform->dy < 0), self->transpose_xy != self->absolute_transform->transpose_xy,
                                    &overlap,
                                    &self->current_area,
                                    &transformed);

    int16_t start_x = (transformed.x1 - self->current_area.x1);
    int16_t end_x = (transformed.x2 - self->current_area.x1);
    int16_t start_y = (transformed.y1 - self->current_area.y1);
    int16_t end_y = (transformed.y2 - self->current_area.y1);

    int16_t y_shift = 0;
    int16_t x_shift = 0;
    if ((self->absolute_transform->dx < 0) != flip_x) {
        x_shift = area->x2 - overlap.x2;
    } else {
        x_shift = overlap.x1 - area->x1;
    }
    if ((self->absolute_transform->dy < 0) != flip_y) {
        y_shift = area->y2 - overlap.y2;
    } else {
        y_shift = overlap.y1 - area->y1;
    }

    // This untransposes x and y so it aligns with bitmap rows.
    if (self->transpose_xy != self->absolute_transform->transpose_xy) {
        int16_t temp_stride = x_stride;
        x_stride = y_stride;
        y_stride = temp_stride;
        int16_t temp_shift = x_shift;
        x_shift = y_shift;
        y_shift = temp_shift;
    }

    for (int16_t y = start_y; y < end_y; y++) {
        int16_t row_start = start + (y - start_y + y_shift) * y_stride;
        int16_t local_y = y / self->absolute_transform->scale;
        for (int16_t x = start_x; x < end_x; x++) {
            // Compute the destination pixel in the buffer and mask based on the transformations.
            int16_t offset = row_start + (x - start_x + x_shift) * x_stride;

            // This is super useful for debugging out range accesses. Uncomment to use.
            // if (offset < 0 || offset >= (int32_t) displayio_area_size(area)) {
            //     asm("bkpt");
            // }

            // Check the mask first to see if the pixel has already been set.
            if ((mask[offset / 32] & (1 << (offset % 32))) != 0) {
                continue;
            }
            int16_t local_x = x / self->absolute_transform->scale;
            uint16_t tile_location = ((local_y / self->tile_height + self->top_left_y) % self->height_in_tiles) * self->width_in_tiles + (local_x / self->tile_width + self->top_left_x) % self->width_in_tiles;
            uint8_t tile = tiles[tile_location];
            uint16_t tile_x = (tile % self->bitmap_width_in_tiles) * self->tile_width + local_x % self->tile_width;
            uint16_t tile_y = (tile / self->bitmap_width_in_tiles) * self->tile_height + local_y % self->tile_height;

            uint32_t value = 0;
            // We always want to read bitmap pixels by row first and then transpose into the destination
            // buffer because most bitmaps are row associated.
            if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_bitmap_type)) {
                value = common_hal_displayio_bitmap_get_pixel(self->bitmap, tile_x, tile_y);
            } else if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_shape_type)) {
                value = common_hal_displayio_shape_get_pixel(self->bitmap, tile_x, tile_y);
            } else if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_ondiskbitmap_type)) {
                value = common_hal_displayio_ondiskbitmap_get_pixel(self->bitmap, tile_x, tile_y);
            }

            uint16_t* pixel = ((uint16_t*) buffer) + offset;
            if (self->pixel_shader == mp_const_none) {
                *pixel = value;
                return true;
            } else if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_palette_type)) {
                if (!displayio_palette_get_color(self->pixel_shader, value, pixel)) {
                    // A pixel is transparent so we haven't fully covered the area ourselves.
                    full_coverage = false;
                } else {
                    mask[offset / 32] |= 1 << (offset % 32);
                }
            } else if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_colorconverter_type)) {
                if (!common_hal_displayio_colorconverter_convert(self->pixel_shader, value, pixel)) {
                    // A pixel is transparent so we haven't fully covered the area ourselves.
                    full_coverage = false;
                } else {
                    mask[offset / 32] |= 1 << (offset % 32);
                }
            }
        }
    }
    return full_coverage;
}

void displayio_tilegrid_finish_refresh(displayio_tilegrid_t *self) {
    if (self->moved || self->first_draw) {
        displayio_area_copy(&self->current_area, &self->previous_area);
    }

    self->moved = false;
    self->full_change = false;
    self->partial_change = false;
    self->first_draw = false;
    if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_palette_type)) {
        displayio_palette_finish_refresh(self->pixel_shader);
    } else if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_colorconverter_type)) {
        displayio_colorconverter_finish_refresh(self->pixel_shader);
    }
    // TODO(tannewt): We could double buffer changes to position and move them over here.
    // That way they won't change during a refresh and tear.
}

displayio_area_t* displayio_tilegrid_get_refresh_areas(displayio_tilegrid_t *self, displayio_area_t* tail) {
    if (self->moved && !self->first_draw) {
        displayio_area_union(&self->previous_area, &self->current_area, &self->dirty_area);
        if (displayio_area_size(&self->dirty_area) <= 2 * self->pixel_width * self->pixel_height) {
            self->dirty_area.next = tail;
            return &self->dirty_area;
        }
        self->previous_area.next = tail;
        self->current_area.next = &self->previous_area;
        return &self->current_area;
    }

    // We must recheck if our sources require a refresh because needs_refresh may or may not have
    // been called.
    self->full_change = self->full_change ||
        (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_palette_type) &&
         displayio_palette_needs_refresh(self->pixel_shader)) ||
        (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_colorconverter_type) &&
         displayio_colorconverter_needs_refresh(self->pixel_shader));
    if (self->full_change || self->first_draw) {
        self->current_area.next = tail;
        return &self->current_area;
    }

    if (self->partial_change) {
        if (self->absolute_transform->transpose_xy) {
            int16_t x1 = self->dirty_area.x1;
            self->dirty_area.x1 = self->absolute_transform->x + self->absolute_transform->dx * (self->y + self->dirty_area.y1);
            self->dirty_area.y1 = self->absolute_transform->y + self->absolute_transform->dy * (self->x + x1);
            int16_t x2 = self->dirty_area.x2;
            self->dirty_area.x2 = self->absolute_transform->x + self->absolute_transform->dx * (self->y + self->dirty_area.y2);
            self->dirty_area.y2 = self->absolute_transform->y + self->absolute_transform->dy * (self->x + x2);
        } else {
            self->dirty_area.x1 = self->absolute_transform->x + self->absolute_transform->dx * (self->x + self->dirty_area.x1);
            self->dirty_area.y1 = self->absolute_transform->y + self->absolute_transform->dy * (self->y + self->dirty_area.y1);
            self->dirty_area.x2 = self->absolute_transform->x + self->absolute_transform->dx * (self->x + self->dirty_area.x2);
            self->dirty_area.y2 = self->absolute_transform->y + self->absolute_transform->dy * (self->y + self->dirty_area.y2);
        }
        if (self->dirty_area.y2 < self->dirty_area.y1) {
            int16_t temp = self->dirty_area.y2;
            self->dirty_area.y2 = self->dirty_area.y1;
            self->dirty_area.y1 = temp;
        }
        if (self->dirty_area.x2 < self->dirty_area.x1) {
            int16_t temp = self->dirty_area.x2;
            self->dirty_area.x2 = self->dirty_area.x1;
            self->dirty_area.x1 = temp;
        }

        self->dirty_area.next = tail;
        return &self->dirty_area;
    }
    return tail;
}