#include <string.h>

#include "shared-module/displayio/__init__.h"

#include "lib/utils/interrupt_char.h"
#include "py/reload.h"
#include "py/runtime.h"
#include "shared-bindings/board/__init__.h"
#include "shared-bindings/displayio/Bitmap.h"
#include "shared-bindings/displayio/Display.h"
#include "shared-bindings/displayio/Group.h"
#include "shared-bindings/displayio/Palette.h"
#include "shared-module/displayio/area.h"
#include "supervisor/shared/autoreload.h"
#include "supervisor/shared/display.h"
#include "supervisor/memory.h"

#include "supervisor/spi_flash_api.h"
#include "py/mpconfig.h"

#if CIRCUITPY_SHARPDISPLAY
#include "shared-bindings/sharpdisplay/SharpMemoryFramebuffer.h"
#include "shared-module/sharpdisplay/SharpMemoryFramebuffer.h"
#endif

primary_display_t displays[CIRCUITPY_DISPLAY_LIMIT];

displayio_buffer_transform_t null_transform = {
    .x = 0,
    .y = 0,
    .dx = 1,
    .dy = 1,
    .scale = 1,
    .width = 0,
    .height = 0,
    .mirror_x = false,
    .mirror_y = false,
    .transpose_xy = false
};


#if CIRCUITPY_RGBMATRIX
STATIC bool any_display_uses_this_framebuffer(mp_obj_base_t *obj) {
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        if (displays[i].display_base.type == &framebufferio_framebufferdisplay_type) {
            framebufferio_framebufferdisplay_obj_t *display = &displays[i].framebuffer_display;
            if (display->framebuffer == obj) {
                return true;
            }
        }
    }
    return false;
}
#endif


void displayio_background(void) {
    if (mp_hal_is_interrupted()) {
        return;
    }
    if (reload_requested) {
        // Reload is about to happen, so don't redisplay.
        return;
    }


    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        if (displays[i].display.base.type == NULL || displays[i].display.base.type == &mp_type_NoneType) {
            // Skip null display.
            continue;
        }
        if (displays[i].display.base.type == &displayio_display_type) {
            displayio_display_background(&displays[i].display);
        #if CIRCUITPY_FRAMEBUFFERIO
        } else if (displays[i].framebuffer_display.base.type == &framebufferio_framebufferdisplay_type) {
            framebufferio_framebufferdisplay_background(&displays[i].framebuffer_display);
        #endif
        } else if (displays[i].epaper_display.base.type == &displayio_epaperdisplay_type) {
            displayio_epaperdisplay_background(&displays[i].epaper_display);
        }
    }

}

void common_hal_displayio_release_displays(void) {
    // Release displays before busses so that they can send any final commands to turn the display
    // off properly.
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        mp_const_obj_t display_type = displays[i].display.base.type;
        if (display_type == NULL || display_type == &mp_type_NoneType) {
            continue;
        } else if (display_type == &displayio_display_type) {
            release_display(&displays[i].display);
        } else if (display_type == &displayio_epaperdisplay_type) {
            release_epaperdisplay(&displays[i].epaper_display);
        #if CIRCUITPY_FRAMEBUFFERIO
        } else if (display_type == &framebufferio_framebufferdisplay_type) {
            release_framebufferdisplay(&displays[i].framebuffer_display);
        #endif
        }
        displays[i].display.base.type = &mp_type_NoneType;
    }
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        mp_const_obj_t bus_type = displays[i].fourwire_bus.base.type;
        if (bus_type == NULL || bus_type == &mp_type_NoneType) {
            continue;
        } else if (bus_type == &displayio_fourwire_type) {
            common_hal_displayio_fourwire_deinit(&displays[i].fourwire_bus);
        } else if (bus_type == &displayio_i2cdisplay_type) {
            common_hal_displayio_i2cdisplay_deinit(&displays[i].i2cdisplay_bus);
        } else if (bus_type == &displayio_parallelbus_type) {
            common_hal_displayio_parallelbus_deinit(&displays[i].parallel_bus);
        #if CIRCUITPY_RGBMATRIX
        } else if (bus_type == &rgbmatrix_RGBMatrix_type) {
            common_hal_rgbmatrix_rgbmatrix_deinit(&displays[i].rgbmatrix);
        #endif
        #if CIRCUITPY_SHARPDISPLAY
        } else if (displays[i].bus_base.type == &sharpdisplay_framebuffer_type) {
            common_hal_sharpdisplay_framebuffer_deinit(&displays[i].sharpdisplay);
        #endif
        }
        displays[i].fourwire_bus.base.type = &mp_type_NoneType;
    }

    supervisor_stop_terminal();
}

void reset_displays(void) {
    // The SPI buses used by FourWires may be allocated on the heap so we need to move them inline.
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        if (displays[i].fourwire_bus.base.type == &displayio_fourwire_type) {
            displayio_fourwire_obj_t *fourwire = &displays[i].fourwire_bus;
            if (((uint32_t)fourwire->bus) < ((uint32_t)&displays) ||
                ((uint32_t)fourwire->bus) > ((uint32_t)&displays + CIRCUITPY_DISPLAY_LIMIT)) {
                busio_spi_obj_t *original_spi = fourwire->bus;
                #if BOARD_SPI
                // We don't need to move original_spi if it is the board.SPI object because it is
                // statically allocated already. (Doing so would also make it impossible to reference in
                // a subsequent VM run.)
                if (original_spi == common_hal_board_get_spi()) {
                    continue;
                }
                #endif
                #ifdef BOARD_USE_INTERNAL_SPI
                if (original_spi == (mp_obj_t)(&supervisor_flash_spi_bus)) {
                    continue;
                }
                #endif
                memcpy(&fourwire->inline_bus, original_spi, sizeof(busio_spi_obj_t));
                fourwire->bus = &fourwire->inline_bus;
                // Check for other displays that use the same spi bus and swap them too.
                for (uint8_t j = i + 1; j < CIRCUITPY_DISPLAY_LIMIT; j++) {
                    if (displays[i].fourwire_bus.base.type == &displayio_fourwire_type &&
                        displays[i].fourwire_bus.bus == original_spi) {
                        displays[i].fourwire_bus.bus = &fourwire->inline_bus;
                    }
                }
            }
        } else if (displays[i].i2cdisplay_bus.base.type == &displayio_i2cdisplay_type) {
            displayio_i2cdisplay_obj_t *i2c = &displays[i].i2cdisplay_bus;
            if (((uint32_t)i2c->bus) < ((uint32_t)&displays) ||
                ((uint32_t)i2c->bus) > ((uint32_t)&displays + CIRCUITPY_DISPLAY_LIMIT)) {
                busio_i2c_obj_t *original_i2c = i2c->bus;
                #if BOARD_I2C
                // We don't need to move original_i2c if it is the board.I2C object because it is
                // statically allocated already. (Doing so would also make it impossible to reference in
                // a subsequent VM run.)
                if (original_i2c == common_hal_board_get_i2c()) {
                    continue;
                }
                #endif
                memcpy(&i2c->inline_bus, original_i2c, sizeof(busio_i2c_obj_t));
                i2c->bus = &i2c->inline_bus;
                // Check for other displays that use the same i2c bus and swap them too.
                for (uint8_t j = i + 1; j < CIRCUITPY_DISPLAY_LIMIT; j++) {
                    if (displays[i].i2cdisplay_bus.base.type == &displayio_i2cdisplay_type &&
                        displays[i].i2cdisplay_bus.bus == original_i2c) {
                        displays[i].i2cdisplay_bus.bus = &i2c->inline_bus;
                    }
                }
            }
        #if CIRCUITPY_RGBMATRIX
        } else if (displays[i].rgbmatrix.base.type == &rgbmatrix_RGBMatrix_type) {
            rgbmatrix_rgbmatrix_obj_t *pm = &displays[i].rgbmatrix;
            if (!any_display_uses_this_framebuffer(&pm->base)) {
                common_hal_rgbmatrix_rgbmatrix_deinit(pm);
            } else {
                common_hal_rgbmatrix_rgbmatrix_set_paused(pm, true);
            }
        #endif
        #if CIRCUITPY_SHARPDISPLAY
        } else if (displays[i].bus_base.type == &sharpdisplay_framebuffer_type) {
            sharpdisplay_framebuffer_obj_t *sharp = &displays[i].sharpdisplay;
            common_hal_sharpdisplay_framebuffer_reset(sharp);
        #endif
        } else {
            // Not an active display bus.
            continue;
        }
    }

    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        // Reset the displayed group. Only the first will get the terminal but
        // that's ok.
        if (displays[i].display.base.type == &displayio_display_type) {
            reset_display(&displays[i].display);
        } else if (displays[i].epaper_display.base.type == &displayio_epaperdisplay_type) {
            displayio_epaperdisplay_obj_t *display = &displays[i].epaper_display;
            common_hal_displayio_epaperdisplay_show(display, NULL);
        #if CIRCUITPY_FRAMEBUFFERIO
        } else if (displays[i].framebuffer_display.base.type == &framebufferio_framebufferdisplay_type) {
            framebufferio_framebufferdisplay_reset(&displays[i].framebuffer_display);
        #endif
        }
    }
}

void displayio_gc_collect(void) {
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        #if CIRCUITPY_RGBMATRIX
        if (displays[i].rgbmatrix.base.type == &rgbmatrix_RGBMatrix_type) {
            rgbmatrix_rgbmatrix_collect_ptrs(&displays[i].rgbmatrix);
        }
        #endif
        #if CIRCUITPY_SHARPDISPLAY
        if (displays[i].bus_base.type == &sharpdisplay_framebuffer_type) {
            common_hal_sharpdisplay_framebuffer_collect_ptrs(&displays[i].sharpdisplay);
        }
        #endif

        if (displays[i].display.base.type == NULL) {
            continue;
        }

        // Alternatively, we could use gc_collect_root over the whole object,
        // but this is more precise, and is the only field that needs marking.
        if (displays[i].display.base.type == &displayio_display_type) {
            displayio_display_collect_ptrs(&displays[i].display);
        #if CIRCUITPY_FRAMEBUFFERIO
        } else if (displays[i].framebuffer_display.base.type == &framebufferio_framebufferdisplay_type) {
            framebufferio_framebufferdisplay_collect_ptrs(&displays[i].framebuffer_display);
        #endif
        } else if (displays[i].epaper_display.base.type == &displayio_epaperdisplay_type) {
            displayio_epaperdisplay_collect_ptrs(&displays[i].epaper_display);
        }
    }
}

void displayio_area_copy(const displayio_area_t *src, displayio_area_t *dst) {
    dst->x1 = src->x1;
    dst->y1 = src->y1;
    dst->x2 = src->x2;
    dst->y2 = src->y2;
}

void displayio_area_scale(displayio_area_t *area, uint16_t scale) {
    area->x1 *= scale;
    area->y1 *= scale;
    area->x2 *= scale;
    area->y2 *= scale;
}

void displayio_area_shift(displayio_area_t *area, int16_t dx, int16_t dy) {
    area->x1 += dx;
    area->y1 += dy;
    area->x2 += dx;
    area->y2 += dy;
}

bool displayio_area_compute_overlap(const displayio_area_t *a,
    const displayio_area_t *b,
    displayio_area_t *overlap) {
    overlap->x1 = a->x1;
    if (b->x1 > overlap->x1) {
        overlap->x1 = b->x1;
    }
    overlap->x2 = a->x2;
    if (b->x2 < overlap->x2) {
        overlap->x2 = b->x2;
    }
    if (overlap->x1 >= overlap->x2) {
        return false;
    }
    overlap->y1 = a->y1;
    if (b->y1 > overlap->y1) {
        overlap->y1 = b->y1;
    }
    overlap->y2 = a->y2;
    if (b->y2 < overlap->y2) {
        overlap->y2 = b->y2;
    }
    if (overlap->y1 >= overlap->y2) {
        return false;
    }
    return true;
}

bool displayio_area_empty(const displayio_area_t *a) {
    return (a->x1 == a->x2) || (a->y1 == a->y2);
}

void displayio_area_canon(displayio_area_t *a) {
    if (a->x1 > a->x2) {
        int16_t t = a->x1;
        a->x1 = a->x2;
        a->x2 = t;
    }
    if (a->y1 > a->y2) {
        int16_t t = a->y1;
        a->y1 = a->y2;
        a->y2 = t;
    }
}

void displayio_area_union(const displayio_area_t *a,
    const displayio_area_t *b,
    displayio_area_t *u) {

    if (displayio_area_empty(a)) {
        displayio_area_copy(b, u);
        return;
    }
    if (displayio_area_empty(b)) {
        displayio_area_copy(a, u);
        return;
    }
    u->x1 = MIN(a->x1, b->x1);
    u->y1 = MIN(a->y1, b->y1);
    u->x2 = MAX(a->x2, b->x2);
    u->y2 = MAX(a->y2, b->y2);
}

uint16_t displayio_area_width(const displayio_area_t *area) {
    return area->x2 - area->x1;
}

uint16_t displayio_area_height(const displayio_area_t *area) {
    return area->y2 - area->y1;
}

uint32_t displayio_area_size(const displayio_area_t *area) {
    return displayio_area_width(area) * displayio_area_height(area);
}

bool displayio_area_equal(const displayio_area_t *a, const displayio_area_t *b) {
    return a->x1 == b->x1 &&
           a->y1 == b->y1 &&
           a->x2 == b->x2 &&
           a->y2 == b->y2;
}

// Original and whole must be in the same coordinate space.
void displayio_area_transform_within(bool mirror_x, bool mirror_y, bool transpose_xy,
    const displayio_area_t *original,
    const displayio_area_t *whole,
    displayio_area_t *transformed) {
    if (mirror_x) {
        transformed->x1 = whole->x1 + (whole->x2 - original->x2);
        transformed->x2 = whole->x2 - (original->x1 - whole->x1);
    } else {
        transformed->x1 = original->x1;
        transformed->x2 = original->x2;
    }
    if (mirror_y) {
        transformed->y1 = whole->y1 + (whole->y2 - original->y2);
        transformed->y2 = whole->y2 - (original->y1 - whole->y1);
    } else {
        transformed->y1 = original->y1;
        transformed->y2 = original->y2;
    }
    if (transpose_xy) {
        int16_t y1 = transformed->y1;
        int16_t y2 = transformed->y2;
        transformed->y1 = whole->y1 + (transformed->x1 - whole->x1);
        transformed->y2 = whole->y1 + (transformed->x2 - whole->x1);
        transformed->x2 = whole->x1 + (y2 - whole->y1);
        transformed->x1 = whole->x1 + (y1 - whole->y1);
    }
}

primary_display_t *allocate_display(void) {
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        mp_const_obj_t display_type = displays[i].display.base.type;
        if (display_type == NULL || display_type == &mp_type_NoneType) {
            return &displays[i];
        }
    }
    return NULL;
}

primary_display_t *allocate_display_or_raise(void) {
    primary_display_t *result = allocate_display();
    if (result) {
        return result;
    }
    mp_raise_RuntimeError(translate("Too many displays"));
}
primary_display_t *allocate_display_bus(void) {
    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
        mp_const_obj_t display_bus_type = displays[i].bus_base.type;
        if (display_bus_type == NULL || display_bus_type == &mp_type_NoneType) {
            return &displays[i];
        }
    }
    return NULL;
}

primary_display_t *allocate_display_bus_or_raise(void) {
    primary_display_t *result = allocate_display_bus();
    if (result) {
        return result;
    }
    mp_raise_RuntimeError(translate("Too many display busses"));
}