// Host stand-in for components/el512/el512_display.h, used by
// tools/render_pages.py to draw the themed pages on a PC: the same drawing
// surface (ESPHome's Display, 512 x 256, 1 bpp) and the same buffer effects,
// without the panel, DMA or ESPHome components.
#pragma once

#include <algorithm>
#include <cstdint>
#include <cstring>

#include "cyberpunk.h"
#include "el512_helpers.h"
#include "esphome/components/display/display.h"
#include "esphome/core/hal.h"
#include "konosuba.h"
#include "steins.h"
#include "trek.h"

namespace esphome::el512 {

class EL512Display : public display::Display {
 public:
  static constexpr int WIDTH = 512, HEIGHT = 256, ROW = WIDTH / 8;

  uint8_t fb[ROW * HEIGHT]{};  // row-major, MSB = leftmost pixel (also PBM P4 order)
  uint32_t shown_at{0};        // millis() when the page was "shown"

  void update() override {}
  display::DisplayType get_display_type() override { return display::DisplayType::DISPLAY_TYPE_BINARY; }

  void fill(Color color) override {
    if (this->get_clipping().is_set()) {
      Display::fill(color);
      return;
    }
    memset(this->fb, color.is_on() ? 0xFF : 0x00, sizeof(this->fb));
  }
  void draw_pixel_at(int x, int y, Color color) override {
    if (!this->get_clipping().inside(x, y))
      return;
    this->set(x, y, color.is_on());
  }

  uint32_t page_age_ms() { return millis() - this->shown_at; }
  uint32_t page_shown_at() const { return this->shown_at; }

  // Same effects as the device (el512_display.cpp).
  void shift_rows(int y, int height, int dx) {
    dx %= WIDTH;
    if (dx < 0)
      dx += WIDTH;
    if (dx == 0)
      return;
    uint8_t src[ROW];
    for (int r = std::max(y, 0); r < std::min(y + height, HEIGHT); r++) {
      uint8_t *row = this->fb + r * ROW;
      memcpy(src, row, ROW);
      memset(row, 0, ROW);
      for (int x = 0; x < WIDTH; x++) {
        const int s = (x - dx + WIDTH) % WIDTH;
        if (src[s >> 3] & (0x80 >> (s & 7)))
          row[x >> 3] |= 0x80 >> (x & 7);
      }
    }
  }
  void invert_rect(int x, int y, int width, int height) {
    for (int py = y; py < y + height; py++)
      for (int px = x; px < x + width; px++)
        if (px >= 0 && py >= 0 && px < WIDTH && py < HEIGHT)
          this->set(px, py, !this->get(px, py));
  }
  void dither_mask(int level) {
    if (level >= 16)
      return;
    static const uint8_t BAYER[4][4] = {{0, 8, 2, 10}, {12, 4, 14, 6}, {3, 11, 1, 9}, {15, 7, 13, 5}};
    uint8_t masks[4];
    for (int r = 0; r < 4; r++) {
      masks[r] = 0;
      for (int x = 0; x < 8; x++)
        if (BAYER[r][x & 3] < level)
          masks[r] |= 0x80 >> x;
    }
    for (int y = 0; y < HEIGHT; y++)
      for (int i = 0; i < ROW; i++)
        this->fb[y * ROW + i] &= masks[y & 3];
  }

  bool get(int x, int y) const { return this->fb[y * ROW + (x >> 3)] & (0x80 >> (x & 7)); }
  void set(int x, int y, bool on) {
    if (x < 0 || y < 0 || x >= WIDTH || y >= HEIGHT)
      return;
    uint8_t &b = this->fb[y * ROW + (x >> 3)];
    if (on)
      b |= 0x80 >> (x & 7);
    else
      b &= ~(0x80 >> (x & 7));
  }

 protected:
  int get_width_internal() override { return WIDTH; }
  int get_height_internal() override { return HEIGHT; }
};

}  // namespace esphome::el512