#include "el512_display.h"

#include <algorithm>
#include <cstring>

#include <esp_heap_caps.h>
#include <esp_private/esp_clk.h>

#include "esphome/core/hal.h"
#include "esphome/core/log.h"

namespace esphome::el512 {

static const char *const TAG = "el512";

void EL512Display::setup() {
  this->panel_ = new EL512Panel(this->pins_);  // NOLINT(cppcoreguidelines-owning-memory)
  if (!this->panel_->begin()) {
    ESP_LOGE(TAG, "Panel init failed (out of DMA memory or no free interrupt)");
    this->mark_failed();
    return;
  }
  // Apply states that switches may have restored before setup ran.
  this->panel_->setLowPower(this->low_power_);
  this->panel_->setEnabled(this->enabled_);
}

void EL512Display::loop() {
  if (this->panel_ == nullptr || !this->panel_->running())
    return;
  this->check_refresh_health_();
  const uint32_t now = millis();
  this->page_age_ms();  // notice page changes even when nothing draws
  if (now - this->animated_at_ >= this->animation_interval_) {
    const auto *page = this->get_active_page();
    for (const auto *p : this->animated_pages_) {
      if (p == page) {
        this->animated_at_ = now;
        this->update();
        break;
      }
    }
  }
  if (this->still_alive_page_ == nullptr)
    return;
  const bool active = this->is_still_alive_playing();
  if (active && !this->still_alive_was_active_) {
    // Remember where we came from, then start the show from the top.
    this->still_alive_return_ = this->previous_page_ != this->still_alive_page_ ? this->previous_page_ : nullptr;
    this->still_alive_.start(now);
    ESP_LOGI(TAG, "Still Alive started; start the song in %u ms", (unsigned) this->still_alive_song_start_ms());
  }
  this->still_alive_was_active_ = active;
  if (!active)
    return;
  if (this->still_alive_.finished(now) && this->still_alive_return_ != nullptr) {
    this->show_page(this->still_alive_return_);
    this->update();
    return;
  }
  if (this->still_alive_.update(now))
    this->update();
}

// Refresh health, checked every 10 s: warn when the ESP32 side of the video
// signal had a problem (DMA FIFO underrun, a refill later than the ring's lead,
// or a frame swap that timed out); otherwise a debug summary once a minute.
// No warnings while the panel misbehaves means the signal left the ESP32
// intact and was disturbed on the wires (e.g. by Wi-Fi transmit bursts).
void EL512Display::check_refresh_health_() {
  const uint32_t now = millis();
  if (this->health_checked_ == 0) {
    // Skip the start-up period (the FIFO is empty once while the DMA starts).
    this->panel_->takeStats();
    this->health_checked_ = now;
    return;
  }
  if (now - this->health_checked_ < 10000)
    return;
  const uint32_t period_ms = now - this->health_checked_;
  this->health_checked_ = now;
  const auto s = this->panel_->takeStats();
  const float max_gap_us = s.maxGapCycles / (float) (esp_clk_cpu_freq() / 1000000);
  const float lead_us = 1e6f * EL512Panel::RING_LINES * EL512Panel::CLOCKS_PER_ROW / EL512Panel::PIXEL_CLOCK_HZ;
  if (s.underruns > 0 || s.showTimeouts > 0 || max_gap_us > lead_us * 0.75f) {
    ESP_LOGW(TAG, "Refresh problem in the last %us: %u FIFO underruns, %u swap timeouts, max refill gap %.0f us",
             (unsigned) (period_ms / 1000), (unsigned) s.underruns, (unsigned) s.showTimeouts, max_gap_us);
  }
  if (now - this->health_logged_ >= 60000) {
    this->health_logged_ = now;
    ESP_LOGD(TAG, "Refresh OK: %.0f refills/s, max gap %.0f us, %u swaps", s.refills * 1000.0f / period_ms,
             max_gap_us, (unsigned) s.swaps);
  }
}

void EL512Display::play_still_alive() {
  if (this->still_alive_page_ == nullptr)
    return;
  if (this->is_still_alive_playing()) {
    this->still_alive_.start(millis());  // already showing: just restart
  } else {
    this->show_page(this->still_alive_page_);  // loop() starts it
  }
}

void EL512Display::draw_still_alive() {
  if (this->panel_ != nullptr)
    this->still_alive_.draw(*this->panel_);
}

uint32_t EL512Display::page_age_ms() {
  const uint32_t now = millis();
  if (this->get_active_page() != this->age_page_) {
    this->age_page_ = this->get_active_page();
    this->age_start_ = now;
  }
  return now - this->age_start_;
}

void EL512Display::shift_rows(int y, int height, int dx) {
  if (this->panel_ == nullptr)
    return;
  constexpr int W = EL512Panel::WIDTH, ROW = W / 8;
  dx %= W;
  if (dx < 0)
    dx += W;
  if (dx == 0)
    return;
  uint8_t *fb = this->panel_->framebuffer();
  uint8_t src[ROW];
  for (int r = std::max(y, 0); r < std::min(y + height, (int) EL512Panel::HEIGHT); r++) {
    uint8_t *row = fb + r * ROW;
    memcpy(src, row, ROW);
    memset(row, 0, ROW);
    for (int x = 0; x < W; x++) {
      const int s = (x - dx + W) % W;
      if (src[s >> 3] & (0x80 >> (s & 7)))
        row[x >> 3] |= 0x80 >> (x & 7);
    }
  }
}

void EL512Display::invert_rect(int x, int y, int width, int height) {
  if (this->panel_ == nullptr)
    return;
  for (int py = y; py < y + height; py++)
    for (int px = x; px < x + width; px++)
      this->panel_->setPixel(px, py, !this->panel_->getPixel(px, py));
}

void EL512Display::dither_mask(int level) {
  if (this->panel_ == nullptr || 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;
  }
  uint8_t *fb = this->panel_->framebuffer();
  constexpr int ROW = EL512Panel::WIDTH / 8;
  for (int y = 0; y < EL512Panel::HEIGHT; y++)
    for (int i = 0; i < ROW; i++)
      fb[y * ROW + i] &= masks[y & 3];
}

void EL512Display::update() {
  if (this->panel_ == nullptr || !this->panel_->running())
    return;
  this->do_update_();
  this->panel_->show();
}

void EL512Display::fill(Color color) {
  // The panel clear is a memset; with clipping active, fall back to per-pixel.
  if (this->panel_ == nullptr || this->get_clipping().is_set()) {
    Display::fill(color);
    return;
  }
  this->panel_->clear(color.is_on());
}

void EL512Display::draw_absolute_pixel_internal(int x, int y, Color color) {
  if (this->panel_ != nullptr)
    this->panel_->setPixel(x, y, color.is_on());
}

void EL512Display::set_enabled(bool on) {
  this->enabled_ = on;
  if (this->panel_ != nullptr)
    this->panel_->setEnabled(on);
}

void EL512Display::set_low_power(bool on) {
  this->low_power_ = on;
  if (this->panel_ != nullptr)
    this->panel_->setLowPower(on);
}

void EL512Display::dump_config() {
  LOG_DISPLAY("", "EL512.256-H", this);
  ESP_LOGCONFIG(TAG,
                "  Pins: VCLK %d, VID %d, TVID %d, HS %d, VS %d, ENABLE %d, _LOWPWR %d\n"
                "  Refresh: %.1f Hz, DMA ring %u bytes\n"
                "  Free internal heap: %u bytes",
                this->pins_.vclk, this->pins_.vid, this->pins_.tvid, this->pins_.hs, this->pins_.vs,
                this->pins_.enable, this->pins_.lowpwr_n, EL512Panel::refreshHz(),
                (unsigned) EL512Panel::RING_BYTES,
                (unsigned) heap_caps_get_free_size(MALLOC_CAP_INTERNAL));
  LOG_UPDATE_INTERVAL(this);
  if (this->is_failed())
    ESP_LOGE(TAG, "  Init failed");
}

}  // namespace esphome::el512