#include "interstellar.h"

#include <algorithm>
#include <cmath>
#include <cstring>
#include <vector>

#include "el512_display.h"
#include "esphome/core/hal.h"

namespace esphome::el512::interstellar {

using display::COLOR_OFF;
using display::COLOR_ON;
using display::Display;
using display::TextAlign;

namespace {

using namespace fx;

constexpr int W = 512, H = 256;
const uint8_t BAYER[4][4] = {{0, 8, 2, 10}, {12, 4, 14, 6}, {3, 11, 1, 9}, {15, 7, 13, 5}};
bool dither(int x, int y, int level) { return BAYER[y & 3][x & 3] < level; }

std::string kw(float w) { return std::isnan(w) ? "--" : watts(w); }

// Faint, slowly twinkling stars; skip(x, y) keeps them off busy areas.
template<typename Skip> void stars(EL512Display &it, uint32_t t, int count, uint32_t seed, Skip skip) {
  for (int i = 0; i < count; i++) {
    const uint32_t r = hash(i, seed);
    const int x = (int) (r % W), y = (int) ((r >> 9) % H);
    if (skip(x, y) || (t / 230 + (r >> 20)) % 17 == 0)
      continue;
    it.draw_pixel_at(x, y, COLOR_ON);
  }
}

// Segmented bar, lit up to frac.
void seg_bar(Display &it, int x, int y, int w, int h, float frac) {
  const int n = w / 5, lit = std::isnan(frac) ? 0 : (int) std::lround(std::clamp(frac, 0.0f, 1.0f) * n);
  for (int i = 0; i < n; i++) {
    if (i < lit)
      it.filled_rectangle(x + i * 5, y, 4, h);
    else
      it.horizontal_line(x + i * 5, y + h - 1, 4);
  }
}

// Seconds on Earth per second on Miller's planet: one hour there is seven
// years here.
constexpr float DILATION = 7 * 365.25f * 24;

// International Morse code, A-Z then 0-9.
const char *const MORSE[] = {".-",    "-...",  "-.-.",  "-..",   ".",     "..-.",  "--.",   "....",  "..",
                             ".---",  "-.-",   ".-..",  "--",    "-.",    "---",   ".--.",  "--.-",  ".-.",
                             "...",   "-",     "..-",   "...-",  ".--",   "-..-",  "-.--",  "--..",  "-----",
                             ".----", "..---", "...--", "....-", ".....", "-....", "--...", "---..", "----."};
const char *morse(char c) {
  if (c >= 'A' && c <= 'Z')
    return MORSE[c - 'A'];
  if (c >= '0' && c <= '9')
    return MORSE[26 + c - '0'];
  return nullptr;  // a space, or something Morse can't send
}

}  // namespace

// --- 1. Gargantua and time dilation ---------------------------------------------------

void gargantua(EL512Display &it, const Fonts &f, ESPTime now) {
  if (f.large == nullptr)
    return;
  const uint32_t t = it.page_age_ms();
  constexpr int CX = 168, CY = 124, SHADOW = 40, DISK = 160;
  stars(it, t, 90, 42, [](int x, int y) {
    const int dx = x - CX, dy = y - CY;
    return x > 320 || dx * dx + dy * dy < 80 * 80 || (std::abs(dy) < 12 && std::abs(dx) < DISK);
  });
  const float spin = t * 0.0025f;

  // The far side of the disk, bent over the top and under the bottom of the
  // shadow by its gravity: a thick halo above, a thinner one below. Streaks
  // run around it; the approaching (left) side is brighter.
  for (int y = CY - 72; y <= CY + 58; y++) {
    for (int x = CX - 72; x <= CX + 72; x++) {
      const int dx = x - CX, dy = y - CY, r2 = dx * dx + dy * dy;
      const int outer = dy < 0 ? 70 : 56;
      if (r2 < (SHADOW + 5) * (SHADOW + 5) || r2 > outer * outer)
        continue;
      const float r = std::sqrt((float) r2), a = std::atan2((float) dy, (float) dx);
      const int level = 8 + (int) (5 * std::sin(a * 7 + spin * 3 + r * 0.35f)) + (dx < 0 ? 3 : -1) -
                        (int) ((r - SHADOW) / 5);
      if (dither(x, y, level))
        it.draw_pixel_at(x, y, COLOR_ON);
    }
  }
  // Photon ring around the shadow.
  it.circle(CX, CY, SHADOW + 2);
  it.circle(CX, CY, SHADOW + 3);

  // The near side of the disk, edge-on across the front of the shadow.
  for (int x = CX - DISK; x <= CX + DISK; x++) {
    const int dx = x - CX;
    const float k = 1.0f - (float) (dx * dx) / (DISK * DISK);
    const int half = (int) (1 + 6 * k);
    for (int y = CY - half; y <= CY + half; y++) {
      const int level = 9 + (int) (5 * std::sin(dx * 0.12f - spin * 9)) + (dx < 0 ? 4 : 0) - 2 * std::abs(y - CY);
      it.draw_pixel_at(x, y, dither(x, y, level) ? COLOR_ON : COLOR_OFF);
    }
  }

  // Time dilation.
  constexpr int X = 336;
  it.print(X, 6, f.title, TextAlign::TOP_LEFT, "GARGANTUA");
  it.print(X, 26, f.mono, TextAlign::TOP_LEFT, "1 HOUR = 7 EARTH YEARS");
  it.horizontal_line(X, 46, W - X - 4);
  const float today = now.is_valid() ? now.hour * 3600.0f + now.minute * 60 + now.second : NAN;
  it.print(X, 54, f.mono, TextAlign::TOP_LEFT, "EARTH, TODAY");
  if (now.is_valid()) {
    it.strftime(X, 70, f.large, TextAlign::TOP_LEFT, "%H:%M", now);
    it.printf(506, 74, f.code, TextAlign::TOP_RIGHT, ":%02d", now.second);
  }
  it.print(X, 116, f.mono, TextAlign::TOP_LEFT, "MILLER'S PLANET, TODAY");
  if (!std::isnan(today)) {
    // One Miller second takes 17 Earth hours: three decimals, a bar for the rest.
    const float miller = today / DILATION;
    it.printf(X, 132, f.large, TextAlign::TOP_LEFT, "%.3f", miller);
    it.print(506, 136, f.code, TextAlign::TOP_RIGHT, "S");
    it.print(X, 178, f.mono, TextAlign::TOP_LEFT, "NEXT MILLER SECOND");
    seg_bar(it, X, 196, 170, 8, miller - std::floor(miller));
    const float left = (1.0f - (miller - std::floor(miller))) * DILATION / 3600;
    it.printf(X, 212, f.mono, TextAlign::TOP_LEFT, "IN %.1f EARTH HOURS", left);
  }
}

// --- 2. TARS and its settings -----------------------------------------------------------

void tars(EL512Display &it, const Fonts &f, const HomeData &d) {
  if (f.mono == nullptr)
    return;
  const uint32_t t = it.page_age_ms();
  constexpr uint32_t QUIP = 7000;
  const int quip = (int) ((t / QUIP) % 6);
  const uint32_t q = t % QUIP;

  // TARS: four slabs; the middle pair and the outer pair step in turn.
  constexpr int BX = 22, BY = 30, SW = 26, GAP = 3, BH = 192;
  const int lift = ((t / 450) % 2) ? 4 : -4;
  int screen_y = 0;
  for (int s = 0; s < 4; s++) {
    const int x = BX + s * (SW + GAP), y = BY + ((s == 1 || s == 2) ? lift : -lift);
    it.rectangle(x, y, SW, BH);
    for (int g = 1; g < 4; g++)
      it.horizontal_line(x + 3, y + g * BH / 4, SW - 6);
    it.vertical_line(x + SW / 2, y + BH - 34, 26);
    if (s == 1)
      screen_y = y + 16;
  }
  // His screen, with a waveform while he talks.
  const int sx = BX + SW + GAP + 3, sw = 2 * SW + GAP - 6;
  it.filled_rectangle(sx, screen_y, sw, 30);
  const bool talking = q < 4000;
  for (int x = 0; x < sw - 4; x++) {
    const float amp = talking ? 9 * std::fabs(std::sin(x * 0.21f + t * 0.013f) * std::sin(x * 0.05f + t * 0.004f)) : 0.6f;
    const int yy = screen_y + 15 + (int) (amp * std::sin(x * 0.7f + t * 0.02f));
    it.draw_pixel_at(sx + 2 + x, yy, COLOR_OFF);
  }

  // Settings and home readings.
  constexpr int X = 150;
  it.print(X, 2, f.large, TextAlign::TOP_LEFT, "TARS");
  it.print(X + text_width(it, f.large, "TARS") + 12, 14, f.title, TextAlign::TOP_LEFT, "SETTINGS");
  const int humor = quip == 5 && q > 2600 ? 60 : 75;
  struct Row {
    const char *name;
    float frac;
    std::string value;
  };
  const Row settings[] = {{"HUMOR", humor / 100.0f, str("%d%%", humor)},
                          {"HONESTY", 0.9f, "90%"},
                          {"DISCRETION", 0.8f, "80%"},
                          {"TRUST", 1.0f, "100%"}};
  const float tf = std::isnan(d.temp) ? NAN : (d.temp + 10) / 45;
  const Row readings[] = {{"SOLAR", d.solar / 5000, kw(d.solar)},
                          {"HOUSE", d.house / 5000, kw(d.house)},
                          {"GRID", std::fabs(d.grid) / 5000, kw(std::fabs(d.grid))},
                          {"OUTSIDE", tf, std::isnan(d.temp) ? "--" : str("%.1f C", d.temp)}};
  for (int i = 0; i < 4; i++) {
    const int y = 48 + i * 27;
    for (int col = 0; col < 2; col++) {
      const Row &r = col == 0 ? settings[i] : readings[i];
      const int x = X + col * 182;
      it.print(x, y, f.mono, TextAlign::TOP_LEFT, r.name);
      it.print(x + 172, y, f.mono, TextAlign::TOP_RIGHT, r.value.c_str());
      seg_bar(it, x, y + 16, 170, 5, r.frac);
    }
  }

  // What TARS has to say about the house.
  std::string say;
  switch (quip) {
    case 0:
      say = std::isnan(d.temp) ? "Outside temperature unknown. I'd bring a jacket anyway."
                               : str("Outside it's %.0f degrees. Humor setting 75%%: ", d.temp) +
                                     (d.temp < 15 ? "bring a jacket." : "leave the jacket.");
      break;
    case 1:
      say = "Solar is delivering " + kw(d.solar) + ". Not bad for a star 150 million kilometers away.";
      break;
    case 2:
      say = "House load " + kw(d.house) + ". Honesty setting 90%: it's probably the dishwasher.";
      break;
    case 3:
      say = std::isnan(d.grid) ? "Grid status unknown. Discretion setting says I shouldn't guess."
            : d.grid < 0       ? "We're sending " + kw(-d.grid) + " back to the grid. Very generous of us."
                               : "We're drawing " + kw(d.grid) + " from the grid. Discretion setting: no comment.";
      break;
    case 4: {
      const auto events = split(d.agenda, ';');
      say = events.empty() ? "No missions on the plan. Initiating relaxation protocol."
                           : "Next on the mission plan: " + field(events[0], 2) + ".";
      break;
    }
    default:
      say = "That was a joke. Lowering humor setting to 60%.";
  }
  it.rectangle(X, 160, W - X - 2, 92);
  int y = 168;
  for (const auto &l : wrap(it, f.mono, typed(say, q, 32), W - X - 20, 5)) {
    it.print(X + 8, y, f.mono, TextAlign::TOP_LEFT, l.c_str());
    y += 16;
  }
}

// --- 3. The Endurance spins while a Ranger docks ---------------------------------------

void endurance(EL512Display &it, const Fonts &f, const HomeData &d, ESPTime now) {
  if (f.large == nullptr)
    return;
  const uint32_t t = it.page_age_ms();
  constexpr int CX = 150, CY = 128, RING = 86;
  constexpr uint32_t CYCLE = 16000, MATCH = 6000, DOCK = 10000;
  const uint32_t c = t % CYCLE;
  const float solar = std::isnan(d.solar) ? 0 : std::max(0.0f, d.solar);
  const float rpm = 20 + std::min(solar, 5000.0f) / 5000 * 50;
  // Degrees per ms, shown at a tenth of the speed, or it would be a blur.
  const float rate = rpm * 6 / 10 / 1000;
  const float rot = rate * t;

  stars(it, t, 80, 7, [](int x, int y) { return (x - CX) * (x - CX) + (y - CY) * (y - CY) < 100 * 100 || x > 286; });

  // The ring: twelve modules around a hub on four spokes.
  it.circle(CX, CY, RING);
  for (int k = 0; k < 4; k++) {
    int x0, y0, x1, y1;
    polar(CX, CY, 18, rot + 45 + k * 90, &x0, &y0);
    polar(CX, CY, RING - 8, rot + 45 + k * 90, &x1, &y1);
    it.line(x0, y0, x1, y1);
  }
  for (int i = 0; i < 12; i++) {
    const float a = rot + i * 30;
    const int half = i % 2 ? 5 : 8;
    int mx, my;
    polar(CX, CY, RING, a, &mx, &my);
    int px[4], py[4];
    for (int k = 0; k < 4; k++)
      polar(mx, my, half * 1.41f, a + 45 + k * 90, &px[k], &py[k]);
    it.filled_triangle(px[0], py[0], px[1], py[1], px[2], py[2]);
    it.filled_triangle(px[0], py[0], px[2], py[2], px[3], py[3]);
  }
  it.filled_circle(CX, CY, 18, COLOR_OFF);
  it.circle(CX, CY, 18);
  it.circle(CX, CY, 9);

  // The Ranger: flies in, spins up to match, then docks in the hub.
  float rx, ry = CY, ang, match;
  const char *status;
  if (c < MATCH) {
    // In from the top right of the starfield, nose at the hub.
    const float k = (float) c / MATCH, e = 1 - (1 - k) * (1 - k);
    rx = 258 + (CX + 40 - 258) * e;
    ry = 20 + (CY - 20) * e;
    ang = std::atan2(CX - rx, -(CY - ry)) * 180 / 3.14159f;
    match = 0;
    status = "APPROACH";
  } else if (c < DOCK) {
    // Spin rate ramps up to the ring's; the angle is its integral.
    const float e = (float) (c - MATCH), k = e / (DOCK - MATCH);
    rx = CX + 40 - 40 * k;
    match = k;
    ang = 270 + rate * e * e / (2 * (DOCK - MATCH));
    status = "MATCHING SPIN";
  } else {
    rx = CX;
    match = 1;
    ang = 270 + rate * (DOCK - MATCH) / 2 + rate * (c - DOCK);
    status = "DOCKED";
  }
  int nx, ny, lx, ly, bx, by, tx, ty;
  polar((int) rx, (int) ry, 16, ang, &nx, &ny);        // nose
  polar((int) rx, (int) ry, 12, ang + 140, &lx, &ly);  // wing
  polar((int) rx, (int) ry, 12, ang - 140, &bx, &by);  // wing
  polar((int) rx, (int) ry, 5, ang + 180, &tx, &ty);   // tail notch
  it.filled_triangle(nx, ny, lx, ly, tx, ty);
  it.filled_triangle(nx, ny, tx, ty, bx, by);

  // Readouts.
  constexpr int X = 300;
  it.print(X, 6, f.title, TextAlign::TOP_LEFT, "ENDURANCE");
  it.horizontal_line(X, 26, W - X - 4);
  it.print(X, 34, f.mono, TextAlign::TOP_LEFT, "RING SPEED");
  it.printf(X, 50, f.large, TextAlign::TOP_LEFT, "%.0f", rpm);
  it.print(X + 70, 62, f.mono, TextAlign::TOP_LEFT, "RPM");
  it.print(X, 96, f.mono, TextAlign::TOP_LEFT, "MATCH SPIN");
  it.printf(506, 96, f.mono, TextAlign::TOP_RIGHT, "%.0f%%", match * 100);
  seg_bar(it, X, 114, 205, 8, match);
  if (c < MATCH)
    it.printf(X, 132, f.mono, TextAlign::TOP_LEFT, "DISTANCE %.0f M", (rx - CX - 18) * 3);
  if (c < DOCK || (t / 400) % 2)  // DOCKED blinks
    it.print(X, 150, f.code, TextAlign::TOP_LEFT, status);
  it.horizontal_line(X, 186, W - X - 4);
  it.printf(X, 194, f.mono, TextAlign::TOP_LEFT, "POWER (SOLAR)  %s", kw(d.solar).c_str());
  if (now.is_valid())
    it.printf(X, 214, f.mono, TextAlign::TOP_LEFT, "MISSION DAY %d  %02d:%02d", now.day_of_year, now.hour, now.minute);
}

// --- 4. The tesseract: books, the time in dust, a message in Morse -----------------------

void tesseract(EL512Display &it, const Fonts &f, const HomeData &d, ESPTime now) {
  if (f.mono == nullptr)
    return;
  const uint32_t t = it.page_age_ms();

  // The bookshelf, seen from behind; now and then a book falls out.
  it.print(4, 2, f.title, TextAlign::TOP_LEFT, "TESSERACT");
  it.rectangle(4, 22, 190, 226);
  const int shelf_y[3] = {96, 170, 246};
  const uint32_t cycle = t / 6000, p = t % 6000;
  int index = 0;
  const int falling = 3 + (int) (hash(cycle, 5) % 8);
  for (int s = 0; s < 3; s++) {
    if (s < 2)
      it.horizontal_line(4, shelf_y[s], 190);
    int x = 8;
    for (int b = 0; x < 186; b++, index++) {
      const uint32_t r = hash(s * 37 + b, 11);
      const int w = std::min(186 - x, 5 + (int) (r % 9)), h = 40 + (int) ((r >> 8) % 26);
      const int y = shelf_y[s] - h;
      if (s == 1 && b == falling) {
        if (p < 500) {
          it.rectangle(x + ((p / 60) % 2), y, w - 1, h);  // it shakes
        } else if (p < 1300) {
          const int drop = (int) ((p - 500) * (p - 500) / 8000);
          if (y + drop < 244)
            it.filled_rectangle(x, y + drop, w - 1, std::min(h, 244 - y - drop));
        } else if (p > 4500) {
          it.rectangle(x, y, w - 1, h);  // back on the shelf
        }
      } else if (r % 4 == 0) {
        it.filled_rectangle(x, y, w - 1, h);
      } else {
        it.rectangle(x, y, w - 1, h);
      }
      x += w;
    }
  }

  // The time in dust: HH:MM as four binary digits, thick bars for 1.
  constexpr int DX = 212, DTOP = 40, DBOT = 224;
  it.print(DX, 4, f.mono, TextAlign::TOP_LEFT, "THE TIME, IN DUST");
  int digits[4] = {0, 0, 0, 0};
  if (now.is_valid()) {
    digits[0] = now.hour / 10;
    digits[1] = now.hour % 10;
    digits[2] = now.minute / 10;
    digits[3] = now.minute % 10;
  }
  std::string code;
  for (int i = 0; i < 16; i++) {
    const bool one = digits[i / 4] & (8 >> (i % 4));
    code += one ? '1' : '0';
    if (i % 4 == 3 && i < 15)
      code += i == 7 ? " : " : " ";
    const int x = DX + i * 10 + (i / 4) * 6;
    const int bw = one ? 8 : 2, bx = x + (one ? 0 : 3);
    for (int y = DTOP + 60; y < DBOT; y++)
      for (int xx = bx; xx < bx + bw; xx++)
        if (dither(xx, y, one ? 11 : 9))
          it.draw_pixel_at(xx, y, COLOR_ON);
    // Grains drifting down into the bar.
    for (int k = 0; k < 4; k++) {
      const uint32_t r = hash(i * 7 + k, 3);
      const int gy = DTOP + (int) ((t / 9 + r) % 70);
      it.draw_pixel_at(bx + (int) (r >> 12) % bw, gy, COLOR_ON);
    }
  }
  it.print(DX, 232, f.mono, TextAlign::TOP_LEFT, code.c_str());

  // A wristwatch ticking the message out in Morse.
  // The message's first word (up to 6 letters, to fit beside the watch).
  std::string word = upper(d.message.empty() ? "STAY" : d.message);
  word = word.substr(0, std::min(word.find(' '), (size_t) 6));
  if (word.empty())
    word = "STAY";
  // Timeline: dot 200 ms, dash 600, 200 between symbols, 600 between letters,
  // 1400 between words, 2000 before it starts over.
  struct Mark {
    uint32_t at, len;
    int letter, symbol;
  };
  std::vector<Mark> marks;
  uint32_t at = 0;
  for (int l = 0; l < (int) word.size(); l++) {
    const char *m = morse(word[l]);
    if (m == nullptr) {
      at += 1400;
      continue;
    }
    for (int s = 0; m[s]; s++) {
      const uint32_t len = m[s] == '.' ? 200 : 600;
      marks.push_back({at, len, l, s});
      at += len + 200;
    }
    at += 400;
  }
  const uint32_t total = at + 2000, mt = t % std::max<uint32_t>(total, 1);
  const Mark *cur = nullptr;
  int letter = -1;
  for (const auto &m : marks) {
    if (mt >= m.at)
      letter = m.letter;
    if (mt >= m.at && mt < m.at + m.len)
      cur = &m;
  }
  constexpr int WX = 456, WY = 84, WR = 40;
  it.circle(WX, WY, WR);
  it.circle(WX, WY, WR - 3);
  for (int k = 0; k < 12; k++) {
    int x0, y0, x1, y1;
    polar(WX, WY, WR - 6, k * 30, &x0, &y0);
    polar(WX, WY, WR - (k % 3 ? 9 : 13), k * 30, &x1, &y1);
    it.line(x0, y0, x1, y1);
  }
  const int sec = now.is_valid() ? now.second : 0;
  int hx, hy;
  polar(WX, WY, WR - 7, sec * 6 + (cur != nullptr ? 12 : 0), &hx, &hy);  // the hand twitches on each mark
  it.line(WX, WY, hx, hy);
  it.filled_circle(WX, WY, 3);
  it.filled_rectangle(WX - 8, WY - WR - 10, 16, 8);
  it.filled_rectangle(WX - 8, WY + WR + 2, 16, 8);

  // The word, the letter being sent, and its dots and dashes.
  // The word in one go; the letter being sent is inverted, its cell measured
  // from the widths of the word's prefixes so it lines up with the glyphs.
  const int x0 = WX - text_width(it, f.code, word.c_str()) / 2;
  it.print(x0, 158, f.code, TextAlign::CENTER_LEFT, word.c_str());
  if (letter >= 0) {
    const int a = text_width(it, f.code, word.substr(0, letter).c_str());
    const int b = text_width(it, f.code, word.substr(0, letter + 1).c_str());
    it.invert_rect(x0 + a - 1, 146, b - a + 2, 24);
  }
  if (letter >= 0) {
    const char *m = morse(word[letter]);
    const int n = (int) strlen(m);
    int mx = WX - (n * 18) / 2;
    for (int s = 0; s < n; s++) {
      const bool on = cur != nullptr && cur->letter == letter && cur->symbol == s;
      if (m[s] == '.') {
        on ? it.filled_circle(mx + 5, 190, 4) : it.circle(mx + 5, 190, 4);
      } else {
        on ? it.filled_rectangle(mx, 187, 14, 7) : it.rectangle(mx, 187, 14, 7);
      }
      mx += 18;
    }
  }
  it.print(WX, 210, f.mono, TextAlign::TOP_CENTER, "MORSE, VIA THE");
  it.print(WX, 226, f.mono, TextAlign::TOP_CENTER, "SECOND HAND");
}

}  // namespace esphome::el512::interstellar