#include "still_alive.h"

#include <string.h>

#include "el512_font.h"
#include "el512_panel.h"
#include "still_alive_data.h"

namespace el512sa {

namespace {

uint8_t fit(int16_t px, int16_t cell, uint8_t cap) {
  const int n = (px - 2 * TextBox::PAD) / cell;
  return n > cap ? cap : (uint8_t) n;
}

bool due(uint32_t now, uint32_t at) { return (int32_t) (now - at) >= 0; }

void drawChar(EL512Panel &panel, int16_t x, int16_t y, char c) {
  if (c < EL512_FONT_FIRST || c > EL512_FONT_LAST)
    c = '?';
  const uint8_t *glyph = &EL512_FONT[(c - EL512_FONT_FIRST) * 5];
  for (int16_t col = 0; col < 5; col++) {
    const uint8_t bits = glyph[col];
    for (int16_t row = 0; row < 8; row++) {
      if (bits & (1 << row))
        panel.setPixel(x + col, y + row, true);
    }
  }
}

}  // namespace

// --- TextBox -----------------------------------------------------------------

TextBox::TextBox(int16_t x, int16_t y, int16_t w, int16_t h)
    : x_(x), y_(y), w_(w), h_(h), cols_(fit(w, CHAR_W, MAX_COLS)), rows_(fit(h, CHAR_H, MAX_ROWS)) {
  clear();
}

void TextBox::clear() {
  memset(text_, 0, sizeof(text_));
  row_ = 0;
  col_ = 0;
}

void TextBox::put(char c) {
  if (c == '\n') {
    newLine();
    return;
  }
  if (col_ >= cols_)
    newLine();
  text_[row_][col_++] = c;
}

void TextBox::print(const char *s) {
  while (*s)
    put(*s++);
}

void TextBox::newLine() {
  col_ = 0;
  if (row_ + 1 < rows_) {
    row_++;
    return;
  }
  memmove(text_[0], text_[1], (size_t) (rows_ - 1) * sizeof(text_[0]));
  memset(text_[rows_ - 1], 0, sizeof(text_[0]));
}

void TextBox::draw(EL512Panel &panel, bool cursor, bool frame) const {
  if (frame) {
    // Dashed outline, 4 px on / 2 px off.
    for (int16_t i = 0; i < w_; i++) {
      if (i % 6 < 4) {
        panel.setPixel(x_ + i, y_, true);
        panel.setPixel(x_ + i, y_ + h_ - 1, true);
      }
    }
    for (int16_t i = 0; i < h_; i++) {
      if (i % 6 < 4) {
        panel.setPixel(x_, y_ + i, true);
        panel.setPixel(x_ + w_ - 1, y_ + i, true);
      }
    }
  }
  for (uint8_t r = 0; r < rows_; r++) {
    for (uint8_t c = 0; c < cols_ && text_[r][c]; c++) {
      if (text_[r][c] != ' ')
        drawChar(panel, x_ + PAD + c * CHAR_W, y_ + PAD + r * CHAR_H, text_[r][c]);
    }
  }
  if (cursor) {
    for (int16_t dy = 6; dy < 8; dy++)
      for (int16_t dx = 0; dx < 5; dx++)
        panel.setPixel(x_ + PAD + col_ * CHAR_W + dx, y_ + PAD + row_ * CHAR_H + dy, true);
  }
}

// --- StillAlivePlayer ----------------------------------------------------------

// 41 x 31 lyrics console | 41 x 9 credits over a 41 x 20 picture.
StillAlivePlayer::StillAlivePlayer()
    : lyrics_(0, 0, 254, 256), credits_(256, 0, 256, 86), art_(256, 88, 256, 168) {}

uint32_t StillAlivePlayer::songStartMs() { return START_DELAY_MS + SONG_START_MS; }

void StillAlivePlayer::start(uint32_t nowMs) {
  lyrics_.clear();
  credits_.clear();
  showArt(ART_NONE);
  showStart_ = nowMs + START_DELAY_MS;
  step_ = 0;
  charIdx_ = 0;
  stepStarted_ = false;
  done_ = false;
  doneAt_ = 0;
  creditIdx_ = 0;
  creditChar_ = 0;
  creditLineOpen_ = false;
  creditsDone_ = false;
  creditLineAt_ = CREDITS_START_MS;
  // Credits are typed on the bottom row and scroll up, as in the game.
  for (uint8_t r = 1; r < credits_.rows(); r++)
    credits_.put('\n');
}

bool StillAlivePlayer::finished(uint32_t nowMs) const { return done_ && due(nowMs, doneAt_ + HOLD_MS); }

void StillAlivePlayer::showArt(int8_t id) {
  art_.clear();
  if (id <= ART_NONE || (size_t) id >= ART_COUNT)
    return;
  const Art &art = ARTS[id];
  size_t width = 0;
  for (uint8_t i = 0; i < art.count; i++) {
    const size_t len = strlen(art.lines[i]);
    if (len > width)
      width = len;
  }
  const uint8_t top = art.count < art_.rows() ? (art_.rows() - art.count) / 2 : 0;
  const uint8_t left = width < art_.cols() ? (art_.cols() - width) / 2 : 0;
  for (uint8_t r = 0; r < top; r++)
    art_.put('\n');
  for (uint8_t i = 0; i < art.count && top + i < art_.rows(); i++) {
    if (i > 0)
      art_.put('\n');
    for (uint8_t c = 0; c < left; c++)
      art_.put(' ');
    // Truncate instead of wrapping so a wide picture keeps its shape.
    for (const char *p = art.lines[i]; *p && left + (p - art.lines[i]) < art_.cols(); p++)
      art_.put(*p);
  }
}

bool StillAlivePlayer::update(uint32_t nowMs) {
  bool changed = false;
  if (due(nowMs, showStart_)) {
    const uint32_t t = nowMs - showStart_;
    changed |= updateLyrics(t, nowMs);
    changed |= updateCredits(t);
  }
  const bool blink = (nowMs / CURSOR_BLINK_MS) & 1;
  const bool creditsBlink = blink && !creditsDone_ && due(nowMs, showStart_ + CREDITS_START_MS);
  changed |= blink != cursor_ || creditsBlink != creditsCursor_;
  cursor_ = blink;
  creditsCursor_ = creditsBlink;
  return changed;
}

// Type whatever the clock says should be on screen by now.
bool StillAlivePlayer::updateLyrics(uint32_t t, uint32_t nowMs) {
  bool changed = false;
  while (step_ < LYRIC_COUNT && t >= LYRICS[step_].startMs) {
    const LyricStep &s = LYRICS[step_];
    if (!stepStarted_) {
      stepStarted_ = true;
      if (s.flags & STEP_CLEAR)
        lyrics_.clear();
      if (s.art != ART_KEEP)
        showArt(s.art);
      changed = true;
    }
    const size_t len = strlen(s.text);
    const uint32_t elapsed = t - s.startMs;
    const size_t want = (s.durMs == 0 || elapsed >= s.durMs) ? len : len * elapsed / s.durMs;
    while (charIdx_ < want) {
      lyrics_.put(s.text[charIdx_++]);
      changed = true;
    }
    if (charIdx_ < len)
      break;  // still typing this step
    if (s.flags & STEP_NEWLINE)
      lyrics_.put('\n');
    step_++;
    charIdx_ = 0;
    stepStarted_ = false;
    changed = true;
    if (step_ == LYRIC_COUNT) {
      done_ = true;
      doneAt_ = nowMs;
    }
  }
  return changed;
}

// Each credits line takes CREDIT_CHAR_US per character (an empty line counts as
// one), typed evenly; then the next line starts on a fresh bottom row.
bool StillAlivePlayer::updateCredits(uint32_t t) {
  if (creditsDone_ || t < CREDITS_START_MS)
    return false;
  bool changed = false;
  while (true) {
    const char *line = CREDITS[creditIdx_];
    const size_t len = strlen(line);
    if (!creditLineOpen_) {
      creditLineOpen_ = true;
      credits_.put('\n');
      changed = true;
    }
    const uint32_t dur = (uint32_t) ((uint64_t) CREDIT_CHAR_US * (len ? len : 1) / 1000);
    const uint32_t elapsed = t - creditLineAt_;
    const size_t want = elapsed >= dur ? len : len * elapsed / dur;
    while (creditChar_ < want) {
      credits_.put(line[creditChar_++]);
      changed = true;
    }
    if (elapsed < dur)
      break;
    creditLineAt_ += dur;
    creditChar_ = 0;
    creditLineOpen_ = false;
    if (++creditIdx_ == CREDIT_COUNT) {
      creditIdx_ = 0;
      if (!CREDITS_LOOP) {
        creditsDone_ = true;
        break;
      }
    }
  }
  return changed;
}

void StillAlivePlayer::draw(EL512Panel &panel) const {
  lyrics_.draw(panel, cursor_);
  credits_.draw(panel, creditsCursor_);
  art_.draw(panel, false, false);  // no frame around the picture, as in the game
}

}  // namespace el512sa