#include "Measurement.h"
#include "Config.h"
#include <string.h>

bool Measurement::start(float hz, float duty, float tolerance, uint32_t timeMs,
                        uint8_t repeats, uint8_t settleCycles) {
  if (!task_ && xTaskCreate(taskEntry, "optical-rx", 4096, this, 4, &task_) != pdPASS) return false;
  expectedHz_ = static_cast<uint32_t>(hz + 0.5f);
  if (!expectedHz_ || !timeMs || !repeats || repeats > 10 ||
      !makePeriodLimits(expectedHz_, duty, tolerance, receiver_.tickHz(), limits_) ||
      !receiver_.start(expectedHz_)) return false;
  timeMs_ = timeMs; repeats_ = repeats; settleLeft_ = settleCycles;
  stats_.reset(); memset(repeatPeriods_, 0, sizeof(repeatPeriods_));
  measurementStartTick_ = deadlineTick_ = 0; startedMs_ = millis();
  measurementStartMs_ = lastPeriodMs_ = 0;
  currentRepeat_ = 0;
  expectedPeriodMs_ = static_cast<uint32_t>((1000ULL + expectedHz_ - 1U) / expectedHz_);
  if (!expectedPeriodMs_) expectedPeriodMs_ = 1;
  state_ = MeasureState::SETTLING;
  xTaskNotifyGive(task_);
  return true;
}

void Measurement::taskEntry(void *context) {
  static_cast<Measurement *>(context)->taskLoop();
}

void Measurement::taskLoop() {
  for (;;) {
    ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
    while (state_ == MeasureState::SETTLING || state_ == MeasureState::RUNNING) processOnce();
  }
}

void Measurement::fail(FailReason reason) {
  if (stats_.reason == FailReason::NONE) stats_.reason = reason;
  receiver_.stop(); state_ = MeasureState::FAIL;
}

void Measurement::completeWindow() {
  receiver_.stop();
  stats_.droppedItems += receiver_.takeDroppedItems();
  if (receiver_.overflowed()) { fail(FailReason::GLITCH); return; }
  for (uint8_t i = 0; i < repeats_; ++i) if (!repeatPeriods_[i]) {
    fail(FailReason::TOO_FEW_PERIODS); return;
  }
  state_ = MeasureState::PASS;
}

MeasureState Measurement::processOnce() {
  if (state_ != MeasureState::SETTLING && state_ != MeasureState::RUNNING) return state_;
  if (receiver_.overflowed()) { fail(FailReason::GLITCH); return state_; }
  bool receivedPeriod = false;
  for (;;) {
    const size_t periodCount = receiver_.readPeriods(periodBatch_, PERIOD_BATCH_SIZE, pdMS_TO_TICKS(2));
    stats_.droppedItems += receiver_.takeDroppedItems();
    if (!periodCount) break;
    receivedPeriod = true;
    for (size_t periodIndex = 0; periodIndex < periodCount; ++periodIndex) {
      if (state_ != MeasureState::SETTLING && state_ != MeasureState::RUNNING) return state_;
      const PulsePeriod &period = periodBatch_[periodIndex];
      if (state_ == MeasureState::SETTLING) {
        if (settleLeft_) --settleLeft_;
        if (!settleLeft_) {
          measurementStartTick_ = period.startTick + period.periodTicks;
          repeatTicks_ = static_cast<uint64_t>(receiver_.tickHz()) * timeMs_ / 1000ULL;
          deadlineTick_ = measurementStartTick_ + repeatTicks_ * repeats_;
          nextRepeatTick_ = measurementStartTick_ + repeatTicks_;
          stats_.reset(); measurementStartMs_ = lastPeriodMs_ = millis(); state_ = MeasureState::RUNNING;
        }
        continue;
      }
      const uint64_t endTick = period.startTick + period.periodTicks;
      if (period.startTick < measurementStartTick_) continue; // leading incomplete period
      if (endTick > deadlineTick_) { completeWindow(); return state_; } // trailing incomplete period
      while (currentRepeat_ + 1U < repeats_ && period.startTick >= nextRepeatTick_) {
        ++currentRepeat_; nextRepeatTick_ += repeatTicks_;
      }
      ++repeatPeriods_[currentRepeat_];
      const FailReason r = evaluatePeriodFast(period, receiver_.tickHz(), limits_, currentRepeat_ + 1, stats_);
      if (r != FailReason::NONE) { fail(r); return state_; }
    }
  }
  if (receivedPeriod && state_ == MeasureState::RUNNING) lastPeriodMs_ = millis();
  const uint64_t edgeBasedTimeout =
    static_cast<uint64_t>(PWM_SETTLE_CYCLES + NO_SIGNAL_TIMEOUT_PERIODS) * expectedPeriodMs_ + 20;
  const uint64_t rmtBatchTimeout =
    static_cast<uint64_t>(RMT_MIN_RECEIVE_SYMBOLS + NO_SIGNAL_TIMEOUT_PERIODS) * expectedPeriodMs_ + 20;
  const uint64_t settleTimeout = edgeBasedTimeout > rmtBatchTimeout ? edgeBasedTimeout : rmtBatchTimeout;
  if (state_ == MeasureState::SETTLING && millis() - startedMs_ > settleTimeout) fail(FailReason::NO_SIGNAL);
  if (state_ == MeasureState::RUNNING && measurementStartTick_) {
    const uint32_t now = millis();
    const uint32_t totalMs = timeMs_ * repeats_;
    const uint32_t edgeTimeoutMs = expectedPeriodMs_ * NO_SIGNAL_TIMEOUT_PERIODS + 2;
    if (now - measurementStartMs_ < totalMs && now - lastPeriodMs_ > edgeTimeoutMs) {
      fail(FailReason::LOST_EDGE); return state_;
    }
    if (now - measurementStartMs_ > totalMs + expectedPeriodMs_ + 2) completeWindow();
  }
  return state_;
}

MeasureState Measurement::update() { return state_; }

void Measurement::abort() { if (state_ == MeasureState::SETTLING || state_ == MeasureState::RUNNING) fail(FailReason::ABORTED); }