#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 (!hz || !timeMs || !repeats || repeats > 10 || !receiver_.start(static_cast<uint32_t>(hz))) return false;
  expectedHz_ = hz; expectedDuty_ = duty; tolerance_ = tolerance;
  timeMs_ = timeMs; repeats_ = repeats; settleLeft_ = settleCycles;
  stats_.reset(); memset(repeatPeriods_, 0, sizeof(repeatPeriods_));
  measurementStartTick_ = deadlineTick_ = 0; startedMs_ = millis();
  measurementStartMs_ = lastPeriodMs_ = 0;
  state_ = MeasureState::SETTLING; return true;
}

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

MeasureState Measurement::update() {
  if (state_ != MeasureState::SETTLING && state_ != MeasureState::RUNNING) return state_;
  if (receiver_.overflowed()) { fail(FailReason::GLITCH); return state_; }
  PulsePeriod period;
  while (receiver_.poll(period)) {
    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_;
        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_) break;                     // trailing incomplete period
    uint8_t repeat = static_cast<uint8_t>((period.startTick - measurementStartTick_) / repeatTicks_);
    if (repeat >= repeats_) repeat = repeats_ - 1;
    ++repeatPeriods_[repeat];
    lastPeriodMs_ = millis();
    const FailReason r = evaluatePeriod(period, receiver_.tickHz(), expectedHz_, expectedDuty_,
                                        tolerance_, repeat + 1, stats_);
    if (r != FailReason::NONE) { fail(r); return state_; }
  }
  const uint64_t expectedPeriodMs = static_cast<uint64_t>(1000.0f / expectedHz_) + 1;
  const uint64_t settleTimeout = (static_cast<uint64_t>(PWM_SETTLE_CYCLES + NO_SIGNAL_TIMEOUT_PERIODS) *
                                  expectedPeriodMs) + 20;
  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 = static_cast<uint32_t>(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) {
      for (uint8_t i = 0; i < repeats_; ++i) if (!repeatPeriods_[i]) {
        fail(FailReason::TOO_FEW_PERIODS); return state_;
      }
      receiver_.stop(); state_ = MeasureState::PASS;
    }
  }
  return state_;
}

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