#pragma once
#include <stdint.h>

// MAX6675 fault sentinels
// 0.0 °C  → VCC or GND missing (no power)
// 1023.75 °C → thermocouple open / disconnected
static constexpr float TEMP_MIN_VALID = 0.5f;
static constexpr float TEMP_MAX_VALID = 1000.0f;

inline bool isValidTemp(float t) {
    return t >= TEMP_MIN_VALID && t <= TEMP_MAX_VALID;
}

// Fixed-capacity rolling average — no heap allocation
template<uint8_t N>
class RollingAverage {
    static_assert(N > 0, "RollingAverage size must be > 0");
public:
    void push(float v) {
        buf[idx] = v;
        idx = (idx + 1) % N;
        if (count < N) ++count;
    }

    float value() const {
        if (count == 0) return 0.0f;
        float sum = 0.0f;
        for (uint8_t i = 0; i < count; ++i) sum += buf[i];
        return sum / count;
    }

    uint8_t size()  const { return count; }
    bool    empty() const { return count == 0; }
    void    reset()       { idx = 0; count = 0; for (uint8_t i = 0; i < N; ++i) buf[i] = 0.0f; }

private:
    float   buf[N] = {};
    uint8_t idx    = 0;
    uint8_t count  = 0;
};