// ResetSequencer: GPIO-driven peripheral reset with calibrated timing.

#pragma once

#include <cstdint>

#include <map>

#include <string>

// Timing configuration for one peripheral model's reset sequence.

// powerdown_us: microseconds to hold the reset line asserted (minimum assert time).

//   Loaded from config key "reset_hold_us".

// powerup_us: microseconds to wait after deassert for DEVICE_READY (startup window).

//   Loaded from config key "boot_wait_us".

struct ResetConfig {

  uint32_t powerdown_us; // hold time while reset is asserted; from "reset_hold_us"

  uint32_t powerup_us;   // maximum startup window after deassert; from "boot_wait_us"

};

// Validates that the timing values meet the hardware minimums.

// Parameters:

//   cfg - timing parameters to check

// Returns: true if powerdown_us >= 50 and powerup_us >= 100

bool validateConfig(const ResetConfig& cfg);

// Drives the GPIO reset sequence for a single peripheral.

class ResetSequencer {

public:

  // Parameters:

  //   gpioResetPin - GPIO pin number used to assert/deassert hardware reset

  //   gpioReadyPin - GPIO pin number connected to the peripheral DEVICE_READY output

  ResetSequencer(int gpioResetPin, int gpioReadyPin);

  // Loads timing parameters from the provided config map.

  // Expected keys: "reset_hold_us" and "boot_wait_us".

  // Parameters:

  //   params - key-value map of timing parameters for this peripheral model

  // Returns: true if both keys are present and pass validateConfig()

  bool configure(const std::map<std::string, uint32_t>& params);

  // Executes the full reset sequence using the loaded timing configuration.

  // Sequence: assert reset -> hold powerdown_us -> deassert -> poll DEVICE_READY

  // Parameters: none

  // Returns: true if DEVICE_READY goes high within powerup_us; false on timeout

  bool reset();

  // Samples the current state of the DEVICE_READY pin.

  // Parameters: none

  // Returns: true if the peripheral is currently signalling ready

  bool isReady() const;

private:

  int          gpioResetPin_; // GPIO used to drive the reset line

  int          gpioReadyPin_; // GPIO used to read DEVICE_READY

  ResetConfig  cfg_{};        // loaded timing parameters

  // Parameters: none

  // Returns: void

  void assertReset() const;

  // Parameters: none

  // Returns: void

  void deassertReset() const;

  // Polls readyPin for up to timeoutUs microseconds.

  // Parameters:

  //   timeoutUs - maximum poll duration in microseconds

  // Returns: true if DEVICE_READY observed high within the window

  bool pollReady(uint32_t timeoutUs) const;

};