//============================================================================
//
//   SSSS    tt          lll  lll
//  SS  SS   tt           ll   ll
//  SS     tttttt  eeee   ll   ll   aaaa
//   SSSS    tt   ee  ee  ll   ll      aa
//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
//  SS  SS   tt   ee      ll   ll  aa  aa
//   SSSS     ttt  eeeee llll llll  aaaaa
//
// Copyright (c) 1995-2020 by Bradford W. Mott, Stephen Anthony
// and the Stella Team
//
// See the file "License.txt" for information on usage and redistribution of
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
//============================================================================

#ifndef CONTROLLER_HXX
#define CONTROLLER_HXX

class Controller;
class ControllerLowLevel;
class Event;
class System;

#include <functional>

#include "Serializable.hxx"
#include "bspf.hxx"

/**
  A controller is a device that plugs into either the left or right
  controller jack of the Video Computer System (VCS).  The pins of
  the controller jacks are mapped as follows:

                           -------------
                           \ 1 2 3 4 5 /
                            \ 6 7 8 9 /
                             ---------

            Left Controller             Right Controller

    pin 1   D4  PIA SWCHA               D0  PIA SWCHA
    pin 2   D5  PIA SWCHA               D1  PIA SWCHA
    pin 3   D6  PIA SWCHA               D2  PIA SWCHA
    pin 4   D7  PIA SWCHA               D3  PIA SWCHA
    pin 5   D7  TIA INPT1 (Dumped)      D7  TIA INPT3 (Dumped)
    pin 6   D7  TIA INPT4 (Latched)     D7  TIA INPT5 (Latched)
    pin 7   +5                          +5
    pin 8   GND                         GND
    pin 9   D7  TIA INPT0 (Dumped)      D7  TIA INPT2 (Dumped)

  Each of the pins connected to the PIA can be configured as an
  input or output pin.  The "dumped" TIA pins are used to charge
  a capacitor.  A potentiometer is sometimes connected to these
  pins for analog input.

  This is a base class for all controllers.  It provides a view
  of the controller from the perspective of the controller's jack.

  @author  Bradford W. Mott
*/
class Controller : public Serializable
{
  /**
    Various classes that need special access to the underlying controller state
  */
  friend class M6532;     // FIXME - only needs two methods from this class
  friend class CompuMate; // FIXME - should go through CMControl instead
  friend class ControllerLowLevel;

  public:
    /**
      Enumeration of the controller jacks
    */
    enum class Jack { Left = 0, Right = 1 };

    /**
      Enumeration of the digital pins of a controller port
    */
    enum class DigitalPin { One, Two, Three, Four, Six };

    /**
      Enumeration of the analog pins of a controller port
    */
    enum class AnalogPin { Five, Nine };

    /**
      Enumeration of the controller types
    */
    enum class Type
    {
      Unknown,
      AmigaMouse, AtariMouse, AtariVox, BoosterGrip, CompuMate,
      Driving, Genesis, Joystick, Keyboard, KidVid, MindLink,
      Paddles, PaddlesIAxis, PaddlesIAxDr, SaveKey, TrakBall,
      Lightgun,
      LastType
    };

    /**
      Callback type for analog pin updates
    */
    using onAnalogPinUpdateCallback = std::function<void(AnalogPin)>;

    /**
      Callback type for general controller messages
    */
    using onMessageCallback = std::function<void(const string&)>;

  public:
    /**
      Create a new controller plugged into the specified jack

      @param jack   The jack the controller is plugged into
      @param event  The event object to use for events
      @param system The system using this controller
      @param type   The type for this controller
    */
    Controller(Jack jack, const Event& event, const System& system,
               Type type);
    virtual ~Controller() = default;

    /**
      Returns the jack that this controller is plugged into.
    */
    Jack jack() const { return myJack; }

    /**
      Returns the type of this controller.
    */
    Type type() const { return myType; }

    /**
      Read the entire state of all digital pins for this controller.
      Note that this method must use the lower 4 bits, and zero the upper bits.

      @return The state of all digital pins
    */
    virtual uInt8 read();

    /**
      Read the value of the specified digital pin for this controller.

      @param pin The pin of the controller jack to read
      @return The state of the pin
    */
    virtual bool read(DigitalPin pin);

    /**
      Read the resistance at the specified analog pin for this controller.
      The returned value is the resistance measured in ohms.

      @param pin The pin of the controller jack to read
      @return The resistance at the specified pin
    */
    virtual Int32 read(AnalogPin pin);

    /**
      Write the given value to the specified digital pin for this
      controller.  Writing is only allowed to the pins associated
      with the PIA.  Therefore you cannot write to pin six.

      @param pin The pin of the controller jack to write to
      @param value The value to write to the pin
    */
    virtual void write(DigitalPin pin, bool value) { }

    /**
      Called after *all* digital pins have been written on Port A.
      Most controllers don't do anything in this case.

      @param value  The entire contents of the SWCHA register
    */
    virtual void controlWrite(uInt8 value) { }

    /**
      Update the entire digital and analog pin state according to the
      events currently set.
    */
    virtual void update() = 0;

    /**
      Returns the name of this controller.
    */
    virtual string name() const = 0;

    /**
      Answers whether the controller is intrinsically an analog controller.
      Specific controllers should override and implement this method.
    */
    virtual bool isAnalog() const { return false; }

    /**
      Notification method invoked by the system after its reset method has
      been called.  It may be necessary to override this method for
      controllers that need to know a reset has occurred.
    */
    virtual void reset() { }

    /**
      Notification method invoked by the system indicating that the
      console is about to be destroyed.  It may be necessary to override
      this method for controllers that need cleanup before exiting.
    */
    virtual void close() { }

    /**
      Determines how this controller will treat values received from the
      X/Y axis and left/right buttons of the mouse.  Since not all controllers
      use the mouse the same way (or at all), it's up to the specific class to
      decide how to use this data.

      In the current implementation, the left button is tied to the X axis,
      and the right one tied to the Y axis.

      @param xtype  The controller to use for x-axis data
      @param xid    The controller ID to use for x-axis data (-1 for no id)
      @param ytype  The controller to use for y-axis data
      @param yid    The controller ID to use for y-axis data (-1 for no id)

      @return  Whether the controller supports using the mouse
    */
    virtual bool setMouseControl(
      Controller::Type xtype, int xid, Controller::Type ytype, int yid)
    { return false; }

    /**
      Returns more detailed information about this controller.
    */
    virtual string about(bool swappedPorts) const
    {
      return name() + " in " + (((myJack == Jack::Left) ^ swappedPorts) ?
          "left port" : "right port");
    }

    /**
      Saves the current state of this controller to the given Serializer.

      @param out The serializer device to save to.
      @return The result of the save.  True on success, false on failure.
    */
    bool save(Serializer& out) const override;

    /**
      Loads the current state of this controller from the given Serializer.

      @param in The serializer device to load from.
      @return The result of the load.  True on success, false on failure.
    */
    bool load(Serializer& in) override;

    /**
      Inject a callback to be notified on analog pin updates.
    */
    void setOnAnalogPinUpdateCallback(const onAnalogPinUpdateCallback& callback) {
      myOnAnalogPinUpdateCallback = callback;
    }

    /**
      Returns the display name of the given controller type
    */
    static string getName(const Type type);

    /**
      Returns the property name of the given controller type
    */
    static string getPropName(const Type type);

    /**
      Returns the controller type of the given property name
    */
    static Type getType(const string& propName);

  public:
    /// Constant which represents maximum resistance for analog pins
    static constexpr Int32 MAX_RESISTANCE = 0x7FFFFFFF;

    /// Constant which represents minimum resistance for analog pins
    static constexpr Int32 MIN_RESISTANCE = 0x00000000;

  protected:
    /**
      Derived classes *must* use these accessor/mutator methods.
      The read/write methods above are meant to be used at a higher level.
    */
    inline bool setPin(DigitalPin pin, bool value) {
      return myDigitalPinState[static_cast<int>(pin)] = value;
    }
    inline bool getPin(DigitalPin pin) const {
      return myDigitalPinState[static_cast<int>(pin)];
    }
    inline void setPin(AnalogPin pin, Int32 value) {
      myAnalogPinValue[static_cast<int>(pin)] = value;
      if(myOnAnalogPinUpdateCallback)
        myOnAnalogPinUpdateCallback(pin);
    }
    inline Int32 getPin(AnalogPin pin) const {
      return myAnalogPinValue[static_cast<int>(pin)];
    }
    inline void resetDigitalPins() {
      setPin(DigitalPin::One,   true);
      setPin(DigitalPin::Two,   true);
      setPin(DigitalPin::Three, true);
      setPin(DigitalPin::Four,  true);
      setPin(DigitalPin::Six,   true);
    }
    inline void resetAnalogPins() {
      setPin(AnalogPin::Five, MAX_RESISTANCE);
      setPin(AnalogPin::Nine, MAX_RESISTANCE);
    }

  protected:
    /// Specifies which jack the controller is plugged in
    const Jack myJack;

    /// Reference to the event object this controller uses
    const Event& myEvent;

    /// Pointer to the System object (used for timing purposes)
    const System& mySystem;

    /// Specifies which type of controller this is (defined by child classes)
    const Type myType{Type::Unknown};

    /// The callback that is dispatched whenver an analog pin has changed
    onAnalogPinUpdateCallback myOnAnalogPinUpdateCallback{nullptr};

  private:
    /// The boolean value on each digital pin
    std::array<bool, 5> myDigitalPinState{true, true, true, true, true};

    /// The analog value on each analog pin
    std::array<Int32, 2> myAnalogPinValue{MAX_RESISTANCE, MAX_RESISTANCE};

  private:
    // Following constructors and assignment operators not supported
    Controller() = delete;
    Controller(const Controller&) = delete;
    Controller(Controller&&) = delete;
    Controller& operator=(const Controller&) = delete;
    Controller& operator=(Controller&&) = delete;
};

#endif
