/**
 * @file pad.h
 * @brief Simple wrapper for the HID Npad API.
 * @author fincs
 * @copyright libnx Authors
 */
#pragma once
#include "../types.h"
#include "../services/hid.h"

/// Mask including all existing controller IDs.
#define PAD_ANY_ID_MASK 0x1000100FFUL

/// Pad state object.
typedef struct {
    u8 id_mask;
    u8 active_id_mask;
    bool read_handheld;
    bool active_handheld;
    u32 style_set;
    u32 attributes;
    u64 buttons_cur;
    u64 buttons_old;
    HidAnalogStickState sticks[2];
    u32 gc_triggers[2];
} PadState;

/// Pad button repeater state object.
typedef struct {
    u64 button_mask;
    s32 counter;
    u16 delay;
    u16 repeat;
} PadRepeater;

/**
 * @brief Configures the input layout supported by the application.
 * @param[in] max_players The maximum supported number of players (1 to 8).
 * @param[in] style_set Bitfield of supported controller styles (see \ref HidNpadStyleTag).
 */
void padConfigureInput(u32 max_players, u32 style_set);

/**
 * @brief Initializes a \ref PadState object to read input from one or more controller input sources.
 * @param[in] _pad Pointer to \ref PadState.
 * @remarks This is a variadic macro, pass the \ref HidNpadIdType value of each controller to add to the set.
 */
#define padInitialize(_pad, ...) ({ \
    const HidNpadIdType _pad_ids[] = { __VA_ARGS__ }; \
    u64 _pad_mask = 0; \
    for (unsigned _pad_i = 0; _pad_i < (sizeof(_pad_ids)/sizeof(_pad_ids[0])); ++_pad_i) \
        _pad_mask |= 1UL << (_pad_ids[_pad_i]); \
    padInitializeWithMask((_pad), _pad_mask); \
})

/**
 * @brief Same as \ref padInitialize, but taking a bitfield of controller IDs directly.
 * @param[in] pad Pointer to \ref PadState.
 * @param[in] mask Bitfield of controller IDs (each bit's position indicates a different \ref HidNpadIdType value).
 */
void padInitializeWithMask(PadState* pad, u64 mask);

/**
 * @brief Same as \ref padInitialize, but including every single controller input source.
 * @param[in] pad Pointer to \ref PadState.
 * @remark Use this function if you want to accept input from any controller.
 */
NX_INLINE void padInitializeAny(PadState* pad) {
    padInitializeWithMask(pad, PAD_ANY_ID_MASK);
}

/**
 * @brief Same as \ref padInitialize, but including \ref HidNpadIdType_No1 and \ref HidNpadIdType_Handheld.
 * @param[in] pad Pointer to \ref PadState.
 * @remark Use this function if you just want to accept input for a single-player application.
 */
NX_INLINE void padInitializeDefault(PadState* pad) {
    padInitialize(pad, HidNpadIdType_No1, HidNpadIdType_Handheld);
}

/**
 * @brief Updates pad state by reading from the controller input sources specified during initialization.
 * @param[in] pad Pointer to \ref PadState.
 */
void padUpdate(PadState* pad);

/**
 * @brief Retrieves whether \ref HidNpadIdType_Handheld is an active input source (i.e. it was possible to read from it).
 * @param[in] pad Pointer to \ref PadState.
 * @return Boolean value.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR bool padIsHandheld(const PadState* pad) {
    return pad->active_handheld;
}

/**
 * @brief Retrieves whether the specified controller is an active input source (i.e. it was possible to read from it).
 * @param[in] pad Pointer to \ref PadState.
 * @param[in] id ID of the controller input source (see \ref HidNpadIdType)
 * @return Boolean value.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR bool padIsNpadActive(const PadState* pad, HidNpadIdType id) {
    if (id <= HidNpadIdType_No8)
        return pad->active_id_mask & BIT(id);
    else if (id == HidNpadIdType_Handheld)
        return pad->active_handheld;
    else
        return false;
}

/**
 * @brief Retrieves the set of input styles supported by the selected controller input sources.
 * @param[in] pad Pointer to \ref PadState.
 * @return Bitfield of \ref HidNpadStyleTag.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR u32 padGetStyleSet(const PadState* pad) {
    return pad->style_set;
}

/**
 * @brief Retrieves the set of attributes reported by the system for the selected controller input sources.
 * @param[in] pad Pointer to \ref PadState.
 * @return Bitfield of \ref HidNpadAttribute.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR u32 padGetAttributes(const PadState* pad) {
    return pad->attributes;
}

/**
 * @brief Retrieves whether any of the selected controller input sources is connected.
 * @param[in] pad Pointer to \ref PadState.
 * @return Boolean value.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR bool padIsConnected(const PadState* pad) {
    return pad->attributes & HidNpadAttribute_IsConnected;
}

/**
 * @brief Retrieves the current set of pressed buttons across all selected controller input sources.
 * @param[in] pad Pointer to \ref PadState.
 * @return Bitfield of \ref HidNpadButton.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR u64 padGetButtons(const PadState* pad) {
    return pad->buttons_cur;
}

/**
 * @brief Retrieves the set of buttons that are newly pressed.
 * @param[in] pad Pointer to \ref PadState.
 * @return Bitfield of \ref HidNpadButton.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR u64 padGetButtonsDown(const PadState* pad) {
    return ~pad->buttons_old & pad->buttons_cur;
}

/**
 * @brief Retrieves the set of buttons that are newly released.
 * @param[in] pad Pointer to \ref PadState.
 * @return Bitfield of \ref HidNpadButton.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR u64 padGetButtonsUp(const PadState* pad) {
    return pad->buttons_old & ~pad->buttons_cur;
}

/**
 * @brief Retrieves the position of an analog stick in a controller.
 * @param[in] pad Pointer to \ref PadState.
 * @param[in] i ID of the analog stick to read (0=left, 1=right).
 * @return \ref HidAnalogStickState.
 * @remark \ref padUpdate must have been previously called.
 */
NX_CONSTEXPR HidAnalogStickState padGetStickPos(const PadState* pad, unsigned i) {
    return pad->sticks[i];
}

/**
 * @brief Retrieves the position of an analog trigger in a GameCube controller.
 * @param[in] pad Pointer to \ref PadState.
 * @param[in] i ID of the analog trigger to read (0=left, 1=right).
 * @return Analog trigger position (range is 0 to 0x7fff).
 * @remark \ref padUpdate must have been previously called.
 * @remark \ref HidNpadStyleTag_NpadGc must have been previously configured as a supported style in \ref padConfigureInput for GC trigger data to be readable.
 */
NX_CONSTEXPR u32 padGetGcTriggerPos(const PadState* pad, unsigned i) {
    return pad->gc_triggers[i];
}

/**
 * @brief Initializes a \ref PadRepeater object with the specified settings.
 * @param[in] r Pointer to \ref PadRepeater.
 * @param[in] delay Number of input updates between button presses being first detected and them being considered for repeat.
 * @param[in] repeat Number of input updates between autogenerated repeat button presses.
 */
NX_CONSTEXPR void padRepeaterInitialize(PadRepeater* r, u16 delay, u16 repeat) {
    r->button_mask = 0;
    r->counter = 0;
    r->delay = delay;
    r->repeat = repeat;
}

/**
 * @brief Updates pad repeat state.
 * @param[in] r Pointer to \ref PadRepeater.
 * @param[in] button_mask Bitfield of currently pressed \ref HidNpadButton that will be considered for repeat.
 */
void padRepeaterUpdate(PadRepeater* r, u64 button_mask);

/**
 * @brief Retrieves the set of buttons that are being repeated according to the parameters specified in \ref padRepeaterInitialize.
 * @param[in] r Pointer to \ref PadRepeater.
 * @return Bitfield of \ref HidNpadButton.
 * @remark It is suggested to bitwise-OR the return value of this function with that of \ref padGetButtonsDown.
 */
NX_CONSTEXPR u64 padRepeaterGetButtons(const PadRepeater* r) {
    return r->counter == 0 ? r->button_mask : 0;
}