#ifndef CORE_USB_UTILS_GE_QUEUE
#define CORE_USB_UTILS_GE_QUEUE

#include <stdbool.h>
#include <stdint.h>

/**
 * Generic Queue.
 */
typedef struct {
    uint32_t writeIdx;  ///< Next block to write
    uint32_t readIdx;   ///< Next block to read
    uint32_t length;    ///< Size of circular buffer
    uint32_t elemSize;  ///< Element size
    uint8_t elements[]; ///< Array of packets
} Queue;

/**
 * Create Queue.
 * @param length length of circular buffer
 * @param elemSize element size
 * @param mem backing memory, should be DWORD-aligned!
 * @return pointer to Queue instance OR NULL on failure
 */
Queue *q_create(uint32_t length, uint32_t elemSize, uint8_t *mem);

/**
 * Create Queue based on storage type.
 */
#define Q_CREATE_T(length, T, mem) q_create((length), sizeof(T), (mem))

/**
 * @brief Calculate required memory size for allocating a new queue fitting
 * length elements of type T.
 */
#define Q_REQ_MEM_SIZE_T(length, T) (sizeof(Queue) + (length * sizeof(T)))

/**
 * Clear circular buffer.
 * @param q pointer to Queue
 */
void q_clear(Queue *q);

/**
 * Get number of available elements.
 * @param q pointer to Queue
 * @return number of available elements
 */
uint32_t q_avail(const Queue *q);

/**
 * Push element to the Queue.
 * @param q pointer to Queue
 * @param raw pointer to raw packet
 * @return true on success, false on failure (e.g.: queue full)
 */
bool q_push(Queue *q, const void *src);

/**
 * Get top element.
 * @param q pointer to Queue
 * @return top element (COPY, NOT POINTER!)
 */
void q_top(Queue *q, void *dest);

/**
 * Pop top element.
 * @param q pointer to Queue
 */
void q_pop(Queue *q);

#endif /* CORE_USB_UTILS_GE_QUEUE */