#ifndef __DISK_IOURING_H__
#define __DISK_IOURING_H__

#include <liburing.h>
#include <pthread.h>
#include <stdint.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/uio.h>
#include <unistd.h>

typedef enum { TASK_READ, TASK_WRITE } task_op_t;

typedef struct task {
    task_op_t op;
    int fd;
    off_t off;

    int res;
    _Atomic int done;

    struct iovec *iovs;
    int iovcnt;

    struct task *next;
} task_t;

typedef struct {
    _Atomic(task_t *) head;
} destroy_queue_t;

typedef struct {
    task_t **slots;
    uint32_t cap;
    _Atomic uint32_t head;
    _Atomic uint32_t tail;
    _Atomic uint32_t size;
} spsc_queue_t;

struct iouring_ctx_s;
typedef struct iouring_ctx_s iouring_ctx_t;

typedef struct {
    struct io_uring ring;
    pthread_t th;
    int event_fd;
    _Atomic int in_flight;
    int max_in_flight;
    int worker_id;
    spsc_queue_t submit_q;
    iouring_ctx_t *parent;
} iouring_worker_t;

struct iouring_ctx_s {
    iouring_worker_t *workers;
    int worker_nr;
    unsigned entries_per_worker;

    _Atomic int stop;
    _Atomic uint32_t rr_next;

    destroy_queue_t destroy_queue;
};

void task_init(task_t *t);
void task_finish(task_t *t, int res);
int task_wait(task_t *t);
void task_destroy(task_t *t);

int iouring_init(iouring_ctx_t *ctx, unsigned entries);
void iouring_shutdown(iouring_ctx_t *ctx);

task_t *submit_write(iouring_ctx_t *ctx, int fd, void **bufs, size_t *lens, int count, off_t off);
int uring_task_complete(iouring_ctx_t *ctx);
void cleanup_finished_iouring_tasks(iouring_ctx_t *ctx);

extern iouring_ctx_t global_uring_ctx;

#endif