#ifndef FUSED_EVENTS_H
#define FUSED_EVENTS_H

#include <stdint.h>
#include <stdbool.h>
#include <sys/epoll.h>
#include "ws_client.h"
#include "queue.h"
#include "executor.h"

#define MAX_EPOLL_FDS 64

/* Identifies the type of a tracked file descriptor */
typedef enum {
    FD_TYPE_WS,             /* WebSocket connection */
    FD_TYPE_TIMER,          /* timerfd */
    FD_TYPE_EVENT,          /* eventfd for queue wakeup */
} fd_type_t;

/* A file descriptor tracked by the epoll event loop */
typedef struct {
    int        fd;            /* the file descriptor */
    fd_type_t  type;          /* type identifier for dispatch */
    uint32_t   ws_conn_idx;   /* WebSocket connection index (if type is FD_TYPE_WS) */
    void      *user_data;     /* optional user data pointer */
} tracked_fd_t;

/* Epoll-based event set for a group of file descriptors */
typedef struct {
    int                epoll_fd;                    /* epoll instance fd */
    struct epoll_event events[MAX_EPOLL_FDS];       /* re-usable event array */
    tracked_fd_t       fds[MAX_EPOLL_FDS];          /* tracked fd descriptors */
    uint32_t           fd_count;                    /* number of tracked fds */
} epoll_set_t;

/* Top-level event loop state, split into hot (ws) and cold (timer/http) paths */
typedef struct {
    epoll_set_t hot_epoll;         /* hot epoll set for latency-sensitive ws events */
    epoll_set_t cold_epoll;        /* cold epoll set for timer/http events */
    ws_client_t *ws_client;        /* WebSocket client instance */
    spsc_queue_t      *signal_queue;    /* signal queue for emitting opportunities */
    executor_shared_t *executor_shared;  /* shared executor state (in_flight + queue lock) */
    int                timer_fd;        /* timerfd for periodic tasks */
    int           wakeup_fd;       /* eventfd for waking the cold loop */
    uint64_t      next_ping_ms;    /* next scheduled WebSocket ping timestamp */
    bool          running;         /* false signals event loops to exit */
} event_loops_t;

/* Initialise both epoll sets, create sockets, and start event loops */
int  event_loops_init(event_loops_t *loops, ws_client_t *ws_client,
                      spsc_queue_t *signal_queue, const config_t *cfg, int wakeup_fd);
/* Tear down event loops, close all sockets */
void event_loops_destroy(event_loops_t *loops);
/* Register a file descriptor with an epoll set */
int  event_loops_add_fd(epoll_set_t *set, int fd, fd_type_t type,
                        uint32_t ws_idx, void *user_data, uint32_t events);
/* Remove a file descriptor from an epoll set */
void event_loops_remove_fd(epoll_set_t *set, int fd);
/* Hot event loop thread: handles WebSocket I/O */
void *event_hot_thread(void *arg);
/* Cold event loop thread (legacy, single-threaded) */
void *event_cold_thread(void *arg);
/* Per-executor-thread entry point: creates its own executor_thread_t and polls signal queue */
void *event_executor_thread(void *arg);

#endif