#include "mlibc/tcb.hpp"
#include <abi-bits/errno.h>
#include <bits/ensure.h>
#include <bits/syscall.h>
#include <mlibc/all-sysdeps.hpp>
#include <string.h>

#include <mlibc/sysdeps.hpp>

#include "syscall.h"
#define SYS_EXIT 60
#define SYS_READ 0
#define SYS_WRITE 1

#define STUB()                                                                                     \
    ({                                                                                             \
        __ensure(!"STUB function was called");                                                     \
        __builtin_unreachable();                                                                   \
    })

namespace mlibc {

void sys_libc_log(const char *msg) {
    ssize_t dummy;
    sys_write(1, msg, strlen(msg), &dummy);
}

void sys_libc_panic() {
    sys_libc_log("!!! mlibc panic !!!\n");
    sys_exit(1);
    __builtin_trap();
}

int sys_isatty(int fd) {
    return 0; // everything is a tty for now
}

int sys_write(int fd, const void *buf, size_t size, ssize_t *ret) {
    long r = syscall(SYS_WRITE, fd, (uintptr_t)buf, size);
    if (ret) *ret = r;
    return r >= 0 ? 0 : -r;
}

int sys_read(int fd, void *buf, size_t size, ssize_t *ret) {
    long r = syscall(SYS_READ, fd, (uintptr_t)buf, size);
    if (ret) *ret = r;
    return r >= 0 ? 0 : -r;
}

void sys_exit(int status) {
    syscall(SYS_EXIT, status);
    __builtin_unreachable();
}

int sys_close(int fd) {
    long r = syscall(SYS_CLOSE, fd);
    return r >= 0 ? 0 : -r;
}

// ─────────────────────────────────────────────────────────────────────────────
// Memory
// ─────────────────────────────────────────────────────────────────────────────

int sys_anon_allocate(size_t size, void **pointer) {
    long r = syscall(SYS_MMAP, 0, size,
                     PROT_READ | PROT_WRITE,
                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

    *pointer = (void*)r;
    return (r == (long)MAP_FAILED) ? ENOMEM : 0;
}

int sys_anon_free(void *ptr, size_t size) {
    if (!ptr || size == 0) return 0;
    long r = syscall(SYS_MUNMAP, (uintptr_t)ptr, size);
    return r == 0 ? 0 : ENOMEM;
}

int sys_vm_map(void *hint, size_t size, int prot, int flags,
                int fd, off_t offset, void **out) {
    long r = syscall(SYS_MMAP,
                     (uintptr_t)hint,
                     size,
                     prot,
                     flags,
                     fd,
                     offset);

    if (r < 0)
        return -r;

    *out = (void *)r;
    return 0;
}

int sys_vm_unmap(void *addr, size_t size) {
    long r = syscall(SYS_MUNMAP, (uintptr_t)addr, size);
    return (r == 0) ? 0 : -r;
}

// ─────────────────────────────────────────────────────────────────────────────
// Others
// ─────────────────────────────────────────────────────────────────────────────

int sys_seek(int, off_t, int, off_t *) {
    return ESPIPE; // no real files yet
}

int sys_tcb_set(void *pointer) {
    sys_libc_log("[sysdeps] sys_tcb_set called");
    
    long ret = syscall(SYS_TCB_SET, (uintptr_t)pointer);
    if (ret < 0)
        return -ret;
    
    sys_libc_log("[sysdeps] TCB set via syscall.\n");
    return 0;
}

int sys_open(const char *path, int flags, unsigned int mode, int *fd) {
    (void)flags; (void)mode;
    long r = syscall(SYS_OPEN, (uintptr_t)path);
    if (r < 0) return -r;
    *fd = (int)r;
    return 0;
}

// Futexes
int sys_futex_wait(int *ptr, int expected, const timespec *time) {
    long r = syscall(SYS_FUTEX, ptr, 0, expected, time);
    return (r < 0) ? -r : 0;
}

int sys_futex_wake(int *ptr) {
    long r = syscall(SYS_FUTEX, ptr, 1, 1, 0);
    return (r < 0) ? -r : 0;
}

int sys_clock_get(int, time_t *, long *) { return ENOSYS; }

} // namespace mlibc