#ifndef TRANS_H
#define TRANS_H

#include <ucontext.h>

#include <stdbool.h>
#include <stdio.h>

struct task
{
    bool pending;
    char stack[SIGSTKSZ];
    ucontext_t context;
    ucontext_t main_context;
};

typedef void (*task_func) (struct task *t);

static inline struct task *
task_new (task_func func)
{
    struct task *t;

    t = calloc (sizeof (struct task), 1);

    getcontext (&t->context);

    t->context.uc_link = 0;
    t->context.uc_stack.ss_sp = t->stack;
    t->context.uc_stack.ss_size = sizeof (t->stack);
    t->context.uc_stack.ss_flags = 0;

    makecontext (&t->context, (void (*)()) func, 1, t);

    swapcontext (&t->main_context, &t->context);

    return t;
}

static inline void
task_free (struct task *t)
{
    free (t);
}

static inline void
task_yield (struct task *t)
{
    t->pending = true;
    swapcontext (&t->context, &t->main_context);
}

static inline void
task_complete (struct task *t)
{
    t->pending = false;
    swapcontext (&t->context, &t->main_context);
}

static inline void
task_handle (struct task *t)
{
    if (t->pending)
        swapcontext (&t->main_context, &t->context);
}

#endif /* TRANS_H */