#include "kernel.h"

void zv_kernel_init(
    zv_kernel_t *self,
    zv_process_t *processes,
    zv_pid_t size
) {
    self->processes = processes;
    self->processes_count = size;
    self->last = 0;
    self->interrupts = 0;
    self->mode = ZV_FIRST_MATCH;
    self->lowest_priority = 0;

    for (zv_pid_t count = 0; count < size; ++count) {
        zv_process_t *current = self->processes + count;
        
        current->state = ZV_EMPTY;
        current->worker = (zv_worker_t) NULL;
        current->param = ZV_NULL_PARAM;
        current->priority = 0;
    }
}

zv_pid_t zv_kernel_add_process(
    zv_kernel_t *self,
    zv_worker_t worker,
    zv_universal_t param,
    zv_priority_t priority
) {
    for (zv_pid_t count = 0; count < self->processes_count; ++count) {
        zv_process_t *current = self->processes + count;

        if (current->state != ZV_EMPTY) {
            continue;
        }

        current->worker = worker;
        current->param = param;
        current->priority = priority;
        current->balance = 0;
        current->state = ZV_READY;

        return count;
    }

    return ZV_ERROR_PID;
}

void __zv_kernel_clean_balance(zv_kernel_t *self) {
    for (zv_pid_t count = 0; count < self->processes_count; ++count) {
        zv_process_t *current = self->processes + count;
        current->balance = 0;
    }
}

zv_result_t zv_kernel_trigger_process(zv_kernel_t *self, zv_pid_t target) {
    zv_process_t *current = __zv_kernel_get_process(self, target);
    
    if (current == NULL || current->state == ZV_EMPTY) {
        return ZV_NOT_EXISTS;
    }

    if (current->state != ZV_INTERRUPT_WAITING) {
        return ZV_BAD_STATE;
    }

    ++self->interrupts;
    self->processes->state = ZV_INTERRUPTED;

    return ZV_SUCCESS;
}  

zv_result_t zv_kernel_awake_process(zv_kernel_t *self, zv_pid_t target) {
    zv_process_t *current = __zv_kernel_get_process(self, target);
    
    if (current == NULL || current->state == ZV_EMPTY) {
        return ZV_NOT_EXISTS;
    }
    
    if (current->state != ZV_WAITING) {
        return ZV_BAD_STATE;
    }

    current->state = ZV_READY;
    return ZV_SUCCESS;
}