import time
from vrtManager.connection import wvmConnect
from vrtManager.util import get_xml_path


def cpu_version(doc):
    for info in doc.xpath('/sysinfo/processor/entry'):
        elem = info.xpath('@name')[0]
        if elem == 'version':
            return info.text
    return 'Unknown'


class wvmHostDetails(wvmConnect):
    def get_memory_usage(self):
        """
        Function return memory usage on node.
        """
        all_mem = self.wvm.getInfo()[1] * 1048576
        freemem = self.wvm.getMemoryStats(-1, 0)
        if isinstance(freemem, dict):
            free = (freemem['buffers'] +
                    freemem['free'] +
                    freemem['cached']) * 1024
            percent = abs(100 - ((free * 100) // all_mem))
            usage = (all_mem - free)
            mem_usage = {'total': all_mem, 'usage': usage, 'percent': percent}
        else:
            mem_usage = {'total': None, 'usage': None, 'percent': None}
        return mem_usage

    def get_cpu_usage(self):
        """
        Function return cpu usage on node.
        """
        prev_idle = 0
        prev_total = 0
        cpu = self.wvm.getCPUStats(-1, 0)
        if isinstance(cpu, dict):
            for num in range(2):
                idle = self.wvm.getCPUStats(-1, 0)['idle']
                total = sum(self.wvm.getCPUStats(-1, 0).values())
                diff_idle = idle - prev_idle
                diff_total = total - prev_total
                diff_usage = (1000 * (diff_total - diff_idle) / diff_total + 5) / 10
                prev_total = total
                prev_idle = idle
                if num == 0:
                    time.sleep(1)
                else:
                    if diff_usage < 0:
                        diff_usage = 0
        else:
            return {'usage': None}
        return {'usage': diff_usage}

    def get_node_info(self):
        """
        Function return host server information: hostname, cpu, memory, ...
        """
        info = list()
        info.append(self.wvm.getHostname())  # hostname
        info.append(self.wvm.getInfo()[0])  # architecture
        info.append(self.wvm.getInfo()[1] * 1048576)  # memory
        info.append(self.wvm.getInfo()[2])  # cpu core count
        info.append(get_xml_path(self.wvm.getSysinfo(0), func=cpu_version))  # cpu version
        info.append(self.wvm.getURI())  # uri
        return info