###
### backmon.lib.updates
###
import os
import os.path
import time

import backup_monitoring.builtins

from .exceptions import BackmonError
from .locking import *

#
# Updates - Wrapper for directory receiving update outputs
#
class Updates(object):

    def __init__(self, logger, path):

        self.logger = logger
        self.path = path
        self.handles = {}
    
    #
    # open() - Open a handle to a monitored file
    #
    def open(self, filename, nolock=False, version=None):

        if version is not None:
            vext = '.%s' % (version)
        else:
            vext = ''

        path = os.path.join(self.path, '%s%s' % (filename, vext))

        if os.path.isfile(path):

            if nolock or lock(path, retries=3, sleep=2):

                try:
                    self.handles[filename] = open(path, 'r')
                    return self.handles[filename]
                except IOError:
                    self.logger.error('Could not open file %s!' % (path))
                    return None
            else:
                self.logger.error('Could not lock file %s!' % (path))
                return None
        else:
            self.logger.error('File %s does not exist!' % (path))
            return None

    #
    # close() - Close the handle to a monitored file
    #
    def close(self, filename, nolock=False, version=None):

        if version is not None:
            vext = '.%s' % (version)
        else:
            vext = ''

        path = os.path.join(self.path, '%s%s' % (filename, vext))

        if os.path.isfile(path):

            if filename in self.handles:

                if hasattr(self.handles, 'close'):
                    self.handles[filename].close()

                del self.handles[filename]

                if nolock or unlock(path):
                    return True
                else:
                    self.logger.error('Could not unlock file %s!' % (path))
                    return False

            else:

                self.logger.error('File %s is not open!' % (path))
                return False

        else:

            self.logger.error('File %s does not exist!' % (path))
            return False

    #
    # info() - Return the info object for a monitored feed
    #
    def info(self, feed, nolock=True, version=None):

        if version is not None:
            vext = '.%s' % (version)
        else:
            vext = ''

        inf_file = '%s.inf%s' % (feed, vext)
        txt_file = '%s.txt%s' % (feed, vext)

        file_path = os.path.join(self.path, txt_file)

        file = self.open(inf_file, nolock=nolock)

        if file is not None:

            info = {}

            for line in file:

                line = line.rstrip('\r\n')

                try:
                    (key, value) = line.split('=')
                    #self.logger.debug('%s=%s' % (key, value))
                    info[key] = value
                except:
                    pass

            self.close(inf_file, nolock=nolock)

            if nolock or lock(file_path, retries=3, sleep=2):

                stat = os.stat(file_path)

                info['SIZE'] = float(stat.st_size)
                info['ATIME'] = float(stat.st_atime)
                info['MTIME'] = float(stat.st_mtime)
                info['CTIME'] = float(stat.st_ctime)

                if not nolock:
                    unlock(file_path)

            else:

                info['SIZE'] = None
                info['ATIME'] = None
                info['MTIME'] = None
                info['CTIME'] = None

            return info

        else:

            return None

    #
    # read() - Return the contents of a monitored file
    #
    def read(self, filename):

        try:

            file = self.open(filename)
            data = file.read()
            self.close(filename)
            return data

        except Exception, e:

            raise BackmonError, e

    #
    # readlines() - Return all lines of a monitored file
    #
    def readlines(self, filename):

        try:

            file = self.open(filename)
            lines = file.readlines()
            self.close(filename)
            return lines

        except Exception, e:

            raise BackmonError, e

    #
    # feed() - Return a file-like object containing the current output of a feed
    #
    def feed(self, feed, storage='ram', version=None):

        if version is not None:
            vext = '.%s' % (version)
        else:
            vext = ''

        txt_file = '%s.txt%s' % (feed, vext)

        try:

            if storage == 'ram':

                return StringAsFile(self.read(txt_file))

            else:

                raise BackmonError, 'no storage specified for Updates feed() method!'

        except Exception, e:

            raise BackmonError, e


    #
    # fopen() - Return an open file handle to a feed
    #
    def fopen(self, feed, nolock=True, version=None):

        txt_file = '%s.txt' % (feed)

        try:

            return self.open(txt_file, nolock, version)

        except Exception, e:

            raise


    #
    # fclose() - Close an open file handle to a feed
    #
    def fclose(self, feed, nolock=True, version=None):

        txt_file = '%s.txt' % (feed)

        try:

            return self.close(txt_file, nolock, version)

        except Exception, e:

            raise