# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
#
# Copyright 2002 Ben Escoto <ben@emerose.org>
# Copyright 2007 Kenneth Loafman <kenneth@loafman.com>
#
# This file is part of duplicity.
#
# Duplicity is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# Duplicity is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

"""Generate and process backup statistics"""

import re, time, os

from duplicity import dup_time


class StatsException(Exception):
    pass

class StatsObj:
    """Contains various statistics, provide string conversion functions"""
    # used when quoting files in get_stats_line
    space_regex = re.compile(" ")

    stat_file_attrs = ('SourceFiles',
                       'SourceFileSize',
                       'NewFiles',
                       'NewFileSize',
                       'DeletedFiles',
                       'ChangedFiles',
                       'ChangedFileSize',
                       'ChangedDeltaSize',
                       'DeltaEntries',
                       'RawDeltaSize')
    stat_misc_attrs = ('Errors',
                       'TotalDestinationSizeChange')
    stat_time_attrs = ('StartTime',
                       'EndTime',
                       'ElapsedTime')
    stat_attrs = (('Filename',) + stat_time_attrs +
                  stat_misc_attrs + stat_file_attrs)

    # Below, the second value in each pair is true iff the value
    # indicates a number of bytes
    stat_file_pairs = (('SourceFiles', False),
                       ('SourceFileSize', True),
                       ('NewFiles', False),
                       ('NewFileSize', True),
                       ('DeletedFiles', False),
                       ('ChangedFiles', False),
                       ('ChangedFileSize', True),
                       ('ChangedDeltaSize', True),
                       ('DeltaEntries', False),
                       ('RawDeltaSize', True))

    # This is used in get_byte_summary_string below
    byte_abbrev_list = ((1024*1024*1024*1024, "TB"),
                        (1024*1024*1024, "GB"),
                        (1024*1024, "MB"),
                        (1024, "KB"))

    def __init__(self):
        """Set attributes to None"""
        for attr in self.stat_attrs:
            self.__dict__[attr] = None

    def get_stat(self, attribute):
        """Get a statistic"""
        return self.__dict__[attribute]

    def set_stat(self, attr, value):
        """Set attribute to given value"""
        self.__dict__[attr] = value

    def increment_stat(self, attr):
        """Add 1 to value of attribute"""
        self.__dict__[attr] += 1

    def get_total_dest_size_change(self):
        """Return total destination size change

        This represents the total increase in the size of the
        duplicity destination directory, or None if not available.

        """
        return 0 # this needs to be re-done for duplicity

    def get_stats_line(self, index, use_repr = 1):
        """Return one line abbreviated version of full stats string"""
        file_attrs = map(lambda attr: str(self.get_stat(attr)),
                         self.stat_file_attrs)
        if not index:
            filename = "."
        else:
            filename = apply(os.path.join, index)
            if use_repr:
                # use repr to quote newlines in relative filename, then
                # take of leading and trailing quote and quote spaces.
                filename = self.space_regex.sub("\\x20", repr(filename)[1:-1])
        return " ".join([filename,] + file_attrs)

    def set_stats_from_line(self, line):
        """Set statistics from given line"""
        def error():
            raise StatsException("Bad line '%s'" % line)
        if line[-1] == "\n":
            line = line[:-1]
        lineparts = line.split(" ")
        if len(lineparts) < len(self.stat_file_attrs):
            error()
        for attr, val_string in zip(self.stat_file_attrs,
                                    lineparts[-len(self.stat_file_attrs):]):
            try:
                val = long(val_string)
            except ValueError:
                try:
                    val = float(val_string)
                except ValueError:
                    error()
            self.set_stat(attr, val)
        return self

    def get_stats_string(self):
        """Return extended string printing out statistics"""
        return "%s%s%s" % (self.get_timestats_string(),
                           self.get_filestats_string(),
                           self.get_miscstats_string())

    def get_timestats_string(self):
        """Return portion of statistics string dealing with time"""
        timelist = []
        if self.StartTime is not None:
            timelist.append("StartTime %.2f (%s)\n" %
                     (self.StartTime, dup_time.timetopretty(self.StartTime)))
        if self.EndTime is not None:
            timelist.append("EndTime %.2f (%s)\n" %
                         (self.EndTime, dup_time.timetopretty(self.EndTime)))
        if self.ElapsedTime or (self.StartTime is not None and
                                self.EndTime is not None):
            if self.ElapsedTime is None:
                self.ElapsedTime = self.EndTime - self.StartTime
            timelist.append("ElapsedTime %.2f (%s)\n" %
                 (self.ElapsedTime, dup_time.inttopretty(self.ElapsedTime)))
        return "".join(timelist)

    def get_filestats_string(self):
        """Return portion of statistics string about files and bytes"""
        def fileline(stat_file_pair):
            """Return zero or one line of the string"""
            attr, in_bytes = stat_file_pair
            val = self.get_stat(attr)
            if val is None:
                return ""
            if in_bytes:
                return "%s %s (%s)\n" % (attr, val,
                                         self.get_byte_summary_string(val))
            else:
                return "%s %s\n" % (attr, val)

        return "".join(map(fileline, self.stat_file_pairs))

    def get_miscstats_string(self):
        """Return portion of extended stat string about misc attributes"""
        misc_string = ""
        tdsc = self.TotalDestinationSizeChange
        if tdsc is not None:
            misc_string += ("TotalDestinationSizeChange %s (%s)\n" %
                            (tdsc, self.get_byte_summary_string(tdsc)))
        if self.Errors is not None:
            misc_string += "Errors %d\n" % self.Errors
        return misc_string

    def get_byte_summary_string(self, byte_count):
        """Turn byte count into human readable string like "7.23GB" """
        if byte_count < 0:
            sign = "-"
            byte_count = -byte_count
        else:
            sign = ""

        for abbrev_bytes, abbrev_string in self.byte_abbrev_list:
            if byte_count >= abbrev_bytes:
                # Now get 3 significant figures
                abbrev_count = float(byte_count)/abbrev_bytes
                if abbrev_count >= 100:
                    precision = 0
                elif abbrev_count >= 10:
                    precision = 1
                else:
                    precision = 2
                return "%s%%.%df %s" % (sign, precision, abbrev_string) \
                       % (abbrev_count,)
        byte_count = round(byte_count)
        if byte_count == 1:
            return sign + "1 byte"
        else:
            return "%s%d bytes" % (sign, byte_count)

    def get_stats_logstring(self, title):
        """Like get_stats_string, but add header and footer"""
        header = "--------------[ %s ]--------------" % title
        footer = "-" * len(header)
        return "%s\n%s%s\n" % (header, self.get_stats_string(), footer)

    def set_stats_from_string(self, s):
        """Initialize attributes from string, return self for convenience"""
        def error(line):
            raise StatsException("Bad line '%s'" % line)

        for line in s.split("\n"):
            if not line:
                continue
            line_parts = line.split()
            if len(line_parts) < 2:
                error(line)
            attr, value_string = line_parts[:2]
            if not attr in self.stat_attrs:
                error(line)
            try:
                try:
                    val1 = long(value_string)
                except ValueError:
                    val1 = None
                val2 = float(value_string)
                if val1 == val2:
                    self.set_stat(attr, val1) # use integer val
                else:
                    self.set_stat(attr, val2) # use float
            except ValueError:
                error(line)
        return self

    def write_stats_to_path(self, path):
        """Write statistics string to given path"""
        fin = path.open("w")
        fin.write(self.get_stats_string())
        assert not fin.close()

    def read_stats_from_path(self, path):
        """Set statistics from path, return self for convenience"""
        fp = path.open("r")
        self.set_stats_from_string(fp.read())
        assert not fp.close()
        return self

    def stats_equal(self, s):
        """Return true if s has same statistics as self"""
        assert isinstance(s, StatsObj)
        for attr in self.stat_file_attrs:
            if self.get_stat(attr) != s.get_stat(attr):
                return None
        return 1

    def set_to_average(self, statobj_list):
        """Set self's attributes to average of those in statobj_list"""
        for attr in self.stat_attrs:
            self.set_stat(attr, 0)
        for statobj in statobj_list:
            for attr in self.stat_attrs:
                if statobj.get_stat(attr) is None:
                    self.set_stat(attr, None)
                elif self.get_stat(attr) is not None:
                    self.set_stat(attr, statobj.get_stat(attr) +
                                  self.get_stat(attr))

        # Don't compute average starting/stopping time
        self.StartTime = None
        self.EndTime = None

        for attr in self.stat_attrs:
            if self.get_stat(attr) is not None:
                self.set_stat(attr,
                              self.get_stat(attr)/float(len(statobj_list)))
        return self

    def get_statsobj_copy(self):
        """Return new StatsObj object with same stats as self"""
        s = StatsObj()
        for attr in self.stat_attrs:
            s.set_stat(attr, self.get_stat(attr))
        return s


class StatsDeltaProcess(StatsObj):
    """Keep track of statistics during DirDelta process"""
    def __init__(self):
        """StatsDeltaProcess initializer - zero file attributes"""
        StatsObj.__init__(self)
        for attr in StatsObj.stat_file_attrs:
            self.__dict__[attr] = 0
        self.Errors = 0
        self.StartTime = time.time()

    def add_new_file(self, path):
        """Add stats of new file path to statistics"""
        filesize = path.getsize()
        self.SourceFiles += 1
        # SourceFileSize is added-to incrementally as read
        self.NewFiles += 1
        self.NewFileSize += filesize
        self.DeltaEntries += 1

    def add_changed_file(self, path):
        """Add stats of file that has changed since last backup"""
        filesize = path.getsize()
        self.SourceFiles += 1
        # SourceFileSize is added-to incrementally as read
        self.ChangedFiles += 1
        self.ChangedFileSize += filesize
        self.DeltaEntries += 1

    def add_deleted_file(self):
        """Add stats of file no longer in source directory"""
        self.DeletedFiles += 1 # can't add size since not available
        self.DeltaEntries += 1

    def add_unchanged_file(self, path):
        """Add stats of file that hasn't changed since last backup"""
        filesize = path.getsize()
        self.SourceFiles += 1
        self.SourceFileSize += filesize

    def close(self):
        """End collection of data, set EndTime"""
        self.EndTime = time.time()
