#!/usr/bin/python
# Copyright 2011  Lars Wirzenius
# 
# This program 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 3 of the License, or
# (at your option) any later version.
# 
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.


import cliapp
import os
import sys
import ttystatus

import genbackupdatalib


class GenbackupdataApp(cliapp.Application):

    def add_settings(self):
        self.settings.bytesize(
            ['create', 'c'], 
            'how much data to create (default: %default)')
        self.settings.bytesize(
            ['file-size'], 
            'size of one file',
            default=16*1024)
        self.settings.bytesize(
            ['chunk-size'], 
            'generate data in chunks of this size',
            default=16*1024)
        self.settings.integer(
            ['depth'], 
            'depth of directory tree',
            default=3)
        self.settings.integer(
            ['max-files'], 
            'max files/dirs per dir',
            default=128)
        self.settings.integer(
            ['seed'], 
            'seed for random number generator',
            default=0)
        self.settings.boolean(
            ['quiet'],
            'do not report progress')
        
    def process_args(self, args):
        outputdir = args[0]
        bytes = self.settings['create']
        self.gen = genbackupdatalib.DataGenerator(self.settings['seed'])
        self.names = genbackupdatalib.NameGenerator(
            outputdir, self.settings['depth'], self.settings['max-files'])
        
        self.setup_ttystatus()
        self.status['total'] = bytes
        while bytes > 0:
            n = min(self.settings['file-size'], bytes)
            self.create_file(n)
            bytes -= n
        self.status.finish()

    def create_file(self, bytes):
        '''Generate one output file.'''
        
        file_size = self.settings['file-size']
        chunk_size = self.settings['chunk-size']
        pathname = self.names.new()
        dirname = os.path.dirname(pathname)
        if not os.path.exists(dirname):
            os.makedirs(dirname)
        with open(pathname, 'wb') as f:
            while bytes >= chunk_size:
                self.write_bytes(f, chunk_size)
                bytes -= chunk_size
            if bytes > 0:
                self.write_bytes(f, bytes)

    def write_bytes(self, f, bytes):
        chunk = self.gen.generate(bytes)
        f.write(chunk)
        self.status['written'] += bytes
        
    def setup_ttystatus(self):
        self.status = ttystatus.TerminalStatus(period=0.1)
        if self.settings['quiet']:
            self.status.disable()
        self.status['written'] = 0
        self.status['total'] = 0
        self.status.format(
            'Generating %ByteSize(written) of %ByteSize(total) '
            '%PercentDone(written,total) (%ByteSpeed(written))')
            

if __name__ == '__main__':
    GenbackupdataApp().run()