# vim: ts=4:sw=4:expandtab

## BleachBit
## Copyright (C) 2011 Andrew Ziem
## http://bleachbit.sourceforge.net
##
## 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/>.



"""
Perform the preview or delete operations
"""


import os
import sys
import traceback

import DeepScan
import FileUtilities
from Cleaner import backends
from Common import _, ungettext

if 'nt' == os.name:
    import Windows
else:
    from General import WindowsError



class Worker:
    """Perform the preview or delete operations"""
    def __init__(self, ui, really_delete, operations):
        """Create a Worker

        ui: an instance with methods
            append_text()
            update_progress_bar()
            update_total_size()
            worker_done()
        really_delete: (boolean) preview or make real changes?
        operations: dictionary where operation-id is the key and
            operation-id are values
        """
        self.ui = ui
        self.really_delete = really_delete
        assert(isinstance(operations, dict))
        self.operations = operations
        self.total_bytes = 0
        self.total_deleted = 0
        self.total_errors = 0
        self.total_special = 0 # special operations
        self.yield_time = None
        if 0 == len(self.operations):
            raise RuntimeError("No work to do")


    def print_exception(self, operation):
        """Display exception"""
        # TRANSLATORS: This indicates an error.  The special keyword
        # %(operation)s will be replaced by 'firefox' or 'opera' or
        # some other cleaner ID.  The special keyword %(msg)s will be
        # replaced by a message such as 'Permission denied.'
        err = _("Exception while running operation '%(operation)s': '%(msg)s'") \
            %  { 'operation': operation, 'msg' : str(sys.exc_info()[1]) }
        print err
        traceback.print_exc()
        self.ui.append_text(err + "\n", 'error')
        self.total_errors += 1


    def execute(self, cmd):
        """Execute or preview the command"""
        ret = None
        try:
            for ret in cmd.execute(self.really_delete):
                if True == ret or isinstance(ret, tuple):
                    # Temporarily pass control to the GTK idle loop,
                    # allow user to abort, and
                    # display progress (if applicable).
                    yield ret
        except SystemExit:
            pass
        except Exception, e:
            # 2 = does not exist
            # 13 = permission denied
            if not (isinstance(e, OSError) and e.errno in (2, 13)):
                traceback.print_exc()
            line = "%s\n" % (str(sys.exc_info()[1]))
            self.total_errors += 1
            self.ui.append_text(line, 'error')
        else:
            if None == ret:
                return
            if isinstance(ret['size'], (int, long)):
                size = FileUtilities.bytes_to_human(ret['size'])
                self.total_bytes += ret['size']
            else:
                size = "?B"
            if ret['path']:
                path = ret['path']
            else:
                path = ''
            path = path.decode('utf8', 'replace') # for invalid encoding
            line = u"%s %s %s\n" % (ret['label'], size, path)
            self.total_deleted += ret['n_deleted']
            self.total_special += ret['n_special']
            self.ui.append_text(line)



    def clean_operation(self, operation):
        """Perform a single cleaning operation"""
        operation_options = self.operations[operation]
        assert(isinstance(operation_options, list))
        print "debug: clean_operation('%s'), options = '%s'" % (operation, operation_options)
        if self.really_delete and backends[operation].is_running():
            # TRANSLATORS: %s expands to a name such as 'Firefox' or 'System'.
            err = _("%s cannot be cleaned because it is currently running.  Close it, and try again.") \
                % backends[operation].get_name()
            self.ui.append_text(err + "\n", 'error')
            self.total_errors += 1
            return
        import time
        self.yield_time = time.time()

        if not operation_options:
            raise StopIteration

        for option_id in operation_options:
            assert(isinstance(option_id, (str, unicode)))
            # normal scan
            for cmd in backends[operation].get_commands(option_id):
                for ret in self.execute(cmd):
                    if True == ret:
                        # Return control to PyGTK idle loop to keep
                        # it responding allow the user to abort
                        self.yield_time = time.time()
                        yield True
                if time.time() - self.yield_time > 0.25:
                    if self.really_delete:
                        self.ui.update_total_size(self.total_bytes)
                    yield True
                    self.yield_time = time.time()
            # deep scan
            for ds in backends[operation].get_deep_scan(option_id):
                if '' == ds['path']:
                    ds['path'] = os.path.expanduser('~')
                if 'delete' != ds['command']:
                    raise NotImplementedError('Deep scan only supports deleting now')
                if not self.deepscans.has_key(ds['path']):
                    self.deepscans[ds['path']] = []
                self.deepscans[ds['path']].append(ds)


    def run(self):
        """Perform the main cleaning process which has these phases
        1. General cleaning
        2. Deep scan
        3. Memory
        4. Free disk space"""
        self.deepscans = {}
        # prioritize
        self.delayed_ops = []
        for operation in self.operations:
            delayables = ['free_disk_space', 'memory']
            for delayable in delayables:
                if operation not in ('system', '_gui'):
                    continue
                if delayable in self.operations[operation]:
                    i = self.operations[operation].index(delayable)
                    del self.operations[operation][i]
                    priority = 99
                    if 'free_disk_space' == delayable:
                        priority = 100
                    new_op = (priority, { operation : [ delayable ] } )
                    self.delayed_ops.append( new_op )

        # standard operations
        for dummy in self.run_operations(self.operations):
            # yield to GTK+ idle loop
            yield True

        # run deep scan
        if self.deepscans:
            for dummy in self.run_deep_scan():
                yield dummy

        # delayed operations
        for op in sorted(self.delayed_ops):
            operation = op[1].keys()[0]
            for option_id in op[1].values()[0]:
                self.ui.update_progress_bar(0.0)
                if 'free_disk_space' == option_id:
                    # TRANSLATORS: 'free' means 'unallocated'
                    msg = _("Please wait.  Wiping free disk space.")
                elif 'memory' == option_id:
                    msg = _("Please wait.  Cleaning %s.") % _("Memory")
                else:
                    raise RuntimeError("Unexpected option_id in delayed ops")
                self.ui.update_progress_bar(msg)
                for cmd in backends[operation].get_commands(option_id):
                    for ret in self.execute(cmd):
                        if isinstance(ret, tuple):
                            # Display progress (for free disk space)
                            self.ui.update_progress_bar(ret[0])
                            mins = int(ret[1] / 60)
                            msg2 = ungettext("About %d minute remaining.", \
                                "About %d minutes remaining.", mins) \
                                % mins
                            self.ui.update_progress_bar(msg + ' ' + msg2)
                        if True == ret or isinstance(ret, tuple):
                            # Return control to PyGTK idle loop to keep
                            # it responding and allow the user to abort.
                            yield True


        # print final stats
        bytes_delete = FileUtilities.bytes_to_human(self.total_bytes)
        if self.really_delete:
            # TRANSLATORS: This refers to disk space that was
            # really recovered (in other words, not a preview)
            line =  _("Disk space recovered: %s") % bytes_delete
        else:
            # TRANSLATORS: This refers to a preview (no real
            # changes were made yet)
            line =  _("Disk space to be recovered: %s") % bytes_delete
        self.ui.append_text("\n%s" % line)
        if self.really_delete:
            # TRANSLATORS: This refers to the number of files really
            # deleted (in other words, not a preview).
            line = _("Files deleted: %d") % self.total_deleted
        else:
            # TRANSLATORS: This refers to the number of files that
            # would be deleted (in other words, simply a preview).
            line = _("Files to be deleted: %d") % self.total_deleted
        self.ui.append_text("\n%s" % line)
        if self.total_special > 0:
            line =  _("Special operations: %d") % self.total_special
            self.ui.append_text("\n%s" % line)
        if self.total_errors > 0:
            line = _("Errors: %d") % self.total_errors
            self.ui.append_text("\n%s" % line, 'error')

        if self.really_delete:
            self.ui.update_total_size(self.total_bytes)
        self.ui.worker_done(self, self.really_delete)

        yield False


    def run_deep_scan(self):
        """Run deep scans"""
        print 'debug: deepscans=', self.deepscans
        # TRANSLATORS: The "deep scan" feature searches over broad
        # areas of the file system such as the user's whole home directory
        # or all the system executables.
        self.ui.update_progress_bar(_("Please wait.  Running deep scan."))
        yield True # allow GTK to update the screen
        ds = DeepScan.DeepScan()
        for (path, dsdict) in self.deepscans.iteritems():
            print 'debug: deepscan path=', path
            print 'debug: deepscan dict=', dsdict
            for dsdict2 in dsdict:
                ds.add_search(path, dsdict2['regex'])

        for path in ds.scan():
            if True == path:
                yield True
                continue
            # fixme: support non-delete commands
            import Command
            cmd = Command.Delete(path)
            for ret in self.execute(cmd):
                yield True

    def run_operations(self, my_operations):
        """Run a set of operations (general, memory, free disk space)"""
        count = 0
        for operation in my_operations:
            self.ui.update_progress_bar(1.0 * count / len(my_operations))
            name = backends[operation].get_name()
            if self.really_delete:
                # TRANSLATORS: %s is replaced with Firefox, System, etc.
                msg = _("Please wait.  Cleaning %s.") % name
            else:
                # TRANSLATORS: %s is replaced with Firefox, System, etc.
                msg = _("Please wait.  Previewing %s.") % name
            self.ui.update_progress_bar(msg)
            yield True # show the progress bar message now
            try:
                for dummy in self.clean_operation(operation):
                    yield True
            except:
                self.print_exception(operation)

            count += 1
