# Copyright (C) 2005, 2008, 2009 Canonical Ltd
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



"""Text UI, write output to the console.
"""

import sys
import time
import warnings

from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
import getpass

from bzrlib import (
    progress,
    osutils,
    symbol_versioning,
    )

""")

from bzrlib.ui import CLIUIFactory


class TextUIFactory(CLIUIFactory):
    """A UI factory for Text user interefaces."""

    def __init__(self,
                 bar_type=None,
                 stdin=None,
                 stdout=None,
                 stderr=None):
        """Create a TextUIFactory.

        :param bar_type: The type of progress bar to create. It defaults to
                         letting the bzrlib.progress.ProgressBar factory auto
                         select.   Deprecated.
        """
        super(TextUIFactory, self).__init__(stdin=stdin,
                stdout=stdout, stderr=stderr)
        if bar_type:
            symbol_versioning.warn(symbol_versioning.deprecated_in((1, 11, 0))
                % "bar_type parameter")
        # paints progress, network activity, etc
        self._progress_view = TextProgressView(self.stderr)

    def prompt(self, prompt):
        """Emit prompt on the CLI."""
        self.stdout.write(prompt)

    def clear_term(self):
        """Prepare the terminal for output.

        This will, clear any progress bars, and leave the cursor at the
        leftmost position."""
        # XXX: If this is preparing to write to stdout, but that's for example
        # directed into a file rather than to the terminal, and the progress
        # bar _is_ going to the terminal, we shouldn't need
        # to clear it.  We might need to separately check for the case of
        self._progress_view.clear()

    def note(self, msg):
        """Write an already-formatted message, clearing the progress bar if necessary."""
        self.clear_term()
        self.stdout.write(msg + '\n')

    def report_transport_activity(self, transport, byte_count, direction):
        """Called by transports as they do IO.

        This may update a progress bar, spinner, or similar display.
        By default it does nothing.
        """
        self._progress_view.show_transport_activity(byte_count)

    def _progress_updated(self, task):
        """A task has been updated and wants to be displayed.
        """
        if not self._task_stack:
            warnings.warn("%r updated but no tasks are active" %
                (task,))
        elif task != self._task_stack[-1]:
            warnings.warn("%r is not the top progress task %r" %
                (task, self._task_stack[-1]))
        self._progress_view.show_progress(task)

    def _progress_all_finished(self):
        self._progress_view.clear()


class TextProgressView(object):
    """Display of progress bar and other information on a tty.

    This shows one line of text, including possibly a network indicator, spinner,
    progress bar, message, etc.

    One instance of this is created and held by the UI, and fed updates when a
    task wants to be painted.

    Transports feed data to this through the ui_factory object.

    The Progress views can comprise a tree with _parent_task pointers, but
    this only prints the stack from the nominated current task up to the root.
    """

    def __init__(self, term_file):
        self._term_file = term_file
        # true when there's output on the screen we may need to clear
        self._have_output = False
        # XXX: We could listen for SIGWINCH and update the terminal width...
        self._width = osutils.terminal_width()
        self._last_transport_msg = ''
        self._spin_pos = 0
        # time we last repainted the screen
        self._last_repaint = 0
        # time we last got information about transport activity
        self._transport_update_time = 0
        self._task_fraction = None
        self._last_task = None
        self._total_byte_count = 0
        self._bytes_since_update = 0

    def _show_line(self, s):
        n = self._width - 1
        self._term_file.write('\r%-*.*s\r' % (n, n, s))

    def clear(self):
        if self._have_output:
            self._show_line('')
        self._have_output = False

    def _render_bar(self):
        # return a string for the progress bar itself
        if (self._last_task is not None) and self._last_task.show_bar:
            spin_str =  r'/-\|'[self._spin_pos % 4]
            self._spin_pos += 1
            f = self._task_fraction or 0
            cols = 20
            # number of markers highlighted in bar
            markers = int(round(float(cols) * f)) - 1
            bar_str = '[' + ('#' * markers + spin_str).ljust(cols) + '] '
            return bar_str
        elif (self._last_task is None) or self._last_task.show_spinner:
            spin_str =  r'/-\|'[self._spin_pos % 4]
            self._spin_pos += 1
            return spin_str + ' '
        else:
            return ''

    def _format_task(self, task):
        if not task.show_count:
            s = ''
        elif task.current_cnt is not None and task.total_cnt is not None:
            s = ' %d/%d' % (task.current_cnt, task.total_cnt)
        elif task.current_cnt is not None:
            s = ' %d' % (task.current_cnt)
        else:
            s = ''
        self._task_fraction = task._overall_completion_fraction()
        # compose all the parent messages
        t = task
        m = task.msg
        while t._parent_task:
            t = t._parent_task
            if t.msg:
                m = t.msg + ':' + m
        return m + s

    def _repaint(self):
        bar_string = self._render_bar()
        if self._last_task:
            task_msg = self._format_task(self._last_task)
        else:
            task_msg = ''
        trans = self._last_transport_msg
        if trans and task_msg:
            trans += ' | '
        s = (bar_string
             + trans
             + task_msg
             )
        self._show_line(s)
        self._have_output = True

    def show_progress(self, task):
        self._last_task = task
        now = time.time()
        if now < self._last_repaint + 0.1:
            return
        if now > self._transport_update_time + 5:
            # no recent activity; expire it
            self._last_transport_msg = ''
        self._last_repaint = now
        self._repaint()

    def show_transport_activity(self, byte_count):
        """Called by transports as they do IO.

        This may update a progress bar, spinner, or similar display.
        By default it does nothing.
        """
        # XXX: Probably there should be a transport activity model, and that
        # too should be seen by the progress view, rather than being poked in
        # here.
        self._total_byte_count += byte_count
        self._bytes_since_update += byte_count
        now = time.time()
        if self._transport_update_time is None:
            self._transport_update_time = now
        elif now >= (self._transport_update_time + 0.5):
            # guard against clock stepping backwards, and don't update too
            # often
            rate = self._bytes_since_update / (now - self._transport_update_time)
            msg = ("%6dkB @ %4dkB/s" %
                (self._total_byte_count>>10, int(rate)>>10,))
            self._transport_update_time = now
            self._last_repaint = now
            self._bytes_since_update = 0
            self._last_transport_msg = msg
            self._repaint()


