#  Copyright (c) 2007, Enthought, Inc.
#  License: BSD Style.

"""
This demo shows a combination of the <b>DirectoryEditor</b>, the
<b>TabularEditor</b> and the <b>CodeEditor</b> used to create a simple Python
source browser:

 - Use the <b>DirectoryEditor</b> on the left to navigate to and select
   directories containing Python source files.
 - Use the <b>TabularEditor</b> on the top-right to view information about and
   to select Python source files in the currently selected directory.
 - View the currently selected Python source file's contents in the
   <b>CodeEditor</b> in the bottom-right.

As an extra <i>feature</i>, the <b>TabularEditor</b> also displays a:

 - Red ball if the file size > 64KB.
 - Blue ball if the file size > 16KB.
"""

from __future__ import absolute_import
from time \
    import localtime, strftime

from os \
    import listdir

from os.path \
    import getsize, getmtime, isfile, join, splitext, basename, dirname

from traits.api \
    import HasPrivateTraits, Str, Float, List, Directory, File, Code, \
    Instance, Property, Font, cached_property

import traitsui.api

from traitsui.api \
    import View, Item, HSplit, VSplit, TabularEditor

from traitsui.tabular_adapter \
    import TabularAdapter

from pyface.image_resource \
    import ImageResource
from io import open

#-- Constants ------------------------------------------------------------

# Necessary because of the dynamic way in which the demos are loaded:
search_path = [join(dirname(traitsui.api.__file__),
                    '..', 'examples', 'demo', 'Applications')]


#-- FileInfo Class Definition --------------------------------------------

class FileInfo(HasPrivateTraits):

    file_name = File
    name = Property
    size = Property
    time = Property
    date = Property

    @cached_property
    def _get_name(self):
        return basename(self.file_name)

    @cached_property
    def _get_size(self):
        return getsize(self.file_name)

    @cached_property
    def _get_time(self):
        return strftime('%I:%M:%S %p',
                        localtime(getmtime(self.file_name)))

    @cached_property
    def _get_date(self):
        return strftime('%m/%d/%Y',
                        localtime(getmtime(self.file_name)))

#-- Tabular Adapter Definition -------------------------------------------


class FileInfoAdapter(TabularAdapter):

    columns = [('File Name', 'name'),
               ('Size', 'size'),
               ('', 'big'),
               ('Time', 'time'),
               ('Date', 'date')]

    even_bg_color = (201, 223, 241)
    # FIXME: Font fails with wx in OSX; see traitsui issue #13:
    font = Font('Courier 10')
    size_alignment = Str('right')
    time_alignment = Str('right')
    date_alignment = Str('right')
    big_text = Str
    big_width = Float(18)
    big_image = Property

    def _get_big_image(self):
        size = self.item.size
        if size > 65536:
            return ImageResource('red_ball')

        return (None, ImageResource('blue_ball'))[size > 16384]

#-- Tabular Editor Definition --------------------------------------------

tabular_editor = TabularEditor(
    editable=False,
    selected='file_info',
    adapter=FileInfoAdapter(),
    operations=[],
    images=[ImageResource('blue_ball', search_path=search_path),
             ImageResource('red_ball', search_path=search_path)]
)

#-- PythonBrowser Class Definition ---------------------------------------


class PythonBrowser(HasPrivateTraits):

    #-- Trait Definitions ----------------------------------------------------

    dir = Directory
    files = List(FileInfo)
    file_info = Instance(FileInfo)
    code = Code

    #-- Traits View Definitions ----------------------------------------------

    view = View(
        HSplit(
            Item('dir', style='custom'),
            VSplit(
                Item('files', editor=tabular_editor),
                Item('code', style='readonly'),
                show_labels=False),
            show_labels=False
        ),
        resizable=True,
        width=0.75,
        height=0.75
    )

    #-- Event Handlers -------------------------------------------------------

    def _dir_changed(self, dir):
        if dir != '':
            self.files = [FileInfo(file_name=join(dir, name))
                        for name in listdir(dir)
                        if ((splitext(name)[1] == '.py') and
                            isfile(join(dir, name)))]
        else:
            self.files = []

    def _file_info_changed(self, file_info):
        fh = None
        try:
            fh = open(file_info.file_name, 'rU', encoding='utf8')
            self.code = fh.read()
        except:
            pass

        if fh is not None:
            fh.close()

# Create the demo:
demo = PythonBrowser(dir=dirname(dirname(__file__)))

# Run the demo (if invoked from the command line):
if __name__ == '__main__':
    demo.configure_traits()