# Copyright (c) 2008 David Aguilar
"""This module provides miscellaneous Qt utility functions.
"""
import os

from PyQt4 import QtGui
from PyQt4 import QtCore
from PyQt4.QtCore import SIGNAL

import cola
from cola import core
from cola import utils
from cola import signals
from cola import resources
from cola.decorators import memoize
import cola.views.log


@memoize
def logger():
    logview = cola.views.log.LogView()
    cola.notifier().connect(signals.log_cmd, logview.log)
    return logview


def log(status, output):
    """Sends messages to the log window.
    """
    if not output:
        return
    cola.notifier().broadcast(signals.log_cmd, status, output)


def SLOT(signal, *args, **opts):
    """
    Returns a callback that broadcasts a message over the notifier.

    If the caller of SLOT() provides args or opts then those are
    used instead of the ones provided by the invoker of the callback.

    """
    def broadcast(*local_args, **local_opts):
        if args or opts:
            cola.notifier().broadcast(signal, *args, **opts)
        else:
            cola.notifier().broadcast(signal, *local_args, **local_opts)
    return broadcast


def prompt(msg, title=None):
    """Presents the user with an input widget and returns the input."""
    if title is None:
        title = msg
    msg = tr(msg)
    title = tr(title)
    parent = QtGui.QApplication.instance().activeWindow()
    result = QtGui.QInputDialog.getText(parent, msg, title)
    return (unicode(result[0]), result[1])


def create_listwidget_item(text, filename):
    """Creates a QListWidgetItem with text and the icon at filename."""
    item = QtGui.QListWidgetItem()
    item.setIcon(QtGui.QIcon(filename))
    item.setText(text)
    return item


def create_treewidget_item(text, filename):
    """Creates a QTreeWidgetItem with text and the icon at filename."""
    icon = cached_icon_from_path(filename)
    item = QtGui.QTreeWidgetItem()
    item.setIcon(0, icon)
    item.setText(0, text)
    return item


@memoize
def cached_icon_from_path(filename):
    return QtGui.QIcon(filename)


def information(title, message=None):
    """Launches a QMessageBox information with the
    provided title and message."""
    if message is None:
        message = title
    title = tr(title)
    message = tr(message)
    parent = QtGui.QApplication.instance().activeWindow()
    QtGui.QMessageBox.information(parent, title, message)

# Register globally with the notifier
cola.notifier().connect(signals.information, information)


def selected_treeitem(tree_widget):
    """Returns a(id_number, is_selected) for a QTreeWidget."""
    id_number = None
    selected = False
    item = tree_widget.currentItem()
    if item:
        id_number = item.data(0, QtCore.Qt.UserRole).toInt()[0]
        selected = True
    return(id_number, selected)

def selected_row(list_widget):
    """Returns a(row_number, is_selected) tuple for a QListWidget."""
    row = list_widget.currentRow()
    item = list_widget.item(row)
    selected = item is not None and item.isSelected()
    return(row, selected)

def selection_list(listwidget, items):
    """Returns an array of model items that correspond to
    the selected QListWidget indices."""
    selected = []
    itemcount = listwidget.count()
    widgetitems = [ listwidget.item(idx) for idx in range(itemcount) ]

    for item, widgetitem in zip(items, widgetitems):
        if widgetitem.isSelected():
            selected.append(item)
    return selected


def tree_selection(treeitem, items):
    """Returns model items that correspond to selected widget indices"""
    itemcount = treeitem.childCount()
    widgetitems = [ treeitem.child(idx) for idx in range(itemcount) ]
    selected = []
    for item, widgetitem in zip(items[:len(widgetitems)], widgetitems):
        if widgetitem.isSelected():
            selected.append(item)

    return selected


def selected_item(list_widget, items):
    """Returns the selected item in a QListWidget."""
    row, selected = selected_row(list_widget)
    if selected and row < len(items):
        return items[row]
    else:
        return None


def open_dialog(parent, title, filename=None):
    """Creates an Open File dialog and returns a filename."""
    title_tr = tr(title)
    return unicode(QtGui.QFileDialog
                        .getOpenFileName(parent, title_tr, filename))


def opendir_dialog(parent, title, path):
    """Prompts for a directory path"""

    flags = (QtGui.QFileDialog.ShowDirsOnly |
             QtGui.QFileDialog.DontResolveSymlinks)
    title_tr = tr(title)
    qstr = (QtGui.QFileDialog
                 .getExistingDirectory(parent, title_tr, path, flags))
    return unicode(qstr)


def save_dialog(parent, title, filename=''):
    """Creates a Save File dialog and returns a filename."""
    title_tr = parent.tr(title)
    return unicode(QtGui.QFileDialog
                        .getSaveFileName(parent, title_tr, filename))


def icon(basename):
    """Given a basename returns a QIcon from the corresponding cola icon."""
    return QtGui.QIcon(resources.icon(basename))


def question(parent, title, message, default=True):
    """Launches a QMessageBox question with the provided title and message.
    Passing "default=False" will make "No" the default choice."""
    yes = QtGui.QMessageBox.Yes
    no = QtGui.QMessageBox.No
    buttons = yes | no
    if default:
        default = yes
    else:
        default = no
    title = tr(title)
    message = tr(message)
    result = QtGui.QMessageBox.question(parent, title, message,
                                        buttons, default)
    return result == QtGui.QMessageBox.Yes


def set_clipboard(text):
    """Sets the copy/paste buffer to text."""
    if not text:
        return
    clipboard = QtGui.QApplication.instance().clipboard()
    clipboard.setText(text, QtGui.QClipboard.Clipboard)
    clipboard.setText(text, QtGui.QClipboard.Selection)


def set_selected_item(widget, idx):
    """Sets a the currently selected item to the item at index idx."""
    if type(widget) is QtGui.QTreeWidget:
        item = widget.topLevelItem(idx)
        if item:
            widget.setItemSelected(item, True)
            widget.setCurrentItem(item)


def add_items(widget, items):
    """Adds items to a widget."""
    for item in items:
        widget.addItem(item)


def set_items(widget, items):
    """Clear the existing widget contents and set the new items."""
    widget.clear()
    add_items(widget, items)


@memoize
def tr(txt):
    """Translate a string into a local language."""
    if type(txt) is QtCore.QString:
        # This has already been translated; leave as-is
        return unicode(txt)
    return unicode(QtGui.QApplication.instance().translate('', txt))


def icon_file(filename, staged=False, untracked=False):
    """Returns a file path representing a corresponding file path."""
    if staged:
        if os.path.exists(core.encode(filename)):
            ifile = resources.icon('staged.png')
        else:
            ifile = resources.icon('removed.png')
    elif untracked:
        ifile = resources.icon('untracked.png')
    else:
        ifile = utils.file_icon(filename)
    return ifile


def icon_for_file(filename, staged=False, untracked=False):
    """Returns a QIcon for a particular file path."""
    ifile = icon_file(filename, staged=staged, untracked=untracked)
    return icon(ifile)


def create_treeitem(filename, staged=False, untracked=False, check=True):
    """Given a filename, return a QListWidgetItem suitable
    for adding to a QListWidget.  "staged" and "untracked"
    controls whether to use the appropriate icons."""
    if check:
        ifile = icon_file(filename, staged=staged, untracked=untracked)
    else:
        ifile = resources.icon('staged.png')
    return create_treewidget_item(filename, ifile)


def update_file_icons(widget, items, staged=True,
            untracked=False, offset=0):
    """Populate a QListWidget with custom icon items."""
    for idx, model_item in enumerate(items):
        item = widget.item(idx+offset)
        if item:
            item.setIcon(icon_for_file(model_item, staged, untracked))

def set_listwidget_strings(widget, items):
    """Sets a list widget to the strings passed in items."""
    widget.clear()
    add_items(widget, [ QtGui.QListWidgetItem(i) for i in items ])

@memoize
def cached_icon(key):
    """Maintain a cache of standard icons and return cache entries."""
    style = QtGui.QApplication.instance().style()
    return style.standardIcon(key)


def dir_icon():
    """Return a standard icon for a directory."""
    return cached_icon(QtGui.QStyle.SP_DirIcon)


def file_icon():
    """Return a standard icon for a file."""
    return cached_icon(QtGui.QStyle.SP_FileIcon)


def diff_font():
    """Return the diff font string."""
    qfont = QtGui.QFont()
    font = cola.model().cola_config('fontdiff')
    if font and qfont.fromString(font):
        return qfont
    family = 'Monospace'
    if cola.utils.is_darwin():
        family = 'Monaco'
    qfont.setFamily(family)
    font = unicode(qfont.toString())
    # TODO this might not be the best place for the default
    cola.model().set_diff_font(font)
    return qfont


def set_diff_font(widget):
    """Updates the diff font based on the configured value."""
    qfont = diff_font()
    block = widget.signalsBlocked()
    widget.blockSignals(True)
    if isinstance(widget, QtGui.QFontComboBox):
        widget.setCurrentFont(qfont)
    else:
        widget.setFont(qfont)
    widget.blockSignals(block)


def add_close_action(widget):
    """Adds a Ctrl+w close action to a widget."""
    action = QtGui.QAction(widget.tr('Close...'), widget)
    action.setShortcut('Ctrl+w')
    widget.addAction(action)
    widget.connect(action, SIGNAL('triggered()'), widget.close)


def center_on_screen(widget):
    """Move widget to the center of the default screen"""
    desktop = QtGui.QApplication.instance().desktop()
    rect = desktop.screenGeometry(QtGui.QCursor().pos())
    cy = rect.height()/2
    cx = rect.width()/2
    widget.move(cx - widget.width()/2, cy - widget.height()/2)
