import os
import logging
from warnings import catch_warnings

import numpy as np
from AnyQt.QtWidgets import \
    QStyle, QComboBox, QMessageBox, QFileDialog, QGridLayout, QLabel, \
    QLineEdit
from AnyQt.QtWidgets import QSizePolicy as Policy
from AnyQt.QtCore import Qt, QTimer, QSize

from Orange.canvas.gui.utils import OSX_NSURL_toLocalFile
from Orange.data import StringVariable
from Orange.data.table import Table, get_sample_datasets_dir
from Orange.data.io import FileFormat, UrlReader
from Orange.widgets import widget, gui
from Orange.widgets.settings import Setting, ContextSetting, \
    PerfectDomainContextHandler, SettingProvider
from Orange.widgets.utils.domaineditor import DomainEditor
from Orange.widgets.utils.itemmodels import PyListModel
from Orange.widgets.utils.filedialogs import RecentPathsWComboMixin

# Backward compatibility: class RecentPath used to be defined in this module,
# and it is used in saved (pickled) settings. It must be imported into the
# module's namespace so that old saved settings still work
from Orange.widgets.utils.filedialogs import RecentPath


log = logging.getLogger(__name__)


def add_origin(examples, filename):
    """
    Adds attribute with file location to each string variable
    Used for relative filenames stored in string variables (e.g. pictures)
    TODO: we should consider a cleaner solution (special variable type, ...)
    """
    if not filename:
        return
    vars = examples.domain.variables + examples.domain.metas
    strings = [var for var in vars if var.is_string]
    dir_name, basename = os.path.split(filename)
    for var in strings:
        if "type" in var.attributes and "origin" not in var.attributes:
            var.attributes["origin"] = dir_name


class NamedURLModel(PyListModel):
    def __init__(self, mapping):
        self.mapping = mapping
        super().__init__()

    def data(self, index, role):
        data = super().data(index, role)
        if role == Qt.DisplayRole:
            return self.mapping.get(data, data)
        return data

    def add_name(self, url, name):
        self.mapping[url] = name
        self.modelReset.emit()


class LineEditSelectOnFocus(QLineEdit):
    def focusInEvent(self, event):
        super().focusInEvent(event)
        # If selectAll is called directly, placing the cursor unselects the text
        QTimer.singleShot(0, self.selectAll)


class OWFile(widget.OWWidget, RecentPathsWComboMixin):
    name = "File"
    id = "orange.widgets.data.file"
    description = "Read data from an input file or network " \
                  "and send a data table to the output."
    icon = "icons/File.svg"
    priority = 10
    category = "Data"
    keywords = ["data", "file", "load", "read"]
    outputs = [widget.OutputSignal(
        "Data", Table,
        doc="Attribute-valued data set read from the input file.")]

    want_main_area = False

    SEARCH_PATHS = [("sample-datasets", get_sample_datasets_dir())]
    SIZE_LIMIT = 1e7
    LOCAL_FILE, URL = range(2)

    settingsHandler = PerfectDomainContextHandler()

    # Overload RecentPathsWidgetMixin.recent_paths to set defaults
    recent_paths = Setting([
        RecentPath("", "sample-datasets", "iris.tab"),
        RecentPath("", "sample-datasets", "titanic.tab"),
        RecentPath("", "sample-datasets", "housing.tab"),
        RecentPath("", "sample-datasets", "heart_disease.tab"),
    ])
    recent_urls = Setting([])
    source = Setting(LOCAL_FILE)
    xls_sheet = ContextSetting("")
    sheet_names = Setting({})
    url = Setting("")

    variables = ContextSetting([])

    dlg_formats = (
        "All readable files ({});;".format(
            '*' + ' *'.join(FileFormat.readers.keys())) +
        ";;".join("{} (*{})".format(f.DESCRIPTION, ' *'.join(f.EXTENSIONS))
                  for f in sorted(set(FileFormat.readers.values()),
                                  key=list(FileFormat.readers.values()).index)))

    domain_editor = SettingProvider(DomainEditor)

    class Warning(widget.OWWidget.Warning):
        file_too_big = widget.Msg("The file is too large to load automatically."
                                  " Press Reload to load.")

    def __init__(self):
        super().__init__()
        RecentPathsWComboMixin.__init__(self)
        self.domain = None
        self.data = None
        self.loaded_file = ""
        self.reader = None

        layout = QGridLayout()
        gui.widgetBox(self.controlArea, margin=0, orientation=layout)
        vbox = gui.radioButtons(None, self, "source", box=True, addSpace=True,
                                callback=self.load_data, addToLayout=False)

        rb_button = gui.appendRadioButton(vbox, "File:", addToLayout=False)
        layout.addWidget(rb_button, 0, 0, Qt.AlignVCenter)

        box = gui.hBox(None, addToLayout=False, margin=0)
        box.setSizePolicy(Policy.MinimumExpanding, Policy.Fixed)
        self.file_combo.setSizePolicy(Policy.MinimumExpanding, Policy.Fixed)
        self.file_combo.activated[int].connect(self.select_file)
        box.layout().addWidget(self.file_combo)
        layout.addWidget(box, 0, 1)

        file_button = gui.button(
            None, self, '...', callback=self.browse_file, autoDefault=False)
        file_button.setIcon(self.style().standardIcon(QStyle.SP_DirOpenIcon))
        file_button.setSizePolicy(Policy.Maximum, Policy.Fixed)
        layout.addWidget(file_button, 0, 2)

        reload_button = gui.button(
            None, self, "Reload", callback=self.load_data, autoDefault=False)
        reload_button.setIcon(self.style().standardIcon(
            QStyle.SP_BrowserReload))
        reload_button.setSizePolicy(Policy.Fixed, Policy.Fixed)
        layout.addWidget(reload_button, 0, 3)

        self.sheet_box = gui.hBox(None, addToLayout=False, margin=0)
        self.sheet_combo = gui.comboBox(None, self, "xls_sheet",
                                        callback=self.select_sheet,
                                        sendSelectedValue=True,)
        self.sheet_combo.setSizePolicy(
            Policy.MinimumExpanding, Policy.Fixed)
        self.sheet_label = QLabel()
        self.sheet_label.setText('Sheet')
        self.sheet_label.setSizePolicy(
            Policy.MinimumExpanding, Policy.Fixed)
        self.sheet_box.layout().addWidget(
            self.sheet_label, Qt.AlignLeft)
        self.sheet_box.layout().addWidget(
            self.sheet_combo, Qt.AlignVCenter)
        layout.addWidget(self.sheet_box, 2, 1)
        self.sheet_box.hide()

        rb_button = gui.appendRadioButton(vbox, "URL:", addToLayout=False)
        layout.addWidget(rb_button, 3, 0, Qt.AlignVCenter)

        self.url_combo = url_combo = QComboBox()
        url_model = NamedURLModel(self.sheet_names)
        url_model.wrap(self.recent_urls
)
        url_combo.setLineEdit(LineEditSelectOnFocus())
        url_combo.setModel(url_model)
        url_combo.setSizePolicy(Policy.MinimumExpanding, Policy.Fixed)
        url_combo.setEditable(True)
        url_combo.setInsertPolicy(url_combo.InsertAtTop)
        url_edit = url_combo.lineEdit()
        l, t, r, b = url_edit.getTextMargins()
        url_edit.setTextMargins(l + 5, t, r, b)
        layout.addWidget(url_
combo, 3, 1, 3, 3)
        url_combo.activated.connect(self._url_set)

        box = gui.vBox(self.controlArea, "Info")
        self.info = gui.widgetLabel(box, 'No data loaded.')
        self.warnings = gui.widgetLabel(box, '')

        box = gui.widgetBox(self.controlArea, "Columns (Double click to edit)")
        self.domain_editor = DomainEditor(self)
        self.editor_model = self.domain_editor.model()
        box.layout().addWidget(self.domain_editor)

        box = gui.hBox(self.controlArea)
        gui.button(
            box, self, "Browse documentation data sets",
            callback=lambda: self.browse_file(True), autoDefault=False)
        gui.rubber(box)
        box.layout().addWidget(self.report_button)
        self.report_button.setFixedWidth(170)

        self.apply_button = gui.button(
            box, self, "Apply", callback=self.apply_domain_edit)
        self.apply_button.setEnabled(False)
        self.apply_button.s