#!/usr/bin/env python3

# Copyright (C) 2017 Damon Lynch <damonlynch@gmail.com>

# This file is part of Rapid Photo Downloader.
#
# Rapid Photo Downloader 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.
#
# Rapid Photo Downloader 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 Rapid Photo Downloader. If not,
# see <http://www.gnu.org/licenses/>.

"""
Error log window for Rapid Photo Downloader
"""

__author__ = 'Damon Lynch'
__copyright__ = "Copyright 2017, Damon Lynch"

import logging
import shlex
import subprocess
import math
from collections import deque, namedtuple
from typing import Optional
from gettext import gettext as _
import re
from html import escape

from PyQt5.QtWidgets import (
    QTextEdit, QDialog, QDialogButtonBox, QLineEdit, QVBoxLayout, QHBoxLayout, QApplication,
    QPushButton, QLabel, QTextBrowser, QStyle
)
from PyQt5.QtGui import (
    QPalette, QIcon, QFontMetrics, QFont, QColor, QKeyEvent, QKeySequence, QTextDocument,
    QTextCursor, QPaintEvent, QPainter, QPen, QMouseEvent, QShowEvent
)
from PyQt5.QtCore import Qt, pyqtSlot, QSize, QUrl, QTimer, QRect, pyqtSignal, QEvent

import raphodo.qrc_resources as qrc_resources
from raphodo.constants import ErrorType
from raphodo.rpdfile import RPDFile
from raphodo.problemnotification import Problem, Problems
from raphodo.viewutils import translateButtons
from raphodo.storage import open_in_file_manager

# ErrorLogMessage = namedtuple('ErrorLogMessage', 'title body name uri')


class QFindLineEdit(QLineEdit):
    """
    LineEdit to be used for search, as in Firefox in page search.
    """


    def __init__(self, find_text='', parent=None) -> None:
        super().__init__(parent=parent)
        if not find_text:
            self.find_text = _('Find')
        else:
            self.find_text = find_text

        self.noTextPalette = QPalette()
        self.noTextPalette.setColor(QPalette.Text, Qt.gray)

        self.setEmptyState()

        self.cursorPositionChanged.connect(self.onCursorPositionChanged)
        self.textEdited.connect(self.onTextEdited)

    def setEmptyState(self) -> None:
        self.empty = True
        self.setText(self.find_text)
        self.setCursorPosition(0)
        self.setPalette(self.noTextPalette)

    @pyqtSlot(str)
    def onTextEdited(self, text: str) -> None:
        if not text:
            self.setEmptyState()
        elif self.empty:
            self.empty = False
            self.setPalette(QPalette())
            self.setText(text[:-len(self.find_text)])

    @pyqtSlot(int, int)
    def onCursorPositionChanged(self, old: int, new: int) -> None:
        if self.empty:
            self.blockSignals(True)
            self.setCursorPosition(0)
            self.blockSignals(False)

    def getText(self) -> str:
        if self.empty:
            return ''
        else:
            return self.text()


class ErrorReport(QDialog):
    """
    Display error messages from the download in a dialog.

    Search/find feature is live, like Firefox. However it's pretty slow
    with a large amount of data, so don't initiate a new search each
    and every time data is appended to the log window. Instead, if a search
    is active, wait for one second after text has been appended before
    doing the search.
    """

    dialogShown = pyqtSignal()
    dialogActivated = pyqtSignal()

    def __init__(self, rapidApp, parent=None) -> None:
        super().__init__(parent=parent)

        self.uris = []
        self.get_href = re.compile('<a href="?\'?([^"\'>]*)')

        self.setModal(False)
        self.setSizeGripEnabled(True)

        self.search_pending = False
        self.add_queue = deque()

        self.rapidApp = rapidApp

        layout = QVBoxLayout()
        self.setWindowTitle(_('Error Reports - Rapid Photo Downloader'))

        self.log = QTextBrowser()
        self.log.setReadOnly(True)

        sheet = """
        h1 {
            font-size: large;
            font-weight: bold;
        }
        """

        document = self.log.document()  # type: QTextDocument
        document.setDefaultStyleSheet(sheet)
        # document.setIndentWidth(QFontMetrics(QFont()).boundingRect('200').width())

        self.highlightColor = QColor('#cb1dfa')
        self.textHighlightColor = QColor(Qt.white)

        self.noFindPalette = QPalette()
        self.noFindPalette.setColor(QPalette.WindowText, QPalette().color(QPalette.Mid))
        self.foundPalette = QPalette()
        self.foundPalette.setColor(QPalette.WindowText, QPalette().color(QPalette.WindowText))

        self.find_cursors = []
        self.current_find_index = -1

        self.log.anchorClicked.connect(self.anchorClicked)
        self.log.setOpenLinks(False)

        self.defaultFont = QFont()
        self.defaultFont.setPointSize(QFont().pointSize() - 1)
        self.log.setFont(self.defaultFont)
        self.log.textChanged.connect(self.textChanged)

        message = _('Find in reports')
        self.find = QFindLineEdit(find_text=message)
        self.find.textEdited.connect(self.onFindChanged)
        style = self.find.style()  # type: QStyle
        frame_width = style.pixelMetric(QStyle.PM_DefaultFrameWidth)
        button_margin = style.pixelMetric(QStyle.PM_ButtonMargin)
        spacing = (frame_width + button_margin) * 2 + 8

        self.find.setMinimumWidth(QFontMetrics(QFont()).boundingRect(message).width() + spacing)

        font_height = QFontMetrics(self.font()).height()
        size = QSize(font_height, font_height)

        self.up = QPushButton()
        self.up.setIcon(QIcon(':/icons/up.svg'))
        self.up.setIconSize(size)
        self.up.clicked.connect(self.upClicked)
        self.up.setToolTip(_('Find the previous occurrence of the phrase'))
        self.down = QPushButton()
        self.down.setIcon(QIcon(':/icons/down.svg'))
        self.down.setIconSize(size)
        self.down.clicked.connect(self.downClicked)
        self.down.setToolTip(_('Find the next occurrence of the phrase'))

        self.highlightAll = QPushButton(_('&Highlight All'))
        self.highlightAll.setToolTip(_('Highlight all occurrences of the phrase'))
        self.matchCase = QPushButton(_('&Match Case'))
        self.matchCase.setToolTip(_('Search with case sensitivity'))
        self.wholeWords = QPushButton(_('&Whole Words'))
        self.wholeWords.setToolTip(_('Search whole words only'))
        for widget in (self.highlightAll, self.matchCase, self.wholeWords):
            widget.setCheckable(True)
            widget.setFlat(True)
        self.highlightAll.toggled.connect(self.highlightAllToggled)
        self.matchCase.toggled.connect(self.matchCaseToggled)
        self.wholeWords.toggled.connect(self.wholeWordsToggled)

        self.findResults = QLabel()
        self.findResults.setMinimumWidth(
            QFontMetrics(QFont()).boundingRect(_('%s of %s matches') % (1000, 1000)).width()
            + spacing
        )

        findLayout = QHBoxLayout()
        findLayout.setSpacing(0)
        spacing = 8
        findLayout.addWidget(self.find)
        findLayout.addWidget(self.up)
        findLayout.addWidget(self.down)
        findLayout.addSpacing(spacing)
        findLayout.addWidget(self.highlightAll)
        findLayout.addSpacing(spacing)
        findLayout.addWidget(self.matchCase)
        findLayout.addSpacing(spacing)
        findLayout.addWidget(self.wholeWords)
        findLayout.addSpacing(spacing)
        findLayout.addWidget(self.findResults)


        buttons = QDialogButtonBox(QDialogButtonBox.Close)
        translateButtons(buttons)
        self.clear = buttons.addButton(_('Clear'), QDialogButtonBox.ActionRole)  # type: QPushButton
        buttons.rejected.connect(self.reject)
        self.clear.clicked.connect(self.clearClicked)
        self.clear.setEnabled(False)

        layout.addWidget(self.log)
        layout.addLayout(findLayout)
        layout.addSpacing(6)
        layout.addWidget(buttons)

        self.setLayout(layout)

        self.onFindChanged('')

        self.icon_lookup = {
            ErrorType.warning: ':/report-warning.png',
            ErrorType.serious_error: ':/report-error.png',
            ErrorType.critical_error: ':/report-critical.png'
        }

    @pyqtSlot()
    def textChanged(self) -> None:
        self.clear.setEnabled(bool(self.log.document().characterCount()))

    def _makeFind(self, back: bool=False) -> int:
        flags = QTextDocument.FindFlags()
        if self.matchCase.isChecked():
            flags |= QTextDocument.FindCaseSensitively
        if self.wholeWords.isChecked():
            flags |= QTextDocument.FindWholeWords
        if back:
            flags |= QTextDocument.FindBackward
        return flags

    def _clearSearch(self) -> None:
        cursor = self.log.textCursor()  # type: QTextCursor
        if cursor.hasSelection():
            cursor.clearSelection()
            self.log.setTextCursor(cursor)
        self.find_cursors = []
        self.log.setExtraSelections([])

    @pyqtSlot()
    def _doFind(self) -> None:
        """
        Do the find / search.

        If text needs to be appended, delay the search for one second.
        """

        if self.add_queue:
            while self.add_queue:
                self._addProblems(problems=self.add_queue.popleft())
            QTimer.singleShot(1000, self._doFind)
            return

        cursor = self.log.textCursor()  # type: QTextCursor
        text = self.find.getText()
        highlight = self.highlightAll.isChecked()

        if self.find.empty or not text:
            self._clearSearch()
            self.findResults.setText('')
            return

        initial_position = cursor.selectionStart()  # type: int

        self.log.moveCursor(QTextCursor.Start)

        flags = self._makeFind()
        extraSelections = deque()

        count = 0
        index = None
        self.find_cursors = []

        while self.log.find(text, flags):
            cursor = self.log.textCursor()  # type: QTextCursor
            self.find_cursors.append(cursor)

            if index is None and cursor.selectionStart() >= initial_position:
                index = count
            count += 1

            if highlight:
                extra = QTextEdit.ExtraSelection()
                extra.format.setBackground(self.highlightColor)
                extra.format.setForeground(self.textHighlightColor)
                extra.cursor = cursor
                extraSelections.append(extra)

        self.log.setExtraSelections(extraSelections)

        if index is None:
            index = len(self.find_cursors) - 1

        if not self.find_cursors:
            cursor.setPosition(initial_position)
            self.log.setTextCursor(cursor)
            if not self.find.empty:
                self.findResults.setText(_('Phrase not found'))
                self.findResults.setPalette(self.noFindPalette)

        else:
            self.goToMatch(index=index)

        self.search_pending = False

    def goToMatch(self, index: int) -> None:
        if self.find_cursors:
            cursor = self.find_cursors[index]
            self.current_find_index = index
            self.log.setTextCursor(cursor)
            self.findResults.setText(_('%s of %s matches') % (index + 1, len(self.find_cursors)))
            self.findResults.setPalette(self.foundPalette)

    @pyqtSlot(bool)
    def upClicked(self, checked: bool) -> None:
        if self.current_find_index >= 0:
            if self.current_find_index == 0:
                index = len(self.find_cursors) - 1
            else:
                index = self.current_find_index - 1
            self.goToMatch(index=index)

    @pyqtSlot(bool)
    def downClicked(self, checked: bool) -> None:
        if self.current_find_index >= 0:
            if self.current_find_index == len(self.find_cursors) - 1:
                index = 0
            else:
                index = self.current_find_index + 1
            self.goToMatch(index=index)

    @pyqtSlot(str)
    def onFindChanged(self, text: str) -> None:
        self.up.setEnabled(not self.find.empty)
        self.down.setEnabled(not self.find.empty)

        self._doFind()

    @pyqtSlot(bool)
    def highlightAllToggled(self, toggled: bool) -> None:
        if self.find_cursors:
            extraSelections = deque()
            if self.highlightAll.isChecked():
                for cursor in self.find_cursors:
                    extra = QTextEdit.ExtraSelection()
                    extra.format.setBackground(self.highlightColor)
                    extra.format.setForeground(self.textHighlightColor)
                    extra.cursor = cursor
                    extraSelections.append(extra)
            self.log.setExtraSelections(extraSelections)

    @pyqtSlot(bool)
    def matchCaseToggled(self, toggled: bool) -> None:
        self._doFind()

    @pyqtSlot(bool)
    def wholeWordsToggled(self, toggled: bool) -> None:
        self._doFind()

    @pyqtSlot(bool)
    def clearClicked(self, toggled: bool) -> None:
        self.log.clear()
        self.clear.setEnabled(False)
        self._doFind()

    @pyqtSlot(QUrl)
    def anchorClicked(self, url: QUrl) -> None:
        if self.rapidApp.file_manager:
            # see documentation for self._saveUrls()
            fake_uri = url.url()
            index = int(fake_uri[fake_uri.find('///') + 3:])
            uri = self.uris[index]

            open_in_file_manager(
                file_manager=self.rapidApp.file_manager,
                file_manager_type=self.rapidApp.file_manager_type,
                uri=uri
            )

    def _saveUrls(self, text: str) -> str:
        """
        Sadly QTextBrowser uses QUrl, which doesn't understand the kind of URIs
        used by Gnome. It totally mangles them, in fact.

        So solution is to substitute in a dummy uri and then
        replace it in self.anchorClicked() when the user clicks on it
        """

        anchor_start = '<a href="'
        anchor_end = '</a>'

        start = text.find(anchor_start)
        if start < 0:
            return text
        new_text = text[:start]
        while start >= 0:
            href_end = text.find('">', start + 9)
            href = text[start + 9:href_end]
            end = text.find(anchor_end, href_end + 2)
            next_start = text.find(anchor_start, end + 4)
            if next_start >= end + 4:
                extra_text = text[end + 4:next_start]
            else:
                extra_text = text[end + 4:]
            new_text = '{}<a href="file:///{}">{}</a>{}'.format(
                new_text, len(self.uris), text[href_end + 2:end], extra_text
            )
            self.uris.append(href)
            start = next_start

        return new_text

    def _getBody(self, problem: Problem) -> str:
        """
        Get the body (subject) of the problem, and any details
        """

        line = self._saveUrls(problem.body)

        if len(problem.details) == 1:
            line = '{}<br><i>{}</i>'.format(line, self._saveUrls(problem.details[0]))
        elif len(problem.details) > 1:
            for detail in problem.details:
                line = '{}<br><i>{}</i>'.format(line, self._saveUrls(detail))

        return line

    def _addProblems(self, problems: Problems) -> None:
        """
        Add problems to the log window
        """

        title = self._saveUrls(problems.title)
        html = '<h1>{}</h1><p></p>'.format(title)
        html = '{}<table>'.format(html)
        for problem in problems:
            line = self._getBody(problem=problem)
            icon = self.icon_lookup[problem.severity]
            icon = '<img src="{}" height=16 width=16>'.format(icon)
            html = '{}<tr><td width=32 align=center>{}</td><td style="padding-bottom: 6px;">' \
                   '{}</td></tr>'.format(html, icon, line)
        html = '{}</table>'.format(html)

        html = '{}<p></p><p></p>'.format(html)
        self.log.append(html)

    def addProblems(self, problems: Problems) -> None:
        if not self.find.empty and self.find_cursors:
            self._clearSearch()

        if not self.find.empty and self.search_pending:
            self.add_queue.append(problems)
        else:
            self._addProblems(problems=problems)

        if not self.find.empty and not self.search_pending:
            self.search_pending = True
            self.findResults.setText(_('Search pending...'))
            self.findResults.setPalette(self.noFindPalette)
            QTimer.singleShot(1000, self._doFind)

    def keyPressEvent(self, event: QKeyEvent) -> None:
        if event.matches(QKeySequence.Find):
            self.find.setFocus()
        else:
            super().keyPressEvent(event)

    @pyqtSlot()
    def activate(self) -> None:
        self.setVisible(True)
        self.activateWindow()
        self.raise_()

    def showEvent(self, event: QShowEvent) -> None:
        super().showEvent(event)
        self.dialogShown.emit()

    def changeEvent(self, event: QEvent) -> None:
        if event.type() == QEvent.ActivationChange and self.isActiveWindow():
            self.dialogActivated.emit()
        super().changeEvent(event)


class SpeechBubble(QLabel):

    """
    Display a speech bubble with a counter in it, that when clicked
    emits a signal and resets.

    Bubble displayed only when counter is > 0.
    """

    clicked = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)
        self.rapidApp = parent
        self.image = QIcon(':/speech-bubble.svg')
        self._count = 0
        self.fillColor = QPalette().color(QPalette.Window)
        self.counterFont = QFont()
        self.counterFont.setPointSize(QFont().pointSize() - 1)
        self.custom_height = max(math.ceil(QFontMetrics(self.counterFont).height() * 1.7), 24)
        self.counterPen = QPen(QColor(Qt.white))
        self.setStyleSheet("QLabel {border: 0px;}")
        self.click_tooltip = _('The number of new entries added to the Error Report since it was '
                               'last open. Click to open the Error Report.')

    @property
    def count(self) -> int:
        return self._count

    @count.setter
    def count(self, value) -> None:
        self._count = value
        if value > 0:
            self.setToolTip(self.click_tooltip)
        self.update()

    def incrementCounter(self, increment: int=1) -> None:
        self._count += increment
        self.setToolTip(self.click_tooltip)
        self.update()

    def paintEvent(self, event: QPaintEvent ):

        painter = QPainter()
        painter.begin(self)

        height = self.height()

        rect = self.rect()  # type: QRect
        if not self._count:
            painter.fillRect(rect, self.fillColor)
        else:
            painter.drawPixmap(0, 0, height, height, self.image.pixmap(height, height))
            painter.setFont(self.counterFont)
            painter.setPen(self.counterPen)
            if self._count > 9:
                value = '9+'
            else:
                value = str(self._count)
            painter.drawText(rect, Qt.AlignCenter, value)
        painter.end()

    def sizeHint(self) -> QSize:
        return QSize(self.custom_height, self.custom_height)

    def mousePressEvent(self, event: QMouseEvent) -> None:
        self.clicked.emit()
        self.reset()

    @pyqtSlot()
    def reset(self) -> None:
        self.count = 0
        self.setToolTip('')


if __name__ == '__main__':

    # Application development test code:

    app = QApplication([])

    log = ErrorReport(None)
    log.show()
    app.exec_()