--[[*************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
***************************************************************************]]
local QtCore = require 'qtcore'
local QtWidgets = require 'qtwidgets'

--! [include finddialog's header]
local FindDialog = require 'finddialog'
--! [include finddialog's header]

local AddressBook = QtCore.Class('AddressBook', QtWidgets.QWidget) {}

--! [Mode enum]
local Mode = {
    NavigationMode = 0,
    AddingMode = 1,
    EditingMode = 2,
}
--! [Mode enum]

function AddressBook:__static_init()
    self:__addslot('addContact()', self.addContact)
    self:__addslot('submitContact()', self.submitContact)
    self:__addslot('cancel()', self.cancel)
    self:__addslot('editContact()', self.editContact)
    self:__addslot('removeContact()', self.removeContact)
    self:__addslot('findContact()', self.findContact)
    self:__addslot('next()', self.next)
    self:__addslot('previous()', self.previous)
--! [save and load functions declaration]
    self:__addslot('saveToFile()', self.saveToFile)
    self:__addslot('loadFromFile()', self.loadFromFile)
--! [save and load functions declaration]
end

function AddressBook:__init()
    self.contacts = { index = 1 }
    self.currentMode = Mode.NavigationMode

    local nameLabel = QtWidgets.QLabel.new(tr 'Name:')
    self.nameLine = QtWidgets.QLineEdit.new()
    self.nameLine:setReadOnly(true)

    local addressLabel = QtWidgets.QLabel.new(tr 'Address:')
    self.addressText = QtWidgets.QTextEdit.new()
    self.addressText:setReadOnly(true)

    self.addButton = QtWidgets.QPushButton.new(tr '&Add')
    self.addButton:show()
    self.submitButton = QtWidgets.QPushButton.new(tr '&Submit')
    self.submitButton:hide()
    self.cancelButton = QtWidgets.QPushButton.new(tr '&Cancel')
    self.cancelButton:hide()
    self.nextButton = QtWidgets.QPushButton.new(tr '&Next')
    self.nextButton:setEnabled(false)
    self.previousButton = QtWidgets.QPushButton.new(tr '&Previous')
    self.previousButton:setEnabled(false)
    self.editButton = QtWidgets.QPushButton.new(tr '&Edit')
    self.editButton:setEnabled(false)
    self.removeButton = QtWidgets.QPushButton.new(tr '&Remove')
    self.removeButton:setEnabled(false)
    self.findButton = QtWidgets.QPushButton.new(tr '&Find')
    self.findButton:setEnabled(false)

    self.loadButton = QtWidgets.QPushButton.new(tr '&Load...')
--! [tooltip 1]
    self.loadButton:setToolTip(tr 'Load contacts from a file')
--! [tooltip 1]
    self.saveButton = QtWidgets.QPushButton.new(tr '&Save...')
--! [tooltip 2]
    self.saveButton:setToolTip(tr 'Save contacts to a file')
--! [tooltip 2]
    self.saveButton:setEnabled(false)

    self.dialog = FindDialog.new { self }

    self.connect(self.addButton, SIGNAL 'clicked()', self, SLOT 'addContact()')
    self.connect(self.submitButton, SIGNAL 'clicked()', self, SLOT 'submitContact()')
    self.connect(self.cancelButton, SIGNAL 'clicked()', self, SLOT 'cancel()')
    self.connect(self.editButton, SIGNAL 'clicked()', self, SLOT 'editContact()')
    self.connect(self.removeButton, SIGNAL 'clicked()', self, SLOT 'removeContact()')
    self.connect(self.findButton, SIGNAL 'clicked()', self, SLOT 'findContact()')
    self.connect(self.nextButton, SIGNAL 'clicked()', self, SLOT 'next()')
    self.connect(self.previousButton, SIGNAL 'clicked()', self, SLOT 'previous()')
    self.connect(self.loadButton, SIGNAL 'clicked()', self, SLOT 'loadFromFile()')
    self.connect(self.saveButton, SIGNAL 'clicked()', self, SLOT 'saveToFile()')

    local buttonLayout1 = QtWidgets.QVBoxLayout.new()
    buttonLayout1:addWidget(self.addButton, QtCore.AlignTop)
    buttonLayout1:addWidget(self.editButton)
    buttonLayout1:addWidget(self.removeButton)
    buttonLayout1:addWidget(self.findButton)
    buttonLayout1:addWidget(self.submitButton)
    buttonLayout1:addWidget(self.cancelButton)
    buttonLayout1:addWidget(self.loadButton)
    buttonLayout1:addWidget(self.saveButton)
    buttonLayout1:addStretch()

    local buttonLayout2 = QtWidgets.QHBoxLayout.new()
    buttonLayout2:addWidget(self.previousButton)
    buttonLayout2:addWidget(self.nextButton)

    local mainLayout = QtWidgets.QGridLayout.new()
    mainLayout:addWidget(nameLabel, 0, 0)
    mainLayout:addWidget(self.nameLine, 0, 1)
    mainLayout:addWidget(addressLabel, 1, 0, QtCore.AlignTop)
    mainLayout:addWidget(self.addressText, 1, 1)
    mainLayout:addLayout(buttonLayout1, 1, 2)
    mainLayout:addLayout(buttonLayout2, 2, 1)

    self:setLayout(mainLayout)
    self:setWindowTitle(tr 'Simple Address Book')
end

function AddressBook:addContact()
    self.oldName = self.nameLine:text()
        :toStdString()
    self.oldAddress = self.addressText:toPlainText()
        :toStdString()

    self.nameLine:clear()
    self.addressText:clear()

    self:updateInterface(Mode.AddingMode)
end

function AddressBook:editContact()
    self.oldName = self.nameLine:text()
        :toStdString()
    self.oldAddress = self.addressText:toPlainText()
        :toStdString()

    self:updateInterface(Mode.EditingMode)
end

function AddressBook:_getContact(name)
    for idx,info in ipairs(self.contacts) do
        if info.name == name then
            return info,idx
        end
    end
    return nil
end

function AddressBook:_addContact(name, address)
    if self:_getContact(name) then
        return false
    end

    table.insert(self.contacts, {
        name = name,
        address = address,
    })
    self.contacts.index = #self.contacts

    return true
end

function AddressBook:_removeContact(name)
    for idx,info in ipairs(self.contacts) do
        if info.name == name then
            table.remove(self.contacts, idx)
            return true
        end
    end
    return false
end

function AddressBook:submitContact()
    local name = self.nameLine:text()
        :toStdString()
    local address = self.addressText:toPlainText()
        :toStdString()

    if #name == 0 or #address == 0 then
        return QtWidgets.QMessageBox.information(self
            , tr 'Empty Field'
            , tr 'Please enter a name and address.'
        )
    end

    if self.currentMode == Mode.AddingMode then

        if self:_addContact(name, address) then
            QtWidgets.QMessageBox.information(self
                , tr 'Add Successful'
                , tr('\'%1\' has been added to your address book.'):arg(name)
            )
        else
            return QtWidgets.QMessageBox.information(self
                , tr 'Add Successful'
                , tr('Sorry, \'%1\' is already in your address book.'):arg(name)
            )
        end
    elseif self.currentMode == Mode.EditingMode then

        if self.oldName ~= name then
            if not self:_getContact(name) then
                QtWidgets.QMessageBox.information(self
                    , tr 'Edit Successful'
                    , tr('\'%1\' has been edited in your address book.'):arg(name)
                )
                self:_removeContact(self.oldName)
                self:_addContact(name, address)
            else
                return QtWidgets.QMessageBox.information(self
                    , tr 'Edit Unsuccessful'
                    , tr('Sorry, \'%1\' is already in your address book.'):arg(name)
                )
            end
        elseif self.oldAddress ~= address then
                QtWidgets.QMessageBox.information(self
                    , tr 'Edit Successful'
                    , tr('\'%1\' has been edited in your address book.'):arg(name)
                )
                local info = self:_getContact(name)
                info.address = address
        end
    end

    self:updateInterface(Mode.NavigationMode)
end

function AddressBook:cancel()
    self.nameLine:setText(self.oldName)
    self.addressText:setText(self.oldAddress)
    self:updateInterface(Mode.NavigationMode)
end

function AddressBook:removeContact()
    local name = self.nameLine:text()
        :toStdString()
    local address = self.addressText:toPlainText()
        :toStdString()

    if self:_getContact(name) then
        local button = QtWidgets.QMessageBox.question(self
            , tr 'Confirm Remove'
            , tr ('Are you sure you want to remove \'%1\'?'):arg(name)
            , QtWidgets.QMessageBox.Yes + QtWidgets.QMessageBox.No
        )

        if button == 'Yes' then
            self:previous()
            self:_removeContact(name)

            QtWidgets.QMessageBox.information(self
                , tr 'Remove Successful'
                , tr('\'%1\' has been removed from your address book.'):arg(name)
            )
        end
    end
    self:updateInterface(Mode.NavigationMode)
end

function AddressBook:next()
    local index = self.contacts.index
    if index < #self.contacts then
        index = index + 1
    else
        index = 1
    end
    self.contacts.index = index

    local info = self.contacts[index]
    self.nameLine:setText(info.name)
    self.addressText:setText(info.address)
end

function AddressBook:previous()
    local index = self.contacts.index
    if index > 1 then
        index = index - 1
    else
        index = #self.contacts
    end
    self.contacts.index = index

    local info = self.contacts[index]
    self.nameLine:setText(info.name)
    self.addressText:setText(info.address)
end

function AddressBook:findContact()
    self.dialog:show()

    if self.dialog:exec() == QtWidgets.QDialog.Accepted then
        local contactName = self.dialog:getFindText()

        local info,idx = self:_getContact(contactName)
        if info then
            self.nameLine:setText(contactName)
            self.addressText:setText(info.address)
            self.contacts.index = idx
        else
            return QtWidgets.QMessageBox.information(self
                , tr 'Contact Not Found'
                , (tr 'Sorry, \'%1\' is not in your address book.'):arg(contactName)
            )
        end
    end
    self:updateInterface(Mode.NavigationMode)
end

function AddressBook:updateInterface(mode)
    self.currentMode = mode

    if mode == Mode.AddingMode or mode == Mode.EditingMode then
        self.nameLine:setReadOnly(false)
        self.nameLine:setFocus(QtCore.OtherFocusReason)
        self.addressText:setReadOnly(false)

        self.addButton:setEnabled(false)
        self.editButton:setEnabled(false)
        self.removeButton:setEnabled(false)

        self.nextButton:setEnabled(false)
        self.previousButton:setEnabled(false)

        self.submitButton:show()
        self.cancelButton:show()

        self.loadButton:setEnabled(false)
        self.saveButton:setEnabled(false)

    elseif mode == Mode.NavigationMode then
        if #self.contacts == 0 then
            self.nameLine:clear()
            self.addressText:clear()
        end

        self.nameLine:setReadOnly(true)
        self.addressText:setReadOnly(true)
        self.addButton:setEnabled(true)

        local number = 0
        for _,_ in ipairs(self.contacts) do
            number = number + 1
        end
        self.editButton:setEnabled(number >= 1)
        self.removeButton:setEnabled(number >= 1)
        self.findButton:setEnabled(number > 2)
        self.nextButton:setEnabled(number > 1)
        self.previousButton:setEnabled(number >1 )

        self.submitButton:hide()
        self.cancelButton:hide()

        self.loadButton:setEnabled(true)
        self.saveButton:setEnabled(number >= 1)
    end
end
--! [saveToFile() function part1]
function AddressBook:saveToFile()
    local fileName = QtWidgets.QFileDialog.getSaveFileName(self
        , tr 'Save Address Book'
        , ''
        , tr 'Address Book (*.abk)All Files (*)'
    )
--! [saveToFile() function part1]
--! [saveToFile() function part2]
    if fileName:isEmpty() then
        return
    else
        local file = QtCore.QFile(fileName)
        if not file:open(QtCore.QIODevice.WriteOnly) then
            QtWidgets.QMessageBox.information(self
                , tr 'Unable to open file'
                , file:errorString()
            )
            return
        end
--! [saveToFile() function part2]
--! [saveToFile() function part3]
        local out = QtCore.QDataStream(file)
        out:setVersion(QtCore.QDataStream.Qt_4_5)
        -- TODO:lqt bindings
--         out << contacts
    end
end
--! [saveToFile() function part3]
--! [loadFromFile() function part1]
function AddressBook:loadFromFile()
    local fileName = QtWidgets.QFileDialog.getOpenFileName(self
        , tr 'Save Address Book'
        , ''
        , tr 'Address Book (*.abk)All Files (*)'
    )
--! [loadFromFile() function part1]

--! [loadFromFile() function part2]
    if fileName:isEmpty() then
        return
    else
        local file = QtCore.QFile(fileName)
        if not file:open(QtCore.QIODevice.ReadOnly) then
            QtWidgets.QMessageBox.information(self
                , tr 'Unable to open file'
                , file:errorString()
            )
            return
        end

        local inf = QtCore.QDataStream(file)
        inf:setVersion(QtCore.QDataStream.Qt_4_5)
        -- TODO:lqt bindings
--         contacts.clear()   -- clear existing contacts
--         in >> contacts
--! [loadFromFile() function part2]

--! [loadFromFile() function part3]
        if #self.contacts == 0 then
            QtWidgets.QMessageBox.information(self
                , tr 'No contacts in file'
                , tr 'The file you are attempting to open contains no contacts.'
            )
        else
            local info = self.contacts[1]
            self.nameLine:setText(info.name)
            self.addressText:setText(info.address)
            self.contacts.index = 1
        end
    end
    self:updateInterface(Mode.NavigationMode)
end
--! [loadFromFile() function part3]

return AddressBook
