/*
    Copyright (C) 2020 Sebastian J. Wolf and other contributors

    This file is part of Fernschreiber.

    Fernschreiber 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.

    Fernschreiber 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 Fernschreiber. If not, see <http://www.gnu.org/licenses/>.
*/
import QtQuick 2.6
import Sailfish.Silica 1.0
import Nemo.Notifications 1.0
import WerkWolf.Fernschreiber 1.0
import "../components"
import "../js/twemoji.js" as Emoji
import "../js/functions.js" as Functions
import "../js/debug.js" as Debug

Page {
    id: overviewPage
    allowedOrientations: Orientation.All

    property bool initializationCompleted: false;
    property bool loading: true;
    property int authorizationState: TelegramAPI.Closed
    property int connectionState: TelegramAPI.WaitingForNetwork
    property int ownUserId;
    property bool chatListCreated: false;

    onStatusChanged: {
        if (status === PageStatus.Active && initializationCompleted && !chatListCreated) {
            updateContent();
        }
    }

    Connections {
        target: dBusAdaptor
        onPleaseOpenMessage: {
            Debug.log("[OverviewPage] Opening chat from external call...")
            if (chatListCreated) {
                pageStack.pop(overviewPage, PageStackAction.Immediate)
                pageStack.push(Qt.resolvedUrl("../pages/ChatPage.qml"), { "chatInformation" : chatListModel.getById(chatId) }, PageStackAction.Immediate)
            }
        }
        onPleaseOpenUrl: {
            Debug.log("[OverviewPage] Opening URL requested: ", url);
            Functions.handleLink(url);
        }
    }

    Timer {
        id: chatListCreatedTimer
        interval: 300
        running: false
        repeat: false
        onTriggered: {
            overviewPage.chatListCreated = true;
            chatListModel.redrawModel();
        }
    }

    function setPageStatus() {
        switch (overviewPage.connectionState) {
        case TelegramAPI.WaitingForNetwork:
            pageStatus.color = "red";
            pageHeader.title = qsTr("Waiting for network...");
            break;
        case TelegramAPI.Connecting:
            pageStatus.color = "gold";
            pageHeader.title = qsTr("Connecting to network...");
            break;
        case TelegramAPI.ConnectingToProxy:
            pageStatus.color = "gold";
            pageHeader.title = qsTr("Connecting to proxy...");
            break;
        case TelegramAPI.ConnectionReady:
            pageStatus.color = "green";
            pageHeader.title = qsTr("Fernschreiber");
            break;
        case TelegramAPI.Updating:
            pageStatus.color = "lightblue";
            pageHeader.title = qsTr("Updating content...");
            break;
        }
    }

    function updateContent() {
        tdLibWrapper.getChats();
        tdLibWrapper.getRecentStickers();
        tdLibWrapper.getInstalledStickerSets();
    }

    function initializePage() {
        overviewPage.authorizationState = tdLibWrapper.getAuthorizationState();
        overviewPage.handleAuthorizationState();
        overviewPage.connectionState = tdLibWrapper.getConnectionState();
        overviewPage.setPageStatus();
    }

    function handleAuthorizationState() {
        switch (overviewPage.authorizationState) {
        case TelegramAPI.WaitPhoneNumber:
        case TelegramAPI.WaitCode:
        case TelegramAPI.WaitPassword:
        case TelegramAPI.WaitRegistration:
            overviewPage.loading = false;
            pageStack.push(Qt.resolvedUrl("../pages/InitializationPage.qml"));
            break;
        case TelegramAPI.AuthorizationReady:
            overviewPage.loading = false;
            overviewPage.initializationCompleted = true;
            overviewPage.updateContent();
            break;
        default:
            // Nothing ;)
        }
    }

    Connections {
        target: tdLibWrapper
        onAuthorizationStateChanged: {
            overviewPage.authorizationState = authorizationState;
            handleAuthorizationState();
        }
        onConnectionStateChanged: {
            overviewPage.connectionState = connectionState;
            setPageStatus();
        }
        onOwnUserIdFound: {
            overviewPage.ownUserId = ownUserId;
        }
        onChatLastMessageUpdated: {
            if (!overviewPage.chatListCreated) {
                chatListCreatedTimer.restart();
            }
        }
        onChatOrderUpdated: {
            if (!overviewPage.chatListCreated) {
                chatListCreatedTimer.restart();
            }
        }
        onChatsReceived: {
            if(chats && chats.chat_ids && chats.chat_ids.length === 0) {
                chatListCreatedTimer.restart();
            }
        }
        onChatReceived: {
            if(chat["@extra"] === "openDirectly") {
                pageStack.pop(overviewPage, PageStackAction.Immediate)
                // if we get a new chat (no messages?), we can not use the provided data
                pageStack.push(Qt.resolvedUrl("../pages/ChatPage.qml"), { "chatInformation" : tdLibWrapper.getChat(chat.id) });
            }
        }
        onErrorReceived: {
            Functions.handleErrorMessage(code, message);
        }
    }

    Component.onCompleted: {
        initializePage();
    }

    SilicaFlickable {
        id: overviewContainer
        contentHeight: parent.height
        contentWidth: parent.width
        anchors.fill: parent
        visible: !overviewPage.loading

        PullDownMenu {
            MenuItem {
                text: qsTr("About Fernschreiber")
                onClicked: pageStack.push(Qt.resolvedUrl("../pages/AboutPage.qml"))
            }
            MenuItem {
                text: qsTr("Settings")
                onClicked: pageStack.push(Qt.resolvedUrl("../pages/SettingsPage.qml"))
            }
        }

        Column {
            id: column
            width: parent.width
            height: parent.height
            spacing: Theme.paddingMedium

            Row {
                id: headerRow
                width: parent.width

                GlassItem {
                    id: pageStatus
                    width: Theme.itemSizeMedium
                    height: Theme.itemSizeMedium
                    color: "red"
                    falloffRadius: 0.1
                    radius: 0.2
                    cache: false
                }

                PageHeader {
                    id: pageHeader
                    title: qsTr("Fernschreiber")
                    width: parent.width - pageStatus.width
                }
            }

            Item {
                id: chatListItem
                width: parent.width
                height: parent.height - Theme.paddingMedium - headerRow.height

                SilicaListView {

                    id: chatListView

                    anchors.fill: parent

                    clip: true
                    opacity: overviewPage.chatListCreated ? 1 : 0
                    Behavior on opacity { NumberAnimation {} }

                    model: chatListModel
                    delegate: ChatListViewItem {
                        ownUserId: overviewPage.ownUserId

                        onClicked: {
                            pageStack.push(Qt.resolvedUrl("../pages/ChatPage.qml"), {
                                chatInformation : display,
                                chatPicture: photo_small
                            })
                        }

                        Connections {
                            target: chatListModel
                            onChatChanged: {
                                if (overviewPage.chatListCreated && changedChatId === chat_id) {
                                    // Force update of some list item elements (currently only last message text seems to create problems). dataChanged() doesn't seem to trigger them all :(
                                    secondaryText.text = last_message_text ? Emoji.emojify(Functions.enhanceHtmlEntities(last_message_text), Theme.fontSizeExtraSmall) : qsTr("Unknown")
                                }
                            }
                        }
                    }

                    ViewPlaceholder {
                        enabled: chatListView.count === 0
                        text: qsTr("You don't have any chats yet.")
                    }

                    VerticalScrollDecorator {}
                }

                Column {
                    width: parent.width
                    height: loadingLabel.height + loadingBusyIndicator.height + Theme.paddingMedium
                    spacing: Theme.paddingMedium
                    anchors.verticalCenter: parent.verticalCenter

                    opacity: overviewPage.chatListCreated ? 0 : 1
                    Behavior on opacity { NumberAnimation {} }
                    visible: !overviewPage.chatListCreated

                    InfoLabel {
                        id: loadingLabel
                        text: qsTr("Loading chat list...")
                    }

                    BusyIndicator {
                        id: loadingBusyIndicator
                        anchors.horizontalCenter: parent.horizontalCenter
                        running: !overviewPage.chatListCreated
                        size: BusyIndicatorSize.Large
                    }
                }
            }
        }
    }
}