Vue.use(VueMaterial.default);

const getCreatePostError = (json) => {
    switch (json.message) {
        case 'ERROR_REQUEST_INVALID_DATA': {
            switch (json.errors[0].param) {
                case 'title': {
                    return 'Invalid title. Must be between 3 and 32 characters.';
                }
                case 'body': {
                    return 'Invalid content. Must be between 3 and 1000 characters';
                }
                case 'category': {
                    return 'Invalid category. Something went wrong.';
                }
                default: {
                    return 'Invalid value sent to server. Something went wrong.';
                }
            }
        }

        case 'ERROR_CATEGORY_NOT_FOUND': {
            return 'The category you tried to post to no longer exists.';
        }

        case 'ERROR_ACCESS_DENIED': {
            return 'You are not allowed to perform this action.'
        }

        default: {
            return 'Unknown error. Something went wrong.';
        }
    }
}

const getCreateCategoryError = (json) => {
    switch (json.message) {
        case 'ERROR_REQUEST_INVALID_DATA': {
            switch (json.errors[0].param) {
                case 'title': {
                    return 'Invalid title. Title must be between 3 and 32 characters.';
                }
            }
        }

        case 'ERROR_ACCESS_DENIED': {
            return 'You are not allowed to perform this action.'
        }

        default: {
            return 'Unknown error. Something went wrong.';
        }
    }
}

class GatewayConnection {
    constructor() {
        this.isConnected = false;
        this.socket = null;

        // TODO: set up proper event listening and such, not this dumb crap
        this.onDisconnect = () => {}
        this.onConnect = () => {}
    }
}

GatewayConnection.prototype.disconnect = function() {
    this.socket?.disconnect();
    this.socket = null;
    this.isConnected = false;
};

GatewayConnection.prototype.connect = function(token) {
    console.log('[*] [gateway] [handshake] Trying to connect to gateway');
    this.socket = io('/gateway', {
        query: {
            token
        },
        transports: ['websocket']
    });

    this.socket.on('connect', () => {
        this.socket.once('hello', (debugInfo) => {
            console.log('[*] [gateway] [handshake] Got hello from server, sending yoo...', debugInfo);
            this.socket.emit('yoo');
            this.isConnected = true;
            this.debugInfo = debugInfo;
            this.onConnect('CONNECT_RECEIVED_HELLO');
            console.log('[*] [gateway] [handshake] Assuming that server received yoo and that connection is completed.');
        });
    })

    this.socket.on('error', (e) => {
        console.log('[E] [gateway] Gateway error', e);
        this.isConnected = false;
        this.socket = null;
        this.onDisconnect('DISCONNECT_ERR', e);
    });
    this.socket.on('disconnectNotification', (e) => {
        console.log('[E] [gateway] Received disconnect notfication', e);
        this.isConnected = false;
        this.socket = null;
        this.onDisconnect('DISCONNECT_NOTIF', e);
    });
    this.socket.on('disconnect', (e) => {
        console.log('[E] [gateway] Disconnected from gateway: ', e);
        this.isConnected = false;
        this.onDisconnect('DISCONNECT', e);
    });
};

GatewayConnection.prototype.sendMessage = function(categoryId, content) {
    if (!this.isConnected) return 1;
    if (content.length >= 2000) return 1;

    this.socket.emit('message', {
        category: {
            _id: categoryId
        },
        content
    });
};

GatewayConnection.prototype.subscribeToCategoryChat = function(categoryId) {
    if (!this.isConnected) return;

    const request = [categoryId];

    console.log('[*] [gateway] Subscribing to channel(s)', request);

    this.socket.emit('subscribe', request);
};


const app = new Vue({
    el: '#app',
    data: {
        showSnackbarNotification: false,
        snackbarNotification: '',
        snackbarNotificationDuration: 999999,
        snackbarButtonText: 'Ok',
        loggedInUser: {},
        showApp: false,
        menuVisible: false,
        selection: {
            category: {
                title: '',
                browsing: false,
                _id: undefined,
                isCategory: false,
                isChatContext: false
            },
            posts: []
        },
        cardButtons: [],
        dialog: {
            show: {
                createPost: false,
                createCategory: false,
                debug: false
            },
            text: {
                createPost: {
                    title: '',
                    body: ''
                },
                createCategory: {
                    title: ''
                }
            }
        },
        viewingProfile: {
            show: false,
            _id: '',
            username: '',
            role: ''
        },
        gateway: new GatewayConnection(),
        messages: {
            'X': [ { username: '__SYSTEM', content: 'TEST MSG' } ]
        },
        userLists: {
            'X': [ { username: '__SYSTEM', _id: 'INVALID_ID' } ]
        },
        message: {
            typed: ''
        }
    },
    mounted: async function() {
        const res = await fetch(`${window.location.origin}/api/v1/users/current/info`, {
            method: 'GET',
            headers: {
                'Accept': 'application/json',
            },
            credentials: 'include'
        });

        if (res.ok) {
            const json = await res.json();
            if (json.user.permissionLevel >= 1) {
                this.loggedInUser = json.user;
                this.showApp = true;
                this.performGatewayConnection();
                this.browseCategories();
                Notification.requestPermission();
            } else {
                this.showApp = false;
                this.snackbarEditButton('Manage', () => {
                    window.location.href = `${window.location.origin}/auth.html`;
                    this.resetSnackbarButton();
                    this.showSnackbarNotification = false;
                });
                this.notification('Your account does not have the required permissions to enter this page');
            }
        } else {
            this.showApp = false;
            this.snackbarEditButton('Manage', () => {
                window.location.href = `${window.location.origin}/auth.html`;
                this.resetSnackbarButton();
                this.showSnackbarNotification = false;
            });
            this.notification('You are not logged in or your session is invalid');
        }
    },
    methods: {
        // Gateway and chat
        performGatewayConnection: function() {
            // TODO: again, the thing im doing with the token is not very secure, since its being sent by the current user info endpoint and is also being send through query parameters
            this.gateway.onDisconnect = (e) => {
                this.okNotification('Connection lost.');
            };
            this.gateway.connect(this.loggedInUser.token);
            this.gateway.socket.on('message', (e) => {
                //console.log('[*] [gateway] Message received', e);
                this.processMessage(e);
            });
            this.gateway.socket.on('clientListUpdate', (e) => {
                console.log('[*] [gateway] Client list update', e);
                this.processUserListUpdate(e);
            });
            this.gateway.socket.on('refreshClient', (e) => {
                console.log('[*] [gateway] Gateway requested refresh', e);
                this.gateway.disconnect();
                this.messages = {};
                this.userLists = {};
                this.message.typed = '';
                if (e.reason === 'exit') {
                    this.showApp = false;
                    this.okNotification('The server has exited. Sit tight!');
                } else if (e.reason === 'upd') {
                    this.showApp = false;
                    this.okNotification('An update has just rolled out! To ensure everything runs smoothly, you need to refresh the page!');
                } else {
                    this.showApp = false;
                    this.okNotification('Sorry, but something happened and a refresh is required to keep using the app!');
                }
                this.snackbarEditButton('Refresh', () => {
                    window.location.reload();
                });
            });
        },
        shouldMergeMessage: function(messageObject, categoryMessageList) {
            const lastMessageIndex = categoryMessageList.length-1;
            const lastMessage = categoryMessageList[lastMessageIndex];

            if (!lastMessage) return;
            if (lastMessage.author._id === messageObject.author._id) {
                if (lastMessage.nickAuthor && messageObject.nickAuthor && lastMessage.nickAuthor.username === messageObject.nickAuthor.username) {
                    return true;
                }
            }
            if (lastMessage.author._id === messageObject.author.id) return true;
        },
        processMessage: async function(messageObject) {
            if (!this.messages[messageObject.category._id]) this.$set(this.messages, messageObject.category._id, []);
            const categoryMessageList = this.messages[messageObject.category._id];
            const lastMessageIndex = categoryMessageList.length-1;

            if (this.shouldMergeMessage(messageObject, categoryMessageList)) {
                categoryMessageList[lastMessageIndex].content += `\n${messageObject.content}`;
            } else {
                this.messages[messageObject.category._id].push(messageObject);
            }
            
            if (messageObject.category._id === this.selection.category._id) {
                this.$nextTick(() => {
                    // TODO: When the user presses back, actually undo this scroll cause its annoying to scroll back up in the category list
                    const container = this.$el.querySelector('#posts-container');
                    container.scrollTop = container.scrollHeight;
                });
            }

            if (messageObject.author.username !== this.loggedInUser.username && messageObject.category._id !== this.selection.category._id) {
                this.okNotification(`${messageObject.category.title}/${messageObject.author.username}: ${messageObject.content}`);
            }

            if (messageObject.author.username !== this.loggedInUser.username) {
                if (Notification.permission === 'granted') {
                    try {
                        new Notification(`${messageObject.category.title}/${messageObject.author.username}`, {
                            body: messageObject.content
                        });
                    } catch(e) {
                        console.log('[E] [chat] Failed to show notification');
                    }

                }
            }
        },
        processUserListUpdate: async function(e) {
            const { category, clientList } = e;
            if (!this.userLists[category._id]) this.$set(this.userLists, category._id, []);
            this.userLists[category._id] = clientList;
        },
        openChatForCategory: async function(categoryId) {
            this.gateway.subscribeToCategoryChat(categoryId);
            
            this.selection.category.isChatContext = true;
            this.selection.category.browsing = true;
            this.selection.category.title = 'Chat';
            this.selection.category._id = categoryId;
        },
        sendCurrentMessage: async function() {
            const status = await this.gateway.sendMessage(this.selection.category._id, this.message.typed);
            if (status === 1) {
                this.okNotification('Failed to send message!');
                return;
            }
            this.message.typed = '';
        },

        // Debug
        toggleDebugDialog: async function() {
            this.dialog.show.debug = !this.dialog.show.debug;
        },
        debugDump: async function() {
            console.log('[DEBUG DUMP] [gateway]', this.gateway);
            console.log('[DEBUG DUMP] [loggedInUser] (this contains sensitive information about the current logged in user, do not leak it to other people lol)', this.loggedInUser);
        },

        // Category and post browsing
        browseCategories: async function() {
            const res = await fetch(`${window.location.origin}/api/v1/content/category/list?count=50`, {
                method: 'GET',
                headers: {
                    'Accept': 'application/json',
                },
                credentials: 'include'
            });

            if (res.ok) {
                const json = await res.json();

                this.selection.category.title = 'categories';
                this.selection.category.browsing = true;
                this.selection.category.isCategory = false;
                this.selection.category.isChatContext = false;
                this.selection.category._id = '__CATEGORY_LIST';
                this.selection.posts = [];

                this.cardButtons = [];

                this.button('chat', (post) => {
                    if (post._id) {
                        this.openChatForCategory(post._id);
                    }
                });
                this.button('topic', (post) => {
                    this.browse(post);
                });

                for (let i = 0; i < json.categories.length; i++) {
                    const v = json.categories[i];
                    this.selection.posts.push({ title: v.title, body: '', _id: v._id, creator: v.creator });
                }
            } else {
                this.okNotification('Failed to fetch category list');
            }
        },
        browse: async function(category) {
            const { _id, title } = category;

            const res = await fetch(`${window.location.origin}/api/v1/content/category/${_id}/info`, {
                method: 'GET',
                headers: {
                    'Accept': 'application/json',
                },
                credentials: 'include'
            });

            if (res.ok) {
                const json = await res.json();

                this.selection.category.title = title;
                this.selection.category._id = _id;
                this.selection.category.browsing = true;
                this.selection.category.isCategory = true;
                this.selection.category.isChatContext = false;
                this.selection.posts = [];

                this.cardButtons = [];

                for (let i = 0; i < json.category.posts.length; i++) {
                    const v = json.category.posts[i];
                    this.selection.posts.push({ title: v.title, body: v.body, _id: v._id, creator: v.creator });
                }
            } else {
                this.okNotification('Failed to fetch category');
            }
        },
        refresh: function() {
            if (this.selection.category.title === 'categories' && this.selection.category.isCategory === false) {
                this.browseCategories();
            } else {
                this.browse(this.selection.category);
            }
        },
        button: function(text, click) {
            this.cardButtons.push({ text, click });
        },
        stopBrowsing: function() {
            this.selection.category = {
                title: '',
                browsing: false,
                _id: undefined,
                isCategory: false,
                isChatContext: false
            };
            this.selection.posts = [];
            this.cardButtons = [];
        },
        viewProfile: async function(id) {
            // TODO: this just returns the username for now
            const res = await fetch(`${window.location.origin}/api/v1/users/user/${id}/info`, {
                method: 'GET',
                headers: {
                    'Accept': 'application/json',
                },
                credentials: 'include'
            });

            if (res.ok) {
                const json = await res.json();
                this.viewingProfile.username = json.user.username;
                this.viewingProfile._id = json.user._id;
                this.viewingProfile.role = json.user.role;
                this.viewingProfile.show = true;
            } else {
                this.okNotification('Failed to fetch user data');
            }
        },

        // Content creation
        showCreatePostDialog: function() {
            if (!this.selection.category.isCategory) {
                this.okNotification('You are not in a category');
                return;
            }

            this.dialog.show.createPost = true;
        },
        createPost: async function() {
            if (!this.selection.category.isCategory) {
                this.okNotification('You are not in a category');
                return;
            }

            const category = this.selection.category;
            const input = this.dialog.text.createPost;

            const res = await fetch(`${window.location.origin}/api/v1/content/post/create`, {
                method: 'POST',
                headers: {
                    'Accept': 'application/json',
                    'Content-Type': 'application/json'
                },
                credentials: 'include',
                body: JSON.stringify({
                    category: category._id,
                    title: input.title,
                    body: input.body
                })
            });

            if (res.ok) {
                this.okNotification('Successfully created post');
                this.dialog.show.createPost = false;
                this.browse(this.selection.category);
                return;
            } else {
                if (res.status === 401 || res.status === 403) {
                    this.okNotification('You are not allowed to do that');
                    return;
                }
                if (res.status === 429) {
                    this.okNotification('Chill! You are posting too much!');
                    return;
                }

                const json = await res.json();
                this.okNotification(getCreatePostError(json));
                return;
            }
        },
        createCategory: async function() {
            const input = this.dialog.text.createCategory;

            const res = await fetch(`${window.location.origin}/api/v1/content/category/create`, {
                method: 'POST',
                headers: {
                    'Accept': 'application/json',
                    'Content-Type': 'application/json'
                },
                credentials: 'include',
                body: JSON.stringify({
                    title: input.title
                })
            });

            if (res.ok) {
                this.okNotification('Successfully created category');
                this.dialog.show.createCategory = false;
                this.browseCategories();
                return;
            } else {
                if (res.status === 401 || res.status === 403) {
                    this.okNotification('You are not allowed to do that');
                    return;
                }
                if (res.status === 429) {
                    this.okNotification('Chill! You are posting too much!');
                    return;
                }

                const json = await res.json();
                this.okNotification(getCreateCategoryError(json));
                return;
            }
        },

        // Navigation
        navigateToAccountManager() {
            window.location.href = `${window.location.origin}/auth.html`;
        },

        // Snackbar
        snackbarButtonAction: function() {
            this.showSnackbarNotification = false;
        },
        snackbarButtonClick: function() {
            this.snackbarButtonAction();
        },
        snackbarEditButton: function(buttonText="Ok", action) {
            this.snackbarButtonText = buttonText;
            this.snackbarButtonAction = action;
        },
        resetSnackbarButton: function() {
            this.snackbarButtonText = 'Ok';
            this.snackbarButtonAction = () => {
                this.showSnackbarNotification = false;
            };
        },
        notification: function(text) {
            this.snackbarNotification = text;
            this.showSnackbarNotification = true;
        },
        okNotification: function(text) {
            this.resetSnackbarButton();
            this.notification(text);
        }
    }
});