sync/lib/channel/filters.js

var FilterList = require('cytubefilters');
var ChannelModule = require("./module");
var XSS = require("../xss");
var Logger = require("../logger");

function validateFilter(f) {
    if (typeof f.source !== "string" || typeof f.flags !== "string" ||
        typeof f.replace !== "string") {
        return false;
    }

    if (typeof f.name !== "string") {
        f.name = f.source;
    }

    f.replace = f.replace.substring(0, 1000);
    f.replace = XSS.sanitizeHTML(f.replace);
    f.flags = f.flags.substring(0, 4);

    try {
        new RegExp(f.source, f.flags);
    } catch (e) {
        return false;
    }

    var filter = {
        name: f.name,
        source: f.source,
        replace: fixReplace(f.replace),
        flags: f.flags,
        active: !!f.active,
        filterlinks: !!f.filterlinks
    };

    return filter;
}

function fixReplace(replace) {
    return replace.replace(/\$(\d)/g, '\\$1');
}

function makeDefaultFilter(name, source, flags, replace) {
    return {
        name: name,
        source: source,
        flags: flags,
        replace: fixReplace(replace),
        active: true,
        filterlinks: false
    };
}

const DEFAULT_FILTERS = [
    makeDefaultFilter("monospace", "`(.+?)`", "g", "<code>$1</code>"),
    makeDefaultFilter("bold", "\\*(.+?)\\*", "g", "<strong>$1</strong>"),
    makeDefaultFilter("italic", "_(.+?)_", "g", "<em>$1</em>"),
    makeDefaultFilter("strike", "~~(.+?)~~", "g", "<s>$1</s>"),
    makeDefaultFilter("inline spoiler", "\\[sp\\](.*?)\\[\\/sp\\]", "ig", "<span class=\"spoiler\">$1</span>")
];

function ChatFilterModule(channel) {
    ChannelModule.apply(this, arguments);
    this.filters = new FilterList(DEFAULT_FILTERS);
}

ChatFilterModule.prototype = Object.create(ChannelModule.prototype);

ChatFilterModule.prototype.load = function (data) {
    if ("filters" in data) {
        for (var i = 0; i < data.filters.length; i++) {
            var f = validateFilter(data.filters[i]);
            if (f) {
                try {
                    this.filters.updateFilter(f);
                } catch (e) {
                    if (e.message.match(/does not exist/i)) {
                        try {
                            this.filters.addFilter(f);
                        } catch (e) {
                            Logger.errlog.log("Filter load failed: " +
                                JSON.stringify(f) + " c:" + this.channel.name);
                        }
                    } else {
                        Logger.errlog.log("Filter load failed: " +
                            JSON.stringify(f) + " c:" + this.channel.name);
                    }
                }
            }
        }
    }
};

ChatFilterModule.prototype.save = function (data) {
    data.filters = this.filters.pack();
};

ChatFilterModule.prototype.packInfo = function (data, isAdmin) {
    if (isAdmin) {
        data.chatFilterCount = this.filters.length;
    }
};

ChatFilterModule.prototype.onUserPostJoin = function (user) {
    user.socket.on("addFilter", this.handleAddFilter.bind(this, user));
    user.socket.on("updateFilter", this.handleUpdateFilter.bind(this, user));
    user.socket.on("importFilters", this.handleImportFilters.bind(this, user));
    user.socket.on("moveFilter", this.handleMoveFilter.bind(this, user));
    user.socket.on("removeFilter", this.handleRemoveFilter.bind(this, user));
    user.socket.on("requestChatFilters", this.handleRequestChatFilters.bind(this, user));
};

ChatFilterModule.prototype.sendChatFilters = function (users) {
    var f = this.filters.pack();
    var chan = this.channel;
    users.forEach(function (u) {
        if (chan.modules.permissions.canEditFilters(u)) {
            u.socket.emit("chatFilters", f);
        }
    });
};

ChatFilterModule.prototype.handleAddFilter = function (user, data) {
    if (typeof data !== "object") {
        return;
    }

    if (!this.channel.modules.permissions.canEditFilters(user)) {
        return;
    }

    data = validateFilter(data);
    if (!data) {
        return;
    }

    try {
        this.filters.addFilter(data);
    } catch (e) {
        user.socket.emit("errorMsg", {
            msg: "Filter add failed: " + e.message,
            alert: true
        });
        return;
    }
    var chan = this.channel;
    chan.users.forEach(function (u) {
        if (chan.modules.permissions.canEditFilters(u)) {
            u.socket.emit("updateChatFilter", data);
        }
    });

    chan.logger.log("[mod] " + user.getName() + " added filter: " + data.name + " -> " +
                    "s/" + data.source + "/" + data.replace + "/" + data.flags + " active: " +
                    data.active + ", filterlinks: " + data.filterlinks);
};

ChatFilterModule.prototype.handleUpdateFilter = function (user, data) {
    if (typeof data !== "object") {
        return;
    }

    if (!this.channel.modules.permissions.canEditFilters(user)) {
        return;
    }

    data = validateFilter(data);
    if (!data) {
        return;
    }

    try {
        this.filters.updateFilter(data);
    } catch (e) {
        if (e.message.match(/filter to be updated does not exist/i)) {
            this.handleAddFilter(user, data);
        } else {
            user.socket.emit("errorMsg", {
                msg: "Filter update failed: " + e.message,
                alert: true
            });
        }
        return;
    }

    var chan = this.channel;
    chan.users.forEach(function (u) {
        if (chan.modules.permissions.canEditFilters(u)) {
            u.socket.emit("updateChatFilter", data);
        }
    });

    chan.logger.log("[mod] " + user.getName() + " updated filter: " + data.name + " -> " +
                    "s/" + data.source + "/" + data.replace + "/" + data.flags + " active: " +
                    data.active + ", filterlinks: " + data.filterlinks);
};

ChatFilterModule.prototype.handleImportFilters = function (user, data) {
    if (!(data instanceof Array)) {
        return;
    }

    /* Note: importing requires a different permission node than simply
       updating/removing */
    if (!this.channel.modules.permissions.canImportFilters(user)) {
        return;
    }

    try {
        this.filters = new FilterList(data.map(validateFilter).filter(function (f) {
            return f !== false;
        }));
    } catch (e) {
        user.socket.emit("errorMsg", {
            msg: "Filter import failed: " + e.message,
            alert: true
        });
        return;
    }

    this.channel.logger.log("[mod] " + user.getName() + " imported the filter list");
    this.sendChatFilters(this.channel.users);
};

ChatFilterModule.prototype.handleRemoveFilter = function (user, data) {
    if (typeof data !== "object") {
        return;
    }

    if (!this.channel.modules.permissions.canEditFilters(user)) {
        return;
    }

    if (typeof data.name !== "string") {
        return;
    }

    try {
        this.filters.removeFilter(data);
    } catch (e) {
        user.socket.emit("errorMsg", {
            msg: "Filter removal failed: " + e.message,
            alert: true
        });
        return;
    }
    var chan = this.channel;
    chan.users.forEach(function (u) {
        if (chan.modules.permissions.canEditFilters(u)) {
            u.socket.emit("deleteChatFilter", data);
        }
    });
    this.channel.logger.log("[mod] " + user.getName() + " removed filter: " + data.name);
};

ChatFilterModule.prototype.handleMoveFilter = function (user, data) {
    if (typeof data !== "object") {
        return;
    }

    if (!this.channel.modules.permissions.canEditFilters(user)) {
        return;
    }

    if (typeof data.to !== "number" || typeof data.from !== "number") {
        return;
    }

    try {
        this.filters.moveFilter(data.from, data.to);
    } catch (e) {
        user.socket.emit("errorMsg", {
            msg: "Filter move failed: " + e.message,
            alert: true
        });
        return;
    }
};

ChatFilterModule.prototype.handleRequestChatFilters = function (user) {
    this.sendChatFilters([user]);
};

module.exports = ChatFilterModule;