Merge branch 'sairajzero:main' into main

args/schema.sql

@@ -100,6 +100,24 @@ status VARCHAR(50) NOT NULL,
 PRIMARY KEY(id)
 );
 
+CREATE TABLE TagList (
+id INT NOT NULL AUTO_INCREMENT,
+tag VARCHAR(50) NOT NULL,
+sellPriority INT,
+buyPriority INT,
+api TINYTEXT,
+PRIMARY KEY(tag),
+KEY (id)
+);
+
+CREATE TABLE Tags (
+id INT NOT NULL AUTO_INCREMENT,
+floID CHAR(34) NOT NULL,
+tag VARCHAR(50) NOT NULL,
+PRIMARY KEY(floID, tag),
+KEY (id)
+);
+
 /* Backup feature (Table and Triggers) */
 
 CREATE TABLE _backup (
@@ -164,4 +182,18 @@ FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('outputRupee', NEW.id) ON
 CREATE TRIGGER outputRupee_U AFTER UPDATE ON outputRupee
 FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('outputRupee', NEW.id) ON DUPLICATE KEY UPDATE mode=TRUE, timestamp=DEFAULT;
 CREATE TRIGGER outputRupee_D AFTER DELETE ON outputRupee
-FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('outputRupee', OLD.id) ON DUPLICATE KEY UPDATE mode=NULL, timestamp=DEFAULT;
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('outputRupee', OLD.id) ON DUPLICATE KEY UPDATE mode=NULL, timestamp=DEFAULT;
+
+CREATE TRIGGER TagList_I AFTER INSERT ON TagList
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('TagList', NEW.id) ON DUPLICATE KEY UPDATE mode=TRUE, timestamp=DEFAULT;
+CREATE TRIGGER TagList_U AFTER UPDATE ON TagList
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('TagList', NEW.id) ON DUPLICATE KEY UPDATE mode=TRUE, timestamp=DEFAULT;
+CREATE TRIGGER TagList_D AFTER DELETE ON TagList
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('TagList', OLD.id) ON DUPLICATE KEY UPDATE mode=NULL, timestamp=DEFAULT;
+
+CREATE TRIGGER Tags_I AFTER INSERT ON Tags
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('Tags', NEW.id) ON DUPLICATE KEY UPDATE mode=TRUE, timestamp=DEFAULT;
+CREATE TRIGGER Tags_U AFTER UPDATE ON Tags
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('Tags', NEW.id) ON DUPLICATE KEY UPDATE mode=TRUE, timestamp=DEFAULT;
+CREATE TRIGGER Tags_D AFTER DELETE ON Tags
+FOR EACH ROW INSERT INTO _backup (t_name, id) VALUES ('Tags', OLD.id) ON DUPLICATE KEY UPDATE mode=NULL, timestamp=DEFAULT;

public/fn.js

@@ -405,4 +405,60 @@ function withdrawRupee(quantity, proxySecret) {
                 .catch(error => reject(error)))
             .catch(error => reject(error))
     })
+}
+
+function addUserTag(floID, tag, proxySecret) {
+    return new Promise((resolve, reject) => {
+        let request = {
+            user: floID,
+            tag: tag,
+            timestamp: Date.now()
+        };
+        request.sign = signRequest({
+            command: "add_Tag",
+            user: request.user,
+            tag: request.tag,
+            timestamp: request.timestamp
+        }, proxySecret);
+        console.debug(request);
+
+        fetch('/add-tag', {
+                method: "POST",
+                headers: {
+                    'Content-Type': 'application/json'
+                },
+                body: JSON.stringify(request)
+            }).then(result => responseParse(result, false)
+                .then(result => resolve(result))
+                .catch(error => reject(error)))
+            .catch(error => reject(error))
+    })
+}
+
+function removeUserTag(floID, tag, proxySecret) {
+    return new Promise((resolve, reject) => {
+        let request = {
+            user: floID,
+            tag: tag,
+            timestamp: Date.now()
+        };
+        request.sign = signRequest({
+            command: "remove_Tag",
+            user: request.user,
+            tag: request.tag,
+            timestamp: request.timestamp
+        }, proxySecret);
+        console.debug(request);
+
+        fetch('/remove-tag', {
+                method: "POST",
+                headers: {
+                    'Content-Type': 'application/json'
+                },
+                body: JSON.stringify(request)
+            }).then(result => responseParse(result, false)
+                .then(result => resolve(result))
+                .catch(error => reject(error)))
+            .catch(error => reject(error))
+    })
 }

setup/configure-settings.js

@@ -16,7 +16,9 @@ try {
         "sql_host": "localhost",
 
         "backup-port": "8081",
-        "backup-floIDs": []
+        "backup-floIDs": [],
+
+        "trusted-floIDs": []
     };
     flag_new = true;
 }
@@ -32,14 +34,14 @@ function flaggedYesOrNo(text) {
     })
 }
 
-function getBackupIDs(ids) {
+function get_IDs(ids) {
     return new Promise((resolve, reject) => {
-        getInput("", "continue").then(id => {
+        getInput.Text("", "continue").then(id => {
             if (id === "continue")
                 resolve(Array.from(new Set(ids)));
             else {
                 ids.push(id);
-                getBackupIDs(ids)
+                get_IDs(ids)
                     .then(result => resolve(result))
                     .catch(error => reject(error));
             }
@@ -55,8 +57,8 @@ function configureBackup() {
                 return resolve(true);
             getInput.YesOrNo('Do you want to add/remove backup floIDs?').then(value => {
                 if (value) {
-                    console("Enter floIDs to add as backup: ");
+                    console.log("Enter floIDs to add as backup: ");
-                    getBackupIDs(config["backup-floIDs"]).then(ids => {
+                    get_IDs(config["backup-floIDs"]).then(ids => {
                         //delete backup IDs
                         let tmp_obj = {};
                         for (let i in ids) {
@@ -84,12 +86,45 @@ function configureBackup() {
     })
 }
 
+function configureTrustedIDs() {
+    return new Promise((resolve, reject) => {
+        getInput.YesOrNo('Do you want to add/remove trusted floIDs?').then(value => {
+            if (value) {
+                console.log("Enter floIDs to add as trusted: ");
+                get_IDs(config["trusted-floIDs"]).then(ids => {
+                    //delete trusted IDs
+                    let tmp_obj = {};
+                    for (let i in ids) {
+                        console.log(i + 1, ":", ids[i]);
+                        tmp_obj[i + 1] = ids[i];
+                    }
+                    getInput.Text("Enter numbers to delete (seperated by comma)", "continue").then(ri => {
+                        if (ri === "continue")
+                            config["trusted-floIDs"] = ids;
+                        else {
+                            for (let i of ri.split(","))
+                                delete tmp_obj[parseInt(i)];
+                            let tmp_array = [];
+                            for (let id of tmp_obj)
+                                tmp_array.push(id);
+                            config["trusted-floIDs"] = tmp_array;
+                        }
+                        resolve(true);
+                    })
+                })
+            } else
+                resolve(true);
+        })
+    })
+}
+
 function configurePort() {
     return new Promise(resolve => {
         getInput.Text('Enter port', config["port"]).then(port => {
             config["port"] = port;
             configureBackup()
-                .then(result => resolve(true))
+                .then(_ => configureTrustedIDs()
+                    .then(_ => resolve(true)));
         })
     })
 }

src/app.js

@@ -5,7 +5,7 @@ const Request = require('./request');
 
 const REFRESH_INTERVAL = 60 * 1000; //1 min
 
-module.exports = function App(secret, DB) {
+module.exports = function App(secret, trustedIDs, DB) {
 
     const app = express();
     //session middleware
@@ -63,6 +63,11 @@ module.exports = function App(secret, DB) {
     app.post('/deposit-rupee', Request.DepositRupee);
     app.post('/withdraw-rupee', Request.WithdrawRupee);
 
+    //Manage user tags (Access to trusted IDs only)
+    Request.trustedIDs = trustedIDs;
+    app.post('/add-tag', Request.addUserTag);
+    app.post('/remove-tag', Request.removeUserTag);
+
     Request.DB = DB;
     Request.periodicProcess();
     let refresher = setInterval(Request.periodicProcess, REFRESH_INTERVAL);

src/group.js

@@ -0,0 +1,369 @@
+var DB; //container for database
+
+function addTag(floID, tag) {
+    return new Promise((resolve, reject) => {
+        DB.query("INSERT INTO Tags (floID, tag) VALUE (?,?)", [floID, tag])
+            .then(result => resolve(`Added ${floID} to ${tag}`))
+            .catch(error => {
+                if (error.code === "ER_DUP_ENTRY")
+                    reject(INVALID(`${floID} already in ${tag}`));
+                else
+                    reject(error);
+            });
+    });
+}
+
+function removeTag(floID, tag) {
+    return new Promise((resolve, reject) => {
+        DB.query("DELETE FROM Tags WHERE floID=? AND tag=?", [floID, tag])
+            .then(result => resolve(`Removed ${floID} from ${tag}`))
+            .catch(error => reject(error));
+    })
+}
+
+function getBestPairs(currentRate) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT tag, sellPriority, buyPriority FROM TagList").then(result => {
+            //Sorted in Ascending (ie, stack; pop for highest)
+            let tags_buy = result.sort((a, b) => a.buyPriority > b.buyPriority ? 1 : -1).map(r => r.tag);
+            let tags_sell = result.sort((a, b) => a.sellPriority > b.sellPriority ? 1 : -1).map(r => r.tag);
+            resolve(new bestPair(currentRate, tags_buy, tags_sell));
+        }).catch(error => reject(error))
+    })
+}
+
+const bestPair = function(cur_rate, tags_buy, tags_sell) {
+    const currentRate = cur_rate;
+
+    Object.defineProperty(this, 'cur_rate', {
+        get: () => currentRate
+    });
+
+    this.get = () => new Promise((resolve, reject) => {
+        Promise.all([getBuyOrder(), getSellOrder()]).then(results => {
+            resolve({
+                buyOrder: results[0],
+                sellOrder: results[1],
+                null_base: getSellOrder.cache.mode_null
+            })
+        }).catch(error => reject(error))
+    });
+
+    this.next = (tx_quantity, incomplete_sell, flag_sell) => {
+        let buy = getBuyOrder.cache,
+            sell = getSellOrder.cache;
+        if (buy.cur_order && sell.cur_order) {
+            //buy order
+            if (tx_quantity < buy.cur_order.quantity)
+                buy.cur_order.quantity -= tx_quantity;
+            else if (tx_quantity == buy.cur_order.quantity)
+                buy.cur_order = null;
+            else
+                throw Error("Tx quantity cannot be more than order quantity");
+            //sell order
+            if (tx_quantity < sell.cur_order.quantity) {
+                sell.cur_order.quantity -= tx_quantity;
+                if (incomplete_sell) {
+                    if (!sell.mode_null && flag_sell)
+                        sell.null_queue.push(sell.cur_order);
+                    sell.cur_order = null;
+                }
+            } else if (tx_quantity == sell.cur_order.quantity)
+                sell.cur_order = null;
+            else
+                throw Error("Tx quantity cannot be more than order quantity");
+        } else
+            throw Error("No current order found");
+    };
+
+    const getSellOrder = () => new Promise((resolve, reject) => {
+        let cache = getSellOrder.cache;
+        if (cache.cur_order) { //If cache already has a pending order
+            verifySellOrder(cache.cur_order, currentRate, cache.mode_null).then(result => {
+                cache.cur_order = result;
+                resolve(result);
+            }).catch(error => {
+                if (error !== false)
+                    return reject(error);
+                //Order not valid (minimum gain)
+                cache.cur_order = null;
+                getSellOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            })
+        } else if (cache.orders && cache.orders.length) { //If cache already has orders in priority
+            getTopValidSellOrder(cache.orders, currentRate, cache.mode_null).then(result => {
+                cache.cur_order = result;
+                resolve(result);
+            }).catch(error => {
+                if (error !== false)
+                    return reject(error);
+                //No valid order found in current tag
+                cache.orders = null;
+                getSellOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            })
+        } else if (cache.tags.length) { //If cache has remaining tags
+            cache.cur_tag = cache.tags.pop();
+            getSellOrdersInTag(cache.cur_tag, currentRate).then(orders => {
+                cache.orders = orders;
+                getSellOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            }).catch(error => reject(error));
+        } else if (!cache.end) { //Un-tagged floID's orders  (do only once)
+            getUntaggedSellOrders(currentRate).then(orders => {
+                cache.orders = orders;
+                cache.cur_tag = null;
+                cache.end = true;
+                getSellOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            }).catch(error => reject(error));
+        } else if (!mode_null) { //Lowest priority Coins (FLO Brought from other sources)
+            cache.orders = cache.null_queue.reverse(); //Reverse it so that we can pop the highest priority
+            cache.mode_null = true;
+            cache.null_queue = null;
+            getSellOrder()
+                .then(result => resolve(result))
+                .catch(error => reject(error))
+        } else
+            reject(false);
+    });
+    getSellOrder.cache = {
+        tags: tags_sell,
+        null_queue: [],
+        mode_null: false
+    };
+
+    const getBuyOrder = () => new Promise((resolve, reject) => {
+        let cache = getBuyOrder.cache;
+        if (cache.cur_order) { //If cache already has a pending order
+            verifyBuyOrder(cache.cur_order, currentRate).then(result => {
+                cache.cur_order = result;
+                resolve(result);
+            }).catch(error => {
+                if (error !== false)
+                    return reject(error);
+                //Order not valid (cash not available)
+                cache.cur_order = null;
+                getBuyOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            })
+        } else if (cache.orders && cache.orders.length) { //If cache already has orders in priority
+            getTopValidBuyOrder(cache.orders, currentRate).then(result => {
+                cache.cur_order = result;
+                resolve(result);
+            }).catch(error => {
+                if (error !== false)
+                    return reject(error);
+                //No valid order found in current tag
+                cache.orders = null;
+                getBuyOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            })
+        } else if (cache.tags.length) { //If cache has remaining tags
+            cache.cur_tag = cache.tags.pop();
+            getBuyOrdersInTag(cache.cur_tag, currentRate).then(orders => {
+                cache.orders = orders;
+                getBuyOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            }).catch(error => reject(error));
+        } else if (!cache.end) { //Un-tagged floID's orders  (do only once)
+            getUntaggedBuyOrders(currentRate).then(orders => {
+                cache.orders = orders;
+                cache.cur_tag = null;
+                cache.end = true;
+                getBuyOrder()
+                    .then(result => resolve(result))
+                    .catch(error => reject(error))
+            }).catch(error => reject(error));
+        } else
+            reject(false);
+    });
+    getBuyOrder.cache = {
+        tags: tags_buy
+    };
+}
+
+function getUntaggedSellOrders(cur_price) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT SellOrder.id, SellOrder.floID, SellOrder.quantity FROM SellOrder" +
+                " LEFT JOIN Tags ON Tags.floID = SellOrder.floID" +
+                " WHERE Tags.floID IS NULL AND SellOrder.minPrice <=? ORDER BY SellOrder.time_placed DESC", [cur_price])
+            .then(orders => resolve(orders))
+            .catch(error => reject(error))
+    })
+}
+
+function getUntaggedBuyOrders(cur_price) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT BuyOrder.id, BuyOrder.floID, BuyOrder.quantity FROM BuyOrder" +
+                " LEFT JOIN Tags ON Tags.floID = BuyOrder.floID" +
+                " WHERE Tags.floID IS NULL AND BuyOrder.maxPrice >=? ORDER BY BuyOrder.time_placed DESC", [cur_price])
+            .then(orders => resolve(orders))
+            .catch(error => reject(error))
+    })
+}
+
+function getSellOrdersInTag(tag, cur_price) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT SellOrder.id, SellOrder.floID, SellOrder.quantity FROM SellOrder" +
+            " INNER JOIN Tags ON Tags.floID = SellOrder.floID" +
+            " WHERE Tags.tag = ? AND SellOrder.minPrice <=? ORDER BY SellOrder.time_placed DESC", [tag, cur_price]).then(orders => {
+            if (orders.length <= 1) // No (or) Only-one order, hence priority sort not required.
+                resolve(orders);
+            else
+                getPointsFromAPI(tag, orders.map(o => o.floID)).then(points => {
+                    let orders_sorted = orders.map(o => [o, points[o.floID]])
+                        .sort((a, b) => a[1] > b[1] ? -1 : a[1] < b[1] ? 1 : 0) //sort by points (ascending)
+                        .map(x => x[0]);
+                    resolve(orders_sorted);
+                }).catch(error => reject(error))
+        }).catch(error => reject(error))
+    });
+}
+
+function getBuyOrdersInTag(tag, cur_price) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT BuyOrder.id, BuyOrder.floID, BuyOrder.quantity FROM BuyOrder" +
+            " INNER JOIN Tags ON Tags.floID = BuyOrder.floID" +
+            " WHERE Tags.tag = ? AND BuyOrder.maxPrice >=? ORDER BY BuyOrder.time_placed DESC", [tag, cur_price]).then(orders => {
+            if (orders.length <= 1) // No (or) Only-one order, hence priority sort not required.
+                resolve(orders);
+            else
+                getPointsFromAPI(tag, orders.map(o => o.floID)).then(points => {
+                    let orders_sorted = orders.map(o => [o, points[o.floID]])
+                        .sort((a, b) => a[1] > b[1] ? -1 : a[1] < b[1] ? 1 : 0) //sort by points (ascending)
+                        .map(x => x[0]);
+                    resolve(orders_sorted);
+                }).catch(error => reject(error))
+        }).catch(error => reject(error))
+    });
+}
+
+function getPointsFromAPI(tag, floIDs) {
+    floIDs = Array.from(new Set(floIDs));
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT api FROM TagList WHERE tag=?", [tag]).then(result => {
+            let api = result[0].api;
+            Promise.allSettled(floIDs.map(id => fetch_api(api, id))).then(result => {
+                let points = {};
+                for (let i in result)
+                    if (result[i].status === "fulfilled")
+                        points[floIDs[i]] = result[i].value;
+                resolve(points);
+            }).catch(error => reject(error))
+        }).catch(error => reject(error))
+    });
+}
+
+function fetch_api(api, id) {
+    return new Promise((resolve, reject) => {
+        //TODO: fetch data from API
+        let url = api.replace('<flo-id>', id);
+        global.fetch(url).then(response => {
+            if (response.ok)
+                response.text()
+                .then(result => resolve(result))
+                .catch(error => reject(error))
+            else
+                reject(response);
+        }).catch(error => reject(error))
+    })
+}
+
+function getTopValidSellOrder(orders, cur_price, mode_null) {
+    return new Promise((resolve, reject) => {
+        if (!orders.length)
+            return reject(false)
+        verifySellOrder(orders.pop(), cur_price, mode_null) //pop: as the orders are sorted in ascending (highest point should be checked 1st)
+            .then(result => resolve(result))
+            .catch(error => {
+                if (error !== false)
+                    return reject(error);
+                getTopValidSellOrder(orders, cur_price, mode_null)
+                    .then(result => resolve(result))
+                    .catch(error => reject(error));
+            });
+    });
+}
+
+function verifySellOrder(sellOrder, cur_price, mode_null) {
+    return new Promise((resolve, reject) => {
+        if (!mode_null)
+            DB.query("SELECT quantity, base FROM Vault WHERE floID=? AND base IS NOT NULL ORDER BY base", [sellOrder.floID]).then(result => {
+                let rem = sellOrder.quantity,
+                    sell_base = 0,
+                    base_quantity = 0;
+                for (let i = 0; i < result.length && rem > 0; i++) {
+                    if (rem < result[i].quantity) {
+                        sell_base += (rem * result[i].base);
+                        base_quantity += rem;
+                        rem = 0;
+                    } else {
+                        sell_base += (result[i].quantity * result[i].base);
+                        base_quantity += result[i].quantity;
+                        rem -= result[i].quantity;
+                    }
+                }
+                if (base_quantity)
+                    sell_base = sell_base / base_quantity;
+                if (sell_base > cur_price)
+                    reject(false);
+                else
+                    resolve(sellOrder);
+            }).catch(error => reject(error));
+        else if (mode_null)
+            DB.query("SELECT SUM(quantity) as total FROM Vault WHERE floID=?", [sellOrder.floID]).then(result => {
+                if (result.total < sellOrder.quantity)
+                    console.warn(`Sell Order ${sellOrder.id} was made without enough FLO. This should not happen`);
+                if (result.total > 0)
+                    resolve(sellOrder);
+                else
+                    reject(false);
+            }).catch(error => reject(error))
+    })
+}
+
+function getTopValidBuyOrder(orders, cur_price) {
+    return new Promise((resolve, reject) => {
+        if (!orders.length)
+            return reject(false)
+        verifyBuyOrder(orders.pop(), cur_price) //pop: as the orders are sorted in ascending (highest point should be checked 1st)
+            .then(result => resolve(result))
+            .catch(error => {
+                if (error !== false)
+                    return reject(error);
+                getTopValidBuyOrder(orders, cur_price)
+                    .then(result => resolve(result))
+                    .catch(error => reject(error));
+            });
+    });
+}
+
+function verifyBuyOrder(buyOrder, cur_price) {
+    return new Promise((resolve, reject) => {
+        DB.query("SELECT rupeeBalance AS bal FROM Cash WHERE floID=?", [buyOrder.floID]).then(result => {
+            if (result[0].bal < cur_price * buyOrder.quantity) {
+                //This should not happen unless a buy order is placed when user doesnt have enough rupee balance
+                console.warn(`Buy order ${buyOrder.id} is active, but rupee# is insufficient`);
+                reject(false);
+            } else
+                resolve(buyOrder);
+        }).catch(error => reject(error));
+    })
+}
+
+module.exports = {
+    addTag,
+    removeTag,
+    getBestPairs,
+    set DB(db) {
+        DB = db;
+    }
+};

src/main.js

@@ -36,7 +36,7 @@ module.exports = function startServer(public_dir) {
     console.debug(PUBLIC_DIR, global.myFloID);
 
     Database(config["sql_user"], config["sql_pwd"], config["sql_db"], config["sql_host"]).then(DB => {
-        const app = App(config['secret'], DB);
+        const app = App(config['secret'], config['trusted-floIDs'], DB);
         app.listen(PORT, () => console.log(`Server Running at port ${PORT}`));
         //start backup
         if (config["backup-port"] && config["backup-floIDs"].length) {

src/market.js

@@ -1,3 +1,5 @@
+const group = require("./group");
+
 var net_FLO_price; //container for FLO price (from API or by model)
 var DB; //container for database
 
@@ -168,124 +170,80 @@ function cancelOrder(type, id, floID) {
     });
 }
 
-function matchBuyAndSell() {
+function initiateCoupling() {
-    let cur_price = net_FLO_price;
+    group.getBestPairs(net_FLO_price)
-    //get the best buyer
+        .then(bestPairQueue => processCoupling(bestPairQueue))
-    getBestBuyer(cur_price).then(buyer_best => {
+        .catch(error => console.error("initiateCoupling", error))
-        //get the best seller
-        getBestSeller(buyer_best.quantity, cur_price).then(result => {
-            let seller_best = result.sellOrder,
-                txQueries = result.txQueries;
-            console.debug("Sell:", seller_best.id, "Buy:", buyer_best.id);
-
-            //process the Txn
-            var tx_quantity;
-            if (seller_best.quantity > buyer_best.quantity)
-                tx_quantity = processBuyOrder(seller_best, buyer_best, txQueries);
-            else if (seller_best.quantity < buyer_best.quantity)
-                tx_quantity = processSellOrder(seller_best, buyer_best, txQueries);
-            else
-                tx_quantity = processBuyAndSellOrder(seller_best, buyer_best, txQueries);
-            updateBalance(seller_best, buyer_best, txQueries, cur_price, tx_quantity);
-            //process txn query in SQL
-            DB.transaction(txQueries).then(results => {
-                console.log(`Transaction was successful! BuyOrder:${buyer_best.id}| SellOrder:${seller_best.id}`);
-                //Since a tx was successful, match again
-                matchBuyAndSell();
-            }).catch(error => console.error(error));
-        }).catch(error => console.error(error));
-    }).catch(error => console.error(error));
 }
 
-function getBestBuyer(cur_price, n = 0) {
+function processCoupling(bestPairQueue) {
-    return new Promise((resolve, reject) => {
+    bestPairQueue.get().then(pair_result => {
-        DB.query("SELECT * FROM BuyOrder WHERE maxPrice >= ? ORDER BY time_placed LIMIT ?,1", [cur_price, n]).then(result => {
+        let buyer_best = pair_result.buyOrder,
-            let buyOrder = result.shift();
+            seller_best = pair_result.sellOrder;
-            if (!buyOrder)
+        console.debug("Sell:", seller_best);
-                return reject("No valid buyers available");
+        console.debug("Buy:", buyer_best);
-            DB.query("SELECT rupeeBalance AS bal FROM Cash WHERE floID=?", [buyOrder.floID]).then(result => {
+        spendFLO(buyer_best, seller_best, pair_result.null_base).then(spend_result => {
-                if (result[0].bal < cur_price * buyOrder.quantity) {
+            let tx_quantity = spend_result.quantity,
-                    //This should not happen unless a buy order is placed when user doesnt have enough rupee balance
+                txQueries = spend_result.txQueries,
-                    console.warn(`Buy order ${buyOrder.id} is active, but rupee# is insufficient`);
+                clear_sell = spend_result.incomplete && !spend_result.flag_baseNull; //clear_sell can be true only if an order is placed without enough FLO
-                    getBestBuyer(cur_price, n + 1)
+            processOrders(seller_best, buyer_best, txQueries, tx_quantity, clear_sell);
-                        .then(result => resolve(result))
+            updateBalance(seller_best, buyer_best, txQueries, bestPairQueue.cur_rate, tx_quantity);
-                        .catch(error => reject(error));
+            //process txn query in SQL
-                } else
+            DB.transaction(txQueries).then(_ => {
-                    resolve(buyOrder);
+                bestPairQueue.next(quantity, spend_result.incomplete, spend_result.flag_baseNull);
-            }).catch(error => reject(error));
+                console.log(`Transaction was successful! BuyOrder:${buyer_best.id}| SellOrder:${seller_best.id}`);
-        }).catch(error => reject(error));
+                //Since a tx was successful, match again
+                processCoupling(bestPairQueue);
+            }).catch(error => console.error(error));
+        }).catch(error => console.error(error));
+    }).catch(error => {
+        if (error !== false)
+            console.error(error);
+        else
+            console.log("No valid orders.");
     });
 }
 
-function getBestSeller(maxQuantity, cur_price, n = 0) {
+function spendFLO(buyOrder, sellOrder, null_base) {
     return new Promise((resolve, reject) => {
-        //TODO: Add order conditions for priority.
+        DB.query("SELECT id, quantity, base FROM Vault WHERE floID=? ORDER BY base", [sellOrder.floID]).then(result => {
-        DB.query("SELECT * FROM SellOrder WHERE minPrice <=? ORDER BY time_placed LIMIT ?,1", [cur_price, n]).then(result => {
+            let rem = Math.min(buyOrder.quantity, sellOrder.quantity),
-            let sellOrder = result.shift();
+                txQueries = []
-            if (!sellOrder)
+            flag_baseNull = false;
-                return reject("No valid sellers available");
+            for (let i = 0; i < result.length && rem > 0; i++)
-            DB.query("SELECT id, quantity, base FROM Vault WHERE floID=? ORDER BY base", [sellOrder.floID]).then(result => {
+                if (result[i].base || null_base) {
-                let rem = Math.min(sellOrder.quantity, maxQuantity),
-                    sell_base = 0,
-                    base_quantity = 0,
-                    txQueries = [];
-                for (let i = 0; i < result.length && rem > 0; i++) {
                     if (rem < result[i].quantity) {
                         txQueries.push(["UPDATE Vault SET quantity=quantity-? WHERE id=?", [rem, result[i].id]]);
-                        if (result[i].base) {
-                            sell_base += (rem * result[i].base);
-                            base_quantity += rem
-                        }
                         rem = 0;
                     } else {
                         txQueries.push(["DELETE FROM Vault WHERE id=?", [result[i].id]]);
-                        if (result[i].base) {
-                            sell_base += (result[i].quantity * result[i].base);
-                            base_quantity += result[i].quantity
-                        }
                         rem -= result[i].quantity;
                     }
-                }
-                if (base_quantity)
-                    sell_base = sell_base / base_quantity;
-                if (rem > 0 || sell_base > cur_price) {
-                    //1st condition (rem>0) should not happen (sell order placement was success when insufficient FLO).
-                    if (rem > 0)
-                        console.warn(`Sell order ${sellOrder.id} is active, but FLO is insufficient`);
-                    getBestSeller(maxQuantity, cur_price, n + 1)
-                        .then(result => resolve(result))
-                        .catch(error => reject(error));
                 } else
-                    resolve({
+                    flag_baseNull = true;
-                        sellOrder,
+            resolve({
-                        txQueries
+                quantity: Math.min(buyOrder.quantity, sellOrder.quantity) - rem,
-                    });
+                txQueries,
-            }).catch(error => reject(error));
+                incomplete: rem > 0,
+                flag_baseNull
+            });
         }).catch(error => reject(error));
-    });
+    })
 }
 
-function processBuyOrder(seller_best, buyer_best, txQueries) {
+function processOrders(seller_best, buyer_best, txQueries, quantity, clear_sell) {
-    let quantity = buyer_best.quantity;
+    if (quantity > buyer_best.quantity || quantity > seller_best.quantity)
-    //Buy order is completed, sell order is partially done.
+        throw Error("Tx quantity cannot be more than order quantity");
-    txQueries.push(["DELETE FROM BuyOrder WHERE id=?", [buyer_best.id]]);
+    //Process Buy Order
-    txQueries.push(["UPDATE SellOrder SET quantity=quantity-? WHERE id=?", [quantity, seller_best.id]]);
+    if (quantity == buyer_best.quantity)
-    return quantity;
+        txQueries.push(["DELETE FROM BuyOrder WHERE id=?", [buyer_best.id]]);
-}
+    else
-
+        txQueries.push(["UPDATE BuyOrder SET quantity=quantity-? WHERE id=?", [quantity, buyer_best.id]]);
-function processSellOrder(seller_best, buyer_best, txQueries) {
+    //Process Sell Order
-    let quantity = seller_best.quantity;
+    if (quantity == seller_best.quantity || clear_sell)
-    //Sell order is completed, buy order is partially done.
+        txQueries.push(["DELETE FROM SellOrder WHERE id=?", [seller_best.id]]);
-    txQueries.push(["DELETE FROM SellOrder WHERE id=?", [seller_best.id]]);
+    else
-    txQueries.push(["UPDATE BuyOrder SET quantity=quantity-? WHERE id=?", [quantity, buyer_best.id]]);
+        txQueries.push(["UPDATE SellOrder SET quantity=quantity-? WHERE id=?", [quantity, seller_best.id]]);
-    return quantity;
-}
-
-function processBuyAndSellOrder(seller_best, buyer_best, txQueries) {
-    //Both sell order and buy order is completed
-    txQueries.push(["DELETE FROM SellOrder WHERE id=?", [seller_best.id]]);
-    txQueries.push(["DELETE FROM BuyOrder WHERE id=?", [buyer_best.id]]);
-    return seller_best.quantity;
 }
 
 function updateBalance(seller_best, buyer_best, txQueries, cur_price, quantity) {
@@ -297,7 +255,6 @@ function updateBalance(seller_best, buyer_best, txQueries, cur_price, quantity)
     txQueries.push(["INSERT INTO Vault(floID, base, quantity) VALUES (?, ?, ?)", [buyer_best.floID, cur_price, quantity]])
     //Record transaction
     txQueries.push(["INSERT INTO Transactions (seller, buyer, quantity, unitValue) VALUES (?, ?, ?, ?)", [seller_best.floID, buyer_best.floID, quantity, cur_price]]);
-    return;
 }
 
 function getAccountDetails(floID) {
@@ -643,7 +600,7 @@ function periodicProcess() {
     let old_rate = net_FLO_price;
     getRates().then(cur_rate => {
         transactionReCheck();
-        matchBuyAndSell();
+        initiateCoupling();
     }).catch(error => console.error(error));
 }
 
@@ -667,7 +624,9 @@ module.exports = {
     depositRupee,
     withdrawRupee,
     periodicProcess,
+    group,
     set DB(db) {
         DB = db;
+        group.DB = db;
     }
 };

src/request.js

@@ -1,5 +1,5 @@
 const market = require("./market");
-var DB; //container for database
+var DB, trustedIDs; //container for database
 
 global.INVALID = function(message) {
     if (!(this instanceof INVALID))
@@ -276,8 +276,11 @@ function Account(req, res) {
                 setLogin("Session Expired! Re-login required");
             else {
                 let floID = req.session.user_id;
-                market.getAccountDetails(floID)
+                market.getAccountDetails(floID).then(result => {
-                    .then(result => res.send(result));
+                    if (trustedIDs.includes(floID))
+                        result.subAdmin = true;
+                    res.send(result)
+                });
             }
         }).catch(_ => res.status(INTERNAL.e_code).send("Try again later!"));
     }
@@ -407,6 +410,75 @@ function WithdrawRupee(req, res) {
     });
 }
 
+function addUserTag(req, res) {
+    let data = req.body,
+        session = req.session;
+    if (!session.user_id)
+        return res.status(INVALID.e_code).send("Login required");
+    else if (!trustedIDs.includes(session.user_id))
+        return res.status(INVALID.e_code).send("Access Denied");
+    validateRequestFromFloID({
+        command: "add_Tag",
+        user: data.user,
+        tag: data.tag,
+        timestamp: data.timestamp
+    }, data.sign, session.user_id).then(req_str => {
+        market.group.addTag(data.user, data.tag).then(result => {
+            storeRequest(session.user_id, req_str, data.sign);
+            res.send(result);
+        }).catch(error => {
+            if (error instanceof INVALID)
+                res.status(INVALID.e_code).send(error.message);
+            else {
+                console.error(error);
+                res.status(INTERNAL.e_code).send("Request processing failed! Try again later!");
+            }
+        });
+    }).catch(error => {
+        if (error instanceof INVALID)
+            res.status(INVALID.e_code).send(error.message);
+        else {
+            console.error(error);
+            res.status(INTERNAL.e_code).send("Request processing failed! Try again later!");
+        }
+    });
+}
+
+function removeUserTag(req, res) {
+    let data = req.body,
+        session = req.session;
+    if (!session.user_id)
+        return res.status(INVALID.e_code).send("Login required");
+    else if (!trustedIDs.includes(session.user_id))
+        return res.status(INVALID.e_code).send("Access Denied");
+    else
+        validateRequestFromFloID({
+            command: "remove_Tag",
+            user: data.user,
+            tag: data.tag,
+            timestamp: data.timestamp
+        }, data.sign, session.user_id).then(req_str => {
+            market.group.removeTag(data.user, data.tag).then(result => {
+                storeRequest(session.user_id, req_str, data.sign);
+                res.send(result);
+            }).catch(error => {
+                if (error instanceof INVALID)
+                    res.status(INVALID.e_code).send(error.message);
+                else {
+                    console.error(error);
+                    res.status(INTERNAL.e_code).send("Request processing failed! Try again later!");
+                }
+            });
+        }).catch(error => {
+            if (error instanceof INVALID)
+                res.status(INVALID.e_code).send(error.message);
+            else {
+                console.error(error);
+                res.status(INTERNAL.e_code).send("Request processing failed! Try again later!");
+            }
+        });
+}
+
 module.exports = {
     SignUp,
     Login,
@@ -424,6 +496,11 @@ module.exports = {
     DepositRupee,
     WithdrawRupee,
     periodicProcess: market.periodicProcess,
+    addUserTag,
+    removeUserTag,
+    set trustedIDs(ids) {
+        trustedIDs = ids;
+    },
     set DB(db) {
         DB = db;
         market.DB = db;