Changeset ef1c1c7 for server/market.go

Timestamp:

09/24/26 17:43:19 (6 days ago)

Author:

Stefan <trsunovstefan@…>

Branches:

main

Children:

0cee8ec

Parents:

a531b45

Message:

Wiki docs, phase 6 and phase 7 added

File:

• server/market.go (modified) (4 diffs)

server/market.go

@@ -4 +4 @@
         "database/sql"
         "fmt"
+        "strconv"
 
         "bp_project/server/db"
@@ -16 +17 @@
 }
 
-// ListMarkets prints all active markets with their latest price.
-func ListMarkets() {
+// ListMarkets prints all active markets, numbered, with their latest price,
+// and returns them in the printed order so a caller can pick one by number.
+func ListMarkets() []Market {
         rows, err := db.DB.Query(`
-                SELECT m.id, c.symbol, m.quote_currency,
+                SELECT m.id, c.id, c.symbol, m.quote_currency,
                        COALESCE(lp.price, 0) AS price
                   FROM markets m
@@ -28 +30 @@
         if err != nil {
                 fmt.Println("Error:", err)
-                return
+                return nil
         }
         defer rows.Close()
@@ -35 +37 @@
         fmt.Printf("  %-4s  %-8s  %-5s  %15s\n", "#", "Symbol", "Quote", "Last price")
         fmt.Println("  -----------------------------------------")
-        i := 1
+        var list []Market
         for rows.Next() {
-                var id, sym, quote string
+                var m Market
                 var price float64
-                if err := rows.Scan(&id, &sym, &quote, &price); err != nil {
+                if err := rows.Scan(&m.ID, &m.CryptoID, &m.Symbol, &m.Quote, &price); err != nil {
                         fmt.Println("scan error:", err)
-                        return
+                        return nil
                 }
-                fmt.Printf("  %-4d  %-8s  %-5s  %15.6f\n", i, sym, quote, price)
-                i++
+                list = append(list, m)
+                fmt.Printf("  %-4d  %-8s  %-5s  %15.6f\n", len(list), m.Symbol, m.Quote, price)
         }
+        return list
 }
 
-// ChooseMarket asks the user to pick a market by symbol and returns it.
+// pickNumber reads a 1-based choice from a list of n items.
+func pickNumber(label string, n int) (int, error) {
+        if n == 0 {
+                return 0, fmt.Errorf("Nothing to choose from.")
+        }
+        k, err := strconv.Atoi(prompt(label))
+        if err != nil || k < 1 || k > n {
+                return 0, fmt.Errorf("Invalid choice, enter a number from 1 to %d.", n)
+        }
+        return k - 1, nil
+}
+
+// ChooseMarket lists the active markets and lets the user pick one by its
+// number in the list.
 func ChooseMarket() (*Market, error) {
-        ListMarkets()
-        sym := prompt("Market symbol (e.g. BTC): ")
-        if sym == "" {
-                return nil, fmt.Errorf("no symbol entered")
-        }
-        var m Market
-        err := db.DB.QueryRow(`
-                SELECT m.id, c.id, c.symbol, m.quote_currency
-                  FROM markets m
-                  JOIN crypto c ON c.id = m.crypto_id
-                 WHERE upper(c.symbol) = upper($1)
-                   AND m.is_active = true
-                 LIMIT 1`, sym,
-        ).Scan(&m.ID, &m.CryptoID, &m.Symbol, &m.Quote)
-        if err == sql.ErrNoRows {
-                return nil, fmt.Errorf("market %s not found", sym)
-        }
+        list := ListMarkets()
+        k, err := pickNumber("Market #: ", len(list))
         if err != nil {
                 return nil, err
         }
-        return &m, nil
+        return &list[k], nil
+}
+
+// ChooseHolding lists only the markets the user can sell in — cryptos they
+// hold with some quantity still free (not reserved by an open sell order) —
+// with how much is held and free, and lets them pick one by number.
+func ChooseHolding(s *Session) (*Market, error) {
+        rows, err := db.DB.Query(`
+                SELECT m.id, c.id, c.symbol, m.quote_currency,
+                       h.quantity, h.quantity - h.reserved_quantity AS free,
+                       COALESCE(lp.price, 0) AS price
+                  FROM holdings h
+                  JOIN crypto  c ON c.id = h.crypto_id
+                  JOIN markets m ON m.crypto_id = c.id AND m.is_active = true
+                  LEFT JOIN v_latest_prices lp ON lp.market_id = m.id
+                 WHERE h.user_id = $1
+                   AND h.quantity - h.reserved_quantity > 0
+                 ORDER BY c.symbol`, s.UserID)
+        if err != nil {
+                return nil, err
+        }
+        defer rows.Close()
+
+        fmt.Println()
+        fmt.Printf("  %-4s  %-8s  %-5s  %12s  %12s  %15s\n", "#", "Symbol", "Quote", "Held", "Free to sell", "Last price")
+        fmt.Println("  -------------------------------------------------------------------")
+        var list []Market
+        for rows.Next() {
+                var m Market
+                var held, free, price float64
+                if err := rows.Scan(&m.ID, &m.CryptoID, &m.Symbol, &m.Quote, &held, &free, &price); err != nil {
+                        return nil, err
+                }
+                list = append(list, m)
+                fmt.Printf("  %-4d  %-8s  %-5s  %12.4f  %12.4f  %15.6f\n", len(list), m.Symbol, m.Quote, held, free, price)
+        }
+        if len(list) == 0 {
+                return nil, fmt.Errorf("you hold no crypto that is free to sell")
+        }
+        k, err := pickNumber("Holding #: ", len(list))
+        if err != nil {
+                return nil, err
+        }
+        return &list[k], nil
 }