🕰️ QuoteHistory (GoMT4)

Goal: load historical quotes (Bid/Ask with timestamps) for a symbol in a given time range — with safe batching for long periods.

Real code refs in this repo:

• Market info demo: examples/mt4/MT4_service.go (see ShowQuoteHistory flow)
• Account layer: examples/mt4/MT4Account.go (history wrapper & helpers)

---

✅ 1) Preconditions

• MT4 terminal is connected and the symbol is visible in Market Watch.
• config.json contains a valid DefaultSymbol or you pass a symbol explicitly.

---

🗓️ 2) Basic request (last N days)

sym  := "EURUSD"
from := timestamppb.New(time.Now().AddDate(0, 0, -7))
to   := timestamppb.New(time.Now())

hist, err := account.ShowQuoteHistory(ctx, sym, from, to)
if err != nil { return err }

for _, q := range hist.GetQuotes() {
    t := q.GetTime().AsTime().Format(time.RFC3339)
    fmt.Printf("%s %s Bid=%.5f Ask=%.5f\n", sym, t, q.GetBid(), q.GetAsk())
}

Mirrors the ShowQuoteHistory example flow in MT4_service.go.

---

📦 3) Batch long ranges (day-by-day)

Large ranges can be heavy. Split by days (or hours) and append.

func LoadQuoteHistoryBatched(ctx context.Context, a *MT4Account, sym string, days int) ([]*pb.Quote, error) {
    var out []*pb.Quote
    end := time.Now()
    start := end.AddDate(0, 0, -days)

    for cur := start; cur.Before(end); cur = cur.AddDate(0, 0, 1) {
        from := timestamppb.New(cur)
        to   := timestamppb.New(cur.AddDate(0, 0, 1))
        h, err := a.ShowQuoteHistory(ctx, sym, from, to)
        if err != nil { return nil, err }
        out = append(out, h.GetQuotes()...)
        // Be gentle with terminal
        if err := waitWithCtx(ctx, 150*time.Millisecond); err != nil { return nil, err }
    }
    return out, nil
}

---

🧪 4) Validate & compute spread (pips)

for _, q := range quotes {
    if q.GetAsk() <= 0 || q.GetBid() <= 0 { continue }
    spreadPips := (q.GetAsk() - q.GetBid()) / q.GetPoint()
    if spreadPips > 50 { // sanity check
        log.Printf("wide spread @ %s: %.1f pips", q.GetTime().AsTime(), spreadPips)
    }
}

---

📤 5) Export to CSV

func SaveQuotesCSV(path, symbol string, quotes []*pb.Quote) error {
    f, err := os.Create(path)
    if err != nil { return err }
    defer f.Close()
    w := csv.NewWriter(f)
    defer w.Flush()

    _ = w.Write([]string{"time","symbol","bid","ask","spread_pips"})
    for _, q := range quotes {
        spread := (q.GetAsk() - q.GetBid()) / q.GetPoint()
        _ = w.Write([]string{
            q.GetTime().AsTime().Format(time.RFC3339),
            symbol,
            fmt.Sprintf("%.5f", q.GetBid()),
            fmt.Sprintf("%.5f", q.GetAsk()),
            fmt.Sprintf("%.1f", spread),
        })
    }
    return w.Error()
}

---

⚠️ Pitfalls

• Empty result → MT4 hasn’t downloaded that range yet; open the symbol chart to force data load.
• Timezones → MT4 server time may differ from local; always log with time.RFC3339.
• Too big queries → prefer batching; add tiny sleeps between requests.
• Context & retries → wrap with short timeout (3–6s) and retry only transport errors (see Reliability).

---

🔗 See also

• GetQuote.md — one‑shot live quote.
• StreamQuotes.md — continuous updates.
• HistoryOrders.md — account history records.