btcpayserver/BTCPayServer/Views/Stores/Rates.cshtml

@model BTCPayServer.Models.StoreViewModels.RatesViewModel
@{
    Layout = "../Shared/_NavLayout.cshtml";
    ViewData.SetActivePageAndTitle(StoreNavPages.Rates, "Rates", Context.GetStoreData().StoreName);
}

<div class="row">
    <div class="col-lg-8">
        <h4 class="mb-3">@ViewData["PageTitle"]</h4>
        @if (!ViewContext.ModelState.IsValid)
        {
            <div asp-validation-summary="All" class="text-danger"></div>
        }
        <form method="post">
            <input type="hidden" asp-for="ShowScripting" />
            @if (Model.ShowScripting)
            {
                <div class="form-group">
                    <h5>Scripting</h5>
                    <p>Rate script allows you to express precisely how you want to calculate rates for currency pairs.</p>
                    <p>We are retrieving the rate of each exchange either directly, or via <a href="https://www.coingecko.com/" target="_blank">CoinGecko (free)</a>.</p>
                    
                    <div class="accordion" id="accordion-info">
                        <div class="accordion-item">
                            <h2 class="accordion-header" id="direct-header">
                                <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#direct-content" aria-expanded="false" aria-controls="direct-content">
                                    Direct integration
                                    <vc:icon symbol="caret-down"/>
                                </button>
                            </h2>
                            <div id="direct-content" class="accordion-collapse collapse" aria-labelledby="direct-header" data-bs-parent="#accordion-info">
                                <div class="accordion-body">
                                    @foreach (var exchange in Model.AvailableExchanges.Where(a => a.Source == BTCPayServer.Rating.RateSource.Direct))
                                    {
                                        <a href="@exchange.Url">@exchange.Id</a><span>&nbsp;</span>
                                    }
                                </div>
                            </div>
                        </div>
                        <div class="accordion-item">
                            <h2 class="accordion-header" id="coingecko-header">
                                <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#coingecko-content" aria-expanded="false" aria-controls="coingecko-content">
                                    Coingecko integration
                                    <vc:icon symbol="caret-down"/>
                                </button>
                            </h2>
                            <div id="coingecko-content" class="accordion-collapse collapse" aria-labelledby="coingecko-header" data-bs-parent="#accordion-info">
                                <div class="accordion-body">
                                    @foreach (var exchange in Model.AvailableExchanges.Where(a => a.Source == BTCPayServer.Rating.RateSource.Coingecko))
                                    {
                                        <a href="@exchange.Url">@exchange.Id</a><span>&nbsp;</span>
                                    }
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            }
            @if (Model.TestRateRules != null)
            {
                <div class="form-group">
                    <h5>Test results:</h5>
                    <table class="table table-sm table-responsive-md">
                        <tbody>
                            @foreach (var result in Model.TestRateRules)
                            {
                                <tr>
                                    @if (result.Error)
                                    {
                                        <th class="small"><span class="text-danger fa fa-times"></span> @result.CurrencyPair</th>
                                    }
                                    else
                                    {
                                        <th class="small"><span class="text-success fa fa-check"></span> @result.CurrencyPair</th>
                                    }
                                    <td class="small">@result.Rule</td>
                                </tr>
                            }
                        </tbody>
                    </table>
                </div>
            }
            @if (Model.ShowScripting)
            {
                <div id="help" class="collapse text-start">
                    <p>
                        The script language is composed of several rules composed of a currency pair and a mathematic expression.
                        The example below will use <code>kraken</code> for both <code>LTC_USD</code> and <code>BTC_USD</code> pairs.
                    </p>
                    <pre>
                        <code>
                            LTC_USD = kraken(LTC_USD);
                            BTC_USD = kraken(BTC_USD);
                        </code>
                    </pre>
                    <p>However, explicitely setting specific pairs like this can be a bit difficult. Instead, you can define a rule <code>X_X</code> which will match any currency pair. The following example will use <code>kraken</code> for getting the rate of any currency pair.</p>
                    <pre>
                        <code>
                            X_X = kraken(X_X);
                        </code>
                    </pre>
                    <p>However, <code>kraken</code> does not support the <code>BTC_CAD</code> pair. For this reason you can add a rule mapping all <code>X_CAD</code> to <code>ndax</code>, a Canadian exchange.</p>
                    <pre>
                    <code>
                            X_CAD = ndax(X_CAD);
                            X_X = kraken(X_X);
                        </code>
                    </pre>
                    <p>A given currency pair match the most specific rule. If two rules are matching and are as specific, the first rule will be chosen.</p>
                    <p>
                        But now, what if you want to support <code>DOGE</code>? The problem with <code>DOGE</code> is that most exchange do not have any pair for it. But <code>bittrex</code> has a <code>DOGE_BTC</code> pair. <br />
                        Luckily, the rule engine allow you to reference rules:
                    </p>
                    <pre>
                    <code>
                            DOGE_X = bittrex(DOGE_BTC) * BTC_X
                            X_CAD = ndax(X_CAD);
                            X_X = kraken(X_X);
                        </code>
                    </pre>
                    <p>
                        With <code>DOGE_USD</code> will be expanded to <code>bittrex(DOGE_BTC) * kraken(BTC_USD)</code>. And <code>DOGE_CAD</code> will be expanded to <code>bittrex(DOGE_BTC) * ndax(BTC_CAD)</code>. <br />
                        However, we advise you to write it that way to increase coverage so that <code>DOGE_BTC</code> is also supported:
                    </p>
                    <pre>
                    <code>
                            DOGE_X = DOGE_BTC * BTC_X
                            DOGE_BTC = bittrex(DOGE_BTC)
                            X_CAD = ndax(X_CAD);
                            X_X = kraken(X_X);
                        </code>
                    </pre>
                    <p>
                        It is worth noting that the inverses of those pairs are automatically supported as well.<br />
                        It means that the rule <code>USD_DOGE = 1 / DOGE_USD</code> implicitely exists.
                    </p>
                </div>
                <div class="form-group">
                    <label asp-for="Script" class="form-label"></label>
                    <a href="#help" data-bs-toggle="collapse">
                        <span class="fa fa-question-circle-o text-secondary" title="More information..."></span>
                    </a>
                    <textarea asp-for="Script" rows="20" cols="80" class="form-control"></textarea>
                    <span asp-validation-for="Script" class="text-danger"></span>
                    <p>
                        <button type="button" class="btn btn-link text-secondary px-0" onclick="document.getElementById('Script').value=defaultScript;return false;">Set to default settings</button>
                    </p>
                </div>
                <p>
                    <button type="submit" class="btn btn-secondary" value="scripting-off" name="command">Turn off advanced rate rule scripting</button>
                </p>
            }
            else
            {
                <div class="form-group">
                    <label asp-for="PreferredExchange" class="form-label"></label>
                    <select asp-for="PreferredExchange" asp-items="Model.Exchanges" class="form-select"></select>
                    <span asp-validation-for="PreferredExchange" class="text-danger"></span>
                    <p id="PreferredExchangeHelpBlock" class="form-text text-muted">
                        Current Rates source is <a href="@Model.RateSource" target="_blank">@Model.PreferredExchange</a>.
                    </p>
                </div>
                <p>
                    <button type="submit" class="btn btn-secondary" value="scripting-on" name="command">Turn on advanced rate rule scripting</button>
                </p>
            }
            <div class="form-group">
                <label asp-for="Spread" class="form-label"></label>
                <div class="input-group">
                    <input asp-for="Spread" class="form-control" />
                    <span class="input-group-text">%</span>
                </div>
                <span asp-validation-for="Spread" class="text-danger"></span>
            </div>
            <h4 class="mt-5 mb-3">Testing</h4>
            <div class="form-group">
                <label asp-for="ScriptTest" class="form-label">Enter currency pairs which you want to test against your rule (eg. <code>DOGE_USD,DOGE_CAD,BTC_CAD,BTC_USD</code>)</label>
                <input asp-for="ScriptTest" class="form-control" placeholder="BTC_USD, BTC_CAD" />
                <span asp-validation-for="ScriptTest" class="text-danger"></span>
            </div>
            <button name="command" value="Test" type="submit" class="btn btn-primary" title="Test">Test</button>

            <h4 class="mt-5 mb-3">Default currency pairs</h4>
            <div class="form-group">
                <label asp-for="DefaultCurrencyPairs" class="form-label">You can query those pairs via REST by querying <a asp-controller="Rate" asp-action="GetRates2" asp-route-storeId="@Model.StoreId" target="_blank">this link</a> without the need to specify currencyPairs.</label>
                <input asp-for="DefaultCurrencyPairs" class="form-control" placeholder="BTC_USD, BTC_CAD" />
                <span asp-validation-for="DefaultCurrencyPairs" class="text-danger"></span>
            </div>
            <button name="command" type="submit" class="btn btn-primary" value="Save">Save</button>
        </form>
    </div>
</div>

@section PageFootContent {
    <script>
        var defaultScript = @Safe.Json(Model.DefaultScript);
    </script>
    <partial name="_ValidationScriptsPartial" />
}