btcpayserver/BTCPayServer/Views/UIStores/Rates.cshtml

@using BTCPayServer.Abstractions.Models
@using BTCPayServer.Abstractions.TagHelpers
@using BTCPayServer.Client
@using Microsoft.AspNetCore.Mvc.TagHelpers
@model BTCPayServer.Models.StoreViewModels.RatesViewModel
@{
    ViewData.SetActivePage(StoreNavPages.Rates, "Rates", Context.GetStoreData().Id);
}

<form method="post" permissioned="@Policies.CanModifyStoreSettings">
    <div class="sticky-header">
        <h2>@ViewData["Title"]</h2>
		<button id="page-primary" name="command" type="submit" class="btn btn-primary" value="Save">Save</button>
    </div>
    <partial name="_StatusMessage" />
    <div class="row">
        <div class="col-xxl-constrain col-xl-8">
            @if (!ViewContext.ModelState.IsValid)
            {
                <div asp-validation-summary="All"></div>
            }
            <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" rel="noreferrer noopener">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" rel="noreferrer noopener">@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" rel="noreferrer noopener">@exchange.Id</a><span>&nbsp;</span>
                                    }
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            }
            @if (Model.TestRateRules != null)
            {
                <h5>Test Results:</h5>
                <div class="table-responsive-md">
                    <table class="table table-hover">
                        <tbody>
                        @foreach (var result in Model.TestRateRules)
                        {
                            <tr>
                                @if (result.Error)
                                {
                                    <th class="small">
                                        <vc:icon symbol="cross" css-class="text-danger" />
                                        @result.CurrencyPair
                                    </th>
                                }
                                else
                                {
                                    <th class="small">
                                        <vc:icon symbol="checkmark" css-class="text-success" />
                                        @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 class="text hljs">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 class="text hljs">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 class="text hljs">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>bitpay</code> has a <code>DOGE_BTC</code> pair. <br />
                        Luckily, the rule engine allow you to reference rules:
                    </p>
                    <pre><code class="text hljs">DOGE_X = bitpay(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>bitpay(DOGE_BTC) * kraken(BTC_USD)</code>. And <code>DOGE_CAD</code> will be expanded to <code>bitpay(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 class="text hljs">DOGE_X = DOGE_BTC * BTC_X;
DOGE_BTC = bitpay(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" title="More information...">
                        <vc:icon symbol="info"/>
                    </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" id="ResetDefaults">Set to default settings</button>
                    </p>
                </div>
            }
            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>
                    <div id="PreferredExchangeHelpBlock" class="form-text">
                        Current Rates source is <a href="@Model.RateSource" target="_blank" rel="noreferrer noopener">@Model.PreferredResolvedExchange</a>.
                    </div>
                </div>
            }
            <div class="form-group">
                <label class="d-flex align-items-center">
                    <button type="submit" id="ShowScripting" class="btcpay-toggle me-3 @if (Model.ShowScripting) { @("btcpay-toggle--active") }" value="scripting-@(Model.ShowScripting ? "off" : "on")" name="command" data-bs-toggle="modal" data-bs-target="#ConfirmModal" permission="@Policies.CanModifyStoreSettings">@(Model.ShowScripting ? "Disable" : "Enable") advanced rate rule scripting</button>
                    <div>
                        <span>Advanced rate rule scripting</span>
                        <div class="form-text">
                            @(Model.ShowScripting ? "Disabling will delete your rate script." : "Enabling will modify your current rate sources. This is a feature for advanced users.")
                        </div>
                    </div>
                </label>
            </div>
            <div class="form-group">
                <label asp-for="Spread" class="form-label"></label>
                <div class="input-group">
                    <input inputmode="decimal" asp-for="Spread" class="form-control" />
                    <span class="input-group-text">%</span>
                </div>
                <span asp-validation-for="Spread" class="text-danger"></span>
            </div>
            <h3 class="mt-5 mb-3">Testing</h3>

            <div class="form-group">
                <label asp-for="ScriptTest" class="form-label">Currency pairs to test against your rule (e.g. <code>DOGE_USD,DOGE_CAD,BTC_CAD,BTC_USD</code>)</label>
                <div class="d-flex">
                    <input asp-for="ScriptTest" class="form-control" placeholder="BTC_USD, BTC_CAD" />
                    <button name="command" value="Test" type="submit" class="btn btn-secondary ms-3" title="Test" permission="@Policies.CanModifyStoreSettings">Test</button>
                </div>
                <span asp-validation-for="ScriptTest" class="text-danger"></span>
            </div>

            <h3 class="mt-5 mb-3">Default Currency Pairs</h3>
            <div class="form-group">
                <label asp-for="DefaultCurrencyPairs" class="form-label">Query pairs via REST by querying <a asp-controller="BitpayRate" 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>
        </div>
    </div>
</form>
<partial name="_Confirm" model="@(new ConfirmModel("Rate rule scripting", Model.ShowScripting ? "This action will delete your rate script. Are you sure to turn off rate rules scripting?" : "This action will modify your current rate sources. Are you sure to turn on rate rules scripting? (Advanced users)", "Continue", Model.ShowScripting ? "btn-danger" : "btn-primary"))" permission="@Policies.CanModifyStoreSettings" />

@section PageHeadContent {
    <link rel="stylesheet" href="~/vendor/highlightjs/default.min.css" asp-append-version="true">
}

@section PageFootContent {
    <script>
        const commandButton = document.querySelector('[data-bs-target="#ConfirmModal"]')
        commandButton.dataset.action = window.location.href + '/confirm?scripting=@(!Model.ShowScripting)'
        commandButton.addEventListener('click', event => {
            event.preventDefault()
        });

        delegate('click', '#ResetDefaults', () => {
            document.getElementById('Script').value = @Safe.Json(Model.DefaultScript);
        });
    </script>
    <partial name="_ValidationScriptsPartial"/>
}