From 06347dfcd6044c0278b84d9785d476bb2c4575e0 Mon Sep 17 00:00:00 2001
From: asara <asara@ranger.minhas.io>
Date: Mon, 4 Jul 2022 19:46:12 -0400
Subject: [PATCH] Coingecko cryptocurrency lookups

---
 coingecko/coingecko.go | 96 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 coingecko/coingecko.go

diff --git a/coingecko/coingecko.go b/coingecko/coingecko.go
new file mode 100644
index 0000000..ece84ab
--- /dev/null
+++ b/coingecko/coingecko.go
@@ -0,0 +1,96 @@
+// Package coingecko implements a Service which returns price info on cryptocurrencies from coingecko
+package coingecko
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/matrix-org/go-neb/types"
+	mevt "maunium.net/go/mautrix/event"
+	"maunium.net/go/mautrix/id"
+)
+
+// ServiceType of the coingecko service
+const ServiceType = "coingecko"
+
+// Service represents the coingecko service. It has no Config fields.
+type Service struct {
+	types.DefaultService
+}
+
+type CoinList struct {
+	Id     string `json:"id"`
+	Symbol string `json:"symbol"`
+	Name   string `json:"name"`
+}
+
+type MarketChart struct {
+	Prices       [][]float32 `json:"prices"`
+	MarketCaps   [][]float32 `json:"market_caps"`
+	TotalVolumes [][]float32 `json:"total_volumes"`
+}
+
+func getId(query string) string {
+	req, _ := http.NewRequest("GET", "https://api.coingecko.com/api/v3/coins/list", nil)
+	req.Header.Set("Accept", "application/json")
+	client := &http.Client{}
+	resp, _ := client.Do(req)
+	defer resp.Body.Close()
+
+	var coinList *[]CoinList
+	json.NewDecoder(resp.Body).Decode(&coinList)
+	for _, coin := range *coinList {
+		// get the coingecko id for the requested coin
+		if coin.Symbol == query {
+			return coin.Id
+		}
+	}
+	// fallback to bitcoin
+	return "bitcoin"
+}
+
+func getData(query string) string {
+	url := fmt.Sprintf("https://api.coingecko.com/api/v3/coins/%s/market_chart?vs_currency=usd&days=1", query)
+	req, _ := http.NewRequest("GET", url, nil)
+	req.Header.Set("Accept", "application/json")
+	client := &http.Client{}
+	resp, _ := client.Do(req)
+	defer resp.Body.Close()
+
+	var coin *MarketChart
+	json.NewDecoder(resp.Body).Decode(&coin)
+
+	latestPrice := coin.Prices[len(coin.Prices)-1][1]
+	marketCap := coin.MarketCaps[len(coin.MarketCaps)-1][1]
+	totalVol := coin.TotalVolumes[len(coin.TotalVolumes)-1][1]
+	return fmt.Sprintf("%s -- Price: $%f, Market Cap: $%.0f, 24hr Volume: $%.0f", query, latestPrice, marketCap, totalVol)
+}
+
+// Commands supported:
+//    !coingecko SYMBOL
+// Responds with price data on the currency
+func (e *Service) Commands(cli types.MatrixClient) []types.Command {
+	return []types.Command{
+		{
+			Path: []string{"cc"},
+			Command: func(roomID id.RoomID, userID id.UserID, args []string) (interface{}, error) {
+				coinId := getId(strings.Join(args, ""))
+				output := getData(coinId)
+				return &mevt.MessageEventContent{
+					MsgType: mevt.MsgNotice,
+					Body:    output,
+				}, nil
+			},
+		},
+	}
+}
+
+func init() {
+	types.RegisterService(func(serviceID string, serviceUserID id.UserID, webhookEndpointURL string) types.Service {
+		return &Service{
+			DefaultService: types.NewDefaultService(serviceID, serviceUserID, ServiceType),
+		}
+	})
+}