From 63a4f3c8b68bb4aab64dc4da7a2e61a177066d3a Mon Sep 17 00:00:00 2001
From: laisolizq <laisolizq@gmail.com>
Date: Thu, 15 Oct 2020 14:21:51 +0200
Subject: [PATCH] Add get token endpoint

---
 api/api_test.go           | 25 +++++++++++++++++++++++++
 api/handlers.go           | 16 +++++++++++++++-
 db/historydb/historydb.go |  9 +++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/api/api_test.go b/api/api_test.go
index 016cb5c..220c560 100644
--- a/api/api_test.go
+++ b/api/api_test.go
@@ -871,6 +871,31 @@ func assertExitAPIs(t *testing.T, expected, actual []exitAPI) {
 	}
 }
 
+func TestGetToken(t *testing.T) {
+	// Get all txs by their ID
+	endpoint := apiURL + "tokens/"
+	fetchedTokens := []historydb.TokenRead{}
+	for _, token := range tc.tokens {
+		fetchedToken := historydb.TokenRead{}
+		assert.NoError(t, doGoodReq("GET", endpoint+strconv.Itoa(int(token.TokenID)), nil, &fetchedToken))
+		fetchedTokens = append(fetchedTokens, fetchedToken)
+	}
+	assertTokensAPIs(t, tc.tokens, fetchedTokens)
+}
+
+func assertTokensAPIs(t *testing.T, expected, actual []historydb.TokenRead) {
+	require.Equal(t, len(expected), len(actual))
+	for i := 0; i < len(actual); i++ { //nolint len(actual) won't change within the loop
+		if expected[i].USDUpdate == nil {
+			assert.Equal(t, expected[i].USDUpdate, actual[i].USDUpdate)
+		} else {
+			assert.Equal(t, expected[i].USDUpdate.Unix(), actual[i].USDUpdate.Unix())
+			expected[i].USDUpdate = actual[i].USDUpdate
+		}
+		assert.Equal(t, expected[i], actual[i])
+	}
+}
+
 func doGoodReqPaginated(
 	path, order string,
 	iterStruct db.Paginationer,
diff --git a/api/handlers.go b/api/handlers.go
index 72fb44e..a999339 100644
--- a/api/handlers.go
+++ b/api/handlers.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/gin-gonic/gin"
+	"github.com/hermeznetwork/hermez-node/common"
 	"github.com/hermeznetwork/hermez-node/db/historydb"
 )
 
@@ -205,7 +206,20 @@ func getTokens(c *gin.Context) {
 }
 
 func getToken(c *gin.Context) {
-
+	// Get TokenID
+	tokenIDUint, err := parseParamUint("id", nil, 0, maxUint32, c)
+	if err != nil {
+		retBadReq(err, c)
+		return
+	}
+	tokenID := common.TokenID(*tokenIDUint)
+	// Fetch token from historyDB
+	token, err := h.GetToken(tokenID)
+	if err != nil {
+		retSQLErr(err, c)
+		return
+	}
+	c.JSON(http.StatusOK, token)
 }
 
 func getRecommendedFee(c *gin.Context) {
diff --git a/db/historydb/historydb.go b/db/historydb/historydb.go
index dc8bea7..21e22de 100644
--- a/db/historydb/historydb.go
+++ b/db/historydb/historydb.go
@@ -288,6 +288,15 @@ func (hdb *HistoryDB) UpdateTokenValue(tokenSymbol string, value float64) error
 	return err
 }
 
+// GetToken returns a token from the DB given a TokenID
+func (hdb *HistoryDB) GetToken(tokenID common.TokenID) (*TokenRead, error) {
+	token := &TokenRead{}
+	err := meddler.QueryRow(
+		hdb.db, token, `SELECT * FROM token WHERE token_id = $1;`, tokenID,
+	)
+	return token, err
+}
+
 // GetTokens returns a list of tokens from the DB
 func (hdb *HistoryDB) GetTokens() ([]TokenRead, error) {
 	var tokens []*TokenRead