From 42011ad10c2c3ddb6b23e576dca687517f78985e Mon Sep 17 00:00:00 2001
From: Howl <the@howl.moe>
Date: Tue, 23 Aug 2016 16:27:09 +0200
Subject: [PATCH] Allow much more freedom to query for different things in
 /api/v1/beatmaps

---
 app/v1/beatmap.go | 44 +++++++++++++++++++++++++++++++-------------
 common/where.go   | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 13 deletions(-)
 create mode 100644 common/where.go

diff --git a/app/v1/beatmap.go b/app/v1/beatmap.go
index 0187829..60e101f 100644
--- a/app/v1/beatmap.go
+++ b/app/v1/beatmap.go
@@ -82,23 +82,16 @@ func BeatmapSetStatusPOST(md common.MethodData) common.CodeMessager {
 		SET ranked = ?, ranked_status_freezed = ?
 		WHERE beatmapset_id = ?`, req.RankedStatus, req.Frozen, param)
 
-	return getSet(md, param)
+	return getMultipleBeatmaps(md)
 }
 
 // BeatmapGET retrieves a beatmap.
 func BeatmapGET(md common.MethodData) common.CodeMessager {
-	if md.Query("s") == "" && md.Query("b") == "" {
-		return common.SimpleResponse(400, "Must pass either querystring param 'b' or 's'")
-	}
-	setID := common.Int(md.Query("s"))
-	if setID != 0 {
-		return getSet(md, setID)
-	}
 	beatmapID := common.Int(md.Query("b"))
 	if beatmapID != 0 {
-		return getBeatmap(md, beatmapID)
+		return getBeatmapSingle(md, beatmapID)
 	}
-	return common.SimpleResponse(400, "Please pass either a valid beatmapset ID or a valid beatmap ID")
+	return getMultipleBeatmaps(md)
 }
 
 const baseBeatmapSelect = `
@@ -111,8 +104,33 @@ SELECT
 FROM beatmaps
 `
 
-func getSet(md common.MethodData, setID int) common.CodeMessager {
-	rows, err := md.DB.Query(baseBeatmapSelect+"WHERE beatmapset_id = ?", setID)
+func getMultipleBeatmaps(md common.MethodData) common.CodeMessager {
+	sort := common.Sort(md, common.SortConfiguration{
+		Allowed: []string{
+			"beatmapset_id",
+			"beatmap_id",
+			"id",
+			"ar",
+			"od",
+			"difficulty_std",
+			"difficulty_taiko",
+			"difficulty_ctb",
+			"difficulty_mania",
+			"max_combo",
+			"latest_update",
+			"playcount",
+			"passcount",
+		},
+		Default: "id DESC",
+		Table:   "beatmaps",
+	})
+	where := common.Where("beatmapsetid = ?", md.Query("s")).
+		Where("song_name = ?", md.Query("song_name")).
+		Where("ranked_status_freezed = ?", md.Query("ranked_status_frozen"), "0", "1")
+
+	rows, err := md.DB.Query(baseBeatmapSelect+
+		where.Clause+" "+sort+" "+
+		common.Paginate(md.Query("p"), md.Query("l"), 50), where.Params...)
 	if err != nil {
 		md.Err(err)
 		return Err500
@@ -138,7 +156,7 @@ func getSet(md common.MethodData, setID int) common.CodeMessager {
 	return r
 }
 
-func getBeatmap(md common.MethodData, beatmapID int) common.CodeMessager {
+func getBeatmapSingle(md common.MethodData, beatmapID int) common.CodeMessager {
 	var b beatmap
 	err := md.DB.QueryRow(baseBeatmapSelect+"WHERE beatmap_id = ? LIMIT 1", beatmapID).Scan(
 		&b.BeatmapID, &b.BeatmapsetID, &b.BeatmapMD5,
diff --git a/common/where.go b/common/where.go
new file mode 100644
index 0000000..96e2bc2
--- /dev/null
+++ b/common/where.go
@@ -0,0 +1,33 @@
+package common
+
+// WhereClause is a struct representing a where clause.
+// This is made to easily create WHERE clauses from parameters passed from a request.
+type WhereClause struct {
+	Clause string
+	Params []interface{}
+}
+
+// Where adds a new WHERE clause to the WhereClause.
+func (w *WhereClause) Where(clause, passedParam string, allowedValues ...string) *WhereClause {
+	if passedParam == "" {
+		return w
+	}
+	if len(allowedValues) != 0 && !contains(allowedValues, passedParam) {
+		return w
+	}
+	// checks passed, if string is empty add "WHERE"
+	if w.Clause == "" {
+		w.Clause += "WHERE "
+	} else {
+		w.Clause += " AND "
+	}
+	w.Clause += clause
+	w.Params = append(w.Params, passedParam)
+	return w
+}
+
+// Where is the same as WhereClause.Where, but creates a new WhereClause.
+func Where(clause, passedParam string, allowedValues ...string) *WhereClause {
+	w := new(WhereClause)
+	return w.Where(clause, passedParam, allowedValues...)
+}