From 698cdb8bd8730ab19722477449d6bc29809f1329 Mon Sep 17 00:00:00 2001
From: mkwcat <cat@mkw.re>
Date: Mon, 4 Dec 2023 23:28:01 -0500
Subject: [PATCH] ServerBrowser: Custom handling of Mario Kart Wii filters

---
 serverbrowser/filter.go      |  2 +-
 serverbrowser/filter/eval.go | 42 ++++++++++++++++++++++++++++++++----
 2 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/serverbrowser/filter.go b/serverbrowser/filter.go
index d1261df..a258afc 100644
--- a/serverbrowser/filter.go
+++ b/serverbrowser/filter.go
@@ -82,7 +82,7 @@ func filterServers(servers []map[string]string, queryGame string, expression str
 			continue
 		}
 
-		ret, err := filter.Eval(tree, server)
+		ret, err := filter.Eval(tree, server, queryGame)
 		if err != nil {
 			logging.Error(ModuleName, "Error evaluating filter:", err.Error())
 			return []map[string]string{}
diff --git a/serverbrowser/filter/eval.go b/serverbrowser/filter/eval.go
index cf1faf7..ad747da 100644
--- a/serverbrowser/filter/eval.go
+++ b/serverbrowser/filter/eval.go
@@ -4,15 +4,17 @@ package filter
 import (
 	"errors"
 	"strconv"
+	"strings"
 )
 
 type expression struct {
-	ast     *TreeNode
-	context map[string]string
+	ast       *TreeNode
+	context   map[string]string
+	queryGame string
 }
 
 // Bug(zdebeer): functions is eval from right to left instead from left to right.
-func Eval(basenode *TreeNode, context map[string]string) (value int64, err error) {
+func Eval(basenode *TreeNode, context map[string]string, queryGame string) (value int64, err error) {
 	defer func() {
 		if str := recover(); str != nil {
 			value = 0
@@ -20,7 +22,7 @@ func Eval(basenode *TreeNode, context map[string]string) (value int64, err error
 		}
 	}()
 
-	this := &expression{basenode, context}
+	this := &expression{basenode, context, queryGame}
 	return this.eval(basenode), nil
 }
 
@@ -116,6 +118,12 @@ func (this *expression) evalEquals(args []*TreeNode) int64 {
 	case cnt < 2:
 		panic("operator missing arguments")
 	case cnt == 2:
+		if n, ok := args[0].Value.(*IdentityToken); ok {
+			if n.Name == "rk" && this.queryGame == "mariokartwii" {
+				return this.evalEqualsRK(this.getString(args[1]))
+			}
+		}
+
 		if this.getString(args[0]) == this.getString(args[1]) {
 			return 1
 		}
@@ -131,6 +139,25 @@ func (this *expression) evalEquals(args []*TreeNode) int64 {
 	}
 }
 
+// Operator override
+func (this *expression) evalEqualsRK(value string) int64 {
+	rk := this.context["rk"]
+	// Check and remove regional searches due to the limited player count
+	// China (ID 6) gets a pass because it was never released
+	if len(rk) == 4 && (strings.HasPrefix(rk, "vs_") || strings.HasPrefix(rk, "bt_")) && rk[3] >= '0' && rk[3] < '6' {
+		rk = rk[:2]
+	}
+
+	if len(value) == 4 && (strings.HasPrefix(value, "vs_") || strings.HasPrefix(value, "bt_")) && value[3] >= '0' && value[3] < '6' {
+		value = value[:2]
+	}
+
+	if rk == value {
+		return 1
+	}
+	return 0
+}
+
 func (this *expression) evalNotEquals(args []*TreeNode) int64 {
 	cnt := len(args)
 	switch {
@@ -208,6 +235,13 @@ func (this *expression) evalMathOperator(fn func(int64, int64) int64, args []*Tr
 	case cnt < 2:
 		panic("operator missing arguments")
 	case cnt == 2:
+		if n, ok := args[0].Value.(*IdentityToken); ok {
+			// Remove VR search due to the limited player count
+			if (n.Name == "ev" || n.Name == "eb") && this.queryGame == "mariokartwii" {
+				return 1
+			}
+		}
+
 		return fn(this.getNumber(args[0]), this.getNumber(args[1]))
 	default:
 		answ := fn(this.getNumber(args[0]), this.getNumber(args[1]))