sing-geosite: add rule-set

pkgs/data/misc/sing-geosite/default.nix

···
   installPhase = ''
     runHook preInstall
     install -Dm644 geosite.db $out/share/sing-box/geosite.db
+    install -Dm644 rule-set/* -t $out/share/sing-box/rule-set
     runHook postInstall
   '';
 

pkgs/data/misc/sing-geosite/main.go

···
 	if err != nil {
 		panic(err)
 	}
+
+	ruleSetOutput := "rule-set"
+	err = os.MkdirAll(ruleSetOutput, 0o755)
+	if err != nil {
+		panic(err)
+	}
+	for code, domains := range domainMap {
+		var headlessRule option.DefaultHeadlessRule
+		defaultRule := geosite.Compile(domains)
+		headlessRule.Domain = defaultRule.Domain
+		headlessRule.DomainSuffix = defaultRule.DomainSuffix
+		headlessRule.DomainKeyword = defaultRule.DomainKeyword
+		headlessRule.DomainRegex = defaultRule.DomainRegex
+		var plainRuleSet option.PlainRuleSet
+		plainRuleSet.Rules = []option.HeadlessRule{
+			{
+				Type:           C.RuleTypeDefault,
+				DefaultOptions: headlessRule,
+			},
+		}
+		srsPath, _ := filepath.Abs(filepath.Join(ruleSetOutput, "geosite-"+code+".srs"))
+		os.Stderr.WriteString("write " + srsPath + "\n")
+		outputRuleSet, err := os.Create(srsPath)
+		if err != nil {
+			panic(err)
+		}
+		err = srs.Write(outputRuleSet, plainRuleSet)
+		if err != nil {
+			outputRuleSet.Close()
+			panic(err)
+		}
+		outputRuleSet.Close()
+	}
 }