Merge pull request #41 from deoxykev/refactor_rulesets

refactor rulesets into separate files and add a ruleset compiler cli …

handlers/cli/cli.go

@@ -0,0 +1,105 @@
+package cli
+
+import (
+	"fmt"
+	"io"
+	"io/fs"
+	"ladder/pkg/ruleset"
+	"os"
+
+	"golang.org/x/term"
+)
+
+// HandleRulesetMerge merges a set of ruleset files, specified by the rulesetPath or RULESET env variable, into either YAML or Gzip format.
+// Exits the program with an error message if the ruleset path is not provided or if loading the ruleset fails.
+//
+// Parameters:
+// - rulesetPath: A pointer to a string specifying the path to the ruleset file.
+// - mergeRulesets: A pointer to a boolean indicating if a merge operation should be performed.
+// - mergeRulesetsGzip: A pointer to a boolean indicating if the merge should be in Gzip format.
+// - mergeRulesetsOutput: A pointer to a string specifying the output file path. If empty, the output is printed to stdout.
+//
+// Returns:
+// - An error if the ruleset loading or merging process fails, otherwise nil.
+func HandleRulesetMerge(rulesetPath *string, mergeRulesets *bool, mergeRulesetsGzip *bool, mergeRulesetsOutput *string) error {
+	if *rulesetPath == "" {
+		*rulesetPath = os.Getenv("RULESET")
+	}
+	if *rulesetPath == "" {
+		fmt.Println("ERROR: no ruleset provided. Try again with --ruleset <ruleset.yaml>")
+		os.Exit(1)
+	}
+
+	rs, err := ruleset.NewRuleset(*rulesetPath)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	if *mergeRulesetsGzip {
+		return gzipMerge(rs, mergeRulesetsOutput)
+	}
+	return yamlMerge(rs, mergeRulesetsOutput)
+}
+
+// gzipMerge takes a RuleSet and an optional output file path pointer. It compresses the RuleSet into Gzip format.
+// If the output file path is provided, the compressed data is written to this file. Otherwise, it prints a warning
+// and outputs the binary data to stdout
+//
+// Parameters:
+// - rs: The ruleset.RuleSet to be compressed.
+// - mergeRulesetsOutput: A pointer to a string specifying the output file path. If empty, the output is directed to stdout.
+//
+// Returns:
+// - An error if compression or file writing fails, otherwise nil.
+func gzipMerge(rs ruleset.RuleSet, mergeRulesetsOutput *string) error {
+	gzip, err := rs.GzipYaml()
+	if err != nil {
+		return err
+	}
+
+	if *mergeRulesetsOutput != "" {
+		out, err := os.Create(*mergeRulesetsOutput)
+		defer out.Close()
+		_, err = io.Copy(out, gzip)
+		if err != nil {
+			return err
+		}
+	}
+
+	if term.IsTerminal(int(os.Stdout.Fd())) {
+		println("WARNING: binary output can mess up your terminal. Use '--merge-rulesets-output <ruleset.gz>' or pipe it to a file.")
+		os.Exit(1)
+	}
+	_, err = io.Copy(os.Stdout, gzip)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// yamlMerge takes a RuleSet and an optional output file path pointer. It converts the RuleSet into YAML format.
+// If the output file path is provided, the YAML data is written to this file. If not, the YAML data is printed to stdout.
+//
+// Parameters:
+// - rs: The ruleset.RuleSet to be converted to YAML.
+// - mergeRulesetsOutput: A pointer to a string specifying the output file path. If empty, the output is printed to stdout.
+//
+// Returns:
+// - An error if YAML conversion or file writing fails, otherwise nil.
+func yamlMerge(rs ruleset.RuleSet, mergeRulesetsOutput *string) error {
+	yaml, err := rs.Yaml()
+	if err != nil {
+		return err
+	}
+	if *mergeRulesetsOutput == "" {
+		fmt.Printf(yaml)
+		os.Exit(0)
+	}
+
+	err = os.WriteFile(*mergeRulesetsOutput, []byte(yaml), fs.FileMode(os.O_RDWR))
+	if err != nil {
+		return fmt.Errorf("ERROR: failed to write merged YAML ruleset to '%s'\n", *mergeRulesetsOutput)
+	}
+	return nil
+}