feat: load packet logs from directory source

internal/isphere/file_source.go

@@ -3,7 +3,10 @@ package isphere
 import (
 	"bufio"
 	"fmt"
+	"io/fs"
 	"os"
+	"path/filepath"
+	"sort"
 	"strings"
 )
 
@@ -13,9 +16,59 @@ func LoadEncryptedPacketLogSourceFromFile(path string) (EncryptedPacketLogSource
 		return EncryptedPacketLogSource{}, fmt.Errorf("packet log file path is empty")
 	}
 
-	file, err := os.Open(trimmedPath)
+	lines, err := readEncryptedPacketLogLinesFromFile(trimmedPath)
 	if err != nil {
-		return EncryptedPacketLogSource{}, fmt.Errorf("open packet log file %q: %w", trimmedPath, err)
+		return EncryptedPacketLogSource{}, err
+	}
+	return EncryptedPacketLogSource{Lines: lines}, nil
+}
+
+func LoadEncryptedPacketLogSourceFromDirectory(path string) (EncryptedPacketLogSource, error) {
+	trimmedPath := strings.TrimSpace(path)
+	if trimmedPath == "" {
+		return EncryptedPacketLogSource{}, fmt.Errorf("packet log directory path is empty")
+	}
+	info, err := os.Stat(trimmedPath)
+	if err != nil {
+		return EncryptedPacketLogSource{}, fmt.Errorf("stat packet log directory %q: %w", trimmedPath, err)
+	}
+	if !info.IsDir() {
+		return EncryptedPacketLogSource{}, fmt.Errorf("packet log directory %q is not a directory", trimmedPath)
+	}
+
+	paths := []string{}
+	if err := filepath.WalkDir(trimmedPath, func(path string, entry fs.DirEntry, walkErr error) error {
+		if walkErr != nil {
+			return walkErr
+		}
+		if entry.IsDir() {
+			return nil
+		}
+		ext := strings.ToLower(filepath.Ext(entry.Name()))
+		if ext == ".log" || ext == ".txt" {
+			paths = append(paths, path)
+		}
+		return nil
+	}); err != nil {
+		return EncryptedPacketLogSource{}, fmt.Errorf("walk packet log directory %q: %w", trimmedPath, err)
+	}
+	sort.Strings(paths)
+
+	lines := []string{}
+	for _, path := range paths {
+		fileLines, err := readEncryptedPacketLogLinesFromFile(path)
+		if err != nil {
+			return EncryptedPacketLogSource{}, err
+		}
+		lines = append(lines, fileLines...)
+	}
+	return EncryptedPacketLogSource{Lines: lines}, nil
+}
+
+func readEncryptedPacketLogLinesFromFile(path string) ([]string, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open packet log file %q: %w", path, err)
 	}
 	defer file.Close()
 
@@ -30,7 +83,7 @@ func LoadEncryptedPacketLogSourceFromFile(path string) (EncryptedPacketLogSource
 		lines = append(lines, line)
 	}
 	if err := scanner.Err(); err != nil {
-		return EncryptedPacketLogSource{}, fmt.Errorf("read packet log file %q: %w", trimmedPath, err)
+		return nil, fmt.Errorf("read packet log file %q: %w", path, err)
 	}
-	return EncryptedPacketLogSource{Lines: lines}, nil
+	return lines, nil
 }

internal/isphere/file_source_test.go

@@ -2,6 +2,7 @@ package isphere
 
 import (
 	"os"
+	"path/filepath"
 	"reflect"
 	"testing"
 )
@@ -19,6 +20,23 @@ func TestLoadEncryptedPacketLogSourceFromFileReadsNonEmptyLines(t *testing.T) {
 	}
 }
 
+func TestLoadEncryptedPacketLogSourceFromDirectoryReadsSortedLogFiles(t *testing.T) {
+	root := t.TempDir()
+	writePacketLogFileAtPathForTest(t, root+"\\b.log", "\n  line-b1  \n")
+	writePacketLogFileAtPathForTest(t, root+"\\a.log", "line-a1\n\nline-a2\n")
+	writePacketLogFileAtPathForTest(t, root+"\\nested\\c.txt", "line-c1\n")
+	writePacketLogFileAtPathForTest(t, root+"\\ignored.tmp", "ignored\n")
+
+	got, err := LoadEncryptedPacketLogSourceFromDirectory(root)
+	if err != nil {
+		t.Fatalf("LoadEncryptedPacketLogSourceFromDirectory returned error: %v", err)
+	}
+	want := EncryptedPacketLogSource{Lines: []string{"line-a1", "line-a2", "line-b1", "line-c1"}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("source = %#v, want %#v", got, want)
+	}
+}
+
 func writePacketLogFileForTest(t *testing.T, content string) string {
 	t.Helper()
 	path := t.TempDir() + "\\packet.log"
@@ -27,3 +45,13 @@ func writePacketLogFileForTest(t *testing.T, content string) string {
 	}
 	return path
 }
+
+func writePacketLogFileAtPathForTest(t *testing.T, path string, content string) {
+	t.Helper()
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		t.Fatalf("create parent for %s: %v", path, err)
+	}
+	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+		t.Fatalf("write test packet log %s: %v", path, err)
+	}
+}