package parser

import (
	"bufio"
	"os"
	"path/filepath"
	"testing"
)

func TestScanDirectory_FindsAccessAndErrorLogs(t *testing.T) {
	dir := t.TempDir()

	// Create test log files
	files := []string{
		"access.log",
		"access.log.1",
		"error.log",
		"error.log.1",
		"other.txt", // should be ignored
	}
	for _, f := range files {
		if err := os.WriteFile(filepath.Join(dir, f), []byte(""), 0644); err != nil {
			t.Fatal(err)
		}
	}

	accessFiles, errorFiles, err := ScanDirectory(dir, false)
	if err != nil {
		t.Fatalf("ScanDirectory error: %v", err)
	}
	if len(accessFiles) != 2 {
		t.Errorf("expected 2 access files, got %d: %v", len(accessFiles), accessFiles)
	}
	if len(errorFiles) != 2 {
		t.Errorf("expected 2 error files, got %d: %v", len(errorFiles), errorFiles)
	}
}

func TestScanDirectory_GzipIncluded(t *testing.T) {
	dir := t.TempDir()
	files := []string{
		"access.log",
		"access.log.1.gz",
		"error.log",
	}
	for _, f := range files {
		if err := os.WriteFile(filepath.Join(dir, f), []byte(""), 0644); err != nil {
			t.Fatal(err)
		}
	}

	accessFiles, _, err := ScanDirectory(dir, true)
	if err != nil {
		t.Fatalf("ScanDirectory error: %v", err)
	}
	if len(accessFiles) != 2 {
		t.Errorf("expected 2 access files (including gz), got %d", len(accessFiles))
	}
}

func TestScanDirectory_GzipExcluded(t *testing.T) {
	dir := t.TempDir()
	files := []string{
		"access.log",
		"access.log.1.gz",
	}
	for _, f := range files {
		if err := os.WriteFile(filepath.Join(dir, f), []byte(""), 0644); err != nil {
			t.Fatal(err)
		}
	}

	accessFiles, _, err := ScanDirectory(dir, false)
	if err != nil {
		t.Fatalf("ScanDirectory error: %v", err)
	}
	if len(accessFiles) != 1 {
		t.Errorf("expected 1 access file (gz excluded), got %d", len(accessFiles))
	}
}

func TestScanDirectory_NonexistentDir(t *testing.T) {
	_, _, err := ScanDirectory("/nonexistent/path/xyz", true)
	if err == nil {
		t.Error("expected error for nonexistent directory, got nil")
	}
}

func TestOpenLogFile_PlainText(t *testing.T) {
	dir := t.TempDir()
	content := "test line\n"
	path := filepath.Join(dir, "test.log")
	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatal(err)
	}

	rc, err := openLogFile(path)
	if err != nil {
		t.Fatalf("openLogFile error: %v", err)
	}
	defer rc.Close()

	scanner := bufio.NewScanner(rc)
	if !scanner.Scan() {
		t.Fatal("expected to read a line")
	}
	if scanner.Text() != "test line" {
		t.Errorf("got %q, want %q", scanner.Text(), "test line")
	}
}

func TestOpenLogFile_Gzip(t *testing.T) {
	// Use the pre-made fixture
	rc, err := openLogFile("testdata/access.log.1.gz")
	if err != nil {
		t.Fatalf("openLogFile gz error: %v", err)
	}
	defer rc.Close()

	scanner := bufio.NewScanner(rc)
	if !scanner.Scan() {
		t.Fatal("expected to read a line from gz file")
	}
	line := scanner.Text()
	if line == "" {
		t.Error("expected non-empty line from gz file")
	}
}

func TestScanDirectory_SortOrder(t *testing.T) {
	dir := t.TempDir()
	files := []string{
		"access.log.2.gz",
		"access.log",
		"access.log.1",
		"access.log.1.gz",
	}
	for _, f := range files {
		if err := os.WriteFile(filepath.Join(dir, f), []byte(""), 0644); err != nil {
			t.Fatal(err)
		}
	}

	accessFiles, _, err := ScanDirectory(dir, true)
	if err != nil {
		t.Fatalf("ScanDirectory error: %v", err)
	}
	if len(accessFiles) != 4 {
		t.Fatalf("expected 4 files, got %d", len(accessFiles))
	}
	// access.log should come first (most recent)
	if filepath.Base(accessFiles[0]) != "access.log" {
		t.Errorf("expected access.log first, got %q", filepath.Base(accessFiles[0]))
	}
}