package srt

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

func TestFormat(t *testing.T) {
	// Create a temporary test file with out-of-order numbers
	content := `2
00:00:05,000 --> 00:00:08,000
This is the second line.

1
00:00:01,000 --> 00:00:04,000
This is the first line.

3
00:00:09,500 --> 00:00:12,800
This is the third line.
`
	tempDir := t.TempDir()
	testFile := filepath.Join(tempDir, "test.srt")
	if err := os.WriteFile(testFile, []byte(content), 0644); err != nil {
		t.Fatalf("Failed to create test file: %v", err)
	}

	// Format the file
	err := Format(testFile)
	if err != nil {
		t.Fatalf("Format failed: %v", err)
	}

	// Read the formatted file
	formatted, err := os.ReadFile(testFile)
	if err != nil {
		t.Fatalf("Failed to read formatted file: %v", err)
	}

	// The Format function should standardize the numbering
	lines := strings.Split(string(formatted), "\n")

	// The numbers should be sequential starting from 1
	if !strings.HasPrefix(lines[0], "1") {
		t.Errorf("First entry should be renumbered to 1, got '%s'", lines[0])
	}

	// Find the second entry (after the first entry's content and a blank line)
	var secondEntryIndex int
	for i := 1; i < len(lines); i++ {
		if lines[i] == "" && i+1 < len(lines) && lines[i+1] != "" {
			secondEntryIndex = i + 1
			break
		}
	}

	if secondEntryIndex > 0 && !strings.HasPrefix(lines[secondEntryIndex], "2") {
		t.Errorf("Second entry should be renumbered to 2, got '%s'", lines[secondEntryIndex])
	}
}

func TestFormat_FileError(t *testing.T) {
	// Test with non-existent file
	err := Format("/nonexistent/file.srt")
	if err == nil {
		t.Error("Expected error when formatting non-existent file, got nil")
	}
}