package txt

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

	"sub-cli/internal/model"
)

func TestGenerateFromSubtitle(t *testing.T) {
	// Create test subtitle
	subtitle := model.NewSubtitle()
	
	entry1 := model.NewSubtitleEntry()
	entry1.Text = "This is the first line."
	
	entry2 := model.NewSubtitleEntry()
	entry2.Text = "This is the second line."
	
	entry3 := model.NewSubtitleEntry()
	entry3.Text = "This is the third line\nwith a line break."
	
	subtitle.Entries = append(subtitle.Entries, entry1, entry2, entry3)

	// Generate TXT file
	tempDir := t.TempDir()
	outputFile := filepath.Join(tempDir, "output.txt")
	err := GenerateFromSubtitle(subtitle, outputFile)
	if err != nil {
		t.Fatalf("GenerateFromSubtitle failed: %v", err)
	}

	// Verify generated content
	content, err := os.ReadFile(outputFile)
	if err != nil {
		t.Fatalf("Failed to read output file: %v", err)
	}

	// Check content
	lines := strings.Split(string(content), "\n")
	if len(lines) < 4 { // 3 entries with one having a line break
		t.Fatalf("Expected at least 4 lines, got %d", len(lines))
	}

	if lines[0] != "This is the first line." {
		t.Errorf("Expected first line to be 'This is the first line.', got '%s'", lines[0])
	}

	if lines[1] != "This is the second line." {
		t.Errorf("Expected second line to be 'This is the second line.', got '%s'", lines[1])
	}
	
	if lines[2] != "This is the third line" {
		t.Errorf("Expected third line to be 'This is the third line', got '%s'", lines[2])
	}
	
	if lines[3] != "with a line break." {
		t.Errorf("Expected fourth line to be 'with a line break.', got '%s'", lines[3])
	}
}

func TestGenerateFromSubtitle_EmptySubtitle(t *testing.T) {
	// Create empty subtitle
	subtitle := model.NewSubtitle()

	// Generate TXT file
	tempDir := t.TempDir()
	outputFile := filepath.Join(tempDir, "empty.txt")
	err := GenerateFromSubtitle(subtitle, outputFile)
	if err != nil {
		t.Fatalf("GenerateFromSubtitle failed with empty subtitle: %v", err)
	}

	// Verify generated content
	content, err := os.ReadFile(outputFile)
	if err != nil {
		t.Fatalf("Failed to read output file: %v", err)
	}

	// Check content is empty
	if len(content) != 0 {
		t.Errorf("Expected empty file, got content: %s", string(content))
	}
}

func TestGenerateFromSubtitle_WithTitle(t *testing.T) {
	// Create subtitle with title
	subtitle := model.NewSubtitle()
	subtitle.Title = "My Test Title"
	
	entry1 := model.NewSubtitleEntry()
	entry1.Text = "This is a test line."
	subtitle.Entries = append(subtitle.Entries, entry1)

	// Generate TXT file
	tempDir := t.TempDir()
	outputFile := filepath.Join(tempDir, "titled.txt")
	err := GenerateFromSubtitle(subtitle, outputFile)
	if err != nil {
		t.Fatalf("GenerateFromSubtitle failed with titled subtitle: %v", err)
	}

	// Verify generated content
	content, err := os.ReadFile(outputFile)
	if err != nil {
		t.Fatalf("Failed to read output file: %v", err)
	}

	// Check content has title and proper formatting
	lines := strings.Split(string(content), "\n")
	if len(lines) < 3 { // Title + blank line + content
		t.Fatalf("Expected at least 3 lines, got %d", len(lines))
	}

	if lines[0] != "My Test Title" {
		t.Errorf("Expected first line to be title, got '%s'", lines[0])
	}

	if lines[1] != "" {
		t.Errorf("Expected second line to be blank, got '%s'", lines[1])
	}
	
	if lines[2] != "This is a test line." {
		t.Errorf("Expected third line to be content, got '%s'", lines[2])
	}
}

func TestGenerateFromSubtitle_FileError(t *testing.T) {
	// Create test subtitle
	subtitle := model.NewSubtitle()
	entry1 := model.NewSubtitleEntry()
	entry1.Text = "Test line"
	subtitle.Entries = append(subtitle.Entries, entry1)

	// Test with invalid file path
	invalidPath := "/nonexistent/directory/file.txt"
	err := GenerateFromSubtitle(subtitle, invalidPath)
	
	// Verify error is returned
	if err == nil {
		t.Errorf("Expected error for invalid file path, got nil")
	}
}