package commands

import (
	"context"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/belphemur/CBZOptimizer/v2/internal/cbz"
	"github.com/belphemur/CBZOptimizer/v2/internal/manga"
	"github.com/belphemur/CBZOptimizer/v2/internal/utils/errs"
	"github.com/belphemur/CBZOptimizer/v2/pkg/converter"
	"github.com/belphemur/CBZOptimizer/v2/pkg/converter/constant"
	"github.com/spf13/cobra"
)

// MockConverter is a mock implementation of the Converter interface
type MockConverter struct{}

func (m *MockConverter) ConvertChapter(ctx context.Context, chapter *manga.Chapter, quality uint8, split bool, progress func(message string, current uint32, total uint32)) (*manga.Chapter, error) {
	chapter.IsConverted = true
	chapter.ConvertedTime = time.Now()
	return chapter, nil
}

func (m *MockConverter) Format() constant.ConversionFormat {
	return constant.WebP
}

func (m *MockConverter) PrepareConverter() error {
	return nil
}

func TestConvertCbzCommand(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_cbz")
	if err != nil {
		log.Fatal(err)
	}
	defer errs.CaptureGeneric(&err, os.RemoveAll, tempDir, "failed to remove temporary directory")

	// Locate the testdata directory
	testdataDir := filepath.Join("../../../testdata")
	if _, err := os.Stat(testdataDir); os.IsNotExist(err) {
		t.Fatalf("testdata directory not found")
	}

	// Copy sample CBZ/CBR files from testdata to the temporary directory
	err = filepath.Walk(testdataDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			fileName := strings.ToLower(info.Name())
			if strings.HasSuffix(fileName, ".cbz") || strings.HasSuffix(fileName, ".cbr") {
				destPath := filepath.Join(tempDir, info.Name())
				data, err := os.ReadFile(path)
				if err != nil {
					return err
				}
				return os.WriteFile(destPath, data, info.Mode())
			}
		}
		return nil
	})
	if err != nil {
		t.Fatalf("Failed to copy sample files: %v", err)
	}

	// Mock the converter.Get function
	originalGet := converter.Get
	converter.Get = func(format constant.ConversionFormat) (converter.Converter, error) {
		return &MockConverter{}, nil
	}
	defer func() { converter.Get = originalGet }()

	// Set up the command
	cmd := &cobra.Command{
		Use: "optimize",
	}
	cmd.Flags().Uint8P("quality", "q", 85, "Quality for conversion (0-100)")
	cmd.Flags().IntP("parallelism", "n", 2, "Number of chapters to convert in parallel")
	cmd.Flags().BoolP("override", "o", false, "Override the original CBZ/CBR files")
	cmd.Flags().BoolP("split", "s", false, "Split long pages into smaller chunks")
	cmd.Flags().DurationP("timeout", "t", 0, "Maximum time allowed for converting a single chapter (e.g., 30s, 5m, 1h). 0 means no timeout")

	// Execute the command
	err = ConvertCbzCommand(cmd, []string{tempDir})
	if err != nil {
		t.Fatalf("Command execution failed: %v", err)
	}

	// Track expected converted files for verification
	expectedFiles := make(map[string]bool)
	convertedFiles := make(map[string]bool)

	// First pass: identify original files and expected converted filenames
	err = filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() {
			return nil
		}
		fileName := strings.ToLower(info.Name())
		if strings.HasSuffix(fileName, ".cbz") || strings.HasSuffix(fileName, ".cbr") {
			if !strings.Contains(fileName, "_converted") {
				// This is an original file, determine expected converted filename
				baseName := strings.TrimSuffix(info.Name(), filepath.Ext(info.Name()))
				expectedConverted := baseName + "_converted.cbz"
				expectedFiles[expectedConverted] = false // false means not yet found
			}
		}
		return nil
	})
	if err != nil {
		t.Fatalf("Error identifying original files: %v", err)
	}

	// Second pass: verify converted files exist and are properly converted
	err = filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() {
			return nil
		}
		fileName := info.Name()

		// Check if this is a converted file (should only be .cbz, never .cbr)
		if strings.HasSuffix(fileName, "_converted.cbz") {
			convertedFiles[fileName] = true
			expectedFiles[fileName] = true // Mark as found
			t.Logf("Archive file found: %s", path)

			// Load the converted chapter
			chapter, err := cbz.LoadChapter(path)
			if err != nil {
				return err
			}

			// Check if the chapter is marked as converted
			if !chapter.IsConverted {
				t.Errorf("Chapter is not marked as converted: %s", path)
			}

			// Check if the ConvertedTime is set
			if chapter.ConvertedTime.IsZero() {
				t.Errorf("ConvertedTime is not set for chapter: %s", path)
			}
			t.Logf("Archive file [%s] is converted: %s", path, chapter.ConvertedTime)
		} else if strings.HasSuffix(fileName, "_converted.cbr") {
			t.Errorf("Found incorrectly named converted file: %s (should be .cbz, not .cbr)", fileName)
		}

		return nil
	})
	if err != nil {
		t.Fatalf("Error verifying converted files: %v", err)
	}

	// Verify all expected files were found
	for expectedFile, found := range expectedFiles {
		if !found {
			t.Errorf("Expected converted file not found: %s", expectedFile)
		}
	}

	// Log summary
	t.Logf("Found %d converted files", len(convertedFiles))
}

// setupTestCommand creates a test command with all required flags for testing.
// It mocks the converter.Get function and sets up a complete command with all flags.
//
// Returns:
//   - *cobra.Command: A configured command ready for testing
//   - func(): A cleanup function that must be deferred to restore the original converter.Get
func setupTestCommand(t *testing.T) (*cobra.Command, func()) {
	t.Helper()
	// Mock the converter.Get function
	originalGet := converter.Get
	converter.Get = func(format constant.ConversionFormat) (converter.Converter, error) {
		return &MockConverter{}, nil
	}
	cleanup := func() { converter.Get = originalGet }
	
	// Set up the command
	cmd := &cobra.Command{
		Use: "optimize",
	}
	cmd.Flags().Uint8P("quality", "q", 85, "Quality for conversion (0-100)")
	cmd.Flags().IntP("parallelism", "n", 1, "Number of chapters to convert in parallel")
	cmd.Flags().BoolP("override", "o", false, "Override the original CBZ/CBR files")
	cmd.Flags().BoolP("split", "s", false, "Split long pages into smaller chunks")
	cmd.Flags().DurationP("timeout", "t", 0, "Maximum time allowed for converting a single chapter")
	
	// Reset converterType to default before test for consistency
	converterType = constant.DefaultConversion
	setupFormatFlag(cmd, &converterType, false)
	
	return cmd, cleanup
}

// TestFormatFlagWithSpace tests that the format flag works with space-separated values
func TestFormatFlagWithSpace(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_format_space")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	cmd, cleanup := setupTestCommand(t)
	defer cleanup()

	// Test with space-separated format flag (--format webp)
	cmd.ParseFlags([]string{"--format", "webp"})
	
	// Execute the command
	err = ConvertCbzCommand(cmd, []string{tempDir})
	if err != nil {
		t.Fatalf("Command execution failed with --format webp: %v", err)
	}

	// Verify the format was set correctly
	if converterType != constant.WebP {
		t.Errorf("Expected format to be WebP, got %v", converterType)
	}
}

// TestFormatFlagWithShortForm tests that the short form of format flag works with space-separated values
func TestFormatFlagWithShortForm(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_format_short")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	cmd, cleanup := setupTestCommand(t)
	defer cleanup()

	// Test with short form and space (-f webp)
	cmd.ParseFlags([]string{"-f", "webp"})
	
	// Execute the command
	err = ConvertCbzCommand(cmd, []string{tempDir})
	if err != nil {
		t.Fatalf("Command execution failed with -f webp: %v", err)
	}

	// Verify the format was set correctly
	if converterType != constant.WebP {
		t.Errorf("Expected format to be WebP, got %v", converterType)
	}
}

// TestFormatFlagWithEquals tests that the format flag works with equals syntax
func TestFormatFlagWithEquals(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_format_equals")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	cmd, cleanup := setupTestCommand(t)
	defer cleanup()

	// Test with equals syntax (--format=webp)
	cmd.ParseFlags([]string{"--format=webp"})
	
	// Execute the command
	err = ConvertCbzCommand(cmd, []string{tempDir})
	if err != nil {
		t.Fatalf("Command execution failed with --format=webp: %v", err)
	}

	// Verify the format was set correctly
	if converterType != constant.WebP {
		t.Errorf("Expected format to be WebP, got %v", converterType)
	}
}

// TestFormatFlagDefaultValue tests that the default format is used when flag is not provided
func TestFormatFlagDefaultValue(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_format_default")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	cmd, cleanup := setupTestCommand(t)
	defer cleanup()

	// Don't set format flag - should use default
	cmd.ParseFlags([]string{})
	
	// Execute the command
	err = ConvertCbzCommand(cmd, []string{tempDir})
	if err != nil {
		t.Fatalf("Command execution failed with default format: %v", err)
	}

	// Verify the default format is used
	if converterType != constant.DefaultConversion {
		t.Errorf("Expected format to be default (%v), got %v", constant.DefaultConversion, converterType)
	}
}

// TestFormatFlagCaseInsensitive tests that the format flag is case-insensitive
func TestFormatFlagCaseInsensitive(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_format_case")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	testCases := []string{"webp", "WEBP", "WebP", "WeBp"}

	for _, formatValue := range testCases {
		t.Run(formatValue, func(t *testing.T) {
			cmd, cleanup := setupTestCommand(t)
			defer cleanup()

			// Test with different case variations
			cmd.ParseFlags([]string{"--format", formatValue})
			
			// Execute the command
			err = ConvertCbzCommand(cmd, []string{tempDir})
			if err != nil {
				t.Fatalf("Command execution failed with format '%s': %v", formatValue, err)
			}

			// Verify the format was set correctly
			if converterType != constant.WebP {
				t.Errorf("Expected format to be WebP for input '%s', got %v", formatValue, converterType)
			}
		})
	}
}

// TestConvertCbzCommand_ManyFiles_NoDeadlock tests that processing many files in parallel
// does not cause a deadlock. This reproduces the scenario where processing
// recursive folders of CBZ files with parallelism > 1 could cause a "all goroutines are asleep - deadlock!" error.
func TestConvertCbzCommand_ManyFiles_NoDeadlock(t *testing.T) {
	// Create a temporary directory for testing
	tempDir, err := os.MkdirTemp("", "test_cbz_many_files")
	if err != nil {
		log.Fatal(err)
	}
	defer errs.CaptureGeneric(&err, os.RemoveAll, tempDir, "failed to remove temporary directory")

	// Locate the testdata directory
	testdataDir := filepath.Join("../../../testdata")
	if _, err := os.Stat(testdataDir); os.IsNotExist(err) {
		t.Fatalf("testdata directory not found")
	}

	// Create subdirectories to simulate the recursive folder structure from the bug report
	subdirs := []string{"author1/book1", "author2/book2", "author3/book3", "author4/book4"}
	for _, subdir := range subdirs {
		err := os.MkdirAll(filepath.Join(tempDir, subdir), 0755)
		if err != nil {
			t.Fatalf("Failed to create subdirectory: %v", err)
		}
	}

	// Find a sample CBZ file to copy
	var sampleCBZ string
	err = filepath.Walk(testdataDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() && strings.HasSuffix(strings.ToLower(info.Name()), ".cbz") && !strings.Contains(info.Name(), "converted") {
			sampleCBZ = path
			return filepath.SkipDir
		}
		return nil
	})
	if err != nil || sampleCBZ == "" {
		t.Fatalf("Failed to find sample CBZ file: %v", err)
	}

	// Copy the sample file to multiple locations (simulating many files to process)
	numFilesPerDir := 5
	totalFiles := 0
	for _, subdir := range subdirs {
		for i := 0; i < numFilesPerDir; i++ {
			destPath := filepath.Join(tempDir, subdir, fmt.Sprintf("Chapter_%d.cbz", i+1))
			data, err := os.ReadFile(sampleCBZ)
			if err != nil {
				t.Fatalf("Failed to read sample file: %v", err)
			}
			err = os.WriteFile(destPath, data, 0644)
			if err != nil {
				t.Fatalf("Failed to write test file: %v", err)
			}
			totalFiles++
		}
	}
	t.Logf("Created %d test files across %d directories", totalFiles, len(subdirs))

	// Mock the converter.Get function
	originalGet := converter.Get
	converter.Get = func(format constant.ConversionFormat) (converter.Converter, error) {
		return &MockConverter{}, nil
	}
	defer func() { converter.Get = originalGet }()

	// Set up the command with parallelism = 2 (same as the bug report)
	cmd := &cobra.Command{
		Use: "optimize",
	}
	cmd.Flags().Uint8P("quality", "q", 85, "Quality for conversion (0-100)")
	cmd.Flags().IntP("parallelism", "n", 2, "Number of chapters to convert in parallel")
	cmd.Flags().BoolP("override", "o", false, "Override the original CBZ/CBR files")
	cmd.Flags().BoolP("split", "s", false, "Split long pages into smaller chunks")
	cmd.Flags().DurationP("timeout", "t", 0, "Maximum time allowed for converting a single chapter")

	converterType = constant.DefaultConversion
	setupFormatFlag(cmd, &converterType, false)

	// Run the command with a timeout to detect deadlocks
	done := make(chan error, 1)
	go func() {
		done <- ConvertCbzCommand(cmd, []string{tempDir})
	}()

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("Command execution failed: %v", err)
		}
		t.Logf("Command completed successfully without deadlock")
	case <-time.After(60 * time.Second):
		t.Fatal("Deadlock detected: Command did not complete within 60 seconds")
	}

	// Verify that converted files were created
	var convertedCount int
	err = filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() && strings.HasSuffix(info.Name(), "_converted.cbz") {
			convertedCount++
		}
		return nil
	})
	if err != nil {
		t.Fatalf("Error counting converted files: %v", err)
	}

	if convertedCount != totalFiles {
		t.Errorf("Expected %d converted files, found %d", totalFiles, convertedCount)
	}
	t.Logf("Found %d converted files as expected", convertedCount)
}

// TestConvertCbzCommand_HighParallelism_NoDeadlock tests processing with high parallelism setting.
func TestConvertCbzCommand_HighParallelism_NoDeadlock(t *testing.T) {
	// Create a temporary directory
	tempDir, err := os.MkdirTemp("", "test_cbz_high_parallel")
	if err != nil {
		log.Fatal(err)
	}
	defer errs.CaptureGeneric(&err, os.RemoveAll, tempDir, "failed to remove temporary directory")

	// Locate the testdata directory
	testdataDir := filepath.Join("../../../testdata")
	if _, err := os.Stat(testdataDir); os.IsNotExist(err) {
		t.Fatalf("testdata directory not found")
	}

	// Find and copy sample CBZ files
	var sampleCBZ string
	err = filepath.Walk(testdataDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() && strings.HasSuffix(strings.ToLower(info.Name()), ".cbz") && !strings.Contains(info.Name(), "converted") {
			sampleCBZ = path
			return filepath.SkipDir
		}
		return nil
	})
	if err != nil || sampleCBZ == "" {
		t.Fatalf("Failed to find sample CBZ file: %v", err)
	}

	// Create many test files
	numFiles := 15
	for i := 0; i < numFiles; i++ {
		destPath := filepath.Join(tempDir, fmt.Sprintf("test_file_%d.cbz", i+1))
		data, err := os.ReadFile(sampleCBZ)
		if err != nil {
			t.Fatalf("Failed to read sample file: %v", err)
		}
		err = os.WriteFile(destPath, data, 0644)
		if err != nil {
			t.Fatalf("Failed to write test file: %v", err)
		}
	}

	// Mock the converter
	originalGet := converter.Get
	converter.Get = func(format constant.ConversionFormat) (converter.Converter, error) {
		return &MockConverter{}, nil
	}
	defer func() { converter.Get = originalGet }()

	// Test with high parallelism (8)
	cmd := &cobra.Command{
		Use: "optimize",
	}
	cmd.Flags().Uint8P("quality", "q", 85, "Quality for conversion (0-100)")
	cmd.Flags().IntP("parallelism", "n", 8, "Number of chapters to convert in parallel")
	cmd.Flags().BoolP("override", "o", false, "Override the original CBZ/CBR files")
	cmd.Flags().BoolP("split", "s", false, "Split long pages into smaller chunks")
	cmd.Flags().DurationP("timeout", "t", 0, "Maximum time allowed for converting a single chapter")

	converterType = constant.DefaultConversion
	setupFormatFlag(cmd, &converterType, false)

	done := make(chan error, 1)
	go func() {
		done <- ConvertCbzCommand(cmd, []string{tempDir})
	}()

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("Command execution failed: %v", err)
		}
	case <-time.After(60 * time.Second):
		t.Fatal("Deadlock detected with high parallelism")
	}
}