package decoder

import (
	"testing"

	"github.com/AFASystems/presence/internal/pkg/model"
)

func TestParserRegistry_AddParser(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	// Add a parser
	config := model.Config{
		Name:   "test-parser",
		Prefix: "02",
		Length: 2,
	}

	registry.Register("test-parser", config)

	// Verify parser was added
	if len(registry.ParserList) != 1 {
		t.Errorf("Expected 1 parser in registry, got %d", len(registry.ParserList))
	}

	if _, exists := registry.ParserList["test-parser"]; !exists {
		t.Error("Parser 'test-parser' should exist in registry")
	}
}

func TestParserRegistry_RemoveParser(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	config := model.Config{
		Name:   "test-parser",
		Prefix: "02",
		Length: 2,
	}

	registry.Register("test-parser", config)

	// Remove parser
	registry.Unregister("test-parser")

	// Verify parser was removed
	if len(registry.ParserList) != 0 {
		t.Errorf("Expected 0 parsers in registry, got %d", len(registry.ParserList))
	}

	if _, exists := registry.ParserList["test-parser"]; exists {
		t.Error("Parser 'test-parser' should not exist in registry")
	}
}

func TestParserRegistry_UpdateParser(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	// Add initial parser
	config1 := model.Config{
		Name:   "test-parser",
		Prefix: "02",
		Length: 2,
	}

	registry.Register("test-parser", config1)

	// Update parser
	config2 := model.Config{
		Name:   "test-parser",
		Prefix: "03",
		Length: 3,
	}

	registry.Register("test-parser", config2)

	// Verify only one parser exists
	if len(registry.ParserList) != 1 {
		t.Errorf("Expected 1 parser in registry, got %d", len(registry.ParserList))
	}

	// Verify it was updated (the new config should be used)
	if _, exists := registry.ParserList["test-parser"]; !exists {
		t.Error("Parser 'test-parser' should exist in registry")
	}
}

func TestParserRegistry_MultipleParsers(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	// Add multiple parsers
	parsers := []model.Config{
		{Name: "parser-1", Prefix: "02", Length: 2},
		{Name: "parser-2", Prefix: "03", Length: 3},
		{Name: "parser-3", Prefix: "04", Length: 4},
	}

	for _, p := range parsers {
		registry.Register(p.Name, p)
	}

	// Verify all parsers were added
	if len(registry.ParserList) != 3 {
		t.Errorf("Expected 3 parsers in registry, got %d", len(registry.ParserList))
	}

	for _, p := range parsers {
		if _, exists := registry.ParserList[p.Name]; !exists {
			t.Errorf("Parser '%s' should exist in registry", p.Name)
		}
	}
}

func TestParserRegistry_RemoveNonExistent(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	// Try to remove non-existent parser - should not panic
	registry.Unregister("non-existent")

	// Verify registry is still empty
	if len(registry.ParserList) != 0 {
		t.Errorf("Expected 0 parsers, got %d", len(registry.ParserList))
	}
}

func TestParserRegistry_ConcurrentAccess(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}
	done := make(chan bool)

	// Concurrent additions
	for i := 0; i < 10; i++ {
		go func(index int) {
			config := model.Config{
				Name:   "parser-" + string(rune('A'+index)),
				Prefix: "02",
				Length: 2,
			}
			registry.Register(config.Name, config)
			done <- true
		}(i)
	}

	// Wait for all goroutines
	for i := 0; i < 10; i++ {
		<-done
	}

	// Verify all parsers were added
	if len(registry.ParserList) != 10 {
		t.Errorf("Expected 10 parsers, got %d", len(registry.ParserList))
	}
}

func TestParserConfig_Structure(t *testing.T) {
	config := model.Config{
		Name:       "test-config",
		Prefix:     "0201",
		MinLength:  10,
		MaxLength:  30,
		ParserType: "sensor",
	}

	if config.Name != "test-config" {
		t.Errorf("Expected name 'test-config', got '%s'", config.Name)
	}

	if config.Prefix != "0201" {
		t.Errorf("Expected prefix '0201', got '%s'", config.Prefix)
	}

	if config.MinLength != 10 {
		t.Errorf("Expected MinLength 10, got %d", config.MinLength)
	}

	if config.MaxLength != 30 {
		t.Errorf("Expected MaxLength 30, got %d", config.MaxLength)
	}
}

func TestKafkaParser_MessageTypes(t *testing.T) {
	testCases := []struct {
		name     string
		id       string
		config   model.Config
		expected string
	}{
		{
			name:     "add parser",
			id:       "add",
			config:   model.Config{Name: "new-parser", Prefix: "02", Length: 2},
			expected: "add",
		},
		{
			name:     "delete parser",
			id:       "delete",
			config:   model.Config{Name: "old-parser", Prefix: "02", Length: 2},
			expected: "delete",
		},
		{
			name:     "update parser",
			id:       "update",
			config:   model.Config{Name: "updated-parser", Prefix: "03", Length: 3},
			expected: "update",
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			msg := model.KafkaParser{
				ID:     tc.id,
				Name:   tc.config.Name,
				Config: tc.config,
			}

			if msg.ID != tc.expected {
				t.Errorf("Expected ID '%s', got '%s'", tc.expected, msg.ID)
			}

			if msg.Name != tc.config.Name {
				t.Errorf("Expected Name '%s', got '%s'", tc.config.Name, msg.Name)
			}
		})
	}
}

func TestParserRegistry_EmptyRegistry(t *testing.T) {
	// Setup empty registry
	registry := &model.ParserRegistry{}

	// Verify it's empty
	if len(registry.ParserList) != 0 {
		t.Errorf("Expected empty registry, got %d parsers", len(registry.ParserList))
	}

	// Should be safe to call Unregister on empty registry
	registry.Unregister("anything")
}

func TestParserRegistry_ParserReplacement(t *testing.T) {
	// Setup
	registry := &model.ParserRegistry{}

	// Add parser with config 1
	config1 := model.Config{
		Name:   "test-parser",
		Prefix: "02",
		Length: 2,
	}

	registry.Register("test-parser", config1)

	// Replace with config 2 (same name)
	config2 := model.Config{
		Name:   "test-parser",
		Prefix: "03",
		Length: 3,
	}

	registry.Register("test-parser", config2)

	// Verify only one entry exists
	if len(registry.ParserList) != 1 {
		t.Errorf("Expected 1 parser after replacement, got %d", len(registry.ParserList))
	}

	// Verify the parser still exists
	if _, exists := registry.ParserList["test-parser"]; !exists {
		t.Error("Parser 'test-parser' should still exist")
	}
}