bzzz/pkg/slurp/intelligence/pattern_detector.go

package intelligence

import (
	"context"
	"fmt"
	"path/filepath"
	"regexp"
	"sort"
	"strings"
	"time"

	slurpContext "chorus.services/bzzz/pkg/slurp/context"
)

// DefaultPatternDetector provides comprehensive pattern detection capabilities
type DefaultPatternDetector struct {
	config           *EngineConfig
	codeAnalyzer     *CodePatternAnalyzer
	namingAnalyzer   *NamingPatternAnalyzer
	orgAnalyzer      *OrganizationalPatternAnalyzer
	designAnalyzer   *DesignPatternAnalyzer
}

// CodePatternAnalyzer detects code-level patterns and anti-patterns
type CodePatternAnalyzer struct {
	languagePatterns map[string]*LanguageCodePatterns
}

// LanguageCodePatterns contains patterns specific to a programming language
type LanguageCodePatterns struct {
	DesignPatterns    []*DesignPatternMatcher
	AntiPatterns      []*AntiPatternMatcher
	ArchPatterns      []*ArchitecturalPatternMatcher
	BestPractices     []*BestPracticeMatcher
}

// DesignPatternMatcher detects specific design patterns
type DesignPatternMatcher struct {
	PatternName     string
	Description     string
	Signatures      []*regexp.Regexp
	StructuralCues  []string
	Confidence      func(matches int, totalLines int) float64
}

// AntiPatternMatcher detects anti-patterns and code smells
type AntiPatternMatcher struct {
	PatternName     string
	Description     string
	Signatures      []*regexp.Regexp
	Severity        string // critical, high, medium, low
	Recommendation  string
}

// ArchitecturalPatternMatcher detects architectural patterns
type ArchitecturalPatternMatcher struct {
	PatternName     string
	Description     string
	FilePatterns    []*regexp.Regexp
	DirectoryHints  []string
	Dependencies    []string
}

// BestPracticeMatcher detects adherence to best practices
type BestPracticeMatcher struct {
	PracticeName    string
	Description     string
	Indicators      []*regexp.Regexp
	Violations      []*regexp.Regexp
	Impact          string
}

// NamingPatternAnalyzer analyzes naming conventions and patterns
type NamingPatternAnalyzer struct {
	conventionRules map[string]*NamingConventionRule
}

// NamingConventionRule defines a naming convention rule
type NamingConventionRule struct {
	Language      string
	Scope         string // function, variable, class, file, etc.
	Pattern       *regexp.Regexp
	Description   string
	Examples      []string
	Violations    []*regexp.Regexp
}

// OrganizationalPatternAnalyzer detects organizational and structural patterns
type OrganizationalPatternAnalyzer struct {
	structuralPatterns []*StructuralPatternMatcher
}

// StructuralPatternMatcher detects structural organization patterns
type StructuralPatternMatcher struct {
	PatternName       string
	Description       string
	DirectoryPatterns []*regexp.Regexp
	FilePatterns      []*regexp.Regexp
	RequiredFiles     []string
	OptionalFiles     []string
	Depth             int
	Characteristics   []string
}

// DesignPatternAnalyzer detects software design patterns
type DesignPatternAnalyzer struct {
	patternLibrary map[string]*DesignPatternDefinition
}

// DesignPatternDefinition defines a comprehensive design pattern
type DesignPatternDefinition struct {
	Name              string
	Category          string // creational, structural, behavioral
	Intent            string
	Applicability     []string
	Structure         *PatternStructure
	Participants      []string
	Collaborations    []string
	Consequences      []string
	Implementation    *PatternImplementation
}

// PatternStructure defines the structural elements of a pattern
type PatternStructure struct {
	Classes         []string
	Interfaces      []string
	Relationships   []string
	KeyComponents   []string
}

// PatternImplementation contains implementation-specific details
type PatternImplementation struct {
	Languages       []string
	CodeSignatures  []*regexp.Regexp
	FileStructure   []string
	Dependencies    []string
}

// NewDefaultPatternDetector creates a comprehensive pattern detector
func NewDefaultPatternDetector(config *EngineConfig) *DefaultPatternDetector {
	return &DefaultPatternDetector{
		config:         config,
		codeAnalyzer:   NewCodePatternAnalyzer(),
		namingAnalyzer: NewNamingPatternAnalyzer(),
		orgAnalyzer:    NewOrganizationalPatternAnalyzer(),
		designAnalyzer: NewDesignPatternAnalyzer(),
	}
}

// NewCodePatternAnalyzer creates a code pattern analyzer
func NewCodePatternAnalyzer() *CodePatternAnalyzer {
	analyzer := &CodePatternAnalyzer{
		languagePatterns: make(map[string]*LanguageCodePatterns),
	}

	// Initialize Go patterns
	goPatterns := &LanguageCodePatterns{
		DesignPatterns: []*DesignPatternMatcher{
			{
				PatternName: "Singleton",
				Description: "Ensures a class has only one instance",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`var\s+instance\s+\*\w+`),
					regexp.MustCompile(`sync\.Once`),
					regexp.MustCompile(`func\s+GetInstance\s*\(\s*\)\s*\*\w+`),
				},
				StructuralCues: []string{"sync.Once", "private constructor", "static instance"},
				Confidence: func(matches, totalLines int) float64 {
					return float64(matches) / 3.0
				},
			},
			{
				PatternName: "Factory",
				Description: "Creates objects without specifying exact class",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`func\s+New\w+\s*\(`),
					regexp.MustCompile(`func\s+Create\w+\s*\(`),
					regexp.MustCompile(`func\s+Make\w+\s*\(`),
				},
				StructuralCues: []string{"factory method", "object creation"},
			},
			{
				PatternName: "Builder",
				Description: "Constructs complex objects step by step",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`func\s+\(\w+\s+\*\w+\)\s+With\w+\(`),
					regexp.MustCompile(`func\s+\(\w+\s+\*\w+\)\s+Set\w+\(`),
					regexp.MustCompile(`func\s+\(\w+\s+\*\w+\)\s+Build\s*\(\s*\)`),
				},
				StructuralCues: []string{"fluent interface", "method chaining", "build method"},
			},
			{
				PatternName: "Observer",
				Description: "Notifies multiple objects about state changes",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`type\s+\w*Observer\w*\s+interface`),
					regexp.MustCompile(`func\s+\w*Subscribe\w*\s*\(`),
					regexp.MustCompile(`func\s+\w*Notify\w*\s*\(`),
				},
				StructuralCues: []string{"observer interface", "subscription", "notification"},
			},
		},
		AntiPatterns: []*AntiPatternMatcher{
			{
				PatternName:    "God Object",
				Description:    "Class that does too much",
				Signatures:     []*regexp.Regexp{regexp.MustCompile(`func\s+\(\w+\s+\*\w+\)\s+\w+`)},
				Severity:       "high",
				Recommendation: "Split responsibilities into smaller, focused types",
			},
			{
				PatternName:    "Magic Numbers",
				Description:    "Unexplained numeric literals",
				Signatures:     []*regexp.Regexp{regexp.MustCompile(`\b\d{2,}\b`)},
				Severity:       "medium",
				Recommendation: "Replace with named constants",
			},
		},
		ArchPatterns: []*ArchitecturalPatternMatcher{
			{
				PatternName:    "Repository Pattern",
				Description:    "Encapsulates data access logic",
				FilePatterns:   []*regexp.Regexp{regexp.MustCompile(`.*repository.*\.go$`)},
				DirectoryHints: []string{"repository", "repo", "storage"},
				Dependencies:   []string{"database", "storage"},
			},
		},
		BestPractices: []*BestPracticeMatcher{
			{
				PracticeName: "Error Handling",
				Description:  "Proper error handling patterns",
				Indicators: []*regexp.Regexp{
					regexp.MustCompile(`if\s+err\s*!=\s*nil`),
					regexp.MustCompile(`return.*,\s*err`),
				},
				Violations: []*regexp.Regexp{
					regexp.MustCompile(`_\s*,\s*_\s*:=`),
				},
				Impact: "high",
			},
		},
	}

	// Initialize JavaScript/TypeScript patterns
	jsPatterns := &LanguageCodePatterns{
		DesignPatterns: []*DesignPatternMatcher{
			{
				PatternName: "Module Pattern",
				Description: "Encapsulates functionality in modules",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`export\s+default`),
					regexp.MustCompile(`module\.exports\s*=`),
					regexp.MustCompile(`export\s+\{.*\}`),
				},
			},
			{
				PatternName: "Singleton",
				Description: "Single instance pattern in JavaScript",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`class\s+\w+\s*\{[\s\S]*static\s+instance`),
					regexp.MustCompile(`getInstance\s*\(\s*\)`),
				},
			},
			{
				PatternName: "Observer",
				Description: "Event-driven programming pattern",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`addEventListener\s*\(`),
					regexp.MustCompile(`on\s*\(`),
					regexp.MustCompile(`subscribe\s*\(`),
				},
			},
		},
		AntiPatterns: []*AntiPatternMatcher{
			{
				PatternName:    "Callback Hell",
				Description:    "Deeply nested callbacks",
				Signatures:     []*regexp.Regexp{regexp.MustCompile(`function\s*\([^)]*\)\s*\{[\s\S]*function\s*\([^)]*\)\s*\{[\s\S]*function`)},
				Severity:       "high",
				Recommendation: "Use Promises or async/await",
			},
		},
	}

	// Initialize Python patterns
	pythonPatterns := &LanguageCodePatterns{
		DesignPatterns: []*DesignPatternMatcher{
			{
				PatternName: "Decorator Pattern",
				Description: "Adds behavior to objects dynamically",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`@\w+`),
					regexp.MustCompile(`def\s+\w+\s*\([^)]*\)\s*->\s*callable`),
				},
			},
			{
				PatternName: "Context Manager",
				Description: "Resource management pattern",
				Signatures: []*regexp.Regexp{
					regexp.MustCompile(`def\s+__enter__\s*\(`),
					regexp.MustCompile(`def\s+__exit__\s*\(`),
					regexp.MustCompile(`with\s+\w+`),
				},
			},
		},
	}

	analyzer.languagePatterns["go"] = goPatterns
	analyzer.languagePatterns["javascript"] = jsPatterns
	analyzer.languagePatterns["typescript"] = jsPatterns
	analyzer.languagePatterns["python"] = pythonPatterns

	return analyzer
}

// NewNamingPatternAnalyzer creates a naming pattern analyzer
func NewNamingPatternAnalyzer() *NamingPatternAnalyzer {
	analyzer := &NamingPatternAnalyzer{
		conventionRules: make(map[string]*NamingConventionRule),
	}

	// Go naming conventions
	goRules := []*NamingConventionRule{
		{
			Language:    "go",
			Scope:       "function",
			Pattern:     regexp.MustCompile(`^[A-Z][a-zA-Z0-9]*$`),
			Description: "Exported functions use PascalCase",
			Examples:    []string{"GetUser", "ProcessData"},
		},
		{
			Language:    "go",
			Scope:       "variable",
			Pattern:     regexp.MustCompile(`^[a-z][a-zA-Z0-9]*$`),
			Description: "Variables use camelCase",
			Examples:    []string{"userName", "totalCount"},
		},
		{
			Language:    "go",
			Scope:       "constant",
			Pattern:     regexp.MustCompile(`^[A-Z][A-Z0-9_]*$`),
			Description: "Constants use SCREAMING_SNAKE_CASE",
			Examples:    []string{"MAX_SIZE", "DEFAULT_TIMEOUT"},
		},
	}

	// JavaScript/TypeScript naming conventions
	jsRules := []*NamingConventionRule{
		{
			Language:    "javascript",
			Scope:       "function",
			Pattern:     regexp.MustCompile(`^[a-z][a-zA-Z0-9]*$`),
			Description: "Functions use camelCase",
			Examples:    []string{"getUserData", "processResults"},
		},
		{
			Language:    "javascript",
			Scope:       "class",
			Pattern:     regexp.MustCompile(`^[A-Z][a-zA-Z0-9]*$`),
			Description: "Classes use PascalCase",
			Examples:    []string{"UserManager", "DataProcessor"},
		},
	}

	// Python naming conventions
	pythonRules := []*NamingConventionRule{
		{
			Language:    "python",
			Scope:       "function",
			Pattern:     regexp.MustCompile(`^[a-z][a-z0-9_]*$`),
			Description: "Functions use snake_case",
			Examples:    []string{"get_user_data", "process_results"},
		},
		{
			Language:    "python",
			Scope:       "class",
			Pattern:     regexp.MustCompile(`^[A-Z][a-zA-Z0-9]*$`),
			Description: "Classes use PascalCase",
			Examples:    []string{"UserManager", "DataProcessor"},
		},
	}

	// Register all rules
	for _, rule := range append(append(goRules, jsRules...), pythonRules...) {
		key := fmt.Sprintf("%s_%s", rule.Language, rule.Scope)
		analyzer.conventionRules[key] = rule
	}

	return analyzer
}

// NewOrganizationalPatternAnalyzer creates an organizational pattern analyzer
func NewOrganizationalPatternAnalyzer() *OrganizationalPatternAnalyzer {
	analyzer := &OrganizationalPatternAnalyzer{
		structuralPatterns: []*StructuralPatternMatcher{},
	}

	// Define common structural patterns
	patterns := []*StructuralPatternMatcher{
		{
			PatternName:   "Hexagonal Architecture",
			Description:   "Ports and adapters architecture",
			DirectoryPatterns: []*regexp.Regexp{
				regexp.MustCompile(`.*/(domain|core)/.*`),
				regexp.MustCompile(`.*/adapters?/.*`),
				regexp.MustCompile(`.*/ports?/.*`),
			},
			RequiredFiles:   []string{"domain", "adapters"},
			Characteristics: []string{"dependency_inversion", "testable", "framework_independent"},
		},
		{
			PatternName: "Clean Architecture",
			Description: "Uncle Bob's clean architecture",
			DirectoryPatterns: []*regexp.Regexp{
				regexp.MustCompile(`.*/entities/.*`),
				regexp.MustCompile(`.*/usecases/.*`),
				regexp.MustCompile(`.*/adapters/.*`),
				regexp.MustCompile(`.*/frameworks?/.*`),
			},
			RequiredFiles:   []string{"entities", "usecases"},
			Characteristics: []string{"dependency_rule", "testable", "ui_independent"},
		},
		{
			PatternName: "Microservices",
			Description: "Service-oriented architecture",
			DirectoryPatterns: []*regexp.Regexp{
				regexp.MustCompile(`.*/services?/.*`),
				regexp.MustCompile(`.*/api-gateway/.*`),
			},
			RequiredFiles:   []string{"services"},
			Characteristics: []string{"distributed", "autonomous", "scalable"},
		},
		{
			PatternName: "Monorepo",
			Description: "Multiple projects in single repository",
			DirectoryPatterns: []*regexp.Regexp{
				regexp.MustCompile(`.*/packages?/.*`),
				regexp.MustCompile(`.*/apps?/.*`),
				regexp.MustCompile(`.*/libs?/.*`),
			},
			RequiredFiles:   []string{"packages", "apps"},
			Characteristics: []string{"shared_dependencies", "atomic_commits", "unified_tooling"},
		},
	}

	analyzer.structuralPatterns = patterns
	return analyzer
}

// NewDesignPatternAnalyzer creates a design pattern analyzer
func NewDesignPatternAnalyzer() *DesignPatternAnalyzer {
	analyzer := &DesignPatternAnalyzer{
		patternLibrary: make(map[string]*DesignPatternDefinition),
	}

	// Define comprehensive design patterns
	patterns := []*DesignPatternDefinition{
		{
			Name:     "Singleton",
			Category: "creational",
			Intent:   "Ensure a class has only one instance and provide global point of access",
			Applicability: []string{
				"exactly one instance needed",
				"instance must be accessible from well-known access point",
				"sole instance should be extensible by subclassing",
			},
			Structure: &PatternStructure{
				Classes:       []string{"Singleton"},
				Interfaces:    []string{},
				Relationships: []string{"self-reference"},
				KeyComponents: []string{"private constructor", "static instance", "getInstance method"},
			},
			Implementation: &PatternImplementation{
				Languages: []string{"go", "java", "javascript", "python"},
				CodeSignatures: []*regexp.Regexp{
					regexp.MustCompile(`getInstance|GetInstance`),
					regexp.MustCompile(`static.*instance|var.*instance`),
				},
			},
		},
		{
			Name:     "Factory Method",
			Category: "creational",
			Intent:   "Create objects without specifying their concrete classes",
			Structure: &PatternStructure{
				Classes:       []string{"Creator", "ConcreteCreator", "Product", "ConcreteProduct"},
				Interfaces:    []string{"Product"},
				Relationships: []string{"creator uses product"},
				KeyComponents: []string{"factory method", "product hierarchy"},
			},
			Implementation: &PatternImplementation{
				Languages: []string{"go", "java", "javascript", "python"},
				CodeSignatures: []*regexp.Regexp{
					regexp.MustCompile(`New\w+|Create\w+|Make\w+`),
					regexp.MustCompile(`factory|Factory`),
				},
			},
		},
		{
			Name:     "Observer",
			Category: "behavioral",
			Intent:   "Define a one-to-many dependency between objects",
			Structure: &PatternStructure{
				Classes:       []string{"Subject", "Observer", "ConcreteSubject", "ConcreteObserver"},
				Interfaces:    []string{"Observer", "Subject"},
				Relationships: []string{"subject notifies observers"},
				KeyComponents: []string{"subscribe", "unsubscribe", "notify"},
			},
			Implementation: &PatternImplementation{
				Languages: []string{"go", "java", "javascript", "python"},
				CodeSignatures: []*regexp.Regexp{
					regexp.MustCompile(`Subscribe|Unsubscribe|Notify`),
					regexp.MustCompile(`Observer|Subject`),
					regexp.MustCompile(`addEventListener|on\(`),
				},
			},
		},
	}

	for _, pattern := range patterns {
		analyzer.patternLibrary[pattern.Name] = pattern
	}

	return analyzer
}

// DetectCodePatterns identifies code patterns and architectural styles
func (pd *DefaultPatternDetector) DetectCodePatterns(ctx context.Context, filePath string, content []byte) ([]*CodePattern, error) {
	patterns := []*CodePattern{}
	
	// Detect language
	language := pd.detectLanguageFromPath(filePath)
	if language == "" {
		return patterns, nil
	}

	// Get language-specific patterns
	langPatterns, exists := pd.codeAnalyzer.languagePatterns[language]
	if !exists {
		return patterns, nil
	}

	contentStr := string(content)
	
	// Detect design patterns
	for _, designPattern := range langPatterns.DesignPatterns {
		if pattern := pd.analyzeDesignPattern(contentStr, designPattern, language); pattern != nil {
			patterns = append(patterns, pattern)
		}
	}

	// Detect architectural patterns
	for _, archPattern := range langPatterns.ArchPatterns {
		if pattern := pd.analyzeArchitecturalPattern(filePath, contentStr, archPattern, language); pattern != nil {
			patterns = append(patterns, pattern)
		}
	}

	// Detect anti-patterns
	for _, antiPattern := range langPatterns.AntiPatterns {
		if pattern := pd.analyzeAntiPattern(contentStr, antiPattern, language); pattern != nil {
			patterns = append(patterns, pattern)
		}
	}

	return patterns, nil
}

// DetectNamingPatterns identifies naming conventions and patterns
func (pd *DefaultPatternDetector) DetectNamingPatterns(ctx context.Context, contexts []*slurpContext.ContextNode) ([]*NamingPattern, error) {
	patterns := []*NamingPattern{}
	
	// Group contexts by language
	langGroups := make(map[string][]*slurpContext.ContextNode)
	for _, context := range contexts {
		if analysis, ok := context.Metadata["analysis"].(*FileAnalysis); ok {
			lang := analysis.Language
			if lang != "" {
				langGroups[lang] = append(langGroups[lang], context)
			}
		}
	}

	// Analyze naming patterns for each language
	for language, langContexts := range langGroups {
		langPatterns := pd.analyzeLanguageNamingPatterns(language, langContexts)
		patterns = append(patterns, langPatterns...)
	}

	return patterns, nil
}

// DetectOrganizationalPatterns identifies organizational patterns
func (pd *DefaultPatternDetector) DetectOrganizationalPatterns(ctx context.Context, rootPath string) ([]*OrganizationalPattern, error) {
	patterns := []*OrganizationalPattern{}

	for _, matcher := range pd.orgAnalyzer.structuralPatterns {
		if pattern := pd.analyzeStructuralPattern(rootPath, matcher); pattern != nil {
			patterns = append(patterns, pattern)
		}
	}

	return patterns, nil
}

// MatchPatterns matches context against known patterns
func (pd *DefaultPatternDetector) MatchPatterns(ctx context.Context, node *slurpContext.ContextNode, patterns []*Pattern) ([]*PatternMatch, error) {
	matches := []*PatternMatch{}

	for _, pattern := range patterns {
		if match := pd.calculatePatternMatch(node, pattern); match != nil {
			matches = append(matches, match)
		}
	}

	// Sort by match score
	sort.Slice(matches, func(i, j int) bool {
		return matches[i].MatchScore > matches[j].MatchScore
	})

	return matches, nil
}

// LearnPatterns learns new patterns from context examples
func (pd *DefaultPatternDetector) LearnPatterns(ctx context.Context, examples []*slurpContext.ContextNode) ([]*Pattern, error) {
	patterns := []*Pattern{}

	// Group examples by similarity
	groups := pd.groupSimilarContexts(examples)

	// Extract patterns from each group
	for groupID, group := range groups {
		if len(group) >= 2 { // Need at least 2 examples to form a pattern
			pattern := pd.extractPatternFromGroup(groupID, group)
			if pattern != nil {
				patterns = append(patterns, pattern)
			}
		}
	}

	return patterns, nil
}

// Helper methods

func (pd *DefaultPatternDetector) detectLanguageFromPath(filePath string) string {
	ext := strings.ToLower(filepath.Ext(filePath))
	langMap := map[string]string{
		".go":   "go",
		".py":   "python",
		".js":   "javascript",
		".jsx":  "javascript",
		".ts":   "typescript",
		".tsx":  "typescript",
		".java": "java",
		".c":    "c",
		".cpp":  "cpp",
		".cs":   "csharp",
		".php":  "php",
		".rb":   "ruby",
		".rs":   "rust",
	}
	return langMap[ext]
}

func (pd *DefaultPatternDetector) analyzeDesignPattern(content string, matcher *DesignPatternMatcher, language string) *CodePattern {
	matches := 0
	matchedSignatures := []string{}

	for _, signature := range matcher.Signatures {
		if signature.MatchString(content) {
			matches++
			matchedSignatures = append(matchedSignatures, signature.String())
		}
	}

	if matches == 0 {
		return nil
	}

	confidence := 0.0
	if matcher.Confidence != nil {
		lines := strings.Count(content, "\n") + 1
		confidence = matcher.Confidence(matches, lines)
	} else {
		confidence = float64(matches) / float64(len(matcher.Signatures))
	}

	if confidence < 0.3 {
		return nil
	}

	return &CodePattern{
		Pattern: Pattern{
			ID:          fmt.Sprintf("%s_%s", language, strings.ToLower(matcher.PatternName)),
			Name:        matcher.PatternName,
			Type:        "design_pattern",
			Description: matcher.Description,
			Confidence:  confidence,
			Examples:    matchedSignatures,
			DetectedAt:  time.Now(),
		},
		Language:   language,
		Complexity: pd.calculatePatternComplexity(matcher.PatternName),
		Usage: &UsagePattern{
			Frequency: pd.determinePatternFrequency(matches),
			Context:   matcher.StructuralCues,
		},
	}
}

func (pd *DefaultPatternDetector) analyzeArchitecturalPattern(filePath, content string, matcher *ArchitecturalPatternMatcher, language string) *CodePattern {
	// Check file path patterns
	pathMatches := false
	for _, pattern := range matcher.FilePatterns {
		if pattern.MatchString(filePath) {
			pathMatches = true
			break
		}
	}

	if !pathMatches {
		return nil
	}

	// Check for dependencies if specified
	hasRequiredDeps := len(matcher.Dependencies) == 0
	if len(matcher.Dependencies) > 0 {
		for _, dep := range matcher.Dependencies {
			if strings.Contains(strings.ToLower(content), strings.ToLower(dep)) {
				hasRequiredDeps = true
				break
			}
		}
	}

	if !hasRequiredDeps {
		return nil
	}

	return &CodePattern{
		Pattern: Pattern{
			ID:          fmt.Sprintf("%s_%s_arch", language, strings.ToLower(matcher.PatternName)),
			Name:        matcher.PatternName,
			Type:        "architectural_pattern",
			Description: matcher.Description,
			Confidence:  0.8,
			Examples:    []string{filepath.Base(filePath)},
			DetectedAt:  time.Now(),
		},
		Language:   language,
		Complexity: 0.7,
		Usage: &UsagePattern{
			Frequency: "common",
			Context:   matcher.DirectoryHints,
		},
	}
}

func (pd *DefaultPatternDetector) analyzeAntiPattern(content string, matcher *AntiPatternMatcher, language string) *CodePattern {
	matches := 0
	for _, signature := range matcher.Signatures {
		matches += len(signature.FindAllString(content, -1))
	}

	if matches == 0 {
		return nil
	}

	severity := 0.5
	switch matcher.Severity {
	case "critical":
		severity = 1.0
	case "high":
		severity = 0.8
	case "medium":
		severity = 0.6
	case "low":
		severity = 0.4
	}

	return &CodePattern{
		Pattern: Pattern{
			ID:          fmt.Sprintf("%s_%s_anti", language, strings.ToLower(matcher.PatternName)),
			Name:        matcher.PatternName,
			Type:        "anti_pattern",
			Description: matcher.Description,
			Confidence:  severity,
			Frequency:   matches,
			Drawbacks:   []string{matcher.Recommendation},
			DetectedAt:  time.Now(),
		},
		Language:   language,
		Complexity: severity,
	}
}

func (pd *DefaultPatternDetector) analyzeLanguageNamingPatterns(language string, contexts []*slurpContext.ContextNode) []*NamingPattern {
	patterns := []*NamingPattern{}

	// Collect all identifiers from contexts
	identifiers := pd.collectIdentifiers(contexts)

	// Analyze patterns for different scopes
	scopes := []string{"function", "variable", "class", "file"}
	for _, scope := range scopes {
		if pattern := pd.analyzeNamingPatternForScope(language, scope, identifiers[scope]); pattern != nil {
			patterns = append(patterns, pattern)
		}
	}

	return patterns
}

func (pd *DefaultPatternDetector) collectIdentifiers(contexts []*slurpContext.ContextNode) map[string][]string {
	identifiers := make(map[string][]string)

	for _, context := range contexts {
		if analysis, ok := context.Metadata["analysis"].(*FileAnalysis); ok {
			identifiers["function"] = append(identifiers["function"], analysis.Functions...)
			identifiers["variable"] = append(identifiers["variable"], analysis.Variables...)
			identifiers["class"] = append(identifiers["class"], analysis.Classes...)
			identifiers["file"] = append(identifiers["file"], filepath.Base(context.Path))
		}
	}

	return identifiers
}

func (pd *DefaultPatternDetector) analyzeNamingPatternForScope(language, scope string, identifiers []string) *NamingPattern {
	if len(identifiers) < 2 {
		return nil
	}

	// Detect dominant convention
	conventions := map[string]int{
		"camelCase":  0,
		"PascalCase": 0,
		"snake_case": 0,
		"kebab-case": 0,
	}

	for _, identifier := range identifiers {
		if matched, _ := regexp.MatchString(`^[a-z][a-zA-Z0-9]*$`, identifier); matched {
			conventions["camelCase"]++
		} else if matched, _ := regexp.MatchString(`^[A-Z][a-zA-Z0-9]*$`, identifier); matched {
			conventions["PascalCase"]++
		} else if matched, _ := regexp.MatchString(`^[a-z][a-z0-9_]*$`, identifier); matched {
			conventions["snake_case"]++
		} else if matched, _ := regexp.MatchString(`^[a-z][a-z0-9-]*$`, identifier); matched {
			conventions["kebab-case"]++
		}
	}

	// Find dominant convention
	maxCount := 0
	dominantConvention := "mixed"
	for convention, count := range conventions {
		if count > maxCount {
			maxCount = count
			dominantConvention = convention
		}
	}

	confidence := float64(maxCount) / float64(len(identifiers))
	if confidence < 0.5 {
		return nil
	}

	return &NamingPattern{
		Pattern: Pattern{
			ID:          fmt.Sprintf("%s_%s_naming", language, scope),
			Name:        fmt.Sprintf("%s %s Naming", strings.Title(language), strings.Title(scope)),
			Type:        "naming_convention",
			Description: fmt.Sprintf("Naming convention for %s %ss", language, scope),
			Confidence:  confidence,
			Examples:    identifiers[:min(5, len(identifiers))],
			DetectedAt:  time.Now(),
		},
		Convention: dominantConvention,
		Scope:      scope,
		CaseStyle:  dominantConvention,
	}
}

func (pd *DefaultPatternDetector) analyzeStructuralPattern(rootPath string, matcher *StructuralPatternMatcher) *OrganizationalPattern {
	// Check if pattern directory structure exists
	matchCount := 0
	totalRequired := len(matcher.RequiredFiles)

	for _, required := range matcher.RequiredFiles {
		checkPath := filepath.Join(rootPath, required)
		if pd.pathExists(checkPath) {
			matchCount++
		}
	}

	if matchCount < totalRequired {
		return nil
	}

	confidence := float64(matchCount) / float64(totalRequired)

	return &OrganizationalPattern{
		Pattern: Pattern{
			ID:          strings.ToLower(strings.ReplaceAll(matcher.PatternName, " ", "_")),
			Name:        matcher.PatternName,
			Type:        "organizational",
			Description: matcher.Description,
			Confidence:  confidence,
			Examples:    matcher.RequiredFiles,
			Benefits:    matcher.Characteristics,
			DetectedAt:  time.Now(),
		},
		Structure:   "hierarchical",
		Depth:       matcher.Depth,
		FanOut:      len(matcher.RequiredFiles),
		Modularity:  confidence,
		Scalability: pd.assessScalability(matcher.Characteristics),
	}
}

func (pd *DefaultPatternDetector) calculatePatternMatch(node *slurpContext.ContextNode, pattern *Pattern) *PatternMatch {
	score := 0.0
	matchedFields := []string{}

	// Check summary match
	if pd.textContainsKeywords(node.Summary, pattern.Examples) {
		score += 0.3
		matchedFields = append(matchedFields, "summary")
	}

	// Check purpose match
	if pd.textContainsKeywords(node.Purpose, pattern.Examples) {
		score += 0.3
		matchedFields = append(matchedFields, "purpose")
	}

	// Check technology match
	for _, tech := range node.Technologies {
		if pd.containsIgnoreCase(pattern.Examples, tech) {
			score += 0.2
			matchedFields = append(matchedFields, "technologies")
			break
		}
	}

	// Check tag match
	for _, tag := range node.Tags {
		if pd.containsIgnoreCase(pattern.Examples, tag) {
			score += 0.2
			matchedFields = append(matchedFields, "tags")
			break
		}
	}

	if score < 0.3 {
		return nil
	}

	return &PatternMatch{
		PatternID:     pattern.ID,
		MatchScore:    score,
		Confidence:    pattern.Confidence * score,
		MatchedFields: matchedFields,
		Explanation:   fmt.Sprintf("Pattern %s matched with score %.2f", pattern.Name, score),
		Suggestions:   pd.generatePatternSuggestions(pattern),
	}
}

func (pd *DefaultPatternDetector) groupSimilarContexts(contexts []*slurpContext.ContextNode) map[string][]*slurpContext.ContextNode {
	groups := make(map[string][]*slurpContext.ContextNode)

	for _, context := range contexts {
		// Simple grouping by primary technology
		groupKey := "unknown"
		if len(context.Technologies) > 0 {
			groupKey = context.Technologies[0]
		}

		groups[groupKey] = append(groups[groupKey], context)
	}

	return groups
}

func (pd *DefaultPatternDetector) extractPatternFromGroup(groupID string, group []*slurpContext.ContextNode) *Pattern {
	// Find common characteristics
	commonTechs := pd.findCommonTechnologies(group)
	commonTags := pd.findCommonTags(group)

	if len(commonTechs) == 0 && len(commonTags) == 0 {
		return nil
	}

	return &Pattern{
		ID:          fmt.Sprintf("learned_%s_%d", groupID, time.Now().Unix()),
		Name:        fmt.Sprintf("Learned %s Pattern", strings.Title(groupID)),
		Type:        "learned",
		Description: fmt.Sprintf("Pattern extracted from %d similar contexts", len(group)),
		Confidence:  pd.calculateLearningConfidence(group),
		Examples:    append(commonTechs, commonTags...),
		DetectedAt:  time.Now(),
	}
}

// Additional helper methods

func (pd *DefaultPatternDetector) calculatePatternComplexity(patternName string) float64 {
	complexityMap := map[string]float64{
		"Singleton":         0.3,
		"Factory":          0.5,
		"Builder":          0.7,
		"Observer":         0.6,
		"Strategy":         0.5,
		"Command":          0.6,
		"Decorator":        0.8,
		"Composite":        0.9,
		"Abstract Factory": 0.9,
		"Prototype":        0.4,
	}

	if complexity, exists := complexityMap[patternName]; exists {
		return complexity
	}
	return 0.5 // Default complexity
}

func (pd *DefaultPatternDetector) determinePatternFrequency(matches int) string {
	if matches > 5 {
		return "frequent"
	} else if matches > 2 {
		return "common"
	} else {
		return "rare"
	}
}

func (pd *DefaultPatternDetector) pathExists(path string) bool {
	_, err := filepath.Abs(path)
	return err == nil
}

func (pd *DefaultPatternDetector) assessScalability(characteristics []string) string {
	for _, char := range characteristics {
		if strings.Contains(char, "scalable") {
			return "excellent"
		}
	}
	return "good"
}

func (pd *DefaultPatternDetector) textContainsKeywords(text string, keywords []string) bool {
	lowerText := strings.ToLower(text)
	for _, keyword := range keywords {
		if strings.Contains(lowerText, strings.ToLower(keyword)) {
			return true
		}
	}
	return false
}

func (pd *DefaultPatternDetector) containsIgnoreCase(slice []string, item string) bool {
	lowerItem := strings.ToLower(item)
	for _, s := range slice {
		if strings.ToLower(s) == lowerItem {
			return true
		}
	}
	return false
}

func (pd *DefaultPatternDetector) generatePatternSuggestions(pattern *Pattern) []string {
	suggestions := []string{}

	switch pattern.Type {
	case "design_pattern":
		suggestions = append(suggestions, "Consider documenting the pattern usage")
		suggestions = append(suggestions, "Ensure pattern implementation follows best practices")
	case "anti_pattern":
		suggestions = append(suggestions, "Refactor to eliminate anti-pattern")
		suggestions = append(suggestions, "Consider alternative design approaches")
	case "architectural_pattern":
		suggestions = append(suggestions, "Document architectural decisions")
		suggestions = append(suggestions, "Ensure pattern consistency across project")
	}

	return suggestions
}

func (pd *DefaultPatternDetector) findCommonTechnologies(contexts []*slurpContext.ContextNode) []string {
	techCount := make(map[string]int)
	
	for _, context := range contexts {
		for _, tech := range context.Technologies {
			techCount[tech]++
		}
	}

	common := []string{}
	threshold := len(contexts) / 2 // At least half should have the technology
	for tech, count := range techCount {
		if count >= threshold {
			common = append(common, tech)
		}
	}

	return common
}

func (pd *DefaultPatternDetector) findCommonTags(contexts []*slurpContext.ContextNode) []string {
	tagCount := make(map[string]int)
	
	for _, context := range contexts {
		for _, tag := range context.Tags {
			tagCount[tag]++
		}
	}

	common := []string{}
	threshold := len(contexts) / 2
	for tag, count := range tagCount {
		if count >= threshold {
			common = append(common, tag)
		}
	}

	return common
}

func (pd *DefaultPatternDetector) calculateLearningConfidence(group []*slurpContext.ContextNode) float64 {
	// Simple confidence based on group size and consistency
	baseConfidence := 0.5
	groupBonus := float64(len(group)) * 0.1
	if groupBonus > 0.3 {
		groupBonus = 0.3
	}

	return baseConfidence + groupBonus
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}