Design an AI Agent Flow System for Mobile Development

// Agent Protocol
protocol AIAgent {
    var name: String { get }
    var supportedTasks: [TaskType] { get }
    var aiService: AIServiceProvider { get }
    
    func execute(task: AgentTask) async throws -> AgentResult
    func estimateCost(task: AgentTask) -> CostEstimate
}

// Example Agents
class CodeReviewAgent: AIAgent { }
class TestGenerationAgent: AIAgent { }
class DocumentationAgent: AIAgent { }
class ArchitectureReviewAgent: AIAgent { }

class AIServiceGateway {
    private let rateLimiter: RateLimiter
    private let costTracker: CostTracker
    private let fallbackManager: FallbackManager
    
    func callService(
        _ service: AIService,
        request: AIRequest
    ) async throws -> AIResponse {
        // Check rate limits
        try await rateLimiter.checkLimit(for: service)
        
        // Estimate cost
        let cost = costTracker.estimate(request, service: service)
        guard costTracker.canAfford(cost) else {
            throw AIServiceError.budgetExceeded
        }
        
        // Make request with retry logic
        do {
            let response = try await service.execute(request)
            costTracker.record(cost, service: service)
            return response
        } catch {
            // Fallback to alternative service
            return try await fallbackManager.fallback(
                from: service,
                request: request
            )
        }
    }
}

class AgentFlowCoordinator {
    func executeWorkflow(_ workflow: Workflow) async throws {
        // Phase 1: Parallel execution (independent tasks)
        async let codeReview = codeReviewAgent.execute(task)
        async let securityScan = securityAgent.execute(task)
        async let lintCheck = lintAgent.execute(task)
        
        let phase1Results = try await [
            codeReview,
            securityScan,
            lintCheck
        ]
        
        // Phase 2: Sequential (depends on Phase 1)
        let testGeneration = try await testAgent.execute(
            task: task,
            context: phase1Results
        )
        
        // Phase 3: Aggregate and report
        let report = aggregateResults(phase1Results + [testGeneration])
        try await reportToGitHub(report)
    }
}

class AgentFlowCoordinator {
    private let workflowParser: WorkflowParser
    private let agentRegistry: AgentRegistry
    private let taskQueue: TaskQueue
    
    func processWorkflow(
        trigger: WorkflowTrigger,
        context: WorkflowContext
    ) async throws {
        // Load workflow definition
        let workflow = try workflowParser.parse(
            trigger: trigger
        )
        
        // Validate workflow
        try validateWorkflow(workflow)
        
        // Execute workflow phases
        for phase in workflow.phases {
            let results = try await executePhase(
                phase,
                context: context
            )
            context.addResults(results)
        }
        
        // Generate final report
        let report = generateReport(
            workflow: workflow,
            results: context.results
        )
        
        // Deliver results
        try await deliverResults(report, to: workflow.output)
    }
    
    private func executePhase(
        _ phase: WorkflowPhase,
        context: WorkflowContext
    ) async throws -> [AgentResult] {
        if phase.parallel {
            // Execute agents in parallel
            return try await withThrowingTaskGroup(
                of: AgentResult.self
            ) { group in
                for agentTask in phase.tasks {
                    group.addTask {
                        try await self.executeAgentTask(
                            agentTask,
                            context: context
                        )
                    }
                }
                return try await group.reduce([], +)
            }
        } else {
            // Execute sequentially
            var results: [AgentResult] = []
            for agentTask in phase.tasks {
                let result = try await executeAgentTask(
                    agentTask,
                    context: context
                )
                results.append(result)
                context.addResult(result)
            }
            return results
        }
    }
}

protocol AIServiceProvider {
    var name: String { get }
    var supportedModels: [String] { get }
    var costPerToken: [String: Double] { get }
    var rateLimit: RateLimit { get }
    
    func generate(
        prompt: String,
        model: String,
        parameters: GenerationParameters
    ) async throws -> AIResponse
    
    func estimateCost(
        prompt: String,
        model: String
    ) -> CostEstimate
}

// Claude API Implementation
class ClaudeService: AIServiceProvider {
    let name = "Claude API"
    let supportedModels = ["claude-3-opus", "claude-3-sonnet", "claude-3-haiku"]
    
    private let apiKey: String
    private let httpClient: HTTPClient
    
    func generate(
        prompt: String,
        model: String,
        parameters: GenerationParameters
    ) async throws -> AIResponse {
        let request = ClaudeRequest(
            model: model,
            messages: [.user(prompt)],
            maxTokens: parameters.maxTokens,
            temperature: parameters.temperature
        )
        
        let response = try await httpClient.post(
            "https://api.anthropic.com/v1/messages",
            body: request,
            headers: [
                "x-api-key": apiKey,
                "anthropic-version": "2023-06-01"
            ]
        )
        
        return ClaudeResponseAdapter.adapt(response)
    }
}

// OpenAI API Implementation
class OpenAIService: AIServiceProvider {
    let name = "OpenAI API"
    let supportedModels = ["gpt-4-turbo", "gpt-4", "gpt-3.5-turbo"]
    
    // Similar implementation...
}

// Cursor API Integration (if available)
class CursorService: AIServiceProvider {
    // Cursor-specific integration
    // May use their API or CLI tools
}

class CodeReviewAgent: AIAgent {
    let name = "CodeReviewAgent"
    let supportedTasks: [TaskType] = [.codeReview, .securityScan]
    
    private let aiService: AIServiceProvider
    private let codeAnalyzer: CodeAnalyzer
    
    func execute(task: AgentTask) async throws -> AgentResult {
        // Extract code from PR
        let codeChanges = try extractCodeChanges(from: task.context)
        
        // Build review prompt
        let prompt = buildReviewPrompt(
            code: codeChanges,
            context: task.context
        )
        
        // Call AI service
        let aiResponse = try await aiService.generate(
            prompt: prompt,
            model: "claude-3-opus",
            parameters: .init(
                maxTokens: 4000,
                temperature: 0.3
            )
        )
        
        // Parse and structure response
        let review = try parseReviewResponse(aiResponse)
        
        // Add code analysis insights
        let analysis = codeAnalyzer.analyze(codeChanges)
        review.addAnalysis(analysis)
        
        return AgentResult(
            agent: self,
            findings: review.findings,
            suggestions: review.suggestions,
            confidence: review.confidence
        )
    }
    
    private func buildReviewPrompt(
        code: CodeChanges,
        context: TaskContext
    ) -> String {
        return """
        You are an expert iOS engineer reviewing a pull request.
        
        Code Changes:
        \(code.diff)
        
        Context:
        - Files changed: \(code.files)
        - Lines changed: \(code.linesAdded) added, \(code.linesRemoved) removed
        - Related files: \(context.relatedFiles)
        
        Please review for:
        1. Code quality and best practices
        2. Potential bugs or edge cases
        3. Security vulnerabilities
        4. Performance issues
        5. Test coverage
        
        Provide specific, actionable feedback.
        """
    }
}

class TestGenerationAgent: AIAgent {
    let name = "TestGenerationAgent"
    let supportedTasks: [TaskType] = [.testGeneration, .testReview]
    
    private let aiService: AIServiceProvider
    
    func execute(task: AgentTask) async throws -> AgentResult {
        let code = try extractCode(from: task.context)
        let existingTests = try findExistingTests(for: code)
        
        let prompt = """
        Generate comprehensive unit tests for this Swift code:
        
        \(code.source)
        
        Existing tests:
        \(existingTests)
        
        Focus on:
        1. Happy path scenarios
        2. Edge cases and error handling
        3. Boundary conditions
        4. Mocking dependencies
        
        Use XCTest framework.
        """
        
        let response = try await aiService.generate(
            prompt: prompt,
            model: "gpt-4-turbo",
            parameters: .init(maxTokens: 2000)
        )
        
        let tests = try parseTestCode(response)
        
        return AgentResult(
            agent: self,
            generatedTests: tests,
            coverageEstimate: calculateCoverage(tests, for: code)
        )
    }
}

class ArchitectureReviewAgent: AIAgent {
    let name = "ArchitectureReviewAgent"
    let supportedTasks: [TaskType] = [.architectureReview, .designPattern]
    
    func execute(task: AgentTask) async throws -> AgentResult {
        let codebaseStructure = try analyzeCodebaseStructure(
            from: task.context
        )
        
        let prompt = """
        Review the architecture of this iOS codebase:
        
        Structure:
        \(codebaseStructure)
        
        Check for:
        1. Separation of concerns (MVVM/MVC/VIPER)
        2. Dependency injection patterns
        3. Testability
        4. Scalability concerns
        5. Code organization
        
        Provide architectural recommendations.
        """
        
        // Use Claude for complex architectural analysis
        let response = try await aiService.generate(
            prompt: prompt,
            model: "claude-3-opus",
            parameters: .init(maxTokens: 3000)
        )
        
        return AgentResult(
            agent: self,
            architectureIssues: parseArchitectureIssues(response),
            recommendations: parseRecommendations(response)
        )
    }
}

class CostOptimizer {
    func selectModel(
        for task: AgentTask,
        budget: Budget
    ) -> String {
        switch task.complexity {
        case .simple:
            // Use cheaper model (Claude Haiku, GPT-3.5)
            return "claude-3-haiku"  // $0.25 per 1M tokens
            
        case .medium:
            // Use mid-tier model (Claude Sonnet, GPT-4)
            return "claude-3-sonnet"  // $3 per 1M tokens
            
        case .complex:
            // Use best model (Claude Opus, GPT-4 Turbo)
            return "claude-3-opus"    // $15 per 1M tokens
        }
    }
}

class RequestBatcher {
    func batchRequests(
        _ requests: [AIRequest],
        maxBatchSize: Int = 10
    ) -> [[AIRequest]] {
        // Group similar requests
        // Send as single API call when possible
        // Reduces API overhead
    }
}

class ResponseCache {
    func cacheKey(for request: AIRequest) -> String {
        // Hash of: prompt + model + parameters
        return SHA256.hash(request.prompt + request.model)
    }
    
    func getCached(
        _ request: AIRequest
    ) -> AIResponse? {
        let key = cacheKey(for: request)
        return cache[key]
    }
}

class CostTracker {
    struct Budget {
        let daily: Double
        let monthly: Double
        let perProject: [String: Double]
    }
    
    func canAfford(
        _ cost: Double,
        for project: String
    ) -> Bool {
        // Check daily, monthly, and project budgets
        return currentDailySpend + cost <= budget.daily &&
               currentMonthlySpend + cost <= budget.monthly &&
               projectSpend[project] + cost <= budget.perProject[project]
    }
    
    func record(
        _ cost: Double,
        service: AIServiceProvider,
        project: String
    ) {
        // Track spending
        // Alert if approaching limits
    }
}

class FallbackManager {
    let fallbackChain: [AIServiceProvider] = [
        ClaudeService(),    // Primary
        OpenAIService(),   // Fallback 1
        // Could add more
    ]
    
    func executeWithFallback(
        _ request: AIRequest
    ) async throws -> AIResponse {
        var lastError: Error?
        
        for service in fallbackChain {
            do {
                return try await service.generate(
                    prompt: request.prompt,
                    model: request.model,
                    parameters: request.parameters
                )
            } catch {
                lastError = error
                logger.warn("Service \(service.name) failed: \(error)")
                continue
            }
        }
        
        throw AIServiceError.allServicesFailed(lastError!)
    }
}

class RetryHandler {
    func executeWithRetry<T>(
        maxAttempts: Int = 3,
        backoff: TimeInterval = 1.0,
        operation: () async throws -> T
    ) async throws -> T {
        var lastError: Error?
        
        for attempt in 1...maxAttempts {
            do {
                return try await operation()
            } catch let error as AIServiceError {
                lastError = error
                
                if error.isRetryable {
                    let delay = backoff * Double(attempt)
                    try await Task.sleep(nanoseconds: UInt64(delay * 1_000_000_000))
                    continue
                } else {
                    throw error
                }
            }
        }
        
        throw lastError!
    }
}

class CircuitBreaker {
    enum State {
        case closed    // Normal operation
        case open      // Failing, reject requests
        case halfOpen  // Testing if service recovered
    }
    
    private var state: State = .closed
    private var failureCount = 0
    private let failureThreshold = 5
    private let timeout: TimeInterval = 60
    
    func execute<T>(
        _ operation: () async throws -> T
    ) async throws -> T {
        switch state {
        case .open:
            if shouldAttemptReset() {
                state = .halfOpen
            } else {
                throw CircuitBreakerError.open
            }
            
        case .halfOpen, .closed:
            break
        }
        
        do {
            let result = try await operation()
            onSuccess()
            return result
        } catch {
            onFailure()
            throw error
        }
    }
    
    private func onSuccess() {
        failureCount = 0
        state = .closed
    }
    
    private func onFailure() {
        failureCount += 1
        if failureCount >= failureThreshold {
            state = .open
        }
    }
}

class APIKeyManager {
    // Store keys in secure vault (AWS Secrets Manager, HashiCorp Vault)
    func getAPIKey(for service: AIServiceProvider) async throws -> String {
        return try await secretsManager.getSecret(
            name: "ai-service-\(service.name)-api-key"
        )
    }
}

class CodeSanitizer {
    func sanitize(_ code: String) -> String {
        // Remove sensitive data before sending to AI
        return code
            .removingAPIKeys()
            .removingSecrets()
            .removingPersonalInfo()
    }
}

class AccessController {
    func canAccessWorkflow(
        _ workflow: Workflow,
        user: User
    ) -> Bool {
        // Check user permissions
        // Verify project access
        // Validate workflow access
        return user.hasPermission(.executeWorkflow) &&
               user.hasProjectAccess(workflow.project)
    }
}

struct Metrics {
    // Workflow metrics
    var workflowsExecuted: Int
    var averageExecutionTime: TimeInterval
    var successRate: Double
    
    // Cost metrics
    var dailySpend: Double
    var costPerWorkflow: Double
    var costByService: [String: Double]
    
    // Quality metrics
    var agentAccuracy: [String: Double]
    var userSatisfaction: Double
}