Add inital implementation of an agent

Change-Id: Ib60c33e8c1a44bc9341cac5c1f1fdc518fb5ed1e
diff --git a/server/agent/agent.go b/server/agent/agent.go
index e901cf6..e3aa766 100644
--- a/server/agent/agent.go
+++ b/server/agent/agent.go
@@ -1,23 +1,399 @@
 package agent
 
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/iomodo/staff/git"
+	"github.com/iomodo/staff/llm"
+	"github.com/iomodo/staff/tm"
+)
+
+// AgentConfig contains configuration for the agent
 type AgentConfig struct {
 	Name        string
 	Role        string
 	GitUsername string
 	GitEmail    string
 	WorkingDir  string
+
+	// LLM Configuration
+	LLMProvider llm.Provider
+	LLMModel    string
+	LLMConfig   llm.Config
+
+	// System prompt for the agent
+	SystemPrompt string
+
+	// Task Manager Configuration
+	TaskManager tm.TaskManager
+
+	// Git Configuration
+	GitRepoPath string
+	GitRemote   string
+	GitBranch   string
 }
 
+// Agent represents an AI agent that can process tasks
 type Agent struct {
-	Config AgentConfig
+	Config       AgentConfig
+	llmProvider  llm.LLMProvider
+	gitInterface git.GitInterface
+	ctx          context.Context
+	cancel       context.CancelFunc
 }
 
-func NewAgent(config AgentConfig) *Agent {
-	return &Agent{
-		Config: config,
+// NewAgent creates a new agent instance
+func NewAgent(config AgentConfig) (*Agent, error) {
+	// Validate configuration
+	if err := validateConfig(config); err != nil {
+		return nil, fmt.Errorf("invalid config: %w", err)
+	}
+
+	// Create LLM provider
+	llmProvider, err := llm.CreateProvider(config.LLMConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create LLM provider: %w", err)
+	}
+
+	// Create git interface
+	gitInterface := git.DefaultGit(config.GitRepoPath)
+
+	// Create context with cancellation
+	ctx, cancel := context.WithCancel(context.Background())
+
+	agent := &Agent{
+		Config:       config,
+		llmProvider:  llmProvider,
+		gitInterface: gitInterface,
+		ctx:          ctx,
+		cancel:       cancel,
+	}
+
+	return agent, nil
+}
+
+// validateConfig validates the agent configuration
+func validateConfig(config AgentConfig) error {
+	if config.Name == "" {
+		return fmt.Errorf("agent name is required")
+	}
+	if config.Role == "" {
+		return fmt.Errorf("agent role is required")
+	}
+	if config.WorkingDir == "" {
+		return fmt.Errorf("working directory is required")
+	}
+	if config.SystemPrompt == "" {
+		return fmt.Errorf("system prompt is required")
+	}
+	if config.TaskManager == nil {
+		return fmt.Errorf("task manager is required")
+	}
+	if config.GitRepoPath == "" {
+		return fmt.Errorf("git repository path is required")
+	}
+	return nil
+}
+
+// Run starts the agent's main loop
+func (a *Agent) Run() error {
+	log.Printf("Starting agent %s (%s)", a.Config.Name, a.Config.Role)
+	defer log.Printf("Agent %s stopped", a.Config.Name)
+
+	// Initialize git repository if needed
+	if err := a.initializeGit(); err != nil {
+		return fmt.Errorf("failed to initialize git: %w", err)
+	}
+
+	// Main agent loop
+	for {
+		select {
+		case <-a.ctx.Done():
+			return a.ctx.Err()
+		default:
+			if err := a.processNextTask(); err != nil {
+				log.Printf("Error processing task: %v", err)
+				// Continue running even if there's an error
+				time.Sleep(30 * time.Second)
+			}
+		}
 	}
 }
 
-func (a *Agent) Run() {
+// Stop stops the agent
+func (a *Agent) Stop() {
+	log.Printf("Stopping agent %s", a.Config.Name)
+	a.cancel()
+	if a.llmProvider != nil {
+		a.llmProvider.Close()
+	}
+}
 
+// initializeGit initializes the git repository
+func (a *Agent) initializeGit() error {
+	ctx := context.Background()
+
+	// Check if repository exists
+	isRepo, err := a.gitInterface.IsRepository(ctx, a.Config.GitRepoPath)
+	if err != nil {
+		return fmt.Errorf("failed to check repository: %w", err)
+	}
+
+	if !isRepo {
+		// Initialize new repository
+		if err := a.gitInterface.Init(ctx, a.Config.GitRepoPath); err != nil {
+			return fmt.Errorf("failed to initialize repository: %w", err)
+		}
+	}
+
+	// Set git user configuration
+	userConfig := git.UserConfig{
+		Name:  a.Config.GitUsername,
+		Email: a.Config.GitEmail,
+	}
+	if err := a.gitInterface.SetUserConfig(ctx, userConfig); err != nil {
+		return fmt.Errorf("failed to set git user config: %w", err)
+	}
+
+	// Checkout to the specified branch
+	if a.Config.GitBranch != "" {
+		if err := a.gitInterface.Checkout(ctx, a.Config.GitBranch); err != nil {
+			// Try to create the branch if it doesn't exist
+			if err := a.gitInterface.CreateBranch(ctx, a.Config.GitBranch, ""); err != nil {
+				return fmt.Errorf("failed to create branch %s: %w", a.Config.GitBranch, err)
+			}
+		}
+	}
+
+	return nil
+}
+
+// processNextTask processes the next available task
+func (a *Agent) processNextTask() error {
+	ctx := context.Background()
+
+	// Get tasks assigned to this agent
+	taskList, err := a.Config.TaskManager.GetTasksByOwner(ctx, a.Config.Name, 0, 10)
+	if err != nil {
+		return fmt.Errorf("failed to get tasks: %w", err)
+	}
+
+	// Find a task that's ready to be worked on
+	var taskToProcess *tm.Task
+	for _, task := range taskList.Tasks {
+		if task.Status == tm.StatusToDo {
+			taskToProcess = task
+			break
+		}
+	}
+
+	if taskToProcess == nil {
+		// No tasks to process, wait a bit
+		time.Sleep(60 * time.Second)
+		return nil
+	}
+
+	log.Printf("Processing task: %s - %s", taskToProcess.ID, taskToProcess.Title)
+
+	// Start the task
+	startedTask, err := a.Config.TaskManager.StartTask(ctx, taskToProcess.ID)
+	if err != nil {
+		return fmt.Errorf("failed to start task: %w", err)
+	}
+
+	// Process the task with LLM
+	solution, err := a.processTaskWithLLM(startedTask)
+	if err != nil {
+		// Mark task as failed or retry
+		log.Printf("Failed to process task with LLM: %v", err)
+		return err
+	}
+
+	// Create PR with the solution
+	if err := a.createPullRequest(startedTask, solution); err != nil {
+		return fmt.Errorf("failed to create pull request: %w", err)
+	}
+
+	// Complete the task
+	if _, err := a.Config.TaskManager.CompleteTask(ctx, startedTask.ID); err != nil {
+		return fmt.Errorf("failed to complete task: %w", err)
+	}
+
+	log.Printf("Successfully completed task: %s", startedTask.ID)
+	return nil
+}
+
+// processTaskWithLLM sends the task to the LLM and gets a solution
+func (a *Agent) processTaskWithLLM(task *tm.Task) (string, error) {
+	ctx := context.Background()
+
+	// Prepare the prompt
+	prompt := a.buildTaskPrompt(task)
+
+	// Create chat completion request
+	req := llm.ChatCompletionRequest{
+		Model: a.Config.LLMModel,
+		Messages: []llm.Message{
+			{
+				Role:    llm.RoleSystem,
+				Content: a.Config.SystemPrompt,
+			},
+			{
+				Role:    llm.RoleUser,
+				Content: prompt,
+			},
+		},
+		MaxTokens:   intPtr(4000),
+		Temperature: float64Ptr(0.7),
+	}
+
+	// Get response from LLM
+	resp, err := a.llmProvider.ChatCompletion(ctx, req)
+	if err != nil {
+		return "", fmt.Errorf("LLM chat completion failed: %w", err)
+	}
+
+	if len(resp.Choices) == 0 {
+		return "", fmt.Errorf("no response from LLM")
+	}
+
+	return resp.Choices[0].Message.Content, nil
+}
+
+// buildTaskPrompt builds the prompt for the LLM based on the task
+func (a *Agent) buildTaskPrompt(task *tm.Task) string {
+	var prompt strings.Builder
+
+	prompt.WriteString(fmt.Sprintf("Task ID: %s\n", task.ID))
+	prompt.WriteString(fmt.Sprintf("Title: %s\n", task.Title))
+	prompt.WriteString(fmt.Sprintf("Priority: %s\n", task.Priority))
+
+	if task.Description != "" {
+		prompt.WriteString(fmt.Sprintf("Description: %s\n", task.Description))
+	}
+
+	if task.DueDate != nil {
+		prompt.WriteString(fmt.Sprintf("Due Date: %s\n", task.DueDate.Format("2006-01-02")))
+	}
+
+	prompt.WriteString("\nPlease provide a detailed solution for this task. ")
+	prompt.WriteString("Include any code, documentation, or other deliverables as needed. ")
+	prompt.WriteString("Format your response appropriately for the type of task.")
+
+	return prompt.String()
+}
+
+// createPullRequest creates a pull request with the solution
+func (a *Agent) createPullRequest(task *tm.Task, solution string) error {
+	ctx := context.Background()
+
+	// Generate branch name
+	branchName := a.generateBranchName(task)
+
+	// Create and checkout to new branch
+	if err := a.gitInterface.CreateBranch(ctx, branchName, ""); err != nil {
+		return fmt.Errorf("failed to create branch: %w", err)
+	}
+
+	if err := a.gitInterface.Checkout(ctx, branchName); err != nil {
+		return fmt.Errorf("failed to checkout branch: %w", err)
+	}
+
+	// Create solution file
+	solutionPath := filepath.Join(a.Config.WorkingDir, fmt.Sprintf("task-%s-solution.md", task.ID))
+	solutionContent := a.formatSolution(task, solution)
+
+	if err := os.WriteFile(solutionPath, []byte(solutionContent), 0644); err != nil {
+		return fmt.Errorf("failed to write solution file: %w", err)
+	}
+
+	// Add and commit the solution
+	if err := a.gitInterface.Add(ctx, []string{solutionPath}); err != nil {
+		return fmt.Errorf("failed to add solution file: %w", err)
+	}
+
+	commitMessage := fmt.Sprintf("feat: Complete task %s - %s", task.ID, task.Title)
+	if err := a.gitInterface.Commit(ctx, commitMessage, git.CommitOptions{}); err != nil {
+		return fmt.Errorf("failed to commit solution: %w", err)
+	}
+
+	// Push the branch
+	if err := a.gitInterface.Push(ctx, "origin", branchName, git.PushOptions{SetUpstream: true}); err != nil {
+		return fmt.Errorf("failed to push branch: %w", err)
+	}
+
+	log.Printf("Created pull request for task %s on branch %s", task.ID, branchName)
+	return nil
+}
+
+// generateBranchName generates a branch name for the task
+func (a *Agent) generateBranchName(task *tm.Task) string {
+	// Clean the task title for branch name
+	cleanTitle := strings.ReplaceAll(task.Title, " ", "-")
+	cleanTitle = strings.ToLower(cleanTitle)
+
+	// Remove special characters that are not allowed in git branch names
+	// Keep only alphanumeric characters and hyphens
+	var result strings.Builder
+	for _, char := range cleanTitle {
+		if (char >= 'a' && char <= 'z') || (char >= '0' && char <= '9') || char == '-' {
+			result.WriteRune(char)
+		}
+	}
+	cleanTitle = result.String()
+
+	// Remove consecutive hyphens
+	for strings.Contains(cleanTitle, "--") {
+		cleanTitle = strings.ReplaceAll(cleanTitle, "--", "-")
+	}
+
+	// Remove leading and trailing hyphens
+	cleanTitle = strings.Trim(cleanTitle, "-")
+
+	// Limit length
+	if len(cleanTitle) > 50 {
+		cleanTitle = cleanTitle[:50]
+		// Ensure we don't end with a hyphen after truncation
+		cleanTitle = strings.TrimSuffix(cleanTitle, "-")
+	}
+
+	return fmt.Sprintf("task/%s-%s", task.ID, cleanTitle)
+}
+
+// formatSolution formats the solution for the pull request
+func (a *Agent) formatSolution(task *tm.Task, solution string) string {
+	var content strings.Builder
+
+	content.WriteString(fmt.Sprintf("# Task Solution: %s\n\n", task.Title))
+	content.WriteString(fmt.Sprintf("**Task ID:** %s\n", task.ID))
+	content.WriteString(fmt.Sprintf("**Agent:** %s (%s)\n", a.Config.Name, a.Config.Role))
+	content.WriteString(fmt.Sprintf("**Completed:** %s\n\n", time.Now().Format("2006-01-02 15:04:05")))
+
+	content.WriteString("## Task Description\n\n")
+	content.WriteString(task.Description)
+	content.WriteString("\n\n")
+
+	content.WriteString("## Solution\n\n")
+	content.WriteString(solution)
+	content.WriteString("\n\n")
+
+	content.WriteString("---\n")
+	content.WriteString("*This solution was generated by AI Agent*\n")
+
+	return content.String()
+}
+
+// ptr helpers for cleaner code
+func intPtr(i int) *int {
+	return &i
+}
+
+func float64Ptr(f float64) *float64 {
+	return &f
 }