main.go

package main

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"prompt-cli/internal/agent"
	"prompt-cli/internal/config"
	"prompt-cli/internal/errors"
	"prompt-cli/internal/logger"
	"prompt-cli/internal/ollama"
	"prompt-cli/internal/tui"

	tea "github.com/charmbracelet/bubbletea"
)

// loadPrompt reads the contents of the prompt file located at the given path.
// It returns the file content as a string and any error that occurs.
func loadPrompt(path string) (string, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return "", err
	}
	return string(content), nil
}

func main() {
	// Define a command-line flag for chat-only mode. This allows the user to
	// start the application without the system prompt that defines the tool-using agent persona.
	chatOnly := flag.Bool("chatonly", false, "Enable chat-only mode, without the tool-using agent persona.")

	// Determine the directory of the running executable.
	exePath, err := os.Executable()
	if err != nil {
		log.Fatalf("Error finding executable path: %v", errors.IOError("Failed to get executable path", err))
	}
	exeDir := filepath.Dir(exePath)

	// Build the path to the configuration file relative to the executable directory.
	configPath := filepath.Join(exeDir, "config.json")

	// Load configuration from the JSON file.
	configs, err := config.LoadConfig(configPath)
	if err != nil {
		var appErr *errors.AppError
		if ok := errors.As(err, &appErr); ok {
			log.Fatalf("Error loading config from %s: %s (type: %s)", configPath, appErr.Message, appErr.Type)
		} else {
			log.Fatalf("Error loading config from %s: %v", configPath, err)
		}
	}

	// Validate the loaded configuration to ensure required fields are set.
	if err := config.ValidateConfig(configs); err != nil {
		var appErr *errors.AppError
		if ok := errors.As(err, &appErr); ok {
			log.Fatalf("Invalid configuration: %s (type: %s)", appErr.Message, appErr.Type)
		} else {
			log.Fatalf("Invalid configuration: %v", err)
		}
	}

	appLogger := logger.NewLogger()
	if configs.LogEnabled {
		appLogger.Toggle()
	}
	appLogger.Setup()

	// Construct the base URL for the Ollama server, adding the HTTP scheme if missing.
	var baseURL string
	if strings.HasPrefix(configs.OllamaServerURL, "http") {
		baseURL = fmt.Sprintf("%s:%d", configs.OllamaServerURL, configs.OllamaServerPort)
	} else {
		baseURL = fmt.Sprintf("http://%s:%d", configs.OllamaServerURL, configs.OllamaServerPort)
	}

	appLogger.Log(fmt.Sprintf("Connecting to Ollama at: %s", baseURL))

	// Retrieve the list of available models from the Ollama server.
	models, err := ollama.GetModels(baseURL, appLogger)
	if err != nil {
		var appErr *errors.AppError
		if ok := errors.As(err, &appErr); ok {
			log.Fatalf("Error getting models: %s (type: %s)", appErr.Message, appErr.Type)
		} else {
			log.Fatalf("Error getting models: %v", err)
		}
	}
	if len(models) == 0 {
		log.Fatal(errors.ValidationError("No models found on the Ollama server", map[string]interface{}{
			"server": baseURL,
			"action": "model_discovery",
		}).Error())
	}

	flag.Parse()

	// Determine which model to use: a default from config or user selection.
	var selectedModel string
	if configs.DefaultLLM != "" {
		selectedModel = configs.DefaultLLM
	} else {
		fmt.Println("Please select a model:")
		for i, m := range models {
			fmt.Printf("%d: %s\n", i+1, m.Name)
		}

		// Prompt the user until a valid model index is entered.
		var choice int
		reader := bufio.NewReader(os.Stdin)
		for {
			fmt.Print("> ")
			input, _ := reader.ReadString('\n')
			choice, err = strconv.Atoi(strings.TrimSpace(input))
			if err == nil && choice > 0 && choice <= len(models) {
				break
			}
			fmt.Println("Invalid choice, please try again.")
		}
		selectedModel = models[choice-1].Name
	}

	// Load the system prompt from a Markdown file; fall back to a default prompt if missing.
	var systemPrompt string
	if *chatOnly {
		systemPrompt = "You are a helpful assistant."
	} else {
		var err error
		systemPrompt, err = loadPrompt("Prompt.MD")
		if err != nil {
			log.Printf("Warning: Could not load system prompt: %v", err)
			systemPrompt = "You are a helpful assistant."
		}
	}

	// Initialize the components.
	ollamaClient := ollama.NewOllamaClient(baseURL, appLogger)
	appAgent := agent.NewAgent(appLogger)
	m := tui.NewModel(baseURL, selectedModel, configs.ContextLength, systemPrompt, configs.LogEnabled, appLogger, appAgent, ollamaClient)

	// Create a new Bubble Tea program with alternate screen and mouse support.
	p := tea.NewProgram(m, tea.WithAltScreen(), tea.WithMouseAllMotion())

	// Run the TUI; terminate on error.
	if _, err := p.Run(); err != nil {
		log.Fatalf("Alas, there's been an error: %v", err)
	}
}