package config

import (
	"crypto/rand"
	"encoding/hex"
	"log"
	"os"
	"strings"
)

type Config struct {
	DNS        string
	ManagerURL string
	AgentPort  string
	AgentID    string
}

var Cfg *Config

func init() {
	Cfg = &Config{
		AgentPort: "5087", // default
	}
}

func LoadConfig() {
	paths := []string{".env", "../.env"}
	for _, p := range paths {
		content, err := os.ReadFile(p)
		if err == nil {
			parseEnv(string(content))
			break
		}
	}

	if h := os.Getenv("MANAGER_URL"); h != "" {
		Cfg.ManagerURL = h
	}
	if Cfg.ManagerURL == "" {
		Cfg.ManagerURL = "http://localhost:5086" // Default
	}

	if d := os.Getenv("DNS"); d != "" {
		Cfg.DNS = d
	}

	loadOrGenerateAgentID()
}

func parseEnv(content string) {
	lines := strings.Split(content, "\n")
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		parts := strings.SplitN(line, "=", 2)
		if len(parts) == 2 {
			os.Setenv(parts[0], parts[1])
		}
	}
}

func loadOrGenerateAgentID() {
	path := "agent_id.txt"
	data, err := os.ReadFile(path)
	if err == nil {
		Cfg.AgentID = strings.TrimSpace(string(data))
		if Cfg.AgentID != "" {
			return
		}
	}

	// Generate new AgentID
	b := make([]byte, 8)
	rand.Read(b)
	Cfg.AgentID = "agent-" + hex.EncodeToString(b)
	err = os.WriteFile(path, []byte(Cfg.AgentID), 0600)
	if err != nil {
		log.Printf("Warning: failed to save agent_id.txt: %v", err)
	}
}

func ResetAgentID() {
	os.Remove("agent_id.txt")
	loadOrGenerateAgentID()
}