package main

import (
	"os"
	"path/filepath"

	"github.com/charmbracelet/bubbles/textinput"
	"github.com/pelletier/go-toml/v2"
)

// Constants for file permissions
const (
	configDirPerm  = 0755
	configFilePerm = 0600
)

// config holds the application configuration.
type config struct {
	Email string `toml:"email"`
}

// configPath returns the path to the configuration file, following XDG config directory conventions.
func configPath() (string, error) {
	xdgConfigHome := os.Getenv("XDG_CONFIG_HOME")
	var configDir string
	if xdgConfigHome != "" {
		configDir = filepath.Join(xdgConfigHome, "sdm-tui")
	} else {
		homeDir, err := os.UserHomeDir()
		if err != nil {
			return "", err
		}
		configDir = filepath.Join(homeDir, ".config", "sdm-tui")
	}
	return filepath.Join(configDir, "config.toml"), nil
}

// saveConfig saves the email to the configuration file.
func saveConfig(email string) error {
	configPath, err := configPath()
	if err != nil {
		return err
	}

	if err := os.MkdirAll(filepath.Dir(configPath), configDirPerm); err != nil {
		return err
	}

	cfg := config{Email: email}
	data, err := toml.Marshal(cfg)
	if err != nil {
		return err
	}

	return os.WriteFile(configPath, data, configFilePerm)
}

// loadConfig loads the email from the configuration file.
// It also handles migration from the old "email" file format to the new TOML format.
func loadConfig() string {
	configPath, err := configPath()
	if err != nil {
		return ""
	}

	data, err := os.ReadFile(configPath)
	if err != nil {
		oldEmailPath := filepath.Join(filepath.Dir(configPath), "email")
		if oldData, err := os.ReadFile(oldEmailPath); err == nil {
			email := string(oldData)
			if email != "" {
				if err := saveConfig(email); err == nil {
					os.Remove(oldEmailPath)
				}
			}
			return email
		}
		return ""
	}

	var cfg config
	if err := toml.Unmarshal(data, &cfg); err != nil {
		return ""
	}

	return cfg.Email
}

// loadEmailIntoInput loads a saved email into the text input and returns whether an email was found.
func loadEmailIntoInput(ti textinput.Model) (textinput.Model, bool) {
	savedEmail := loadConfig()
	if savedEmail != "" {
		ti.SetValue(savedEmail)
		return ti, true
	}
	return ti, false
}