package main

import (
	"fmt"
	"os"
	"path/filepath"

	"gopkg.in/yaml.v3"
)

type Config struct {
	LogLevel string          `yaml:"log_level"`
	Accounts []AccountConfig `yaml:"accounts"`
}

type AccountConfig struct {
	Name            string `yaml:"name"`
	MaildirPath     string `yaml:"maildir_path"`
	MbsyncAccount   string `yaml:"mbsync_account"`
	PasswordCommand string `yaml:"password_command"`
	TokenFile       string `yaml:"token_file"`
	TokenEnv        string `yaml:"token_env"`
}

// mbsyncChannel returns the mbsync channel/group name to pass to mbsync,
// falling back to the account name if mbsync_account is not set.
func (a AccountConfig) mbsyncChannel() string {
	if a.MbsyncAccount != "" {
		return a.MbsyncAccount
	}
	return a.Name
}

func (a AccountConfig) validate() error {
	if a.Name == "" {
		return fmt.Errorf("account name is required")
	}
	if a.MaildirPath == "" {
		return fmt.Errorf("account %q: maildir_path is required", a.Name)
	}
	n := 0
	if a.PasswordCommand != "" {
		n++
	}
	if a.TokenFile != "" {
		n++
	}
	if a.TokenEnv != "" {
		n++
	}
	if n == 0 {
		return fmt.Errorf("account %q: one of password_command, token_file, or token_env is required", a.Name)
	}
	if n > 1 {
		return fmt.Errorf("account %q: only one of password_command, token_file, or token_env may be set", a.Name)
	}
	return nil
}

func (c *Config) unmarshal(data []byte) error {
	return yaml.Unmarshal(data, c)
}

func defaultConfigPath() string {
	if xdg := os.Getenv("XDG_CONFIG_HOME"); xdg != "" {
		return filepath.Join(xdg, "mbrts", "config.yaml")
	}
	home, _ := os.UserHomeDir()
	return filepath.Join(home, ".config", "mbrts", "config.yaml")
}