package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

// Config represents the full NextWks configuration.
type Config struct {
	Server   ServerConfig   `yaml:"server"`
	Admin    AdminConfig    `yaml:"admin"`
	Database DatabaseConfig `yaml:"database"`
	Authelia AutheliaConfig `yaml:"authelia"`
	OIDC     OIDCConfig     `yaml:"oidc"`
	SMTP     SMTPConfig     `yaml:"smtp"`
	IMAP     IMAPConfig     `yaml:"imap"`
	Session  SessionConfig  `yaml:"session"`
}

type ServerConfig struct {
	Host string `yaml:"host"`
	Port int    `yaml:"port"`
}

type AdminConfig struct {
	SecretToken string `yaml:"secret_token"`
}

type DatabaseConfig struct {
	Type string `yaml:"type"`
	Path string `yaml:"path"`
}

type AutheliaConfig struct {
	Host        string `yaml:"host"`
	ConfigPath  string `yaml:"config_path"`
	UsersDBPath string `yaml:"users_db_path"`
}

// OIDCConfig holds the OIDC provider settings (Authelia).
type OIDCConfig struct {
	IssuerURL    string `yaml:"issuer_url"` // Public-facing URL users reach (e.g., https://auth.sechpoint.app)
	ClientID     string `yaml:"client_id"`
	ClientSecret string `yaml:"client_secret"`
	RedirectURL  string `yaml:"redirect_url"`
	Domain       string `yaml:"domain"`
}

type SMTPConfig struct {
	Host     string `yaml:"host"`
	Port     int    `yaml:"port"`
	Username string `yaml:"username"`
	Password string `yaml:"password"`
	From     string `yaml:"from"`
}

type IMAPConfig struct {
	Host string `yaml:"host"`
	Port int    `yaml:"port"`
}

type SessionConfig struct {
	Secret        string `yaml:"secret"`
	ExpiryMinutes int    `yaml:"expiry_minutes"`
}

// Load reads and parses the YAML configuration file.
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config file: %w", err)
	}

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config file: %w", err)
	}

	return &cfg, nil
}

// AutheliaSessionSecret extracts the session.secret from Authelia's configuration.
func AutheliaSessionSecret(cfgPath string) (string, error) {
	data, err := os.ReadFile(cfgPath)
	if err != nil {
		return "", fmt.Errorf("read authelia config: %w", err)
	}

	var autheliaCfg struct {
		Session struct {
			Secret string `yaml:"secret"`
		} `yaml:"session"`
	}

	if err := yaml.Unmarshal(data, &autheliaCfg); err != nil {
		return "", fmt.Errorf("parse authelia config: %w", err)
	}

	if autheliaCfg.Session.Secret == "" {
		return "", fmt.Errorf("authelia session.secret not found in %s", cfgPath)
	}

	return autheliaCfg.Session.Secret, nil
}