package config

import (
	"fmt"
	"strings"

	"github.com/spf13/viper"
)

// Config represents the application configuration
type Config struct {
	Server struct {
		Port                int `mapstructure:"port"`
		ReadTimeoutSeconds  int `mapstructure:"read_timeout_seconds"`
		WriteTimeoutSeconds int `mapstructure:"write_timeout_seconds"`
		IdleTimeoutSeconds  int `mapstructure:"idle_timeout_seconds"`
	} `mapstructure:"server"`

	LogLevel string `mapstructure:"log_level"`

	Google struct {
		ProjectID       string `mapstructure:"project_id"`
		Location        string `mapstructure:"location"`
		Dataset         string `mapstructure:"dataset"`
		DicomStore      string `mapstructure:"dicom_store"`
		CredentialsPath string `mapstructure:"credentials_path"`
	} `mapstructure:"google"`

	Auth struct {
		JWTSecret          string `mapstructure:"jwt_secret"`
		AccessTokenExpiry  int    `mapstructure:"access_token_expiry"`  // in minutes
		RefreshTokenExpiry int    `mapstructure:"refresh_token_expiry"` // in hours
		EnableDatabaseAuth bool   `mapstructure:"enable_database_auth"`
	} `mapstructure:"auth"`

	Shortlink struct {
		BaseURL            string `mapstructure:"base_url"`             // Base URL for shortlinks (e.g., https://example.com)
		DefaultExpiryHours int    `mapstructure:"default_expiry_hours"` // Default expiry time in hours
		MaxAttempts        int    `mapstructure:"max_attempts"`         // Maximum failed attempts allowed
	} `mapstructure:"shortlink"`

	Database struct {
		Host                string `mapstructure:"host"`
		Port                int    `mapstructure:"port"`
		User                string `mapstructure:"user"`
		Password            string `mapstructure:"password"`
		Name                string `mapstructure:"name"`
		MaxOpenConns        int    `mapstructure:"max_open_conns"`
		MaxIdleConns        int    `mapstructure:"max_idle_conns"`
		ConnMaxLifetimeMins int    `mapstructure:"conn_max_lifetime_mins"`
	} `mapstructure:"database"`

	AllowedOrigins []string `mapstructure:"allowed_origins"`
}

// Load reads configuration from file and environment variables
func Load() (*Config, error) {
	viper.SetConfigName("config")
	viper.SetConfigType("yaml")
	viper.AddConfigPath("./config")
	viper.AddConfigPath(".")

	viper.AutomaticEnv()
	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))

	if err := viper.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("failed to read config file: %w", err)
	}

	var cfg Config
	if err := viper.Unmarshal(&cfg); err != nil {
		return nil, fmt.Errorf("failed to unmarshal config: %w", err)
	}

	return &cfg, nil
}