package config

import (
	"errors"
	"fmt"
	"net"
	"time"
)

type Config struct {
	Server   ServerConfig   `mapstructure:"server"`
	Database DatabaseConfig `mapstructure:"database"`
	Storage  StorageConfig  `mapstructure:"storage"`
	JWT      JWTConfig      `mapstructure:"jwt"`
}

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

type DatabaseConfig struct {
	Driver   string         `mapstructure:"driver"`
	SQLite   SQLiteConfig   `mapstructure:"sqlite"`
	Postgres PostgresConfig `mapstructure:"postgres"`
}

type SQLiteConfig struct {
	Path string `mapstructure:"path"`
}

type PostgresConfig struct {
	Host     string `mapstructure:"host"`
	Port     int    `mapstructure:"port"`
	User     string `mapstructure:"user"`
	Password string `mapstructure:"password"`
	DBName   string `mapstructure:"dbname"`
	SSLMode  string `mapstructure:"sslmode"`
}

type StorageConfig struct {
	Driver string             `mapstructure:"driver"`
	Local  LocalStorageConfig `mapstructure:"local"`
}

type LocalStorageConfig struct {
	Path string `mapstructure:"path"`
}

type JWTConfig struct {
	Secret     string        `mapstructure:"secret"`
	AccessTTL  time.Duration `mapstructure:"access_ttl"`
	RefreshTTL time.Duration `mapstructure:"refresh_ttl"`
}

func (c *Config) Validate() error {
	var errs []error

	if c.Server.Port < 1 || c.Server.Port > 65535 {
		errs = append(errs, fmt.Errorf("server.port: %d out of range [1, 65535]", c.Server.Port))
	}

	if addr := net.ParseIP(c.Server.Host); c.Server.Host != "" && addr == nil {
		errs = append(errs, fmt.Errorf("server.host: %q is not a valid IP address", c.Server.Host))
	}

	switch c.Database.Driver {
	case "sqlite3":
		if c.Database.SQLite.Path == "" {
			errs = append(errs, errors.New("database.sqlite.path: must not be empty"))
		}
	case "postgres":
		if c.Database.Postgres.Host == "" {
			errs = append(errs, errors.New("database.postgres.host: must not be empty"))
		}
		if c.Database.Postgres.Port < 1 || c.Database.Postgres.Port > 65535 {
			errs = append(errs, fmt.Errorf("database.postgres.port: %d out of range [1, 65535]", c.Database.Postgres.Port))
		}
		if c.Database.Postgres.User == "" {
			errs = append(errs, errors.New("database.postgres.user: must not be empty"))
		}
		if c.Database.Postgres.DBName == "" {
			errs = append(errs, errors.New("database.postgres.dbname: must not be empty"))
		}
	default:
		errs = append(errs, fmt.Errorf("database.driver: %q is not supported (use sqlite3 or postgres)", c.Database.Driver))
	}

	if c.Storage.Local.Path == "" {
		errs = append(errs, errors.New("storage.local.path: must not be empty"))
	}

	if c.JWT.Secret == "" {
		errs = append(errs, errors.New("jwt.secret: must not be empty"))
	}

	if c.JWT.AccessTTL <= 0 {
		errs = append(errs, errors.New("jwt.access_ttl: must be positive"))
	}

	if c.JWT.RefreshTTL <= 0 {
		errs = append(errs, errors.New("jwt.refresh_ttl: must be positive"))
	}

	return errors.Join(errs...)
}