//nolint:forbidigo // Allow printing for prettyprint
package config

import (
	"fmt"
	"net"
	"net/url"
	"time"

	errs "git.maronato.dev/maronato/goshort/internal/errs"
)

const (
	DBTypeMemory = "memory"
	DBTypeSQLite = "sqlite"
)

func GetDBTypeList() []string {
	return []string{
		DBTypeMemory,
		DBTypeSQLite,
	}
}

type VerboseLevel int

const (
	VerboseLevelQuiet VerboseLevel = iota - 1
	VerboseLevelInfo
	VerboseLevelAccessLogs
	VerboseLevelDebug
)

const (
	// DefaultProd is the default mode.
	DefaultProd = false
	// DefaultDBType is the default type of database to use.
	DefaultDBType = DBTypeSQLite
	// DefaultDBURL is the default connection string for the database.
	DefaultDBURL = "goshort.db"
	// DefaultPort is the default port to listen on.
	DefaultPort = "8080"
	// DefaultHost is the default host to listen on. This is set to 0.0.0.0 when running in Docker.
	DefaultHost = "localhost"
	// DefaultUIPort is the default port to listen on for the UI.
	DefaultUIPort = "3000"
	// DefaultDebug is the default debug mode.
	DefaultDebug = false
	// DefaultSessionDuration is the default session duration.
	DefaultSessionDuration = 7 * 24 * time.Hour
	// DefaultDisableRegistration is the default value for diable registration.
	DefaultDisableRegistration = false
	// DefaultVerbose is the default verbosity level.
	DefaultVerbose = VerboseLevelInfo
	// DefaultQuiet is the default quiet mode.
	DefaultQuiet = false
	// DefaultDisableCredentialsLogin is the default value for diable credential login.
	DefaultDisableCredentialsLogin = false
	// DefaultOIDCIssuerName is the default name of the OIDC issuer.
	DefaultOIDCIssuerName = "OpenID"
)

const (
	// ReadTimeout is the maximum duration for reading the entire
	// request, including the body.
	ReadTimeout = 5 * time.Second
	// WriteTimeout is the maximum duration before timing out
	// writes of the response.
	WriteTimeout = 10 * time.Second
	// IdleTimeout is the maximum amount of time to wait for the
	// next request when keep-alives are enabled.
	IdleTimeout = 30 * time.Second
	// ReadHeaderTimeout is the amount of time allowed to read
	// request headers.
	ReadHeaderTimeout = 2 * time.Second
	// RequestTimeout is the maximum duration for the entire
	// request.
	RequestTimeout = 7 * 24 * time.Hour
)

// Config defines the default configuration for the backend.
type Config struct {
	// Prod is a flag that indicates if the server is running in production mode.
	Prod bool `json:"prod"`
	// Debug is a flag that indicates if the server is running in debug mode.
	Debug bool
	// Host is the host to listen on.
	Host string
	// Port is the port to listen on.
	Port string
	// UiPort is the port to listen on for the UI.
	UIPort string
	// DBType is the type of database to use.
	DBType string
	// DBURL is the connection string for the database.
	DBURL string
	// SessionDuration is the duration of the session.
	SessionDuration time.Duration
	// DisableRegistration defines whether or not registration are disabled.
	DisableRegistration bool `json:"disableRegistration"`
	// Verbose defines the verbosity level.
	Verbose VerboseLevel `json:"verbose"`
	// Quiet defines whether or not the server should be quiet.
	Quiet bool
	// DisableCredentialsLogin defines whether or not the server should disable credential login.
	DisableCredentialsLogin bool `json:"disableCredentialLogin"`
	// OIDCIssuerURL is the URL of the OIDC issuer.
	OIDCIssuerURL string `json:"oidcIssuerUrl"`
	// OIDCIssueName is the name of the OIDC issuer.
	OIDCIssuerName string
	// OIDCClientID is the client ID for OIDC.
	OIDCClientID string
	// OIDCClientSecret is the client secret for OIDC.
	OIDCClientSecret string
	// OIDCRedirectURL is the redirect URL for OIDC.
	OIDCRedirectURL string
}

func NewConfig() *Config {
	return &Config{
		Prod:                    DefaultProd,
		Debug:                   DefaultDebug,
		Host:                    DefaultHost,
		Port:                    DefaultPort,
		UIPort:                  DefaultUIPort,
		DBType:                  DefaultDBType,
		DBURL:                   DefaultDBURL,
		SessionDuration:         DefaultSessionDuration,
		DisableRegistration:     DefaultDisableRegistration,
		Verbose:                 DefaultVerbose,
		Quiet:                   DefaultQuiet,
		DisableCredentialsLogin: DefaultDisableCredentialsLogin,
		OIDCIssuerName:          DefaultOIDCIssuerName,
	}
}

// Validate validates the configuration modifies user-inaccessible fields.
func Validate(cfg *Config) error {
	// Host and port have to be valid.
	if _, err := url.ParseRequestURI("http://" + net.JoinHostPort(cfg.Host, cfg.Port)); err != nil {
		return errs.Errorf(fmt.Sprintf("invalid host and/or port: %s", err), errs.ErrInvalidConfig)
	}
	// UI port has to be valid.
	if cfg.UIPort != "" {
		if _, err := url.ParseRequestURI("http://" + net.JoinHostPort(cfg.Host, cfg.UIPort)); err != nil {
			return errs.Errorf(fmt.Sprintf("invalid UI port: %s", err), errs.ErrInvalidConfig)
		}
	}

	// Verbose has to be valid.
	if cfg.Verbose < VerboseLevelInfo || cfg.Verbose > VerboseLevelDebug {
		return errs.Errorf(fmt.Sprintf("invalid verbosity level: %d", cfg.Verbose), errs.ErrInvalidConfig)
	}

	if cfg.Verbose != VerboseLevelInfo && cfg.Quiet {
		return errs.Errorf("cannot set both verbose and quiet", errs.ErrInvalidConfig)
	}

	if cfg.DBType != "" {
		// DB type has to be valid.
		valid := false

		for _, dbType := range GetDBTypeList() {
			if cfg.DBType == dbType {
				valid = true

				break
			}
		}

		if !valid {
			return errs.Errorf(fmt.Sprintf("invalid database type: %s", cfg.DBType), errs.ErrInvalidConfig)
		}
	}

	// If verbose == 2, set debug to true for backwards compatibility.
	if cfg.Verbose >= VerboseLevelDebug {
		cfg.Debug = true
	}

	// If quiet is true, set verbose to -1.
	if cfg.Quiet {
		cfg.Verbose = VerboseLevelQuiet
	}

	// Either OIDC or credential login has to be enabled.
	if cfg.DisableCredentialsLogin && cfg.OIDCIssuerURL == "" {
		return errs.Errorf("either OIDC or credential login has to be enabled", errs.ErrInvalidConfig)
	}

	if cfg.OIDCIssuerURL != "" {
		// If OIDC is enabled, all OIDC fields have to be set.
		if cfg.OIDCClientID == "" || cfg.OIDCClientSecret == "" || cfg.OIDCRedirectURL == "" {
			return errs.Errorf("all OIDC fields have to be set", errs.ErrInvalidConfig)
		}

		// OIDC fields must be valid
		if _, err := url.ParseRequestURI(cfg.OIDCIssuerURL); err != nil {
			return errs.Errorf(fmt.Sprintf("invalid OIDC issuer URL: %s", err), errs.ErrInvalidConfig)
		}

		if _, err := url.ParseRequestURI(cfg.OIDCRedirectURL); err != nil {
			return errs.Errorf(fmt.Sprintf("invalid OIDC redirect URL: %s", err), errs.ErrInvalidConfig)
		}
	}

	return nil
}

func (c *Config) PrettyPrint() {
	fmt.Println("Configuration:")
	fmt.Println("  - Production mode:", c.Prod)
	fmt.Println("  - Debug mode:", c.Debug)
	fmt.Println("  - Host:", c.Host)
	fmt.Println("  - Port:", c.Port)
	fmt.Println("  - UI Port:", c.UIPort)
	fmt.Println("  - Database type:", c.DBType)
	fmt.Println("  - Database URL:", c.DBURL)
	fmt.Println("  - Session duration:", c.SessionDuration)
	fmt.Println("  - Disable registration:", c.DisableRegistration)
	fmt.Println("  - Verbose level:", c.Verbose)
	fmt.Println("  - Quiet mode:", c.Quiet)
}