package validator

import (
	"fmt"
	"path"
	"strings"

	"github.com/authelia/authelia/internal/configuration/schema"
	"github.com/authelia/authelia/internal/utils"
)

// ValidateServer checks a server configuration is correct.
func ValidateServer(configuration *schema.Configuration, validator *schema.StructValidator) {
	applyDeprecatedServerConfiguration(configuration, validator)

	if configuration.Server.Host == "" {
		configuration.Server.Host = schema.DefaultServerConfiguration.Host
	}

	if configuration.Server.Port == 0 {
		configuration.Server.Port = schema.DefaultServerConfiguration.Port
	}

	if configuration.Server.TLS.Key != "" && configuration.Server.TLS.Certificate == "" {
		validator.Push(fmt.Errorf("server: no TLS certificate provided to accompany the TLS key, please configure the 'server.tls.certificate' option"))
	} else if configuration.Server.TLS.Key == "" && configuration.Server.TLS.Certificate != "" {
		validator.Push(fmt.Errorf("server: no TLS key provided to accompany the TLS certificate, please configure the 'server.tls.key' option"))
	}

	switch {
	case strings.Contains(configuration.Server.Path, "/"):
		validator.Push(fmt.Errorf("server path must not contain any forward slashes"))
	case !utils.IsStringAlphaNumeric(configuration.Server.Path):
		validator.Push(fmt.Errorf("server path must only be alpha numeric characters"))
	case configuration.Server.Path == "": // Don't do anything if it's blank.
	default:
		configuration.Server.Path = path.Clean("/" + configuration.Server.Path)
	}

	if configuration.Server.ReadBufferSize == 0 {
		configuration.Server.ReadBufferSize = schema.DefaultServerConfiguration.ReadBufferSize
	} else if configuration.Server.ReadBufferSize < 0 {
		validator.Push(fmt.Errorf("server read buffer size must be above 0"))
	}

	if configuration.Server.WriteBufferSize == 0 {
		configuration.Server.WriteBufferSize = schema.DefaultServerConfiguration.WriteBufferSize
	} else if configuration.Server.WriteBufferSize < 0 {
		validator.Push(fmt.Errorf("server write buffer size must be above 0"))
	}
}

func applyDeprecatedServerConfiguration(configuration *schema.Configuration, validator *schema.StructValidator) {
	if configuration.Host != "" {
		validator.PushWarning(fmt.Errorf(errFmtDeprecatedConfigurationKey, "host", "4.33.0", "server.host"))

		if configuration.Server.Host == "" {
			configuration.Server.Host = configuration.Host
		}
	}

	if configuration.Port != 0 {
		validator.PushWarning(fmt.Errorf(errFmtDeprecatedConfigurationKey, "port", "4.33.0", "server.port"))

		if configuration.Server.Port == 0 {
			configuration.Server.Port = configuration.Port
		}
	}

	if configuration.TLSCert != "" {
		validator.PushWarning(fmt.Errorf(errFmtDeprecatedConfigurationKey, "tls_cert", "4.33.0", "server.tls_cert"))

		if configuration.Server.TLS.Certificate == "" {
			configuration.Server.TLS.Certificate = configuration.TLSCert
		}
	}

	if configuration.TLSKey != "" {
		validator.PushWarning(fmt.Errorf(errFmtDeprecatedConfigurationKey, "tls_key", "4.33.0", "server.tls_key"))

		if configuration.Server.TLS.Key == "" {
			configuration.Server.TLS.Key = configuration.TLSKey
		}
	}
}