/*
	Copyright NetFoundry Inc.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	https://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
*/

package db

import (
	"fmt"
	"github.com/michaelquigley/pfxlog"
	"github.com/openziti/foundation/v2/errorz"
	"github.com/openziti/storage/ast"
	"github.com/openziti/storage/boltz"
)

const (
	FieldAuthenticatorMethod   = "method"
	FieldAuthenticatorIdentity = "identity"

	FieldAuthenticatorCertFingerprint = "certFingerprint"
	FieldAuthenticatorCertPem         = "certPem"

	FieldAuthenticatorUnverifiedCertPem         = "unverifiedCertPem"
	FieldAuthenticatorUnverifiedCertFingerprint = "unverifiedCertFingerprint"

	FieldAuthenticatorUpdbUsername = "updbUsername"
	FieldAuthenticatorUpdbPassword = "updbPassword"
	FieldAuthenticatorUpdbSalt     = "updbSalt"

	MethodAuthenticatorUpdb = "updb"
	MethodAuthenticatorCert = "cert"
	// MethodAuthenticatorCertCaExternalId represents authentication with a certificate that isn't directly
	// registered with an authenticator. Instead, it uses `externalId` values on identities and matches them to a
	// "x509 claim" (custom values stuffed into SANs or other x509 properties). This type will never actually
	// be stored for persistence and is defined here for as tobe near the other authenticator methods.
	MethodAuthenticatorCertCaExternalId = "certCaExternalId"
)

type AuthenticatorSubType interface {
	Fingerprints() []string
}

type AuthenticatorCert struct {
	Authenticator `json:"-"`
	Fingerprint   string `json:"fingerprint"`
	Pem           string `json:"pem"`

	UnverifiedPem         string `json:"unverifiedPem"`
	UnverifiedFingerprint string `json:"unverifiedFingerprint"`
}

func (entity *AuthenticatorCert) Fingerprints() []string {
	return []string{entity.Fingerprint}
}

type AuthenticatorUpdb struct {
	Authenticator `json:"-"`
	Username      string `json:"username"`
	Password      string `json:"password"`
	Salt          string `json:"salt"`
}

func (entity *AuthenticatorUpdb) Fingerprints() []string {
	return nil
}

type Authenticator struct {
	boltz.BaseExtEntity
	Type       string               `json:"type"`
	IdentityId string               `json:"identityId"`
	SubType    AuthenticatorSubType `json:"subType"`
}

func (entity *Authenticator) GetEntityType() string {
	return EntityTypeAuthenticators
}

var authenticatorFieldMappings = map[string]string{
	FieldAuthenticatorIdentity:        "identityId",
	FieldAuthenticatorUpdbPassword:    "password",
	FieldAuthenticatorUpdbUsername:    "username",
	FieldAuthenticatorUpdbSalt:        "salt",
	FieldAuthenticatorCertFingerprint: "fingerprint"}

func (entity *Authenticator) ToUpdb() *AuthenticatorUpdb {
	if updb, ok := entity.SubType.(*AuthenticatorUpdb); ok {
		updb.Authenticator = *entity
		return updb
	}
	return nil
}

func (entity *Authenticator) ToCert() *AuthenticatorCert {
	if cert, ok := entity.SubType.(*AuthenticatorCert); ok {
		cert.Authenticator = *entity
		return cert
	}
	return nil
}

func (entity *Authenticator) ToSubType() AuthenticatorSubType {
	if entity.Type == MethodAuthenticatorCert {
		return entity.ToCert()
	}
	if entity.Type == MethodAuthenticatorUpdb {
		return entity.ToUpdb()
	}

	pfxlog.Logger().Panicf("unknown authenticator subtype %s", entity.Type)
	return nil
}

var _ ApiSessionStore = (*apiSessionStoreImpl)(nil)

type AuthenticatorStore interface {
	Store[*Authenticator]
}

func newAuthenticatorStore(stores *stores) *authenticatorStoreImpl {
	store := &authenticatorStoreImpl{}
	store.baseStore = newBaseStore[*Authenticator](stores, store)
	store.InitImpl(store)
	return store
}

type authenticatorStoreImpl struct {
	*baseStore[*Authenticator]
	symbolIdentityId boltz.EntitySymbol
}

func (store *authenticatorStoreImpl) initializeLocal() {
	store.AddExtEntitySymbols()

	store.AddSymbol(FieldAuthenticatorMethod, ast.NodeTypeString)
	store.AddSymbol(FieldAuthenticatorCertFingerprint, ast.NodeTypeString)
	store.AddSymbol(FieldAuthenticatorCertPem, ast.NodeTypeString)
	store.AddSymbol(FieldAuthenticatorUpdbUsername, ast.NodeTypeString)
	store.AddSymbol(FieldAuthenticatorUpdbPassword, ast.NodeTypeString)
	store.AddSymbol(FieldAuthenticatorUpdbSalt, ast.NodeTypeString)

	store.symbolIdentityId = store.AddFkSymbol(FieldAuthenticatorIdentity, store.stores.identity)
}

func (store *authenticatorStoreImpl) initializeLinked() {
	store.AddFkIndex(store.symbolIdentityId, store.stores.identity.symbolAuthenticators)
}

func (store *authenticatorStoreImpl) NewEntity() *Authenticator {
	return &Authenticator{}
}

func (store *authenticatorStoreImpl) FillEntity(entity *Authenticator, bucket *boltz.TypedBucket) {
	entity.Type = bucket.GetStringOrError(FieldAuthenticatorMethod)
	entity.IdentityId = bucket.GetStringOrError(FieldAuthenticatorIdentity)

	if entity.Type == MethodAuthenticatorCert {
		authCert := &AuthenticatorCert{}
		authCert.Fingerprint = bucket.GetStringWithDefault(FieldAuthenticatorCertFingerprint, "")
		authCert.Pem = bucket.GetStringWithDefault(FieldAuthenticatorCertPem, "")

		authCert.UnverifiedPem = bucket.GetStringWithDefault(FieldAuthenticatorUnverifiedCertPem, "")
		authCert.UnverifiedFingerprint = bucket.GetStringWithDefault(FieldAuthenticatorUnverifiedCertFingerprint, "")
		entity.SubType = authCert
	} else if entity.Type == MethodAuthenticatorUpdb {
		authUpdb := &AuthenticatorUpdb{}
		authUpdb.Username = bucket.GetStringWithDefault(FieldAuthenticatorUpdbUsername, "")
		authUpdb.Password = bucket.GetStringWithDefault(FieldAuthenticatorUpdbPassword, "")
		authUpdb.Salt = bucket.GetStringWithDefault(FieldAuthenticatorUpdbSalt, "")
		entity.SubType = authUpdb
	}
}

func (store *authenticatorStoreImpl) PersistEntity(entity *Authenticator, ctx *boltz.PersistContext) {
	ctx.WithFieldOverrides(authenticatorFieldMappings)

	entity.SetBaseValues(ctx)
	ctx.SetString(FieldAuthenticatorMethod, entity.Type)
	ctx.SetString(FieldAuthenticatorIdentity, entity.IdentityId)

	if entity.Type == MethodAuthenticatorCert {
		if authCert, ok := entity.SubType.(*AuthenticatorCert); ok {
			ctx.SetString(FieldAuthenticatorCertFingerprint, authCert.Fingerprint)
			ctx.SetString(FieldAuthenticatorCertPem, authCert.Pem)

			ctx.SetString(FieldAuthenticatorUnverifiedCertFingerprint, authCert.UnverifiedFingerprint)
			ctx.SetString(FieldAuthenticatorUnverifiedCertPem, authCert.UnverifiedPem)
		} else {
			pfxlog.Logger().Panic("type conversion error setting values for AuthenticatorCert")
		}
	} else if entity.Type == MethodAuthenticatorUpdb {
		if authUpdb, ok := entity.SubType.(*AuthenticatorUpdb); ok {
			ctx.SetString(FieldAuthenticatorUpdbPassword, authUpdb.Password)
			ctx.SetString(FieldAuthenticatorUpdbUsername, authUpdb.Username)
			ctx.SetString(FieldAuthenticatorUpdbSalt, authUpdb.Salt)
		} else {
			pfxlog.Logger().Panic("type conversion error setting values for AuthenticatorUpdb")
		}
	}

	_, identityId := store.symbolIdentityId.Eval(ctx.Tx(), []byte(entity.Id))
	if identityId != nil {
		identityType := boltz.FieldToString(store.stores.identity.symbolIdentityTypeId.Eval(ctx.Tx(), identityId))
		if identityType != nil && *identityType == RouterIdentityType {
			err := errorz.NewFieldError("may not create authenticators for router identities", "identityId", string(identityId))
			ctx.Bucket.SetError(errorz.NewFieldApiError(err))
		}
	}
}

func (store *authenticatorStoreImpl) DeleteById(ctx boltz.MutateContext, id string) error {
	err := store.baseStore.DeleteById(ctx, id)

	if err == nil {
		return store.stores.apiSession.DeleteWhere(ctx, fmt.Sprintf(`%s="%s"`, FieldApiSessionAuthenticator, id))
	}
	return err
}