package eventsourcing

import (
	"context"

	"github.com/caos/zitadel/internal/cache/config"
	caos_errs "github.com/caos/zitadel/internal/errors"
	es_int "github.com/caos/zitadel/internal/eventstore"
	"github.com/caos/zitadel/internal/eventstore/models"
	es_models "github.com/caos/zitadel/internal/eventstore/models"
	es_sdk "github.com/caos/zitadel/internal/eventstore/sdk"
	"github.com/caos/zitadel/internal/id"
	grant_model "github.com/caos/zitadel/internal/usergrant/model"
	"github.com/caos/zitadel/internal/usergrant/repository/eventsourcing/model"
)

type UserGrantEventStore struct {
	es_int.Eventstore
	userGrantCache *UserGrantCache
	idGenerator    id.Generator
}

type UserGrantConfig struct {
	es_int.Eventstore
	Cache *config.CacheConfig
}

func StartUserGrant(conf UserGrantConfig) (*UserGrantEventStore, error) {
	userGrantCache, err := StartCache(conf.Cache)
	if err != nil {
		return nil, err
	}
	return &UserGrantEventStore{
		Eventstore:     conf.Eventstore,
		userGrantCache: userGrantCache,
		idGenerator:    id.SonyFlakeGenerator,
	}, nil
}

func (es *UserGrantEventStore) UserGrantByID(ctx context.Context, id string) (*grant_model.UserGrant, error) {
	grant := es.userGrantCache.getUserGrant(id)

	query, err := UserGrantByIDQuery(grant.AggregateID, grant.Sequence)
	if err != nil {
		return nil, err
	}
	err = es_sdk.Filter(ctx, es.FilterEvents, grant.AppendEvents, query)
	if err != nil && caos_errs.IsNotFound(err) && grant.Sequence == 0 {
		return nil, err
	}
	es.userGrantCache.cacheUserGrant(grant)
	if grant.State == int32(grant_model.UserGrantStateRemoved) {
		return nil, caos_errs.ThrowNotFound(nil, "EVENT-2ks8d", "Errors.UserGrant.NotFound")
	}
	return model.UserGrantToModel(grant), nil
}

func (es *UserGrantEventStore) AddUserGrant(ctx context.Context, grant *grant_model.UserGrant) (*grant_model.UserGrant, error) {
	repoGrant, addAggregates, err := es.PrepareAddUserGrant(ctx, grant)
	if err != nil {
		return nil, err
	}
	err = es_sdk.PushAggregates(ctx, es.PushAggregates, repoGrant.AppendEvents, addAggregates...)
	if err != nil {
		return nil, err
	}
	return model.UserGrantToModel(repoGrant), nil
}

func (es *UserGrantEventStore) AddUserGrants(ctx context.Context, grants ...*grant_model.UserGrant) error {
	aggregates := make([]*es_models.Aggregate, 0)
	for _, grant := range grants {
		_, addAggregates, err := es.PrepareAddUserGrant(ctx, grant)
		if err != nil {
			return err
		}
		for _, agg := range addAggregates {
			aggregates = append(aggregates, agg)
		}
	}
	return es_sdk.PushAggregates(ctx, es.PushAggregates, nil, aggregates...)
}

func (es *UserGrantEventStore) PrepareAddUserGrant(ctx context.Context, grant *grant_model.UserGrant) (*model.UserGrant, []*es_models.Aggregate, error) {
	if grant == nil || !grant.IsValid() {
		return nil, nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-sdiw3", "Errors.UserGrant.Invalid")
	}
	id, err := es.idGenerator.Next()
	if err != nil {
		return nil, nil, err
	}
	grant.AggregateID = id

	repoGrant := model.UserGrantFromModel(grant)

	addAggregates, err := UserGrantAddedAggregate(ctx, es.Eventstore.AggregateCreator(), repoGrant)
	if err != nil {
		return nil, nil, err
	}
	return repoGrant, addAggregates, nil
}

func (es *UserGrantEventStore) PrepareChangeUserGrant(ctx context.Context, grant *grant_model.UserGrant, cascade bool) (*model.UserGrant, *es_models.Aggregate, error) {
	if grant == nil {
		return nil, nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-lo0s9", "Errors.UserGrant.Invalid")
	}
	existingGrant, err := es.UserGrantByID(ctx, grant.AggregateID)
	if err != nil {
		return nil, nil, err
	}
	repoExistingGrant := model.UserGrantFromModel(existingGrant)
	repoGrant := model.UserGrantFromModel(grant)

	aggFunc := UserGrantChangedAggregate(es.Eventstore.AggregateCreator(), repoExistingGrant, repoGrant, cascade)
	projectAggregate, err := aggFunc(ctx)
	if err != nil {
		return nil, nil, err
	}
	return repoExistingGrant, projectAggregate, err
}

func (es *UserGrantEventStore) ChangeUserGrant(ctx context.Context, grant *grant_model.UserGrant) (*grant_model.UserGrant, error) {
	repoGrant, agg, err := es.PrepareChangeUserGrant(ctx, grant, false)
	if err != nil {
		return nil, err
	}

	err = es_sdk.PushAggregates(ctx, es.PushAggregates, repoGrant.AppendEvents, agg)
	if err != nil {
		return nil, err
	}
	es.userGrantCache.cacheUserGrant(repoGrant)
	return model.UserGrantToModel(repoGrant), nil
}

func (es *UserGrantEventStore) ChangeUserGrants(ctx context.Context, grants ...*grant_model.UserGrant) error {
	aggregates := make([]*es_models.Aggregate, len(grants))
	for i, grant := range grants {
		_, agg, err := es.PrepareChangeUserGrant(ctx, grant, false)
		if err != nil {
			return err
		}
		aggregates[i] = agg
	}
	return es_sdk.PushAggregates(ctx, es.PushAggregates, nil, aggregates...)
}

func (es *UserGrantEventStore) RemoveUserGrant(ctx context.Context, grantID string) error {
	grant, projectAggregates, err := es.PrepareRemoveUserGrant(ctx, grantID, false)
	if err != nil {
		return err
	}
	err = es_sdk.PushAggregates(ctx, es.PushAggregates, grant.AppendEvents, projectAggregates...)
	if err != nil {
		return err
	}
	es.userGrantCache.cacheUserGrant(grant)
	return nil
}

func (es *UserGrantEventStore) RemoveUserGrants(ctx context.Context, grantIDs ...string) error {
	aggregates := make([]*es_models.Aggregate, 0)
	for _, grantID := range grantIDs {
		_, aggs, err := es.PrepareRemoveUserGrant(ctx, grantID, false)
		if err != nil {
			return err
		}
		for _, agg := range aggs {
			aggregates = append(aggregates, agg)
		}
	}
	return es_sdk.PushAggregates(ctx, es.PushAggregates, nil, aggregates...)
}

func (es *UserGrantEventStore) PrepareRemoveUserGrant(ctx context.Context, grantID string, cascade bool) (*model.UserGrant, []*es_models.Aggregate, error) {
	grant, err := es.UserGrantByID(ctx, grantID)
	if err != nil {
		return nil, nil, err
	}
	repoExisting := model.UserGrantFromModel(grant)
	repoGrant := &model.UserGrant{ObjectRoot: models.ObjectRoot{AggregateID: grantID}}
	projectAggregates, err := UserGrantRemovedAggregate(ctx, es.Eventstore.AggregateCreator(), repoExisting, repoGrant, cascade)
	if err != nil {
		return nil, nil, err
	}
	return repoExisting, projectAggregates, nil
}

func (es *UserGrantEventStore) DeactivateUserGrant(ctx context.Context, grantID string) (*grant_model.UserGrant, error) {
	if grantID == "" {
		return nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-8si34", "Errors.UserGrant.IDMissing")
	}
	grant, err := es.UserGrantByID(ctx, grantID)
	if err != nil {
		return nil, err
	}
	if !grant.IsActive() {
		return nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-lo9sw", "Errors.UserGrant.NotActive")
	}
	repoExistingGrant := model.UserGrantFromModel(grant)
	repoGrant := &model.UserGrant{ObjectRoot: models.ObjectRoot{AggregateID: grantID}}

	projectAggregate := UserGrantDeactivatedAggregate(es.Eventstore.AggregateCreator(), repoExistingGrant, repoGrant)
	err = es_sdk.Push(ctx, es.PushAggregates, repoExistingGrant.AppendEvents, projectAggregate)
	if err != nil {
		return nil, err
	}
	es.userGrantCache.cacheUserGrant(repoGrant)
	return model.UserGrantToModel(repoExistingGrant), nil
}

func (es *UserGrantEventStore) ReactivateUserGrant(ctx context.Context, grantID string) (*grant_model.UserGrant, error) {
	if grantID == "" {
		return nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-sksiw", "Errors.UserGrant.IDMissing")
	}
	grant, err := es.UserGrantByID(ctx, grantID)
	if err != nil {
		return nil, err
	}
	if !grant.IsInactive() {
		return nil, caos_errs.ThrowPreconditionFailed(nil, "EVENT-lo9sw", "Errors.UserGrant.NotInactive")
	}
	repoExistingGrant := model.UserGrantFromModel(grant)
	repoGrant := &model.UserGrant{ObjectRoot: models.ObjectRoot{AggregateID: grantID}}

	projectAggregate := UserGrantReactivatedAggregate(es.Eventstore.AggregateCreator(), repoExistingGrant, repoGrant)
	err = es_sdk.Push(ctx, es.PushAggregates, repoExistingGrant.AppendEvents, projectAggregate)
	if err != nil {
		return nil, err
	}
	es.userGrantCache.cacheUserGrant(repoExistingGrant)
	return model.UserGrantToModel(repoExistingGrant), nil
}