package resources

import (
	"encoding/json"
	"net/http"
	"slices"

	"github.com/gorilla/mux"

	"github.com/zitadel/zitadel/internal/api/scim/resources/patch"
	"github.com/zitadel/zitadel/internal/api/scim/serrors"
	"github.com/zitadel/zitadel/internal/zerrors"
)

type ResourceHandlerAdapter[T ResourceHolder] struct {
	handler ResourceHandler[T]
}

func NewResourceHandlerAdapter[T ResourceHolder](handler ResourceHandler[T]) *ResourceHandlerAdapter[T] {
	return &ResourceHandlerAdapter[T]{
		handler,
	}
}

func (adapter *ResourceHandlerAdapter[T]) Create(r *http.Request) (T, error) {
	entity, err := adapter.readEntityFromBody(r)
	if err != nil {
		return entity, err
	}

	return adapter.handler.Create(r.Context(), entity)
}

func (adapter *ResourceHandlerAdapter[T]) Replace(r *http.Request) (T, error) {
	entity, err := adapter.readEntityFromBody(r)
	if err != nil {
		return entity, err
	}

	id := mux.Vars(r)["id"]
	return adapter.handler.Replace(r.Context(), id, entity)
}

func (adapter *ResourceHandlerAdapter[T]) Update(r *http.Request) error {
	request := new(patch.OperationRequest)
	err := json.NewDecoder(r.Body).Decode(request)
	if err != nil {
		if zerrors.IsZitadelError(err) {
			return err
		}

		return serrors.ThrowInvalidSyntax(zerrors.ThrowInvalidArgumentf(nil, "SCIM-ucrjson2", "Could not deserialize json: %v", err.Error()))
	}

	err = request.Validate()
	if err != nil {
		return err
	}

	if len(request.Operations) == 0 {
		return nil
	}

	id := mux.Vars(r)["id"]
	return adapter.handler.Update(r.Context(), id, request.Operations)
}

func (adapter *ResourceHandlerAdapter[T]) Delete(r *http.Request) error {
	id := mux.Vars(r)["id"]
	return adapter.handler.Delete(r.Context(), id)
}

func (adapter *ResourceHandlerAdapter[T]) List(r *http.Request) (*ListResponse[T], error) {
	request, err := readListRequest(r)
	if err != nil {
		return nil, err
	}

	return adapter.handler.List(r.Context(), request)
}

func (adapter *ResourceHandlerAdapter[T]) Get(r *http.Request) (T, error) {
	id := mux.Vars(r)["id"]
	return adapter.handler.Get(r.Context(), id)
}

func (adapter *ResourceHandlerAdapter[T]) readEntityFromBody(r *http.Request) (T, error) {
	entity := adapter.handler.NewResource()
	err := json.NewDecoder(r.Body).Decode(entity)
	if err != nil {
		if serrors.IsScimOrZitadelError(err) {
			return entity, err
		}

		return entity, serrors.ThrowInvalidSyntax(zerrors.ThrowInvalidArgumentf(nil, "SCIM-ucrjson", "Could not deserialize json: %v", err.Error()))
	}

	resource := entity.GetResource()
	if resource == nil {
		return entity, serrors.ThrowInvalidSyntax(zerrors.ThrowInvalidArgument(nil, "SCIM-xxrjson", "Could not get resource, is the schema correct?"))
	}

	if !slices.Contains(resource.Schemas, adapter.handler.SchemaType()) {
		return entity, serrors.ThrowInvalidSyntax(zerrors.ThrowInvalidArgumentf(nil, "SCIM-xxrschema", "Expected schema %v is not provided", adapter.handler.SchemaType()))
	}

	return entity, nil
}