package svc

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

	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
	storageprovider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"

	"github.com/owncloud/ocis/v2/services/graph/pkg/errorcode"
)

// StrictJSONUnmarshal is a wrapper around json.Unmarshal that returns an error if the json contains unknown fields.
func StrictJSONUnmarshal(r io.Reader, v interface{}) error {
	dec := json.NewDecoder(r)
	dec.DisallowUnknownFields()
	return dec.Decode(v)
}

// IsSpaceRoot returns true if the resourceID is a space root.
func IsSpaceRoot(rid *storageprovider.ResourceId) bool {
	if rid == nil {
		return false
	}
	if rid.GetSpaceId() == "" || rid.GetOpaqueId() == "" {
		return false
	}

	return rid.GetSpaceId() == rid.GetOpaqueId()
}

// GetDriveAndItemIDParam parses the driveID and itemID from the request,
// validates the common fields and returns the parsed IDs if ok.
func (g Graph) GetDriveAndItemIDParam(r *http.Request) (storageprovider.ResourceId, storageprovider.ResourceId, error) {
	empty := storageprovider.ResourceId{}

	driveID, err := parseIDParam(r, "driveID")
	if err != nil {
		g.logger.Debug().Err(err).Msg("could not parse driveID")
		return empty, empty, errorcode.New(errorcode.InvalidRequest, "invalid driveID")
	}

	itemID, err := parseIDParam(r, "itemID")
	if err != nil {
		g.logger.Debug().Err(err).Msg("could not parse itemID")
		return empty, empty, errorcode.New(errorcode.InvalidRequest, "invalid itemID")
	}

	if itemID.GetOpaqueId() == "" {
		g.logger.Debug().Interface("driveID", driveID).Interface("itemID", itemID).Msg("empty item opaqueID")
		return empty, empty, errorcode.New(errorcode.InvalidRequest, "invalid itemID")
	}

	if driveID.GetStorageId() != itemID.GetStorageId() || driveID.GetSpaceId() != itemID.GetSpaceId() {
		g.logger.Debug().Interface("driveID", driveID).Interface("itemID", itemID).Msg("driveID and itemID do not match")
		return empty, empty, errorcode.New(errorcode.ItemNotFound, "driveID and itemID do not match")
	}

	return driveID, itemID, nil
}

// GetGatewayClient returns a gateway client from the gatewaySelector.
func (g Graph) GetGatewayClient(w http.ResponseWriter, r *http.Request) (gateway.GatewayAPIClient, bool) {
	gatewayClient, err := g.gatewaySelector.Next()
	if err != nil {
		g.logger.Debug().Err(err).Msg("selecting gatewaySelector failed")
		errorcode.GeneralException.Render(w, r, http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError))
		return nil, false
	}

	return gatewayClient, true
}