package handlers

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

	"galaxy/gamemaster/internal/domain/engineversion"
	engineversionsvc "galaxy/gamemaster/internal/service/engineversion"
)

// updateEngineVersionRequestBody mirrors the OpenAPI
// UpdateEngineVersionRequest schema. Every field is optional; the
// service rejects calls with no fields set as `invalid_request`.
type updateEngineVersionRequestBody struct {
	ImageRef *string          `json:"image_ref,omitempty"`
	Options  *json.RawMessage `json:"options,omitempty"`
	Status   *string          `json:"status,omitempty"`
}

// newUpdateEngineVersionHandler returns the handler for
// `PATCH /api/v1/internal/engine-versions/{version}`.
func newUpdateEngineVersionHandler(deps Dependencies) http.HandlerFunc {
	logger := loggerFor(deps.Logger, "internal_rest.update_engine_version")
	return func(writer http.ResponseWriter, request *http.Request) {
		if deps.EngineVersions == nil {
			writeError(writer, http.StatusInternalServerError, errorCodeInternal, "engine version service is not wired")
			return
		}

		version, ok := extractVersion(writer, request)
		if !ok {
			return
		}

		var body updateEngineVersionRequestBody
		if err := decodeStrictJSON(request.Body, &body); err != nil {
			writeError(writer, http.StatusBadRequest, errorCodeInvalidRequest, err.Error())
			return
		}

		input := engineversionsvc.UpdateInput{
			Version:   version,
			ImageRef:  body.ImageRef,
			OpSource:  resolveOpSource(request),
			SourceRef: requestSourceRef(request),
		}
		if body.Options != nil {
			optionBytes := []byte(*body.Options)
			input.Options = &optionBytes
		}
		if body.Status != nil {
			candidate := engineversion.Status(*body.Status)
			input.Status = &candidate
		}

		record, err := deps.EngineVersions.Update(request.Context(), input)
		if err != nil {
			logger.ErrorContext(request.Context(), "update engine version failed",
				"version", version,
				"err", err.Error(),
			)
			status, code, message := mapServiceError(err)
			writeError(writer, status, code, message)
			return
		}

		writeJSON(writer, http.StatusOK, encodeEngineVersion(record))
	}
}