package panel

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

	"github.com/gorilla/mux"
	"github.com/pkg/errors"

	"github.com/mattermost/mattermost/server/public/model"
	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/common"
	"github.com/mattermost/mattermost/server/public/pluginapi/experimental/panel/settings"
)

type handler struct {
	panel Panel
}

func Init(r *mux.Router, panel Panel) {
	sh := &handler{
		panel: panel,
	}

	panelRouter := r.PathPrefix("/").Subrouter()
	panelRouter.HandleFunc(panel.URL(), sh.handleAction).Methods(http.MethodPost)
}

func (sh *handler) handleAction(w http.ResponseWriter, r *http.Request) {
	mattermostUserID := r.Header.Get("Mattermost-User-ID")
	if mattermostUserID == "" {
		common.SlackAttachmentError(w, errors.New("Not authorized"))
		return
	}

	var request model.PostActionIntegrationRequest
	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
		common.SlackAttachmentError(w, errors.New("invalid request"))
		return
	}

	id, ok := request.Context[settings.ContextIDKey]
	if !ok {
		common.SlackAttachmentError(w, errors.New("missing setting id"))
		return
	}

	value, ok := request.Context[settings.ContextButtonValueKey]
	if !ok {
		value, ok = request.Context[settings.ContextOptionValueKey]
		if !ok {
			common.SlackAttachmentError(w, errors.New("valid key not found"))
			return
		}
	}

	idString := id.(string)
	err := sh.panel.Set(mattermostUserID, idString, value)
	if err != nil {
		common.SlackAttachmentError(w, errors.Wrap(err, "cannot save setting"))
		return
	}

	response := model.PostActionIntegrationResponse{}
	post, err := sh.panel.ToPost(mattermostUserID)
	if err == nil {
		response.Update = post
	}
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(response)
}