package api

import (
	"errors"
	"net/http"

	"github.com/grafana/grafana/pkg/api/response"
	"github.com/grafana/grafana/pkg/infra/log"
	"github.com/grafana/grafana/pkg/models"
	apimodels "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
	ngmodels "github.com/grafana/grafana/pkg/services/ngalert/models"
	"github.com/grafana/grafana/pkg/services/ngalert/notifier"
	"github.com/grafana/grafana/pkg/services/ngalert/store"
	"github.com/grafana/grafana/pkg/util"
)

type AlertmanagerSrv struct {
	am    Alertmanager
	store store.AlertingStore
	log   log.Logger
}

func (srv AlertmanagerSrv) RouteCreateSilence(c *models.ReqContext, postableSilence apimodels.PostableSilence) response.Response {
	silenceID, err := srv.am.CreateSilence(&postableSilence)
	if err != nil {
		if errors.Is(err, notifier.ErrSilenceNotFound) {
			return response.Error(http.StatusNotFound, err.Error(), nil)
		}

		if errors.Is(err, notifier.ErrCreateSilenceBadPayload) {
			return response.Error(http.StatusBadRequest, err.Error(), nil)
		}

		return response.Error(http.StatusInternalServerError, "failed to create silence", err)
	}
	return response.JSON(http.StatusAccepted, util.DynMap{"message": "silence created", "id": silenceID})
}

func (srv AlertmanagerSrv) RouteDeleteAlertingConfig(c *models.ReqContext) response.Response {
	// not implemented
	return response.Error(http.StatusNotImplemented, "", nil)
}

func (srv AlertmanagerSrv) RouteDeleteSilence(c *models.ReqContext) response.Response {
	silenceID := c.Params(":SilenceId")
	if err := srv.am.DeleteSilence(silenceID); err != nil {
		if errors.Is(err, notifier.ErrSilenceNotFound) {
			return response.Error(http.StatusNotFound, err.Error(), nil)
		}
		return response.Error(http.StatusInternalServerError, err.Error(), nil)
	}
	return response.JSON(http.StatusOK, util.DynMap{"message": "silence deleted"})
}

func (srv AlertmanagerSrv) RouteGetAlertingConfig(c *models.ReqContext) response.Response {
	query := ngmodels.GetLatestAlertmanagerConfigurationQuery{}
	if err := srv.store.GetLatestAlertmanagerConfiguration(&query); err != nil {
		if errors.Is(err, store.ErrNoAlertmanagerConfiguration) {
			return response.Error(http.StatusNotFound, err.Error(), nil)
		}
		return response.Error(http.StatusInternalServerError, "failed to get latest configuration", err)
	}

	cfg, err := notifier.Load([]byte(query.Result.AlertmanagerConfiguration))
	if err != nil {
		return response.Error(http.StatusInternalServerError, "failed to unmarshal alertmanager configuration", err)
	}

	var apiReceiverName string
	var receivers []*apimodels.GettableGrafanaReceiver
	alertmanagerCfg := cfg.AlertmanagerConfig
	if len(alertmanagerCfg.Receivers) > 0 {
		apiReceiverName = alertmanagerCfg.Receivers[0].Name
		receivers = make([]*apimodels.GettableGrafanaReceiver, 0, len(alertmanagerCfg.Receivers[0].PostableGrafanaReceivers.GrafanaManagedReceivers))
		for _, pr := range alertmanagerCfg.Receivers[0].PostableGrafanaReceivers.GrafanaManagedReceivers {
			secureFields := make(map[string]bool, len(pr.SecureSettings))
			for k := range pr.SecureSettings {
				secureFields[k] = true
			}
			gr := apimodels.GettableGrafanaReceiver{
				Uid:                   pr.Uid,
				Name:                  pr.Name,
				Type:                  pr.Type,
				IsDefault:             pr.IsDefault,
				SendReminder:          pr.SendReminder,
				DisableResolveMessage: pr.DisableResolveMessage,
				Frequency:             pr.Frequency,
				Settings:              pr.Settings,
				SecureFields:          secureFields,
			}
			receivers = append(receivers, &gr)
		}
	}

	gettableApiReceiver := apimodels.GettableApiReceiver{
		GettableGrafanaReceivers: apimodels.GettableGrafanaReceivers{
			GrafanaManagedReceivers: receivers,
		},
	}
	gettableApiReceiver.Name = apiReceiverName
	result := apimodels.GettableUserConfig{
		TemplateFiles: cfg.TemplateFiles,
		AlertmanagerConfig: apimodels.GettableApiAlertingConfig{
			Config: alertmanagerCfg.Config,
			Receivers: []*apimodels.GettableApiReceiver{
				&gettableApiReceiver,
			},
		},
	}

	return response.JSON(http.StatusOK, result)
}

func (srv AlertmanagerSrv) RouteGetAMAlertGroups(c *models.ReqContext) response.Response {
	groups, err := srv.am.GetAlertGroups(
		c.QueryBoolWithDefault("active", true),
		c.QueryBoolWithDefault("silenced", true),
		c.QueryBoolWithDefault("inhibited", true),
		c.QueryStrings("filter"),
		c.Query("receiver"),
	)
	if err != nil {
		if errors.Is(err, notifier.ErrGetAlertGroupsBadPayload) {
			return response.Error(http.StatusBadRequest, err.Error(), nil)
		}
		// any other error here should be an unexpected failure and thus an internal error
		return response.Error(http.StatusInternalServerError, err.Error(), nil)
	}

	return response.JSON(http.StatusOK, groups)
}

func (srv AlertmanagerSrv) RouteGetAMAlerts(c *models.ReqContext) response.Response {
	alerts, err := srv.am.GetAlerts(
		c.QueryBoolWithDefault("active", true),
		c.QueryBoolWithDefault("silenced", true),
		c.QueryBoolWithDefault("inhibited", true),
		c.QueryStrings("filter"),
		c.Query("receiver"),
	)
	if err != nil {
		if errors.Is(err, notifier.ErrGetAlertsBadPayload) {
			return response.Error(http.StatusBadRequest, err.Error(), nil)
		}
		// any other error here should be an unexpected failure and thus an internal error
		return response.Error(http.StatusInternalServerError, err.Error(), nil)
	}

	return response.JSON(http.StatusOK, alerts)
}

func (srv AlertmanagerSrv) RouteGetSilence(c *models.ReqContext) response.Response {
	silenceID := c.Params(":SilenceId")
	gettableSilence, err := srv.am.GetSilence(silenceID)
	if err != nil {
		if errors.Is(err, notifier.ErrSilenceNotFound) {
			return response.Error(http.StatusNotFound, err.Error(), nil)
		}
		// any other error here should be an unexpected failure and thus an internal error
		return response.Error(http.StatusInternalServerError, err.Error(), nil)
	}
	return response.JSON(http.StatusOK, gettableSilence)
}

func (srv AlertmanagerSrv) RouteGetSilences(c *models.ReqContext) response.Response {
	gettableSilences, err := srv.am.ListSilences(c.QueryStrings("filter"))
	if err != nil {
		if errors.Is(err, notifier.ErrListSilencesBadPayload) {
			return response.Error(http.StatusBadRequest, err.Error(), nil)
		}
		// any other error here should be an unexpected failure and thus an internal error
		return response.Error(http.StatusInternalServerError, err.Error(), nil)
	}
	return response.JSON(http.StatusOK, gettableSilences)
}

func (srv AlertmanagerSrv) RoutePostAlertingConfig(c *models.ReqContext, body apimodels.PostableUserConfig) response.Response {
	if err := srv.am.SaveAndApplyConfig(&body); err != nil {
		return response.Error(http.StatusInternalServerError, "failed to save and apply Alertmanager configuration", err)
	}

	return response.JSON(http.StatusAccepted, util.DynMap{"message": "configuration created"})
}

func (srv AlertmanagerSrv) RoutePostAMAlerts(c *models.ReqContext, body apimodels.PostableAlerts) response.Response {
	// not implemented
	return response.Error(http.StatusNotImplemented, "", nil)
}