package watchdog

import (
	"encoding/json"
	"log"

	"github.com/TwiN/gatus/v3/alerting"
	"github.com/TwiN/gatus/v3/alerting/alert"
	"github.com/TwiN/gatus/v3/core"
)

// HandleAlerting takes care of alerts to resolve and alerts to trigger based on result success or failure
func HandleAlerting(endpoint *core.Endpoint, result *core.Result, alertingConfig *alerting.Config, debug bool) {
	if alertingConfig == nil {
		return
	}
	if result.Success {
		handleAlertsToResolve(endpoint, result, alertingConfig, debug)
	} else {
		handleAlertsToTrigger(endpoint, result, alertingConfig, debug)
	}
}

func handleAlertsToTrigger(endpoint *core.Endpoint, result *core.Result, alertingConfig *alerting.Config, debug bool) {
	endpoint.NumberOfSuccessesInARow = 0
	endpoint.NumberOfFailuresInARow++
	for _, endpointAlert := range endpoint.Alerts {
		// If the alert hasn't been triggered, move to the next one
		if !endpointAlert.IsEnabled() || endpointAlert.FailureThreshold > endpoint.NumberOfFailuresInARow {
			continue
		}
		if endpointAlert.Triggered {
			if debug {
				log.Printf("[watchdog][handleAlertsToTrigger] Alert for endpoint=%s with description='%s' has already been TRIGGERED, skipping", endpoint.Name, endpointAlert.GetDescription())
			}
			continue
		}
		alertProvider := alertingConfig.GetAlertingProviderByAlertType(endpointAlert.Type)
		if alertProvider != nil && alertProvider.IsValid() {
			log.Printf("[watchdog][handleAlertsToTrigger] Sending %s alert because alert for endpoint=%s with description='%s' has been TRIGGERED", endpointAlert.Type, endpoint.Name, endpointAlert.GetDescription())
			customAlertProvider := alertProvider.ToCustomAlertProvider(endpoint, endpointAlert, result, false)
			// TODO: retry on error
			var err error
			// We need to extract the DedupKey from PagerDuty's response
			if endpointAlert.Type == alert.TypePagerDuty {
				var body []byte
				if body, err = customAlertProvider.Send(endpoint.Name, endpointAlert.GetDescription(), false); err == nil {
					var response pagerDutyResponse
					if err = json.Unmarshal(body, &response); err != nil {
						log.Printf("[watchdog][handleAlertsToTrigger] Ran into error unmarshaling pagerduty response: %s", err.Error())
					} else {
						endpointAlert.ResolveKey = response.DedupKey
					}
				}
			} else {
				// All other alert types don't need to extract anything from the body, so we can just send the request right away
				_, err = customAlertProvider.Send(endpoint.Name, endpointAlert.GetDescription(), false)
			}
			if err != nil {
				log.Printf("[watchdog][handleAlertsToTrigger] Failed to send an alert for endpoint=%s: %s", endpoint.Name, err.Error())
			} else {
				endpointAlert.Triggered = true
			}
		} else {
			log.Printf("[watchdog][handleAlertsToResolve] Not sending alert of type=%s despite being TRIGGERED, because the provider wasn't configured properly", endpointAlert.Type)
		}
	}
}

func handleAlertsToResolve(endpoint *core.Endpoint, result *core.Result, alertingConfig *alerting.Config, debug bool) {
	endpoint.NumberOfSuccessesInARow++
	for _, endpointAlert := range endpoint.Alerts {
		if !endpointAlert.IsEnabled() || !endpointAlert.Triggered || endpointAlert.SuccessThreshold > endpoint.NumberOfSuccessesInARow {
			continue
		}
		// Even if the alert provider returns an error, we still set the alert's Triggered variable to false.
		// Further explanation can be found on Alert's Triggered field.
		endpointAlert.Triggered = false
		if !endpointAlert.IsSendingOnResolved() {
			continue
		}
		alertProvider := alertingConfig.GetAlertingProviderByAlertType(endpointAlert.Type)
		if alertProvider != nil && alertProvider.IsValid() {
			log.Printf("[watchdog][handleAlertsToResolve] Sending %s alert because alert for endpoint=%s with description='%s' has been RESOLVED", endpointAlert.Type, endpoint.Name, endpointAlert.GetDescription())
			customAlertProvider := alertProvider.ToCustomAlertProvider(endpoint, endpointAlert, result, true)
			// TODO: retry on error
			_, err := customAlertProvider.Send(endpoint.Name, endpointAlert.GetDescription(), true)
			if err != nil {
				log.Printf("[watchdog][handleAlertsToResolve] Failed to send an alert for endpoint=%s: %s", endpoint.Name, err.Error())
			} else {
				if endpointAlert.Type == alert.TypePagerDuty {
					endpointAlert.ResolveKey = ""
				}
			}
		} else {
			log.Printf("[watchdog][handleAlertsToResolve] Not sending alert of type=%s despite being RESOLVED, because the provider wasn't configured properly", endpointAlert.Type)
		}
	}
	endpoint.NumberOfFailuresInARow = 0
}

type pagerDutyResponse struct {
	Status   string `json:"status"`
	Message  string `json:"message"`
	DedupKey string `json:"dedup_key"`
}