package server

import (
	"encoding/json"
	"fmt"
	"log/slog"
	"net/http"
	"strings"
	"time"

	"git.t-juice.club/torjus/alerttonotify/bus"
)

type Server struct {
	logger *slog.Logger
	nbus   *bus.NotifyBus
	http.Server
}

type Alert struct {
	Status       string            `json:"status"`
	Labels       map[string]string `json:"labels"`
	Annotations  map[string]string `json:"annotations"`
	StartsAt     time.Time         `json:"startsAt"`
	EndsAt       time.Time         `json:"endsAt"`
	GeneratorURL string            `json:"generatorURL"`
	Fingerprint  string            `json:"fingerprint"`
}
type AlertMessage struct {
	Version           string            `json:"version"`
	GroupKey          string            `json:"groupKey"`
	TruncatedAlerts   int               `json:"truncatedAlerts"`
	Status            string            `json:"status"`
	Receiver          string            `json:"receiver"`
	GroupLabels       map[string]string `json:"groupLabels"`
	CommonLabels      map[string]string `json:"commonLabels"`
	CommonAnnotations map[string]string `json:"commonAnnotations"`
	ExternalURL       string            `json:"externalURL"`
	Alerts            []Alert           `json:"alerts"`
}

func NewServer(nbus *bus.NotifyBus, logger *slog.Logger) *Server {
	srv := &Server{
		nbus:   nbus,
		logger: logger,
	}

	mux := http.NewServeMux()
	mux.HandleFunc("GET /", srv.handleIndex)
	mux.HandleFunc("POST /alert", srv.handleAlert)

	srv.Handler = mux

	return srv
}

func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
	s.logger.Info("index page")
	w.Write([]byte("Hello!"))
}

func (s *Server) handleAlert(w http.ResponseWriter, r *http.Request) {
	s.logger.Debug("Got new alert", "remoteAddr", r.RemoteAddr)

	decoder := json.NewDecoder(r.Body)
	var alertMessage AlertMessage
	if err := decoder.Decode(&alertMessage); err != nil {
		s.logger.Error("Failed to decode alert message", "error", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	s.logger.Debug("Decoded alert message", "alert", alertMessage)

	s.logger.Info("Incoming message", "status", alertMessage.Status)
	var sb strings.Builder
	for _, alert := range alertMessage.Alerts {
		s.logger.Debug("Incoming alert", "status", alert.Status, "fingerprint", alert.Fingerprint)
		if summary, ok := alert.Annotations["summary"]; ok {
			sb.WriteString(fmt.Sprintf("[%s] %s\n", strings.ToUpper(alert.Status), summary))
		} else {
			sb.WriteString(fmt.Sprintf("[%s]: %s\n", strings.ToUpper(alert.Status), alert.Fingerprint))
		}
	}

	notification := bus.BusNotification{
		Summary: fmt.Sprintf("%d alerts %s", len(alertMessage.Alerts), alertMessage.Status),
		Body:    sb.String(),
	}
	s.logger.Debug("Sending notification", "notification", notification)
	s.nbus.Notify(notification)
}