package healthcheck

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

	"github.com/rs/zerolog"
	"go.uber.org/fx"
	"sneak.berlin/go/directory/internal/config"
	"sneak.berlin/go/directory/internal/database"
	"sneak.berlin/go/directory/internal/globals"
	"sneak.berlin/go/directory/internal/logger"
)

type HealthcheckParams struct {
	fx.In
	Globals  *globals.Globals
	Config   *config.Config
	Logger   *logger.Logger
	Database *database.Database
}

type Healthcheck struct {
	StartupTime time.Time
	log         *zerolog.Logger
	params      *HealthcheckParams
}

func New(lc fx.Lifecycle, params HealthcheckParams) (*Healthcheck, error) {
	s := new(Healthcheck)
	s.params = &params
	s.log = params.Logger.Get()

	lc.Append(fx.Hook{
		OnStart: func(ctx context.Context) error {
			s.StartupTime = time.Now()
			return nil
		},
		OnStop: func(ctx context.Context) error {
			// FIXME do server shutdown here
			return nil
		},
	})
	return s, nil
}

func (s *Healthcheck) uptime() time.Duration {
	return time.Since(s.StartupTime)
}

type HealthcheckResponse struct {
	Status        string `json:"status"`
	Now           string `json:"now"`
	UptimeSeconds int64  `json:"uptime_seconds"`
	UptimeHuman   string `json:"uptime_human"`
	Version       string `json:"version"`
	Appname       string `json:"appname"`
	Maintenance   bool   `json:"maintenance_mode"`
}

func (s *Healthcheck) Healthcheck() *HealthcheckResponse {

	resp := &HealthcheckResponse{
		Status:        "ok",
		Now:           time.Now().UTC().Format(time.RFC3339Nano),
		UptimeSeconds: int64(s.uptime().Seconds()),
		UptimeHuman:   s.uptime().String(),
		Appname:       s.params.Globals.Appname,
		Version:       s.params.Globals.Version,
	}
	return resp
}

func (s *Healthcheck) HealthcheckHandler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		resp := s.Healthcheck()
		w.Header().Set("Content-Type", "application/json; charset=utf-8")
		json.NewEncoder(w).Encode(resp)
	}
}