// Copyright © 2023 Ory Corp
// SPDX-License-Identifier: Apache-2.0

package courier

import (
	"context"
	"net/http"

	"github.com/spf13/cobra"
	"github.com/urfave/negroni"
	"golang.org/x/sync/errgroup"

	"github.com/ory/graceful"
	"github.com/ory/kratos/driver"
	"github.com/ory/x/configx"
	"github.com/ory/x/prometheusx"
	"github.com/ory/x/reqlog"
)

func NewWatchCmd(dOpts []driver.RegistryOption) *cobra.Command {
	c := &cobra.Command{
		Use:   "watch",
		Short: "Starts the Ory Kratos message courier",
		RunE: func(cmd *cobra.Command, args []string) error {
			r, err := driver.New(cmd.Context(), cmd.ErrOrStderr(), append(dOpts, driver.WithConfigOptions(configx.WithFlags(cmd.Flags())))...)
			if err != nil {
				return err
			}

			return StartCourier(cmd.Context(), r)
		},
	}
	c.PersistentFlags().Int("expose-metrics-port", 0, "The port to expose the metrics endpoint on (not exposed by default)")
	return c
}

func StartCourier(ctx context.Context, r driver.Registry) error {
	eg, ctx := errgroup.WithContext(ctx)

	if port := r.Config().CourierExposeMetricsPort(ctx); port != 0 {
		eg.Go(func() error {
			return ServeMetrics(ctx, r, port)
		})
	}

	eg.Go(func() error {
		return Watch(ctx, r)
	})

	return eg.Wait()
}

func ServeMetrics(ctx context.Context, r driver.Registry, port int) error {
	cfg := r.Config().ServeAdmin(ctx)
	l := r.Logger()

	recovery := negroni.NewRecovery()
	recovery.Logger = l

	n := negroni.New(
		recovery,
		reqlog.NewMiddlewareFromLogger(l, "admin#"+cfg.BaseURL.String()),
	)

	router := http.NewServeMux()
	router.Handle(prometheusx.MetricsPrometheusPath, prometheusx.Handler())
	n.UseHandler(router)

	var handler http.Handler = n

	//#nosec G112 -- the correct settings are set by graceful.WithDefaults
	server := graceful.WithDefaults(&http.Server{
		Addr:    configx.GetAddress(cfg.Host, port),
		Handler: handler,
	})

	l.WithField("addr", server.Addr).Info("Starting the metrics httpd")
	if err := graceful.GracefulContext(ctx, server.ListenAndServe, server.Shutdown); err != nil {
		l.Errorln("Failed to gracefully shutdown metrics httpd")
		return err
	}
	l.Println("Metrics httpd was shutdown gracefully")
	return nil
}

func Watch(ctx context.Context, r driver.Registry) error {
	ctx, cancel := context.WithCancel(ctx)

	r.Logger().Println("Courier worker started.")
	if err := graceful.Graceful(func() error {
		c, err := r.Courier(ctx)
		if err != nil {
			return err
		}

		return c.Work(ctx)
	}, func(_ context.Context) error {
		cancel()
		return nil
	}); err != nil {
		r.Logger().WithError(err).Error("Failed to run courier worker.")
		return err
	}

	r.Logger().Println("Courier worker was shutdown gracefully.")
	return nil
}