package main

import (
	"context"
	"flag"
	"fmt"
	"sync"
	"time"

	pb "code.hackerspace.pl/hscloud/bgpwtf/cccampix/proto"
	"code.hackerspace.pl/hscloud/bgpwtf/cccampix/verifier/model"
	"code.hackerspace.pl/hscloud/go/mirko"
	"code.hackerspace.pl/hscloud/go/pki"
	"code.hackerspace.pl/hscloud/go/statusz"
	"github.com/golang/glog"
	"github.com/lib/pq"
	"golang.org/x/net/trace"
	"google.golang.org/grpc"
)

type processorState struct {
	name    string
	p       processor
	lastRun *time.Time
	lastErr error
}

type routerState struct {
	name    string
	last    *time.Time
	version string
}

func (p *processorState) nextRun() *time.Time {
	if p.lastRun == nil {
		return nil
	}
	nr := p.p.NextRun(*p.lastRun, p.lastErr != nil)
	return &nr
}

type service struct {
	model model.Model

	processors   map[string]*processorState
	processorsMu sync.RWMutex

	routers            map[string]*routerState
	routersLastVersion string
	routersMu          sync.RWMutex

	requiredChecks []string

	pgp pb.PGPEncryptorClient
}

func (s *service) run(ctx context.Context) {
	t := time.NewTicker(time.Second)
	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			break
		}

		s.runProcessors(ctx)
	}
}

func (s *service) runProcessors(ctx context.Context) {
	s.processorsMu.RLock()
	defer s.processorsMu.RUnlock()

	now := time.Now()

	for _, p := range s.processors {
		nr := p.nextRun()
		if nr == nil || nr.Before(now) {
			glog.Infof("Running processor %q...", p.name)
			start := time.Now()

			tr := trace.New(fmt.Sprintf("processor.%s", p.name), "Run")
			pctx := trace.NewContext(ctx, tr)
			err := p.p.RunAll(pctx, s.model)
			tr.LazyPrintf("Processor done: %v", err)
			tr.Finish()

			if err != nil {
				glog.Errorf("Running processor %q failed: %v", p.name, err)
			} else {
				diff := time.Since(start)
				tr.LazyPrintf("Took %s", diff.String())
				glog.Infof("Processor %q took %s", p.name, diff.String())
			}
			p.lastErr = err
			p.lastRun = &now
		}
	}
}

var (
	flagDSN          string
	flagIRR          string
	flagOctoRPKI     string
	flagPGPEncryptor string
	flagPeeringDB    string
)

func main() {
	flag.StringVar(&flagDSN, "dsn", "", "PostrgreSQL connection string")
	flag.StringVar(&flagIRR, "irr", "", "Address of irr service")
	flag.StringVar(&flagOctoRPKI, "octorpki", "", "Address of octorpki service")
	flag.StringVar(&flagPGPEncryptor, "pgpencryptor", "", "Address of pgpencryptor service")
	flag.StringVar(&flagPeeringDB, "peeringdb", "", "Address of peeringdb service")
	flag.Parse()

	// Picking an existing postgres-like driver for sqlx.BindType to work
	// See: https://github.com/jmoiron/sqlx/blob/ed7c52c43ee1e12a35efbcfea8dbae2d62a90370/bind.go#L24
	mirko.TraceSQL(&pq.Driver{}, "pgx")
	mi := mirko.New()

	m, err := model.Connect(mi.Context(), "pgx", flagDSN)
	if err != nil {
		glog.Exitf("Failed to create model: %v", err)
	}

	err = m.MigrateUp()
	if err != nil {
		glog.Exitf("Failed to migrate up: %v", err)
	}

	if err := mi.Listen(); err != nil {
		glog.Exitf("Listen failed: %v", err)
	}

	conn, err := grpc.Dial(flagPGPEncryptor, pki.WithClientHSPKI())
	if err != nil {
		glog.Exitf("could not connect to pgpencryptor service: %v", err)
	}

	s := &service{
		model:          m,
		processors:     make(map[string]*processorState),
		requiredChecks: []string{"irr", "pgp"},
		routers:        make(map[string]*routerState),
		pgp:            pb.NewPGPEncryptorClient(conn),
	}

	must := func(p processor, err error) processor {
		if err != nil {
			panic(err)
		}
		return p
	}
	s.addProcessor(must(newPeeringDB(flagPeeringDB)))
	s.addProcessor(must(newIRR(flagIRR)))
	s.addProcessor(must(newSecretGen()))
	s.addProcessor(must(newRPKI(flagOctoRPKI)))
	s.addProcessor(must(newPGP(s.pgp)))
	statusz.AddStatusPart("Processors", processorsFragment, s.statuszProcessors)

	go s.run(mi.Context())

	pb.RegisterVerifierServer(mi.GRPC(), s)

	if err := mi.Serve(); err != nil {
		glog.Exitf("Serve failed: %v", err)
	}

	<-mi.Done()
}

func (s *service) addProcessor(p processor) {
	s.processorsMu.Lock()
	defer s.processorsMu.Unlock()

	name := p.Name()
	if _, ok := s.processors[name]; ok {
		panic(fmt.Sprintf("duplicated processor %q", name))
	}
	s.processors[name] = &processorState{
		name:    name,
		p:       p,
		lastRun: nil,
	}
}