package model

import (
	"context"
	"fmt"
	"net"
	"strings"
	"time"

	pb "code.hackerspace.pl/hscloud/bgpwtf/cccampix/proto"
	"code.hackerspace.pl/hscloud/bgpwtf/cccampix/verifier/model/migrations"
	migrate "github.com/golang-migrate/migrate/v4"
	_ "github.com/golang-migrate/migrate/v4/database/cockroachdb"
	"github.com/jmoiron/sqlx"
	_ "github.com/lib/pq"
)

type Model interface {
	MigrateUp() error

	RecordPeeringDBPeers(ctx context.Context, members []*pb.PeeringDBMember) error
	RecordPeeringDBPeerRouters(ctx context.Context, members []*pb.PeeringDBMember) error
	GetPeeringDBPeer(ctx context.Context, asn int64) (*pb.PeeringDBMember, error)

	GetCheckablePeers(ctx context.Context) ([]*Peer, error)
	SubmitPeerCheckResults(ctx context.Context, checkName string, res []*PeerCheckResult) error
	GetPeerCheckResults(ctx context.Context, asn []int64) ([]*PeerCheckResult, error)

	UpdatePGPKey(ctx context.Context, key *PeerPGPKey) error
	GetPGPKeysRequiringAttention(ctx context.Context) ([]*PeerPGPKey, error)
	ValidatePGPKeys(ctx context.Context, positive, negative []string) error
	GetPeerPGPKey(ctx context.Context, asn int64) (*PeerPGPKey, error)

	ConfigureMissingSessions(ctx context.Context, gen func() SessionConfig) error

	GetPeerConfiguration(ctx context.Context) ([]*PeerConfiguration, error)

	UpdateAllowedPrefixes(ctx context.Context, asn int64, prefixes []*AllowedPrefix) error
	GetAllowedPrefixes(ctx context.Context, asn int64) ([]*AllowedPrefix, error)
}

type Router struct {
	V6     net.IP
	V4     net.IP
	Config *SessionConfig
}

func (p *Router) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type Peer struct {
	ASN     int64
	Name    string
	Routers []*Router
}

func (p *Peer) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type PeerCheckStatus int

const (
	PeerCheckStatus_Invalid PeerCheckStatus = iota
	PeerCheckStatus_Okay
	PeerCheckStatus_Failed
	PeerCheckStatus_SoftFailed
)

type PeerCheckResult struct {
	PeerASN   int64
	CheckName string
	Time      time.Time
	Status    PeerCheckStatus
	Message   string
}

func (p *PeerCheckResult) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type PeerPGPKey struct {
	PeerASN     int64
	Fingerprint string
	State       string
}

func (p *PeerPGPKey) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type SessionConfig struct {
	BGPSecret string
}

func (p *SessionConfig) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type PeerConfiguration struct {
	Peer Peer
	Key  PeerPGPKey
}

func (p *PeerConfiguration) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type AllowedPrefix struct {
	Prefix    net.IPNet
	MaxLength int64
	TA        string
}

func (p *AllowedPrefix) String() string {
	if p == nil {
		return "<nil>"
	}
	return fmt.Sprintf("%+v", *p)
}

type sqlModel struct {
	db  *sqlx.DB
	dsn string
}

func Connect(ctx context.Context, driver, dsn string) (Model, error) {
	if dsn == "" {
		return nil, fmt.Errorf("dsn cannot be empty")
	}

	db, err := sqlx.ConnectContext(ctx, driver, dsn)
	if err != nil {
		return nil, fmt.Errorf("could not connect to database: %v", err)
	}

	return &sqlModel{
		db:  db,
		dsn: dsn,
	}, nil
}

func (m *sqlModel) MigrateUp() error {
	dsn := "cockroach://" + strings.TrimPrefix(m.dsn, "postgres://")
	mig, err := migrations.New(dsn)
	if err != nil {
		return err
	}
	err = mig.Up()
	switch err {
	case migrate.ErrNoChange:
		return nil
	default:
		return err
	}
}