// SPDX-License-Identifier: GPL-2.0-only
// Copyright (C) 2020 Michael Crute <mike@crute.us>. All rights reserved.
//
// Use of this source code is governed by a license that can be found in the
// LICENSE file.

package six

import (
	"net"
	"time"
)

// IP protocol version number
type IPVersion int

const (
	IPv6 IPVersion = 6
	IPv4           = 4
)

// IPv4 and IPv6 union type, contains a full network for IPv4 and IPv6
// addresses
type Addresses struct {
	IPv4 *net.IPNet
	IPv6 *net.IPNet
}

// IRR statistical data. Contains the counts of various IRR data for a
// participant.
type IRRData struct {
	PrefixCount int
	ASNCount    int
	ASSetCount  int
}

// Set of prefixes, optionally with an AS-SET name that a participant has
// registered with the exchange.
type PrefixSet struct {
	Timestamp time.Time
	ASSet     *string
	Prefixes  []net.IPNet
}

// Set of AS numbers with an AS-SET that the participant has registered with
// the exchange.
type ASSet struct {
	Timestamp time.Time
	Name      string
	ASNumbers []int
}

// Set of ROA record summaries that have been parsed from the raw ROA data for
// a participant.
type ROASet struct {
	Timestamp time.Time
	ROAS      []ROA
}

// Individual ROA summary
type ROA struct {
	TrustAnchor string
	ASN         int
	MaxLength   int
	Prefix      net.IPNet
}

// A SIX participant is a record of an organization's connection to the Seattle
// Internet Exchange. It contains information about their connect, the prefixes
// and ASes that they have registered with the exchange, and their usage of the
// route server.
//
// Not all data exists for all participants, and the data that does exist isn't
// always in a nice clean format. The parsers attempt to make sense of whatever
// is available but some data may be missing or inconsistent.
//
// The default contains summary data for the participant and more detailed data
// can be fetched with the methods attached to this struct as well as to the
// RouteServer structs, if the participant is using the route server.
type SIXParticipant struct {
	Organization           string
	URL                    string
	ASN                    int
	Speed                  int    // Connection speed in Mbit/s
	Switch                 string // Connected Switch or Location
	Contact                string // Contact Email
	Comment                string
	IsConnected            bool
	IsVoter                bool
	Update                 *time.Time
	Options                []string // Currently: IPv6 and MTU9k
	PeeringPolicy          string
	ROACount               int
	PeeringDBPrefixCountv4 int
	PeeringDBPrefixCountv6 int
	Addresses              Addresses
	JumboAddresses         *Addresses
	IRRv4                  IRRData
	IRRv6                  IRRData
	RouteServer2           *RouteServer
	RouteServer3           *RouteServer
}

// Get the set of prefixes that the participant has registered.
//
// This does an HTTP fetch to get the detailed file.
func (p *SIXParticipant) GetPrefixes(ip IPVersion) (*PrefixSet, error) {
	return fetchParsePrefixList(p.ASN, ip, false)
}

// Get the prefix to AS associations that the participant has registered.
//
// This does an HTTP fetch to get the detailed file.
func (p *SIXParticipant) GetASPrefixes(ip IPVersion) (*PrefixSet, error) {
	return fetchParsePrefixList(p.ASN, ip, true)
}

// Get the AS sets that the participant has registered
//
// This does an HTTP fetch to get the detailed file.
func (p *SIXParticipant) GetASSet(ip IPVersion) (*ASSet, error) {
	return fetchParseASSet(p.ASN, ip)
}

// Get the ROA set and more detailed records for the ROAs that the participant
// has registered. This does not fetch the raw ROAs, just the summary that the
// exchange has computed.
//
// This does an HTTP fetch to get the detailed file.
func (p *SIXParticipant) GetROASet() (*ROASet, error) {
	return fetchParseROAFile(p.ASN)
}

// List of lines from the file containing route data dumped from the route
// server
type RouteFile struct {
	Timestamp time.Time
	Lines     []string
}

// Lists of errors that the route server has exported. These are parsed for
// more details if possible, but if that fails the attached ErrorRecords object
// contains a list of un-parsable lines for consumption.
type Errors struct {
	IPv4      *ErrorRecords
	IPv6      *ErrorRecords
	IPv4Jumbo *ErrorRecords
	IPv6Jumbo *ErrorRecords
}

// List of error records for route server errors. Also contains a list of lines
// that could not be parsed by the parser.
type ErrorRecords struct {
	Records         []ErrorRecord
	UnparsableLines []string
}

// Create a new ErrorRecords struct
func NewErrorRecords() *ErrorRecords {
	return &ErrorRecords{
		Records:         []ErrorRecord{},
		UnparsableLines: []string{},
	}
}

// Contains the parsed data for a route server error.
type ErrorRecord struct {
	Timestamp   time.Time
	ASN         int
	MTU         int
	Version     IPVersion
	NetworkName string
	Network     net.IPNet
	Router      net.IP
	Path        []int
	Message     string
}

// Data about the participant's connection to a route server. If the
// participant is making use of the route servers this will always contain some
// basic statistics about their connection. More detailed information can be
// obtained by calling the methods attached to this struct.
type RouteServer struct {
	Number    int
	IPv4      RouteServerStats
	IPv6      RouteServerStats
	IPv4Jumbo RouteServerStats
	IPv6Jumbo RouteServerStats
	asn       int
}

// Route server statistics. Contains the counts of various types of route
// server entries.
type RouteServerStats struct {
	Prefixes      int
	Errors        int
	TransitErrors int
}

// Gets the list of routes being advertised by the participant. Note that this
// file is the raw lines from the route server and no attempt has been made to
// parse these lines. The lines are in BIRD format.
//
// This does an HTTP fetch to get the detailed file.
func (s *RouteServer) GetRoutes(ip IPVersion, jumbo bool) (*RouteFile, error) {
	return fetchParseRoutes(s.Number, s.asn, ip, jumbo)
}

// Gets the errors returned by the route server for all IP protocols and all
// VLANs to which the participant is connected. If the participant is using
// multiple route servers, this data is scoped to the current route server.
//
// This does an HTTP fetch to get the detailed file.
func (s *RouteServer) GetErrors() (*Errors, error) {
	return fetchParseRSErrors(s.Number, s.asn, false), nil
}

// Get a list of transit errors from the route server. Otherwise return value
// and behavior is identical to GetErrors.
//
// This does an HTTP fetch to get the detailed file.
func (s *RouteServer) GetTransitErrors() (*Errors, error) {
	return fetchParseRSErrors(s.Number, s.asn, true), nil
}