package stats

import (
	"context"
	"strings"
	"time"

	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
)

type SourceIdentity struct {
	Protocol       envelope.Protocol
	SourceIP       string
	SourceEndpoint string
}

func NewSourceIdentity(protocol envelope.Protocol, endpoint string) (SourceIdentity, bool) {
	sourceIP := NormalizeSourceIP(endpoint)
	if sourceIP == "" {
		return SourceIdentity{}, false
	}
	return SourceIdentity{
		Protocol:       protocol,
		SourceIP:       sourceIP,
		SourceEndpoint: strings.TrimSpace(endpoint),
	}, true
}

func NormalizeSourceIP(endpoint string) string {
	endpoint = strings.TrimSpace(endpoint)
	if endpoint == "" {
		return ""
	}
	if host, _, ok := strings.Cut(endpoint, ":"); ok {
		return strings.TrimSpace(host)
	}
	return endpoint
}

func UpsertDataSource(ctx context.Context, exec Execer, identity SourceIdentity, now time.Time) error {
	if exec == nil {
		panic("stats execer must not be nil")
	}
	if identity.SourceIP == "" {
		return nil
	}
	if now.IsZero() {
		now = time.Now()
	}
	_, err := exec.ExecContext(ctx, upsertDataSourceSQL,
		string(identity.Protocol),
		identity.SourceIP,
		identity.SourceEndpoint,
		now,
		now,
	)
	return err
}

const upsertDataSourceSQL = `
INSERT INTO vehicle_data_source
  (protocol, source_ip, latest_source_endpoint, first_seen_at, latest_seen_at)
VALUES (?, ?, ?, ?, ?)
ON DUPLICATE KEY UPDATE
  latest_source_endpoint = VALUES(latest_source_endpoint),
  latest_seen_at = VALUES(latest_seen_at),
  updated_at = CURRENT_TIMESTAMP
`