package wireguard

import (
	"context"
	"errors"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"

	"git.netcell-it.de/projekte/edgeguard-native/internal/models"
)

var ErrPeerNotFound = errors.New("wireguard peer not found")

type PeersRepo struct {
	Pool *pgxpool.Pool
}

func NewPeersRepo(pool *pgxpool.Pool) *PeersRepo { return &PeersRepo{Pool: pool} }

const peerBaseSelect = `
SELECT id, interface_id, name, public_key, private_key_enc, psk_enc,
       allowed_ips, keepalive, last_handshake, transfer_rx, transfer_tx,
       enabled, description, created_at, updated_at
FROM wireguard_peers
`

func (r *PeersRepo) ListForInterface(ctx context.Context, ifaceID int64) ([]models.WireguardPeer, error) {
	rows, err := r.Pool.Query(ctx, peerBaseSelect+" WHERE interface_id = $1 ORDER BY name ASC", ifaceID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.WireguardPeer, 0, 8)
	for rows.Next() {
		p, err := scanPeer(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *p)
	}
	return out, rows.Err()
}

func (r *PeersRepo) ListAll(ctx context.Context) ([]models.WireguardPeer, error) {
	rows, err := r.Pool.Query(ctx, peerBaseSelect+" ORDER BY interface_id, name ASC")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.WireguardPeer, 0, 16)
	for rows.Next() {
		p, err := scanPeer(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *p)
	}
	return out, rows.Err()
}

func (r *PeersRepo) Get(ctx context.Context, id int64) (*models.WireguardPeer, error) {
	row := r.Pool.QueryRow(ctx, peerBaseSelect+" WHERE id = $1", id)
	p, err := scanPeer(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrPeerNotFound
		}
		return nil, err
	}
	return p, nil
}

func (r *PeersRepo) Create(ctx context.Context, p models.WireguardPeer) (*models.WireguardPeer, error) {
	row := r.Pool.QueryRow(ctx, `
INSERT INTO wireguard_peers (
  interface_id, name, public_key, private_key_enc, psk_enc, allowed_ips,
  keepalive, enabled, description
) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9)
RETURNING id, interface_id, name, public_key, private_key_enc, psk_enc,
          allowed_ips, keepalive, last_handshake, transfer_rx, transfer_tx,
          enabled, description, created_at, updated_at`,
		p.InterfaceID, p.Name, p.PublicKey, p.PrivateKeyEnc, p.PSKEnc, p.AllowedIPs,
		p.Keepalive, p.Enabled, p.Description)
	return scanPeer(row)
}

func (r *PeersRepo) Update(ctx context.Context, id int64, p models.WireguardPeer) (*models.WireguardPeer, error) {
	row := r.Pool.QueryRow(ctx, `
UPDATE wireguard_peers SET
   name = $1, public_key = $2, private_key_enc = $3, psk_enc = $4,
   allowed_ips = $5, keepalive = $6, enabled = $7, description = $8,
   updated_at = NOW()
WHERE id = $9
RETURNING id, interface_id, name, public_key, private_key_enc, psk_enc,
          allowed_ips, keepalive, last_handshake, transfer_rx, transfer_tx,
          enabled, description, created_at, updated_at`,
		p.Name, p.PublicKey, p.PrivateKeyEnc, p.PSKEnc,
		p.AllowedIPs, p.Keepalive, p.Enabled, p.Description, id)
	out, err := scanPeer(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrPeerNotFound
		}
		return nil, err
	}
	return out, nil
}

func (r *PeersRepo) Delete(ctx context.Context, id int64) error {
	tag, err := r.Pool.Exec(ctx, `DELETE FROM wireguard_peers WHERE id = $1`, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrPeerNotFound
	}
	return nil
}

func scanPeer(row interface{ Scan(...any) error }) (*models.WireguardPeer, error) {
	var p models.WireguardPeer
	if err := row.Scan(
		&p.ID, &p.InterfaceID, &p.Name, &p.PublicKey, &p.PrivateKeyEnc, &p.PSKEnc,
		&p.AllowedIPs, &p.Keepalive, &p.LastHandshake, &p.TransferRX, &p.TransferTX,
		&p.Enabled, &p.Description, &p.CreatedAt, &p.UpdatedAt,
	); err != nil {
		return nil, err
	}
	p.HasPrivateKey = len(p.PrivateKeyEnc) > 0
	return &p, nil
}