// Package ipaddresses implements CRUD against the `ip_addresses`
// table — addresses bound to operator-declared network interfaces,
// with is_vip + vip_priority for cluster-failover semantics.
package ipaddresses

import (
	"context"
	"errors"

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

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

var ErrNotFound = errors.New("ip address not found")

type Repo struct {
	Pool *pgxpool.Pool
}

func New(pool *pgxpool.Pool) *Repo { return &Repo{Pool: pool} }

const baseSelect = `
SELECT id, interface_id, address, prefix, is_vip, vip_priority,
       description, active, created_at, updated_at
FROM ip_addresses
`

func (r *Repo) List(ctx context.Context) ([]models.IPAddress, error) {
	rows, err := r.Pool.Query(ctx, baseSelect+" ORDER BY interface_id ASC, address ASC")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.IPAddress, 0, 8)
	for rows.Next() {
		a, err := scan(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *a)
	}
	return out, rows.Err()
}

func (r *Repo) ListForInterface(ctx context.Context, ifaceID int64) ([]models.IPAddress, error) {
	rows, err := r.Pool.Query(ctx, baseSelect+
		" WHERE interface_id = $1 ORDER BY address ASC", ifaceID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.IPAddress, 0, 4)
	for rows.Next() {
		a, err := scan(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *a)
	}
	return out, rows.Err()
}

func (r *Repo) Get(ctx context.Context, id int64) (*models.IPAddress, error) {
	row := r.Pool.QueryRow(ctx, baseSelect+" WHERE id = $1", id)
	a, err := scan(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return a, nil
}

func (r *Repo) Create(ctx context.Context, a models.IPAddress) (*models.IPAddress, error) {
	row := r.Pool.QueryRow(ctx, `
INSERT INTO ip_addresses (interface_id, address, prefix, is_vip, vip_priority, description, active)
VALUES ($1, $2, $3, $4, $5, $6, $7)
RETURNING id, interface_id, address, prefix, is_vip, vip_priority,
          description, active, created_at, updated_at`,
		a.InterfaceID, a.Address, a.Prefix, a.IsVIP, a.VIPPriority, a.Description, a.Active)
	return scan(row)
}

func (r *Repo) Update(ctx context.Context, id int64, a models.IPAddress) (*models.IPAddress, error) {
	row := r.Pool.QueryRow(ctx, `
UPDATE ip_addresses SET
   interface_id = $1, address = $2, prefix = $3,
   is_vip = $4, vip_priority = $5, description = $6, active = $7,
   updated_at = NOW()
WHERE id = $8
RETURNING id, interface_id, address, prefix, is_vip, vip_priority,
          description, active, created_at, updated_at`,
		a.InterfaceID, a.Address, a.Prefix, a.IsVIP, a.VIPPriority, a.Description, a.Active, id)
	out, err := scan(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return out, nil
}

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

func scan(row interface{ Scan(...any) error }) (*models.IPAddress, error) {
	var a models.IPAddress
	if err := row.Scan(
		&a.ID, &a.InterfaceID, &a.Address, &a.Prefix,
		&a.IsVIP, &a.VIPPriority,
		&a.Description, &a.Active,
		&a.CreatedAt, &a.UpdatedAt,
	); err != nil {
		return nil, err
	}
	return &a, nil
}