// Package networkifs implements CRUD against the
// `network_interfaces` table — operator-declared interfaces
// (ethernet, vlan, bond, bridge, wireguard).
package networkifs

import (
	"context"
	"encoding/json"
	"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("network interface not found")

type Repo struct {
	Pool *pgxpool.Pool
}

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

const baseSelect = `
SELECT id, name, type, parent, vlan_id, members, role, mtu, active, description,
       created_at, updated_at
FROM network_interfaces
`

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

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

func (r *Repo) Create(ctx context.Context, i models.NetworkInterface) (*models.NetworkInterface, error) {
	row := r.Pool.QueryRow(ctx, `
INSERT INTO network_interfaces (name, type, parent, vlan_id, members, role, mtu, active, description)
VALUES ($1, $2, $3, $4, $5::jsonb, $6, $7, $8, $9)
RETURNING id, name, type, parent, vlan_id, members, role, mtu, active, description,
          created_at, updated_at`,
		i.Name, i.Type, i.Parent, i.VLANID, membersJSON(i.Members), i.Role, i.MTU, i.Active, i.Description)
	return scan(row)
}

func (r *Repo) Update(ctx context.Context, id int64, i models.NetworkInterface) (*models.NetworkInterface, error) {
	row := r.Pool.QueryRow(ctx, `
UPDATE network_interfaces SET
   name = $1, type = $2, parent = $3, vlan_id = $4, members = $5::jsonb,
   role = $6, mtu = $7, active = $8, description = $9,
   updated_at = NOW()
WHERE id = $10
RETURNING id, name, type, parent, vlan_id, members, role, mtu, active, description,
          created_at, updated_at`,
		i.Name, i.Type, i.Parent, i.VLANID, membersJSON(i.Members), i.Role, i.MTU, i.Active, i.Description, 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 network_interfaces WHERE id = $1`, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// membersJSON normalises a Go slice into a JSON array literal that
// Postgres can cast to JSONB. nil → "[]" so the NOT NULL constraint
// always holds.
func membersJSON(m []string) string {
	if m == nil {
		return "[]"
	}
	b, _ := json.Marshal(m)
	return string(b)
}

func scan(row interface{ Scan(...any) error }) (*models.NetworkInterface, error) {
	var (
		i   models.NetworkInterface
		raw []byte
	)
	if err := row.Scan(
		&i.ID, &i.Name, &i.Type, &i.Parent, &i.VLANID, &raw,
		&i.Role, &i.MTU, &i.Active, &i.Description,
		&i.CreatedAt, &i.UpdatedAt,
	); err != nil {
		return nil, err
	}
	if len(raw) > 0 {
		if err := json.Unmarshal(raw, &i.Members); err != nil {
			return nil, err
		}
	}
	if i.Members == nil {
		i.Members = []string{}
	}
	return &i, nil
}