package db

import (
	"context"
	"database/sql"
	"errors"
)

type SSHKey struct {
	ID          int64
	UserID      int64
	Name        string
	PublicKey   string
	Fingerprint string
	CreatedAt   string
}

func (d *DB) ListSSHKeys(ctx context.Context, userID int64) ([]SSHKey, error) {
	rows, err := d.QueryContext(ctx,
		`SELECT id, user_id, name, public_key, fingerprint, created_at
		 FROM ssh_keys WHERE user_id = ?`, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []SSHKey
	for rows.Next() {
		var k SSHKey
		if err := rows.Scan(&k.ID, &k.UserID, &k.Name, &k.PublicKey, &k.Fingerprint, &k.CreatedAt); err != nil {
			return nil, err
		}
		out = append(out, k)
	}
	return out, rows.Err()
}

func (d *DB) CreateSSHKey(ctx context.Context, userID int64, name, publicKey, fingerprint, createdAt string) error {
	_, err := d.ExecContext(ctx,
		`INSERT INTO ssh_keys (user_id, name, public_key, fingerprint, created_at)
		 VALUES (?, ?, ?, ?, ?)`,
		userID, name, publicKey, fingerprint, createdAt)
	return err
}

// SSHKeyOwner returns the id and user of one key, used to check ownership
// before a delete.
func (d *DB) SSHKeyOwner(ctx context.Context, id int64) (int64, bool, error) {
	var userID int64
	err := d.QueryRowContext(ctx, `SELECT user_id FROM ssh_keys WHERE id = ?`, id).Scan(&userID)
	if errors.Is(err, sql.ErrNoRows) {
		return 0, false, nil
	}
	if err != nil {
		return 0, false, err
	}
	return userID, true, nil
}

func (d *DB) DeleteSSHKey(ctx context.Context, id int64) error {
	_, err := d.ExecContext(ctx, `DELETE FROM ssh_keys WHERE id = ?`, id)
	return err
}

// SSHKeyUser is the identity behind an SSH public key offered at login.
type SSHKeyUser struct {
	UserID    int64
	Username  string
	PublicKey string
}

// SSHKeyByFingerprint resolves an SSH key to its (non-pending) owner.
func (d *DB) SSHKeyByFingerprint(ctx context.Context, fingerprint string) (*SSHKeyUser, error) {
	var k SSHKeyUser
	err := d.QueryRowContext(ctx,
		`SELECT users.id, users.username, ssh_keys.public_key
		 FROM ssh_keys
		 JOIN users ON users.id = ssh_keys.user_id
		 WHERE ssh_keys.fingerprint = ? AND users.is_pending = 0`,
		fingerprint).Scan(&k.UserID, &k.Username, &k.PublicKey)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return &k, nil
}