package firewall

import (
	"context"
	"errors"

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

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

var ErrNATRuleNotFound = errors.New("nat rule not found")

type NATRulesRepo struct {
	Pool *pgxpool.Pool
}

func NewNATRulesRepo(pool *pgxpool.Pool) *NATRulesRepo { return &NATRulesRepo{Pool: pool} }

const natRuleBaseSelect = `
SELECT id, name, priority, enabled, kind,
       in_zone, out_zone, proto,
       match_src_cidr, match_dst_cidr, match_dport_start, match_dport_end,
       target_addr, target_port_start, target_port_end,
       comment, created_at, updated_at
FROM firewall_nat_rules
`

func (r *NATRulesRepo) List(ctx context.Context) ([]models.FirewallNATRule, error) {
	rows, err := r.Pool.Query(ctx, natRuleBaseSelect+" ORDER BY priority DESC, id ASC")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.FirewallNATRule, 0, 8)
	for rows.Next() {
		x, err := scanNATRule(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *x)
	}
	return out, rows.Err()
}

func (r *NATRulesRepo) Get(ctx context.Context, id int64) (*models.FirewallNATRule, error) {
	row := r.Pool.QueryRow(ctx, natRuleBaseSelect+" WHERE id = $1", id)
	x, err := scanNATRule(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNATRuleNotFound
		}
		return nil, err
	}
	return x, nil
}

func (r *NATRulesRepo) Create(ctx context.Context, x models.FirewallNATRule) (*models.FirewallNATRule, error) {
	row := r.Pool.QueryRow(ctx, `
INSERT INTO firewall_nat_rules (
    name, priority, enabled, kind,
    in_zone, out_zone, proto,
    match_src_cidr, match_dst_cidr, match_dport_start, match_dport_end,
    target_addr, target_port_start, target_port_end,
    comment
) VALUES (
    $1, $2, $3, $4,
    $5, $6, $7,
    $8, $9, $10, $11,
    $12, $13, $14,
    $15
)
RETURNING id, name, priority, enabled, kind,
          in_zone, out_zone, proto,
          match_src_cidr, match_dst_cidr, match_dport_start, match_dport_end,
          target_addr, target_port_start, target_port_end,
          comment, created_at, updated_at`,
		x.Name, x.Priority, x.Enabled, x.Kind,
		x.InZone, x.OutZone, x.Proto,
		x.MatchSrcCIDR, x.MatchDstCIDR, x.MatchDPortStart, x.MatchDPortEnd,
		x.TargetAddr, x.TargetPortStart, x.TargetPortEnd,
		x.Comment)
	return scanNATRule(row)
}

func (r *NATRulesRepo) Update(ctx context.Context, id int64, x models.FirewallNATRule) (*models.FirewallNATRule, error) {
	row := r.Pool.QueryRow(ctx, `
UPDATE firewall_nat_rules SET
   name = $1, priority = $2, enabled = $3, kind = $4,
   in_zone = $5, out_zone = $6, proto = $7,
   match_src_cidr = $8, match_dst_cidr = $9, match_dport_start = $10, match_dport_end = $11,
   target_addr = $12, target_port_start = $13, target_port_end = $14,
   comment = $15, updated_at = NOW()
WHERE id = $16
RETURNING id, name, priority, enabled, kind,
          in_zone, out_zone, proto,
          match_src_cidr, match_dst_cidr, match_dport_start, match_dport_end,
          target_addr, target_port_start, target_port_end,
          comment, created_at, updated_at`,
		x.Name, x.Priority, x.Enabled, x.Kind,
		x.InZone, x.OutZone, x.Proto,
		x.MatchSrcCIDR, x.MatchDstCIDR, x.MatchDPortStart, x.MatchDPortEnd,
		x.TargetAddr, x.TargetPortStart, x.TargetPortEnd,
		x.Comment, id)
	out, err := scanNATRule(row)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNATRuleNotFound
		}
		return nil, err
	}
	return out, nil
}

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

func scanNATRule(row interface{ Scan(...any) error }) (*models.FirewallNATRule, error) {
	var x models.FirewallNATRule
	if err := row.Scan(
		&x.ID, &x.Name, &x.Priority, &x.Enabled, &x.Kind,
		&x.InZone, &x.OutZone, &x.Proto,
		&x.MatchSrcCIDR, &x.MatchDstCIDR, &x.MatchDPortStart, &x.MatchDPortEnd,
		&x.TargetAddr, &x.TargetPortStart, &x.TargetPortEnd,
		&x.Comment, &x.CreatedAt, &x.UpdatedAt,
	); err != nil {
		return nil, err
	}
	return &x, nil
}