// Package domainheaders implements CRUD against the
// `domain_response_headers` table. Pro-Domain Response-Header die
// HAProxy via `http-response set-header` setzt.
package domainheaders

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("domain response header not found")

type Repo struct {
	Pool *pgxpool.Pool
}

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

const baseSelect = `
SELECT id, domain_id, name, value, position, created_at, updated_at
FROM domain_response_headers
`

// ListForDomain liefert alle Header einer Domain in stabiler Position-Sortierung.
func (r *Repo) ListForDomain(ctx context.Context, domainID int64) ([]models.DomainResponseHeader, error) {
	rows, err := r.Pool.Query(ctx,
		baseSelect+` WHERE domain_id = $1 ORDER BY position ASC, id ASC`, domainID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.DomainResponseHeader, 0, 4)
	for rows.Next() {
		h, err := scan(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *h)
	}
	return out, rows.Err()
}

// ListAll holt alle Header (über alle Domains) — der HAProxy-Renderer
// braucht das, um pro Domain die Einträge zu gruppieren.
func (r *Repo) ListAll(ctx context.Context) ([]models.DomainResponseHeader, error) {
	rows, err := r.Pool.Query(ctx, baseSelect+` ORDER BY domain_id, position, id`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := make([]models.DomainResponseHeader, 0, 16)
	for rows.Next() {
		h, err := scan(rows)
		if err != nil {
			return nil, err
		}
		out = append(out, *h)
	}
	return out, rows.Err()
}

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

func (r *Repo) Create(ctx context.Context, h models.DomainResponseHeader) (*models.DomainResponseHeader, error) {
	row := r.Pool.QueryRow(ctx, `
INSERT INTO domain_response_headers (domain_id, name, value, position)
VALUES ($1, $2, $3, $4)
RETURNING id, domain_id, name, value, position, created_at, updated_at`,
		h.DomainID, h.Name, h.Value, h.Position)
	return scan(row)
}

func (r *Repo) Update(ctx context.Context, id int64, h models.DomainResponseHeader) (*models.DomainResponseHeader, error) {
	row := r.Pool.QueryRow(ctx, `
UPDATE domain_response_headers SET
   name = $1, value = $2, position = $3, updated_at = NOW()
WHERE id = $4
RETURNING id, domain_id, name, value, position, created_at, updated_at`,
		h.Name, h.Value, h.Position, 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 domain_response_headers 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.DomainResponseHeader, error) {
	var h models.DomainResponseHeader
	if err := row.Scan(
		&h.ID, &h.DomainID, &h.Name, &h.Value, &h.Position,
		&h.CreatedAt, &h.UpdatedAt,
	); err != nil {
		return nil, err
	}
	return &h, nil
}