package kuknos

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"gl/domain/ledger"
)

// Submitter sends a pre-signed Stellar/Kuknos transaction to Horizon. Signing
// remains outside GL; GL owns durable admission, retry, and reconciliation.
type Submitter struct {
	Endpoint string
	Client   *http.Client
}

func (s Submitter) Submit(ctx context.Context, record ledger.Settlement) (string, error) {
	if s.Endpoint == "" || record.SignedTransactionXDR == "" {
		return "", fmt.Errorf("kuknos submission endpoint and signed xdr are required")
	}
	form := url.Values{"tx": {record.SignedTransactionXDR}}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, strings.TrimRight(s.Endpoint, "/")+"/transactions", strings.NewReader(form.Encode()))
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	client := s.Client
	if client == nil {
		client = http.DefaultClient
	}
	resp, err := client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	var body struct {
		Hash   string `json:"hash"`
		Extras struct {
			ResultCodes struct {
				Transaction string `json:"transaction"`
			} `json:"result_codes"`
		} `json:"extras"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
		return "", fmt.Errorf("decode kuknos response: %w", err)
	}
	if resp.StatusCode < 200 || resp.StatusCode >= 300 || body.Hash == "" {
		return "", fmt.Errorf("kuknos rejected transaction: status=%d code=%s", resp.StatusCode, body.Extras.ResultCodes.Transaction)
	}
	return body.Hash, nil
}