External services (QRZ/Clublog/LoTW) + QSL Manager

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/extsvc/lotw.go

@@ -4,6 +4,9 @@ import (
 	"context"
 	"encoding/xml"
 	"fmt"
+	"io"
+	"net/http"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -11,6 +14,60 @@ import (
 	"time"
 )
 
+// lotwReportURL is LoTW's confirmation-report endpoint. It returns an ADIF
+// document of the user's QSOs (optionally only confirmed ones).
+const lotwReportURL = "https://lotw.arrl.org/lotwuser/lotwreport.adi"
+
+// DownloadLoTWConfirmations fetches confirmed QSOs from LoTW as ADIF text.
+// Uses the LoTW *website* login (Username/Password), not the TQSL cert. When
+// since is non-empty (YYYY-MM-DD) only confirmations received since then are
+// returned — used for incremental "Last download" updates.
+func DownloadLoTWConfirmations(ctx context.Context, client *http.Client, cfg ServiceConfig, since string) (string, error) {
+	user := strings.TrimSpace(cfg.Username)
+	if user == "" || cfg.Password == "" {
+		return "", fmt.Errorf("lotw: website login (username/password) not set")
+	}
+	q := url.Values{}
+	q.Set("login", user)
+	q.Set("password", cfg.Password)
+	q.Set("qso_query", "1")
+	q.Set("qso_qsl", "yes")        // only QSLed (confirmed) records
+	q.Set("qso_qsldetail", "yes")  // include QSL_RCVD / QSLRDATE detail
+	if s := strings.TrimSpace(since); s != "" {
+		q.Set("qso_qslsince", s)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, lotwReportURL+"?"+q.Encode(), nil)
+	if err != nil {
+		return "", fmt.Errorf("lotw: build request: %w", err)
+	}
+	if client == nil {
+		client = &http.Client{Timeout: 120 * time.Second}
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("lotw: request failed: %w", err)
+	}
+	defer resp.Body.Close()
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 32*1024*1024))
+	if err != nil {
+		return "", fmt.Errorf("lotw: read response: %w", err)
+	}
+	text := string(body)
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("lotw: http %d", resp.StatusCode)
+	}
+	// LoTW returns a plain-text error (not ADIF) on bad login.
+	if !strings.Contains(strings.ToUpper(text), "<EOH>") && !strings.Contains(strings.ToLower(text), "<eor>") {
+		msg := strings.TrimSpace(text)
+		if len(msg) > 200 {
+			msg = msg[:200]
+		}
+		return "", fmt.Errorf("lotw: unexpected response: %s", msg)
+	}
+	return text, nil
+}
+
 // LoTW uploads go through TQSL (ARRL's Trusted QSL signer): there is no
 // plain HTTP API — every QSO must be signed with the station certificate
 // before LoTW accepts it. We write the QSO to a temporary ADIF file and run