feat(server/m7-352): GET /api/me/system-playlists-status for home placeholders

internal/api/me_system_playlists.go

@@ -0,0 +1,52 @@
+package api
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/jackc/pgx/v5"
+
+	"git.fabledsword.com/bvandeusen/minstrel/internal/auth"
+	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
+)
+
+// systemPlaylistsStatusResp is the wire shape for the home page's placeholder
+// state lookup. Fields are nullable to distinguish "no row exists yet" (all
+// nulls) from "row exists with these values".
+type systemPlaylistsStatusResp struct {
+	InFlight  bool    `json:"in_flight"`
+	LastRunAt *string `json:"last_run_at"`
+	LastError *string `json:"last_error"`
+}
+
+// handleGetSystemPlaylistsStatus implements GET /api/me/system-playlists-status.
+// Returns the caller's system_playlist_runs row, or zero-values when no row
+// exists yet (i.e. the user has never had a build attempted).
+func (h *handlers) handleGetSystemPlaylistsStatus(w http.ResponseWriter, r *http.Request) {
+	caller, ok := auth.UserFromContext(r.Context())
+	if !ok {
+		writeErr(w, http.StatusUnauthorized, "unauthenticated", "no session")
+		return
+	}
+
+	row, err := dbq.New(h.pool).GetSystemPlaylistRun(r.Context(), caller.ID)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			writeJSON(w, http.StatusOK, systemPlaylistsStatusResp{})
+			return
+		}
+		h.logger.Error("api: get system playlists status", "err", err)
+		writeErr(w, http.StatusInternalServerError, "server_error", "lookup failed")
+		return
+	}
+
+	resp := systemPlaylistsStatusResp{InFlight: row.InFlight}
+	if row.LastRunAt.Valid {
+		s := row.LastRunAt.Time.Format("2006-01-02T15:04:05Z07:00")
+		resp.LastRunAt = &s
+	}
+	if row.LastError != nil {
+		resp.LastError = row.LastError
+	}
+	writeJSON(w, http.StatusOK, resp)
+}