Feature/chart library catalog

internal/engine/baker/meta.go

@@ -0,0 +1,85 @@
+package baker
+
+import (
+	"sort"
+	"strconv"
+)
+
+// CellMeta is the per-cell metadata extracted at import time for the chart
+// library to display. It comes from the cell's S-57 header (DSID/DSPM) plus its
+// M_COVR coverage — gathered with the same cheap coverage-only parse the bake's
+// pass 1 uses, so it adds no full re-parse. Title is left to the caller to fill
+// from the exchange-set catalogue (CATALOG.031 LFIL), since S-57 headers carry
+// no human chart name.
+type CellMeta struct {
+	Name      string     `json:"name"`            // cell stem, e.g. "US5MD1MC"
+	Title     string     `json:"title,omitempty"` // human chart name (from CATALOG.031 LFIL); empty if none — consumers show Name
+	Scale     int        `json:"scale,omitempty"` // compilation scale denominator (CSCL)
+	Edition   string     `json:"edition,omitempty"`
+	Update    string     `json:"update,omitempty"`
+	IssueDate string     `json:"issueDate,omitempty"` // YYYYMMDD
+	Agency    int        `json:"agency,omitempty"`    // IHO producing-agency code (550 = NOAA)
+	BBox      [4]float64 `json:"bbox,omitempty"`      // [west, south, east, north]
+	HasBBox   bool       `json:"-"`
+}
+
+// ExtractCellMeta parses each cell's header + coverage (coverage-only, cheap) and
+// returns per-cell metadata keyed by cell stem. Cells that fail to parse are
+// reported via onSkip and omitted. Title is left empty (S-57 headers carry no human
+// chart name — only the cell code); the caller overlays the CATALOG.031 long name
+// where the exchange set provides one.
+func ExtractCellMeta(cells map[string]CellData, onSkip func(name string, err error)) map[string]CellMeta {
+	out := make(map[string]CellMeta, len(cells))
+	names := make([]string, 0, len(cells))
+	for n := range cells {
+		names = append(names, n)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		cd := cells[name]
+		chart, err := ParseCellCoverage(name, cd.Base, cd.Updates)
+		if err != nil {
+			if onSkip != nil {
+				onSkip(name, err)
+			}
+			continue
+		}
+		stem := cellStem(chart.DatasetName())
+		if stem == "" {
+			stem = cellStem(name)
+		}
+		m := CellMeta{
+			Name:      stem,
+			Scale:     int(chart.CompilationScale()),
+			Edition:   chart.Edition(),
+			Update:    chart.UpdateNumber(),
+			IssueDate: chart.IssueDate(),
+			Agency:    chart.ProducingAgency(),
+		}
+		b := chart.Bounds()
+		if b.MaxLon > b.MinLon && b.MaxLat > b.MinLat {
+			m.BBox = [4]float64{b.MinLon, b.MinLat, b.MaxLon, b.MaxLat}
+			m.HasBBox = true
+		}
+		out[stem] = m
+	}
+	return out
+}
+
+// cellStem trims a trailing ".000"/".NNN" or directory path from a cell name.
+func cellStem(name string) string {
+	// Strip any directory.
+	for i := len(name) - 1; i >= 0; i-- {
+		if name[i] == '/' || name[i] == '\\' {
+			name = name[i+1:]
+			break
+		}
+	}
+	// Strip a 3-digit S-57 extension.
+	if n := len(name); n >= 4 && name[n-4] == '.' {
+		if _, err := strconv.Atoi(name[n-3:]); err == nil {
+			return name[:n-4]
+		}
+	}
+	return name
+}

internal/engine/baker/meta_test.go

@@ -0,0 +1,42 @@
+package baker
+
+import (
+	"os"
+	"testing"
+)
+
+func TestExtractCellMeta(t *testing.T) {
+	data, err := os.ReadFile("../../../testdata/US5MD1MC.000")
+	if err != nil {
+		t.Fatal(err)
+	}
+	meta := ExtractCellMeta(map[string]CellData{"US5MD1MC.000": {Base: data}}, nil)
+	m, ok := meta["US5MD1MC"]
+	if !ok {
+		t.Fatalf("no metadata for US5MD1MC; got keys %v", keys(meta))
+	}
+	if m.Scale != 12000 {
+		t.Errorf("Scale = %d, want 12000", m.Scale)
+	}
+	if m.Agency != 550 { // 550 = NOAA (US)
+		t.Errorf("Agency = %d, want 550 (NOAA)", m.Agency)
+	}
+	if m.IssueDate == "" {
+		t.Error("expected an issue date")
+	}
+	if !m.HasBBox {
+		t.Error("expected a coverage bbox")
+	}
+	// Annapolis Harbor is around 38.9–39.0 N, -76.5–-76.4 W.
+	if m.BBox[0] < -77 || m.BBox[0] > -76 || m.BBox[3] < 38 || m.BBox[3] > 40 {
+		t.Errorf("bbox looks wrong: %v", m.BBox)
+	}
+}
+
+func keys(m map[string]CellMeta) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}

internal/engine/server/http.go

@@ -264,6 +264,8 @@ func (s *Server) handleAPI(w http.ResponseWriter, r *http.Request) {
 		s.handleImport(w, r) // POST: server-side native bake → register a tile set; status polling
 	case r.URL.Path == "/api/packs":
 		s.handlePacks(w, r) // GET: all baked packs + enabled state
+	case strings.HasPrefix(r.URL.Path, "/api/pack/"):
+		s.handlePackDetail(w, r) // GET: one pack's full extracted metadata (per-cell)
 	case r.URL.Path == "/api/set/enable" || r.URL.Path == "/api/set/disable":
 		s.handleSetEnabled(w, r) // POST: show/hide a pack on the map (data kept)
 	case r.URL.Path == "/api/set":