Adding a --tilejson arg to the show command (#110)

* adding funcs to read tilejson

* adding tilejson option to show command

* refactoring tilejson creation into function

main.go

@@ -32,9 +32,11 @@ var cli struct {
 	} `cmd:"" help:"Convert an MBTiles or older spec version to PMTiles."`
 
 	Show struct {
-		Path     string `arg:""`
-		Bucket   string `help:"Remote bucket"`
-		Metadata bool   `help:"Print only the JSON metadata."`
+		Path      string `arg:""`
+		Bucket    string `help:"Remote bucket"`
+		Metadata  bool   `help:"Print only the JSON metadata."`
+		Tilejson  bool   `help:"Print the TileJSON."`
+		PublicUrl string `help:"Public URL of tile endpoint to use in the Tilejson output e.g. https://example.com/tiles/pmtiles/{z}/{x}/{y}"`
 	} `cmd:"" help:"Inspect a local or remote archive."`
 
 	Tile struct {
@@ -113,12 +115,12 @@ func main() {
 
 	switch ctx.Command() {
 	case "show <path>":
-		err := pmtiles.Show(logger, cli.Show.Bucket, cli.Show.Path, cli.Show.Metadata, false, 0, 0, 0)
+		err := pmtiles.Show(logger, cli.Show.Bucket, cli.Show.Path, cli.Show.Metadata, cli.Show.Tilejson, cli.Show.PublicUrl, false, 0, 0, 0)
 		if err != nil {
 			logger.Fatalf("Failed to show archive, %v", err)
 		}
 	case "tile <path> <z> <x> <y>":
-		err := pmtiles.Show(logger, cli.Tile.Bucket, cli.Tile.Path, false, true, cli.Tile.Z, cli.Tile.X, cli.Tile.Y)
+		err := pmtiles.Show(logger, cli.Tile.Bucket, cli.Tile.Path, false, false, "", true, cli.Tile.Z, cli.Tile.X, cli.Tile.Y)
 		if err != nil {
 			logger.Fatalf("Failed to show tile, %v", err)
 		}

pmtiles/server.go

@@ -234,29 +234,16 @@ func (server *Server) get_tilejson(ctx context.Context, http_headers map[string]
 	var metadata_map map[string]interface{}
 	json.Unmarshal(metadata_bytes, &metadata_map)
 
-	tilejson := make(map[string]interface{})
-
 	if server.publicHostname == "" {
 		return 501, http_headers, []byte("PUBLIC_HOSTNAME must be set for TileJSON")
 	}
 
+	tilejson_bytes, err := CreateTilejson(header, metadata_bytes, server.publicHostname+"/"+name+"/{z}/{x}/{y}"+headerExt(header))
+	if err != nil {
+		return 500, http_headers, []byte("Error generating tilejson")
+	}
+
 	http_headers["Content-Type"] = "application/json"
-	tilejson["tilejson"] = "3.0.0"
-	tilejson["scheme"] = "xyz"
-	tilejson["tiles"] = []string{server.publicHostname + "/" + name + "/{z}/{x}/{y}" + headerExt(header)}
-	tilejson["vector_layers"] = metadata_map["vector_layers"]
-	tilejson["attribution"] = metadata_map["attribution"]
-	tilejson["description"] = metadata_map["description"]
-	tilejson["name"] = metadata_map["name"]
-	tilejson["version"] = metadata_map["version"]
-
-	E7 := 10000000.0
-	tilejson["bounds"] = []float64{float64(header.MinLonE7) / E7, float64(header.MinLatE7) / E7, float64(header.MaxLonE7) / E7, float64(header.MaxLatE7) / E7}
-	tilejson["center"] = []interface{}{float64(header.CenterLonE7) / E7, float64(header.CenterLatE7) / E7, header.CenterZoom}
-	tilejson["minzoom"] = header.MinZoom
-	tilejson["maxzoom"] = header.MaxZoom
-
-	tilejson_bytes, err := json.Marshal(tilejson)
 
 	return 200, http_headers, tilejson_bytes
 }

pmtiles/show.go

@@ -6,13 +6,14 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+
 	// "github.com/dustin/go-humanize"
 	"io"
 	"log"
 	"os"
 )
 
-func Show(logger *log.Logger, bucketURL string, key string, show_metadata_only bool, show_tile bool, z int, x int, y int) error {
+func Show(logger *log.Logger, bucketURL string, key string, show_metadata_only bool, show_tilejson bool, public_url string, show_tile bool, z int, x int, y int) error {
 	ctx := context.Background()
 
 	bucketURL, key, err := NormalizeBucketKey(bucketURL, "", key)
@@ -87,8 +88,25 @@ func Show(logger *log.Logger, bucketURL string, key string, show_metadata_only b
 		}
 		metadata_reader.Close()
 
+		if show_metadata_only && show_tilejson {
+			return fmt.Errorf("Cannot use --metadata and --tilejson together.")
+		}
+
 		if show_metadata_only {
 			fmt.Print(string(metadata_bytes))
+		} else if show_tilejson {
+			if public_url == "" {
+				// Using Fprintf instead of logger here, as this message should be written to Stderr in case
+				// Stdout is being redirected.
+				fmt.Fprintln(os.Stderr, "Warning: No --public-url specified; using placeholder tiles URL.")
+				public_url = "https://example.com/{z}/{x}/{y}.mvt"
+
+			}
+			tilejson_bytes, err := CreateTilejson(header, metadata_bytes, public_url)
+			if err != nil {
+				return fmt.Errorf("Failed to create tilejson for %s, %w", key, err)
+			}
+			fmt.Print(string(tilejson_bytes))
 		} else {
 			fmt.Printf("pmtiles spec version: %d\n", header.SpecVersion)
 			// fmt.Printf("total size: %s\n", humanize.Bytes(uint64(r.Size())))

pmtiles/tilejson.go

@@ -0,0 +1,29 @@
+package pmtiles
+
+import (
+	"encoding/json"
+)
+
+func CreateTilejson(header HeaderV3, metadata_bytes []byte, tileUrl string) ([]byte, error) {
+	var metadata_map map[string]interface{}
+	json.Unmarshal(metadata_bytes, &metadata_map)
+
+	tilejson := make(map[string]interface{})
+
+	tilejson["tilejson"] = "3.0.0"
+	tilejson["scheme"] = "xyz"
+	tilejson["tiles"] = []string{tileUrl}
+	tilejson["vector_layers"] = metadata_map["vector_layers"]
+	tilejson["attribution"] = metadata_map["attribution"]
+	tilejson["description"] = metadata_map["description"]
+	tilejson["name"] = metadata_map["name"]
+	tilejson["version"] = metadata_map["version"]
+
+	E7 := 10000000.0
+	tilejson["bounds"] = []float64{float64(header.MinLonE7) / E7, float64(header.MinLatE7) / E7, float64(header.MaxLonE7) / E7, float64(header.MaxLatE7) / E7}
+	tilejson["center"] = []interface{}{float64(header.CenterLonE7) / E7, float64(header.CenterLatE7) / E7, header.CenterZoom}
+	tilejson["minzoom"] = header.MinZoom
+	tilejson["maxzoom"] = header.MaxZoom
+
+	return json.MarshalIndent(tilejson, "", "\t")
+}

pmtiles/tilejson_test.go

@@ -0,0 +1,60 @@
+package pmtiles
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCreateTilejson(t *testing.T) {
+	// Define test inputs
+	header := HeaderV3{
+		MinZoom:     0.0,
+		MaxZoom:     14.0,
+		MinLonE7:    -1144000000,
+		MinLatE7:    479000000,
+		MaxLonE7:    -1139000000,
+		MaxLatE7:    483000000,
+		CenterLonE7: -1141500000,
+		CenterLatE7: 481000000,
+	}
+	metadataBytes := []byte(`
+	{
+		"vector_layers": [{"id": "layer1"}],
+		"attribution": "Attribution",
+		"description": "Description",
+		"name": "Name",
+		"version": "1.0"
+	}`)
+	tileURL := "https://example.com/tiles.pmtiles/{z}/{x}/{y}"
+
+	// Call the function
+	tilejsonBytes, err := CreateTilejson(header, metadataBytes, tileURL)
+
+	// Check for errors
+	if err != nil {
+		t.Errorf("CreateTilejson returned an error: %v", err)
+	}
+
+	// Parse the tilejsonBytes to check the output
+	var tilejson map[string]interface{}
+	err = json.Unmarshal(tilejsonBytes, &tilejson)
+	if err != nil {
+		t.Errorf("Failed to parse the generated TileJSON: %v", err)
+	}
+
+	assert.Equal(t, "3.0.0", tilejson["tilejson"])
+	assert.Equal(t, "xyz", tilejson["scheme"])
+	assert.Equal(t, []interface{}{"https://example.com/tiles.pmtiles/{z}/{x}/{y}"}, tilejson["tiles"])
+	assert.Equal(t, []interface{}{map[string]interface{}{"id": "layer1"}}, tilejson["vector_layers"])
+	assert.Equal(t, "Attribution", tilejson["attribution"])
+	assert.Equal(t, "Description", tilejson["description"])
+	assert.Equal(t, "Name", tilejson["name"])
+	assert.Equal(t, "1.0", tilejson["version"])
+
+	assert.Equal(t, []interface{}{-114.400000, 47.900000, -113.900000, 48.300000}, tilejson["bounds"])
+	assert.Equal(t, []interface{}{-114.150000, 48.100000, 0.0}, tilejson["center"])
+	assert.Equal(t, 0.0, tilejson["minzoom"])
+	assert.Equal(t, 14.0, tilejson["maxzoom"])
+}