Fix HTML diff output

Generate it from the `geojson` diff rather than the `json` one,
because the `json` one now uses hexWKB geometries.

Because the layout's a bit different, this means the JS in the
HTML template needs to do a bit more work, but it's quite achievable.
Yay for ES7

sno/diff-view.html

@@ -125,8 +125,8 @@
             }).addTo(map)
 
             var layerGroup = L.featureGroup()
-            for (let [dataset, diff] of Object.entries(DATA['sno.diff/v1+hexwkb'])) {
-                if (!diff.featureChanges.length) {
+            for (let [dataset, diff] of Object.entries(DATA)) {
+                if (!diff.features.length) {
                     continue
                 }
 
@@ -139,16 +139,18 @@
                 layers[dataset] = {}
                 featureMap[dataset] = {}
 
-                for (let change of diff.featureChanges) {
-                    const fOld = change['-']
-                    const fNew = change['+']
-                    if (fOld && fNew) {
-                        fc['updateOld'].push(fOld)
-                        fc['updateNew'].push(fNew)
-                    } else if (fOld) {
-                        fc['delete'].push(fOld)
-                    } else if (fNew) {
-                        fc['insert'].push(fNew)
+                for (let change of diff.features) {
+                    const id = change['id']
+                    if (id.startsWith('U+::')) {
+                        fc['updateNew'].push(change)
+                    } else if (id.startsWith('U-::')) {
+                        fc['updateOld'].push(change)
+                    } else if (id.startsWith('D::')) {
+                        fc['delete'].push(change)
+                    } else if (id.startsWith('I::')) {
+                        fc['insert'].push(change)
+                    } else {
+                        console.log('unknown ID format: ' + id)
                     }
                 }
 
@@ -224,14 +226,40 @@
             }
             selectedFeature = [row, f]
         }
+        function getFeaturesByRealId(diff) {
+            let featuresByRealId = {}
+            for (let fc of diff.features) {
+                const id = fc['id']
+                const realId = id.split('::')[1]
+                if (id.startsWith('U')) {
+                    if (!featuresByRealId[realId]) {
+                        featuresByRealId[realId] = [null, null]
+                    }
+                    if (id.startsWith('U+::')) {
+                        // 'new'
+                        featuresByRealId[realId][1] = fc
+                    } else {
+                        // 'old'
+                        featuresByRealId[realId][0] = fc
+                    }
+                } else if (id.startsWith('D::')) {
+                    featuresByRealId[realId] = [fc, null]
+                } else if (id.startsWith('I::')) {
+                    featuresByRealId[realId] = [fc, null]
+                } else {
+                    console.log('unknown ID format: ' + id)
+                    continue
+                }
+            }
+            return featuresByRealId
+        }
 
-        function getSchema(diff) {
+        function getSchema(featuresByRealId) {
             // if schema has changed then it'll show up in every single feature
             let oldSchema = null
             let newSchema = null
-            for (let change of diff.featureChanges) {
-                const fOld = change['-']
-                const fNew = change['+']
+            for (let [realId, change] of Object.entries(featuresByRealId)) {
+                let [fOld, fNew] = change
                 if (fOld && !oldSchema) {
                     oldSchema = Object.keys(fOld.properties)
                     oldSchema.splice(0, 0, GEOM)
@@ -273,8 +301,8 @@
                 return isArrayEqual(a.coordinates, b.coordinates)
             }
 
-            for (let [dataset, diff] of Object.entries(DATA['sno.diff/v1+hexwkb'])) {
-                if (!diff.featureChanges.length) {
+            for (let [dataset, diff] of Object.entries(DATA)) {
+                if (!diff.features.length) {
                     continue
                 }
 
@@ -288,7 +316,8 @@
                 let thead = table.createTHead()
                 let row = thead.insertRow()
 
-                let schema = getSchema(diff)
+                let features = getFeaturesByRealId(diff)
+                let schema = getSchema(features)
 
                 for (let col of schema) {
                     let th = document.createElement("th")
@@ -300,18 +329,16 @@
                 }
 
                 let tbody = table.createTBody()
-                for (let fc of diff.featureChanges) {
-                    let fOld = fc['-']
-                    let fNew = fc['+']
-                    let change;
+                for (let [realId, fc] of Object.entries(features)) {
+                    let [fOld, fNew] = fc
+                    let change
                     if (fOld && fNew) {
                         change = 'update'
                     } else if (fOld) {
                         change = 'delete'
                     } else {
                         change = 'insert'
                     }
-
                     fOld = fOld || {properties: {}}
                     fNew = fNew || {properties: {}}
                     let oldRow = document.createElement('tr')

sno/diff_output.py

@@ -1,13 +1,14 @@
 import contextlib
 import io
 import json
+import os
 import string
 import sys
+import tempfile
 import webbrowser
 from pathlib import Path
 
 import click
-from osgeo import ogr
 
 from . import gpkg
 from .output_util import dump_json_output, resolve_output_path
@@ -154,7 +155,7 @@ def repr_row(row, prefix="", exclude=None):
 
 
 @contextlib.contextmanager
-def diff_output_geojson(*, output_path, dataset_count, json_style, **kwargs):
+def diff_output_geojson(*, output_path, dataset_count, json_style='pretty', **kwargs):
     """
     Contextmanager.
 
@@ -196,6 +197,8 @@ def diff_output_geojson(*, output_path, dataset_count, json_style, **kwargs):
     def _out(dataset, diff):
         if not output_path or output_path == '-':
             fp = sys.stdout
+        elif isinstance(output_path, io.StringIO):
+            fp = output_path
         elif output_path.is_dir():
             fp = (output_path / f"{dataset.name}.geojson").open("w")
         else:
@@ -343,27 +346,37 @@ def diff_output_html(*, output_path, repo, base, target, dataset_count, **kwargs
             raise click.BadParameter(
                 "Directory is not valid for --output with --html", param_hint="--output"
             )
-
-    json_data = io.StringIO()
-    with diff_output_json(
-        output_path=json_data, dataset_count=dataset_count
-    ) as json_writer:
-        yield json_writer
-
     with open(
         Path(__file__).resolve().with_name("diff-view.html"), "r", encoding="utf8"
     ) as ft:
         template = string.Template(ft.read())
 
     title = f"{Path(repo.path).name}: {base.short_id} .. {target.short_id if target else 'working-copy'}"
 
-    if not output_path:
-        output_path = Path(repo.path) / "DIFF.html"
-    fo = resolve_output_path(output_path)
+    with tempfile.TemporaryDirectory() as tempdir:
+        tempdir = Path(tempdir)
+        # Write a bunch of geojson files to a temporary directory
+        with diff_output_geojson(
+            output_path=tempdir, dataset_count=dataset_count, json_style="extracompact",
+        ) as json_writer:
+            yield json_writer
 
-    fo.write(
-        template.substitute({"title": title, "geojson_data": json_data.getvalue()})
-    )
+        if not output_path:
+            output_path = Path(repo.path) / "DIFF.html"
+        fo = resolve_output_path(output_path)
+
+        # Read all the geojson back in, and stick them in a dict
+        all_datasets_geojson = {}
+        for filename in os.listdir(tempdir):
+            with open(tempdir / filename) as json_file:
+                all_datasets_geojson[os.path.splitext(filename)[0]] = json.load(
+                    json_file
+                )
+        fo.write(
+            template.substitute(
+                {"title": title, "geojson_data": json.dumps(all_datasets_geojson)}
+            )
+        )
     if fo != sys.stdout:
         fo.close()
         webbrowser.open_new(f"file://{output_path.resolve()}")