1 files changed, 91 insertions, 0 deletions
diff --git a/bin/mrCoopDiff.js b/bin/mrCoopDiff.js
new file mode 100755
index 0000000..080aa28
--- /dev/null
+++ b/bin/mrCoopDiff.js
@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+
+/**
+ * Takes a MapRoulette Cooperative Challenge file and creates a JSON with before and after for visualisation
+ */
+
+const fs = require('fs')
+const { Readable, Transform, pipeline } = require('stream')
+const ndjson = require('ndjson')
+const cloneDeep = require('clone-deep')
+
+const argv = require('yargs/yargs')(process.argv.slice(2))
+  .argv
+
+if (argv._.length < 2) {
+  console.error("Usage: ./mrCoopDiff.js input.json output.json")
+  process.exit(1)
+}
+
+const inputFile = argv._[0]
+const outputFile = argv._[1]
+
+if (!fs.existsSync(inputFile)) {
+  console.error(`${inputFile} not found`)
+  process.exit(1)
+}
+
+let challengeCount = 0
+const features = {}
+
+const applyOperations = new Transform({
+  readableObjectMode: true,
+  writableObjectMode: true,
+  transform(challenge, encoding, callback) {
+    challengeCount++
+
+    if (!argv.quiet) {
+      if (process.stdout.isTTY && challengeCount % 1000 === 0) {
+        process.stdout.write(` ${challengeCount.toLocaleString()}\r`)
+      }
+    }
+
+    for (const feature of challenge.features) {
+      const key = `${feature.properties['@type']}/${feature.properties['@id']}`
+      if (key in features) {
+        console.log(`${key} was found a second time`)
+      }
+
+      features[key] = {
+        before: feature
+      }
+    }
+
+    if (challenge && challenge.cooperativeWork && challenge.cooperativeWork.operations) {
+      for (const operation of challenge.cooperativeWork.operations) {
+        if (operation.operationType === 'modifyElement' && operation.data) {
+          const id = operation.data.id
+          if (id in features) {
+            const afterFeature = cloneDeep(features[id].before)
+            for (const featureOperation of operation.data.operations) {
+              if (featureOperation.operation === 'setTags') {
+                for (const [key, value] of Object.entries(featureOperation.data)) {
+                  afterFeature.properties[key] = value
+                }
+              }
+            }
+            features[id].after = afterFeature
+          }
+        }
+      }
+    }
+
+    callback()
+  }
+})
+
+console.log('Converting challenges into diff previews')
+pipeline(
+  fs.createReadStream(inputFile),
+  ndjson.parse(),
+  applyOperations,
+  err => {
+    if (err) {
+      console.log(err)
+      process.exit(1)
+    } else {
+      fs.writeFileSync(outputFile, JSON.stringify(features))
+      process.exit(0)
+    }
+  }
+)