Make the number of website visitors by referrer

Refs #77

src/data/visitors-by-referrer.json.ts

@@ -0,0 +1,61 @@
+import { HttpClient, HttpClientRequest, HttpClientResponse, Terminal } from '@effect/platform'
+import { NodeTerminal } from '@effect/platform-node'
+import { Schema } from '@effect/schema'
+import { Array, Config, Effect, Option, Redacted } from 'effect'
+import * as Iso3166 from '../lib/Iso3166.js'
+import * as Temporal from '../lib/Temporal.js'
+import * as Url from '../lib/Url.js'
+
+const Visitors = Schema.Array(
+  Schema.Struct({
+    visits: Schema.NumberFromString,
+    date: Temporal.PlainYearMonthFromStringSchema,
+    referrer_hostname: Schema.OptionFromNullOr(Url.UrlFromStringSchema),
+  }),
+)
+
+const Output = Schema.Array(
+  Schema.Struct({
+    number: Schema.NumberFromString,
+    yearMonth: Temporal.PlainYearMonthFromStringSchema,
+    referrer: Schema.OptionFromNullOr(Url.UrlFromStringSchema),
+  }),
+)
+
+const program = Effect.gen(function* () {
+  const terminal = yield* Terminal.Terminal
+  const token = yield* Config.redacted('FATHOM_TOKEN')
+
+  const request = HttpClientRequest.bearerToken(
+    HttpClientRequest.get('https://api.usefathom.com/v1/aggregations', {
+      urlParams: {
+        entity: 'pageview',
+        entity_id: 'FEAJEBBA',
+        aggregates: 'visits',
+        date_grouping: 'month',
+        field_grouping: 'referrer_hostname',
+      },
+    }),
+    Redacted.value(token),
+  )
+
+  const data = yield* HttpClient.fetchOk(request).pipe(
+    Effect.andThen(HttpClientResponse.schemaBodyJson(Visitors)),
+    Effect.scoped,
+  )
+
+  const transformedData = Array.map(
+    Array.filter(data, visitors => visitors.visits > 0),
+    visitors => ({
+      number: visitors.visits,
+      yearMonth: visitors.date,
+      referrer: visitors.referrer_hostname,
+    }),
+  )
+
+  const encoded = yield* Schema.encode(Schema.parseJson(Output))(transformedData)
+
+  yield* terminal.display(encoded)
+})
+
+await Effect.runPromise(program.pipe(Effect.provide(NodeTerminal.layer)))