add analytics CSV export

Downloads a ZIP with one CSV per report (overview, trend, pages, entry/exit
pages, sources, referrers, countries, devices, funnel). Export button lives
next to the period selector and picks up the current period and any active
filters using a JS hook + JS.set_attribute, so the downloaded data always
matches what's on screen.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/js/app.js

@@ -509,6 +509,31 @@ const CardRadioScroll = {
   }
 }
 
+// Analytics export: reads the current period and filters from the DOM at click time
+// so the download URL is always correct, even if clicked before the LiveView re-render.
+const AnalyticsExport = {
+  mounted() {
+    this.el.addEventListener("click", (e) => {
+      e.preventDefault()
+      const params = new URLSearchParams()
+      params.set("period", this.el.getAttribute("data-period") || "30d")
+      document.querySelectorAll("[data-filter-dimension]").forEach((span) => {
+        const dim = span.getAttribute("data-filter-dimension")
+        const val = span.getAttribute("data-filter-value")
+        if (dim && val) params.set(`filter[${dim}]`, val)
+      })
+      // Use a temporary anchor click so the download doesn't navigate away and
+      // kill the LiveView WebSocket.
+      const a = document.createElement("a")
+      a.href = `/admin/analytics/export?${params}`
+      a.download = ""
+      document.body.appendChild(a)
+      a.click()
+      document.body.removeChild(a)
+    })
+  }
+}
+
 // Analytics: send screen width for device classification (Layer 3)
 const AnalyticsInit = {
   mounted() {
@@ -592,7 +617,7 @@ const ChartTooltip = {
 const csrfToken = document.querySelector("meta[name='csrf-token']").getAttribute("content")
 const liveSocket = new LiveSocket("/live", Socket, {
   params: {_csrf_token: csrfToken, screen_width: window.innerWidth},
-  hooks: {...colocatedHooks, ColorSync, Lightbox, CartPersist, CartDrawer, ProductImageScroll, SearchModal, CollectionFilters, CardRadioScroll, AnalyticsInit, ChartTooltip},
+  hooks: {...colocatedHooks, ColorSync, Lightbox, CartPersist, CartDrawer, ProductImageScroll, SearchModal, CollectionFilters, CardRadioScroll, AnalyticsInit, AnalyticsExport, ChartTooltip},
 })
 
 // Show progress bar on live navigation and form submits

lib/berrypod_web/controllers/analytics_export_controller.ex

@@ -0,0 +1,209 @@
+defmodule BerrypodWeb.AnalyticsExportController do
+  use BerrypodWeb, :controller
+
+  alias Berrypod.Analytics
+
+  @periods %{
+    "today" => 0,
+    "7d" => 6,
+    "30d" => 29,
+    "12m" => 364
+  }
+
+  @filterable ~w(pathname referrer_source country_code browser os screen_size)
+
+  def export(conn, params) do
+    period = if Map.has_key?(@periods, params["period"]), do: params["period"], else: "30d"
+    filters = parse_filters(params)
+    range = date_range(period)
+
+    trend_data =
+      if period == "today",
+        do: Analytics.visitors_by_hour(range, filters),
+        else: Analytics.visitors_by_date(range, filters)
+
+    visitors = Analytics.count_visitors(range, filters)
+    pageviews = Analytics.count_pageviews(range, filters)
+    bounce_rate = Analytics.bounce_rate(range, filters)
+    avg_duration = Analytics.avg_duration(range, filters)
+
+    top_pages = Analytics.top_pages(range, filters: filters, limit: 10_000)
+    entry_pages = Analytics.entry_pages(range, filters: filters, limit: 10_000)
+    exit_pages = Analytics.exit_pages(range, filters: filters, limit: 10_000)
+    top_sources = Analytics.top_sources(range, filters: filters, limit: 10_000)
+    top_referrers = Analytics.top_referrers(range, filters: filters, limit: 10_000)
+    countries = Analytics.top_countries(range, filters: filters, limit: 10_000)
+    browsers = Analytics.device_breakdown(range, :browser, filters)
+    oses = Analytics.device_breakdown(range, :os, filters)
+    screen_sizes = Analytics.device_breakdown(range, :screen_size, filters)
+    funnel = Analytics.funnel(range, filters)
+    revenue = Analytics.total_revenue(range, filters)
+
+    csv_files = [
+      {"overview.csv", overview_csv(visitors, pageviews, bounce_rate, avg_duration)},
+      {trend_filename(period), trend_csv(trend_data, period)},
+      {"pages.csv", pages_csv(top_pages)},
+      {"entry_pages.csv", entry_exit_csv(entry_pages)},
+      {"exit_pages.csv", entry_exit_csv(exit_pages)},
+      {"sources.csv", sources_csv(top_sources)},
+      {"referrers.csv", referrers_csv(top_referrers)},
+      {"countries.csv", countries_csv(countries)},
+      {"browsers.csv", devices_csv(browsers)},
+      {"operating_systems.csv", devices_csv(oses)},
+      {"screen_sizes.csv", devices_csv(screen_sizes)},
+      {"funnel.csv", funnel_csv(funnel, revenue)}
+    ]
+
+    zip_entries =
+      Enum.map(csv_files, fn {name, content} ->
+        {String.to_charlist(name), content}
+      end)
+
+    {:ok, {_name, zip_data}} = :zip.create(~c"export.zip", zip_entries, [:memory])
+
+    today = Date.to_iso8601(Date.utc_today())
+    filename = "analytics-#{period}-#{today}.zip"
+
+    conn
+    |> put_resp_content_type("application/zip")
+    |> put_resp_header("content-disposition", ~s(attachment; filename="#{filename}"))
+    |> send_resp(200, zip_data)
+  end
+
+  # -- CSV builders --
+
+  defp overview_csv(visitors, pageviews, bounce_rate, avg_duration) do
+    encode_csv([
+      ["metric", "value"],
+      ["visitors", visitors],
+      ["pageviews", pageviews],
+      ["bounce_rate_pct", bounce_rate],
+      ["avg_duration_seconds", avg_duration]
+    ])
+  end
+
+  defp trend_filename("today"), do: "visitors_by_hour.csv"
+  defp trend_filename(_), do: "visitors_by_date.csv"
+
+  defp trend_csv(data, "today") do
+    rows = [["hour", "visitors"] | Enum.map(data, fn r -> [r.hour, r.visitors] end)]
+    encode_csv(rows)
+  end
+
+  defp trend_csv(data, _period) do
+    rows = [["date", "visitors"] | Enum.map(data, fn r -> [r.date, r.visitors] end)]
+    encode_csv(rows)
+  end
+
+  defp pages_csv(rows) do
+    encode_csv([
+      ["pathname", "visitors", "pageviews"]
+      | Enum.map(rows, fn r -> [r.pathname, r.visitors, r.pageviews] end)
+    ])
+  end
+
+  defp entry_exit_csv(rows) do
+    encode_csv([
+      ["pathname", "sessions"]
+      | Enum.map(rows, fn r -> [r.pathname, r.sessions] end)
+    ])
+  end
+
+  defp sources_csv(rows) do
+    encode_csv([
+      ["source", "visitors"]
+      | Enum.map(rows, fn r -> [r.source, r.visitors] end)
+    ])
+  end
+
+  defp referrers_csv(rows) do
+    encode_csv([
+      ["referrer", "visitors"]
+      | Enum.map(rows, fn r -> [r.referrer, r.visitors] end)
+    ])
+  end
+
+  defp countries_csv(rows) do
+    encode_csv([
+      ["country_code", "visitors"]
+      | Enum.map(rows, fn r -> [r.country_code, r.visitors] end)
+    ])
+  end
+
+  defp devices_csv(rows) do
+    encode_csv([
+      ["name", "visitors"]
+      | Enum.map(rows, fn r -> [r.name, r.visitors] end)
+    ])
+  end
+
+  defp funnel_csv(funnel, revenue) do
+    top = funnel.product_views
+
+    steps = [
+      {"product_views", funnel.product_views},
+      {"add_to_carts", funnel.add_to_carts},
+      {"checkouts", funnel.checkouts},
+      {"purchases", funnel.purchases}
+    ]
+
+    step_rows =
+      Enum.map(steps, fn {name, count} ->
+        pct = if top > 0, do: Float.round(count / top * 100, 1), else: 0.0
+        [name, count, pct]
+      end)
+
+    encode_csv(
+      [["step", "count", "conversion_pct"]] ++ step_rows ++ [["revenue_pence", revenue, ""]]
+    )
+  end
+
+  # -- CSV encoding --
+
+  defp encode_csv(rows) do
+    rows
+    |> Enum.map(fn row ->
+      row
+      |> Enum.map(&encode_field/1)
+      |> Enum.join(",")
+    end)
+    |> Enum.join("\r\n")
+    |> then(&(&1 <> "\r\n"))
+  end
+
+  defp encode_field(nil), do: ""
+
+  defp encode_field(val) when is_binary(val) do
+    if String.contains?(val, [",", "\"", "\n", "\r"]) do
+      ~s("#{String.replace(val, "\"", "\"\"")}")
+    else
+      val
+    end
+  end
+
+  defp encode_field(val), do: to_string(val)
+
+  # -- Helpers --
+
+  defp date_range(period) do
+    days = Map.fetch!(@periods, period)
+    today = Date.utc_today()
+    start_date = Date.add(today, -days)
+    end_date = Date.add(today, 1)
+
+    {DateTime.new!(start_date, ~T[00:00:00], "Etc/UTC"),
+     DateTime.new!(end_date, ~T[00:00:00], "Etc/UTC")}
+  end
+
+  defp parse_filters(params) do
+    filter_params = Map.get(params, "filter", %{})
+
+    Enum.reduce(filter_params, %{}, fn {key, val}, acc ->
+      if key in @filterable do
+        Map.put(acc, String.to_existing_atom(key), val)
+      else
+        acc
+      end
+    end)
+  end
+end

lib/berrypod_web/live/admin/analytics.ex

@@ -144,15 +144,30 @@ defmodule BerrypodWeb.Admin.Analytics do
     <.header>Analytics</.header>
 
     <%!-- Period selector --%>
-    <div class="analytics-periods" style="display: flex; gap: 0.25rem; margin-top: 1rem;">
+    <div
+      class="analytics-periods"
+      style="display: flex; gap: 0.25rem; margin-top: 1rem; align-items: center;"
+    >
       <button
         :for={period <- ["today", "7d", "30d", "12m"]}
-        phx-click="change_period"
-        phx-value-period={period}
+        phx-click={
+          JS.push("change_period", value: %{period: period})
+          |> JS.set_attribute({"data-period", period}, to: "#analytics-export-link")
+        }
         class={["admin-btn admin-btn-sm", @period == period && "admin-btn-primary"]}
       >
         {period_label(period)}
       </button>
+      <a
+        id="analytics-export-link"
+        data-period={@period}
+        href={export_url(@period, @filters)}
+        class="admin-btn admin-btn-sm"
+        style="margin-left: auto;"
+        phx-hook="AnalyticsExport"
+      >
+        Export CSV
+      </a>
     </div>
 
     <%!-- Active filters --%>
@@ -308,7 +323,11 @@ defmodule BerrypodWeb.Admin.Analytics do
     assigns = assign(assigns, label: filter_label(assigns.dimension, assigns.value))
 
     ~H"""
-    <span style="display: inline-flex; align-items: center; gap: 0.25rem; padding: 0.25rem 0.5rem; font-size: 0.75rem; background: var(--color-base-200, #e5e5e5); border-radius: 0.25rem;">
+    <span
+      data-filter-dimension={@dimension}
+      data-filter-value={@value}
+      style="display: inline-flex; align-items: center; gap: 0.25rem; padding: 0.25rem 0.5rem; font-size: 0.75rem; background: var(--color-base-200, #e5e5e5); border-radius: 0.25rem;"
+    >
       {@label}
       <button
         phx-click="remove_filter"
@@ -745,6 +764,15 @@ defmodule BerrypodWeb.Admin.Analytics do
   defp period_label("30d"), do: "30 days"
   defp period_label("12m"), do: "12 months"
 
+  defp export_url(period, filters) do
+    params =
+      Enum.reduce(filters, %{"period" => period}, fn {k, v}, acc ->
+        Map.put(acc, "filter[#{k}]", v)
+      end)
+
+    "/admin/analytics/export?" <> URI.encode_query(params)
+  end
+
   defp format_number(n) when n >= 1_000_000, do: "#{Float.round(n / 1_000_000, 1)}M"
   defp format_number(n) when n >= 1_000, do: "#{Float.round(n / 1_000, 1)}k"
   defp format_number(n), do: to_string(n)

lib/berrypod_web/router.ex

@@ -187,6 +187,8 @@ defmodule BerrypodWeb.Router do
   scope "/admin", BerrypodWeb do
     pipe_through [:browser, :require_authenticated_user, :admin]
 
+    get "/analytics/export", AnalyticsExportController, :export
+
     live_session :admin,
       layout: {BerrypodWeb.Layouts, :admin},
       on_mount: [