create backend

lib/mound_hunters/repo.ex

@@ -0,0 +1,107 @@
+defmodule MoundHunters.Repo do
+  @moduledoc """
+  Mnesia database helpers for tiles and geometries.
+  """
+
+  require Logger
+
+  # Tile statuses
+  @type tile_status :: :processing | :ready | :error
+
+  @doc """
+  Get a tile by ID from Mnesia.
+  """
+  def get_tile(tile_id) do
+    case :mnesia.transaction(fn ->
+           :mnesia.read(:tiles, tile_id)
+         end) do
+      {:atomic, [tile]} -> {:ok, tile_to_map(tile)}
+      {:atomic, []} -> {:error, :not_found}
+      {:aborted, reason} -> {:error, reason}
+    end
+  end
+
+  @doc """
+  Insert or update a tile record.
+  """
+  def upsert_tile(attrs) do
+    tile_id = Map.fetch!(attrs, :id)
+    now = System.system_time(:second)
+
+    tile_record =
+      {:tiles, tile_id, Map.get(attrs, :min_lat), Map.get(attrs, :max_lat),
+       Map.get(attrs, :min_lng), Map.get(attrs, :max_lng), Map.get(attrs, :status),
+       Map.get(attrs, :error_message), Map.get(attrs, :created_at, now), now}
+
+    case :mnesia.transaction(fn ->
+           :mnesia.write(tile_record)
+         end) do
+      {:atomic, :ok} -> {:ok, tile_to_map(tile_record)}
+      {:aborted, reason} -> {:error, reason}
+    end
+  end
+
+  @doc """
+  Get a shared geometry by ID.
+  """
+  def get_geometry(geometry_id) do
+    case :mnesia.transaction(fn ->
+           :mnesia.read(:geometries, geometry_id)
+         end) do
+      {:atomic, [geometry]} -> {:ok, geometry_to_map(geometry)}
+      {:atomic, []} -> {:error, :not_found}
+      {:aborted, reason} -> {:error, reason}
+    end
+  end
+
+  @doc """
+  Create a new shared geometry.
+  """
+  def create_geometry(geojson) do
+    geometry_id = generate_id()
+    now = System.system_time(:second)
+
+    geometry_record = {:geometries, geometry_id, geojson, now}
+
+    case :mnesia.transaction(fn ->
+           :mnesia.write(geometry_record)
+         end) do
+      {:atomic, :ok} -> {:ok, %{id: geometry_id}}
+      {:aborted, reason} -> {:error, reason}
+    end
+  end
+
+  # Convert Mnesia tile record to map
+  defp tile_to_map(
+         {:tiles, id, min_lat, max_lat, min_lng, max_lng, status, error_message, created_at,
+          updated_at}
+       ) do
+    %{
+      id: id,
+      min_lat: min_lat,
+      max_lat: max_lat,
+      min_lng: min_lng,
+      max_lng: max_lng,
+      status: status,
+      error_message: error_message,
+      created_at: created_at,
+      updated_at: updated_at
+    }
+  end
+
+  # Convert Mnesia geometry record to map
+  defp geometry_to_map({:geometries, id, geojson, created_at}) do
+    %{
+      id: id,
+      geojson: geojson,
+      created_at: created_at
+    }
+  end
+
+  # Generate random 8-character alphanumeric ID
+  defp generate_id do
+    :crypto.strong_rand_bytes(6)
+    |> Base.url_encode64(padding: false)
+    |> binary_part(0, 8)
+  end
+end