adds insert functionality dwyl/alog#45

lib/alog_adapter.ex

@@ -35,4 +35,79 @@ defmodule AlogAdapter do
 
   @impl true
   defdelegate structure_load(default, config), to: Postgres
+
+  # def insert(adapter_meta, %{source: source, prefix: prefix}, params, on_conflict, returning, opts) do
+  #   # params is a keyword list. Looks like ...
+  #   # [
+  #   #   comment: "hi",
+  #   #   comment_id_no: "1",
+  #   #   inserted_at: ~N[2019-02-19 19:17:18],
+  #   #   updated_at: ~N[2019-02-19 19:17:18]
+  #   # ]
+  #   # add cid: Cid.cid(%{comment: "hi", comment_id_no: "1"}) to the list
+  #   # entry_id will replace comment_id_no in the real deal.
+  #   # this SHOULD take care of both the fields and values which will produce
+  #   # a correct query.
+  #
+  #   params = params ++ [show: true]
+  #
+  #   # Ecto.Adapters.SQL.query(adapter_meta, "SELECT * FROM #{source} where ", [])
+  #
+  #   {kind, conflict_params, _} = on_conflict
+  #   {fields, values} = :lists.unzip(params)
+  #   sql = @conn.insert(prefix, source, fields, [fields], on_conflict, returning)
+  #   Ecto.Adapters.SQL.struct(adapter_meta, @conn, sql, :insert, source, [], values ++ conflict_params, kind, returning, opts)
+  # end
+
+  def insert(adapter_meta, %{source: source, prefix: prefix}, params, on_conflict, returning, opts) do
+    # converts params from a keyword list to a map
+    params_map = Enum.into(params, %{})
+
+    # removes inserted_at and updated_at from map (will not error if keys are not in map)
+    map_for_cid = Map.drop(params_map, [:inserted_at, :updated_at])
+
+    # creates a cid from the map witout the inserted_at and updated_at_values
+    cid = Cid.cid(map_for_cid)
+
+    # creates a unique entry_id for the data based on the CID generated
+    entry_id = create_entry_id(source, adapter_meta, cid, 2)
+
+    # updates params to ensure that timestamps, cid, and entry_id are all added.
+    # then converts the map back into a list for use in existing functionality (original format)
+    params =
+      map_for_cid
+      |> add_timestamps()
+      |> Map.put(:cid, cid)
+      |> Map.put(:entry_id, entry_id)
+      |> Enum.into([])
+
+    {kind, conflict_params, _} = on_conflict
+    {fields, values} = :lists.unzip(params)
+    sql = @conn.insert(prefix, source, fields, [fields], on_conflict, returning)
+    Ecto.Adapters.SQL.struct(adapter_meta, @conn, sql, :insert, source, [], values ++ conflict_params, kind, returning, opts)
+  end
+
+  # I think that this step need to also make sure that the data is not an exact copy.
+  # if the full cid already exists then this is duplicate data.
+  # Should we insert duplicate data.
+  # i was thinking maybe if it was existing data but not the most recent data we should re-insert the data
+  # e.g. if the comment was hi, edited to hey, and then changed back to hi.
+  defp create_entry_id(source, adapter_meta, cid, n) do
+    entry_id = String.slice(cid, 0..n)
+    entry_id_query = "SELECT * FROM #{source} where entry_id='#{entry_id}'"
+    {:ok, results} = Ecto.Adapters.SQL.query(adapter_meta, entry_id_query, [])
+
+    if results.num_rows == 0 do
+      entry_id
+    else
+      create_entry_id(source, adapter_meta, cid, n+1)
+    end
+  end
+
+  defp add_timestamps(params) do
+    params
+    |> Enum.into(%{})
+    |> Map.put_new(:inserted_at, NaiveDateTime.utc_now())
+    |> Map.put_new(:updated_at, NaiveDateTime.utc_now())
+  end
 end