defmodule Fsdb do
  @moduledoc """
    API module.

## Standard API

    ```elixir
    :ok = Fsdb.create("table1")
    {1, "row1"} = Fsdb.insert("table1", "row1")
    {1, "row1+"} = Fsdb.update("table1", 1, "row1+")
    {1, "row1+"} = Fsdb.fetch("table1", 1)
    {1, "row1+"} = Fsdb.delete("table1", 1)
    {:not_found, "table1", 1} = Fsdb.fetch("table1", 1)
    [] = Fsdb.list("table1")
    #bypass the id generator
    {2, "row2"} = Fsdb.save("table1", 2, "row2")
    {3, "row3"} = Fsdb.save("table1", 3, "row3")
    #FIXME tuples may not be ID ordered
    [{2, "row2"}, {3, "row3"}] = Fsdb.list("table1")
    :ok = Fsdb.drop("table1")
    ```
## Extended API

    ```elixir
    path = Path.expand("~/.fsdb")
    {:ok, pid} = Fsdb.Server.start_link([path: path])
    :ok = Fsdb.create(pid, "table1")
    {1, "row1"} = Fsdb.insert(pid, "table1", "row1")
    {1, "row1+"} = Fsdb.update(pid, "table1", 1, "row1+")
    {1, "row1+"} = Fsdb.fetch(pid, "table1", 1)
    {1, "row1+"} = Fsdb.delete(pid, "table1", 1)
    {:not_found, "table1", 1} = Fsdb.fetch(pid, "table1", 1)
    [] = Fsdb.list(pid, "table1")
    #bypass the id generator
    {2, "row2"} = Fsdb.save(pid, "table1", 2, "row2")
    {3, "row3"} = Fsdb.save(pid, "table1", 3, "row3")
    #FIXME tuples may not be ID ordered
    [{2, "row2"}, {3, "row3"}] = Fsdb.list(pid, "table1")
    :ok = Fsdb.drop(pid, "table1")
    :ok = Fsdb.Server.stop(pid)
    ```
  """

  ##########################################
  # App API
  ##########################################

  @doc """
  Creates a table with name `table`.

  Returns `:ok`.
  """
  def create(table) do
    GenServer.call(Fsdb.Server, {:create, table})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def create(pid, table) do
    GenServer.call(pid, {:create, table})
  end

  @doc """
  Drops the table named `table`.

  Returns `:ok`.
  """
  def drop(table) do
    GenServer.call(Fsdb.Server, {:drop, table})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def drop(pid, table) do
    GenServer.call(pid, {:drop, table})
  end

  @doc """
  Returns all rows in table `table`.

  Returns `[{id, row}, ...]`.
  """
  def list(table) do
    GenServer.call(Fsdb.Server, {:list, table})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def list(pid, table) do
    GenServer.call(pid, {:list, table})
  end

  @doc """
  Inserts row `row` in table `table` with auto generated ID.

  Returns `{id, row}`.
  """
  def insert(table, row) do
    GenServer.call(Fsdb.Server, {:insert, table, row})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def insert(pid, table, row) do
    GenServer.call(pid, {:insert, table, row})
  end

  @doc """
  Inserts or updates row `row` in table `table` with specific id `id`.

  Returns `{id, row}`.
  """
  def save(table, id, row) do
    GenServer.call(Fsdb.Server, {:save, table, id, row})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def save(pid, table, id, row) do
    GenServer.call(pid, {:save, table, id, row})
  end

  @doc """
  Fetches the row in table `table` having the id `id`.

  Returns `{id, row} | {:not_found, table, id}`.
  """
  def fetch(table, id) do
    GenServer.call(Fsdb.Server, {:fetch, table, id})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def fetch(pid, table, id) do
    GenServer.call(pid, {:fetch, table, id})
  end

  @doc """
  Updates the row in table `table` having the id `id`.

  Returns `{id, row} | {:not_found, table, id}`.
  """
  def update(table, id, row) do
    GenServer.call(Fsdb.Server, {:update, table, id, row})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def update(pid, table, id, row) do
    GenServer.call(pid, {:update, table, id, row})
  end

  @doc """
  Deletes the row in table `table` having the id `id`.

  Returns `{id, row} | {:not_found, table, id}`.
  """
  def delete(table, id) do
    GenServer.call(Fsdb.Server, {:delete, table, id})
  end

  @doc """
  Same as above but addresses an specific Fsdb.Server.

  `pid` can be either a pid or a registered name.
  """
  def delete(pid, table, id) do
    GenServer.call(pid, {:delete, table, id})
  end

end