defmodule Tempus.Slots do
@moduledoc """
The interface to deal with the implementation of `Tempus.Slot` ordered collection.
Comes with several default implementations, backed up by ordered list of slots,
by `Stream`, by `AVLTree`¹, and by Year-Month² tree.
### Examples
iex> slots = [
...> Tempus.Slot.wrap(~D|2020-08-07|),
...> Tempus.Slot.wrap(~D|2020-08-10|),
...> %Tempus.Slot{
...> from: ~U|2020-08-07 01:00:00Z|, to: ~U|2020-08-08 01:00:00Z|}]
...> Enum.into(slots, %Tempus.Slots{})
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-08 01:00:00Z]},
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}]}}
iex> Enum.map(slots, & &1.from)
[~U[2020-08-07 00:00:00.000000Z], ~U[2020-08-10 00:00:00.000000Z], ~U[2020-08-07 01:00:00Z]]
"""
alias Tempus.{Slot, Slots, Slots.Group}
import Tempus.Guards
@type container :: Enumerable.t(Slot.t())
@type implementation(group, exact_implementation) :: %{
__struct__: group,
slots: exact_implementation
}
@type implementation(group) :: implementation(group, container())
@type t(group, exact_implementation) :: %{
__struct__: Slots,
slots: implementation(group, exact_implementation)
}
@type t(group) :: t(group, implementation(group))
@type t :: t(module())
@typedoc "The type to use in navigation and/or rewinding slots enumerables"
@type locator :: Slot.origin() | (Slot.t() -> boolean())
@implementation Application.compile_env(:tempus, :implementation, Tempus.Slots.List)
defstruct slots: struct!(@implementation, [])
@doc """
Creates an instance of slots, using a backend given as a parameter.
"""
def new(implementation \\ @implementation, data)
def new(@implementation, %implementation{} = data), do: new(implementation, data)
def new(:list, data), do: new(Slots.List, data)
def new(:stream, data), do: new(Slots.Stream, data)
def new(implementation, data), do: %Slots{slots: Enum.into(data, implementation.new())}
@spec size(t()) :: non_neg_integer()
@doc deprecated: "Use `count/1` instead"
@doc false
def size(%Slots{} = slots), do: count(slots)
@spec count(t()) :: non_neg_integer()
@doc "Returns the number of slots"
def count(%Slots{} = slots), do: Enum.count(slots)
@spec identity(t()) :: container()
@doc false
def identity(%Slots{slots: slots}), do: %Slots{slots: Group.identity(slots)}
@spec flatten(t(), keyword()) :: [Slot.t()]
def flatten(%Slots{slots: slots}, options \\ []), do: Group.flatten(slots, options)
@spec split(t(), locator(), keyword()) :: {t(), t()}
def split(%Slots{slots: %implementation{} = slots}, origin, options \\ [])
when is_locator(origin) do
case Group.split(slots, origin, options) do
{:ok, head, tail} ->
{%Slots{slots: head}, %Slots{slots: tail}}
{:error, _} ->
%Slots.List{slots: Group.flatten(slots, options)}
|> Slots.List.split(origin)
|> Tuple.to_list()
|> Enum.map(&wrap(&1, Keyword.put(options, :implementation, implementation)))
|> List.to_tuple()
end
end
@spec drop_until(t(), locator(), keyword()) :: t()
def drop_until(%Slots{} = slots, pivot, options \\ []),
do: slots |> split(pivot, options) |> elem(1)
@spec take_until(t(), locator(), keyword()) :: t()
def take_until(%Slots{} = slots, pivot, options \\ []),
do: slots |> split(pivot, options) |> elem(0)
@spec span(t() | [Slot.t()], non_neg_integer(), unit :: System.time_unit()) :: Enumerable.t()
def span(slots, duration, unit \\ :second) do
duration_in_microseconds = System.convert_time_unit(duration, unit, :microsecond)
slots
|> Enum.reduce_while({[], duration_in_microseconds}, fn
%Slot{from: nil} = slot, {[], _ms} ->
{:halt, [slot]}
%Slot{from: from, to: nil}, {slots, ms} ->
{:halt,
Enum.reverse([%Slot{from: from, to: DateTime.add(from, ms, :microsecond)} | slots])}
%Slot{from: from} = slot, {slots, ms} ->
duration = Slot.duration(slot, :microsecond)
if duration < ms do
{:cont, {[slot | slots], ms - duration}}
else
{:halt,
Enum.reverse([%Slot{from: from, to: DateTime.add(from, ms, :microsecond)} | slots])}
end
end)
|> case do
{slots, _duration} -> slots
slots -> slots
end
end
@spec add(slots :: t(), slot :: Slot.origin()) :: t()
@doc """
Adds another slot to the slots collection.
Joins slots intersecting with the new one, if any.
### Example
iex> Tempus.Slots.add(%Tempus.Slots{}, Tempus.Slot.wrap(~D|2020-08-07|))
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]}]}}
iex> %Tempus.Slots{}
...> |> Tempus.Slots.add(Tempus.Slot.wrap(~D|2020-08-07|))
...> |> Tempus.Slots.add(Tempus.Slot.wrap(~D|2020-08-10|))
...> |> Tempus.Slots.add(%Tempus.Slot{
...> from: ~U|2020-08-07 01:00:00Z|, to: ~U|2020-08-08 01:00:00Z|})
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-08 01:00:00Z]},
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}]}}
"""
def add(%Slots{slots: slots}, slot, options \\ []) when is_origin(slot),
do: %Slots{slots: Group.add(slots, Slot.wrap(slot), options)}
@spec merge(slots :: t() | [t()], Enumerable.t(Slot.t()) | keyword(), keyword()) :: t()
@doc """
Merges many slots into the first element in the list given as an argument.
Other arguments might be enumerables, the first one must be a `Tempus.Slots` instance.
### Examples
iex> slots = [
...> Tempus.Slot.wrap(~D|2020-08-07|),
...> Tempus.Slot.wrap(~D|2020-08-10|)
...> ] |> Enum.into(%Tempus.Slots{})
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-07 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]}]}}
iex> other = [
...> %Tempus.Slot{from: ~U|2020-08-07 23:00:00Z|, to: ~U|2020-08-08 12:00:00Z|},
...> %Tempus.Slot{from: ~U|2020-08-12 23:00:00Z|, to: ~U|2020-08-12 23:30:00Z|}
...> ]
iex> Tempus.Slots.merge([slots, other])
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-08 12:00:00Z]},
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-12 23:00:00Z], to: ~U[2020-08-12 23:30:00Z]}]}}
iex> Tempus.Slots.merge([slots, Tempus.Slots.wrap(other, Tempus.Slots.Stream)]) |> Enum.to_list()
[%Tempus.Slot{from: ~U[2020-08-07 00:00:00.000000Z], to: ~U[2020-08-08 12:00:00Z]},
%Tempus.Slot{from: ~U[2020-08-10 00:00:00.000000Z], to: ~U[2020-08-10 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-12 23:00:00Z], to: ~U[2020-08-12 23:30:00Z]}]
"""
def merge(slots, enum \\ [], options \\ [])
def merge(%Slots{} = slots, enum, options), do: do_merge([slots, enum], options)
def merge(slots, options, []), do: do_merge(slots, options)
defp do_merge([], _options), do: %Slots.Void{}
defp do_merge([%Slots{} = slots], _options), do: slots
defp do_merge([%Slots{slots: %_{} = head} = slots, %Slots{slots: %_{} = next} | rest], options) do
case Group.merge(head, next, options) do
{:ok, merged} -> merge([%Slots{slots: merged} | rest], options)
{:error, _} -> do_merge([slots, Group.flatten(next, options) | rest], options)
end
end
defp do_merge([%Slots{slots: %_{} = head}, next | rest], options) when is_list(next) do
next = Enum.reduce(next, head, &Group.add(&2, &1, options))
merge([%Slots{slots: next} | rest], options)
end
@spec inverse(slots :: Slots.t(), keyword()) :: Slots.t()
@doc """
Inverses `Slots` returning the new `Slots` instance with slots set where
there were blanks.
### Example
iex> [
...> Tempus.Slot.wrap(~D|2020-08-07|),
...> Tempus.Slot.wrap(~D|2020-08-08|),
...> Tempus.Slot.wrap(~D|2020-08-10|),
...> Tempus.Slot.wrap(~D|2020-08-12|)
...> ] |> Enum.into(%Tempus.Slots{})
...> |> Tempus.Slots.inverse()
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: nil, to: ~U[2020-08-06 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-09 00:00:00.000000Z], to: ~U[2020-08-09 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-11 00:00:00.000000Z], to: ~U[2020-08-11 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-13 00:00:00.000000Z], to: nil}]}}
iex> [
...> %Tempus.Slot{to: ~U[2020-08-08 23:59:59.999999Z]},
...> Tempus.Slot.wrap(~D|2020-08-10|),
...> %Tempus.Slot{from: ~U[2020-08-12 00:00:00.000000Z]}
...> ] |> Enum.into(%Tempus.Slots{})
...> |> Tempus.Slots.inverse()
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-09 00:00:00.000000Z], to: ~U[2020-08-09 23:59:59.999999Z]},
%Tempus.Slot{from: ~U[2020-08-11 00:00:00.000000Z], to: ~U[2020-08-11 23:59:59.999999Z]}]}}
"""
def inverse(slots, options \\ [])
def inverse(%Slots{slots: slots}, options) do
case Group.inverse(slots, options) do
{:ok, inversed} -> %Slots{slots: inversed}
{:error, _} -> raise "Not yet implemented"
end
end
@spec wrap([Slot.origin()] | Slots.t(), keyword()) :: Slots.t()
@doc since: "0.3.0"
@doc """
Wraps the argument into a slots instance. For `nil` it’d be an empty slots.
For everything else it’d call `Slot.wrap/1` on an argument and add it to empty slots.
## Examples
iex> Tempus.Slots.wrap(~D|2020-08-06|)
%Tempus.Slots{slots: %Tempus.Slots.List{slots: [
%Tempus.Slot{from: ~U[2020-08-06 00:00:00.000000Z], to: ~U[2020-08-06 23:59:59.999999Z]}]}}
"""
def wrap(any, options \\ [])
def wrap(any, implementation) when is_atom(implementation),
do: do_wrap(any, implementation, [])
def wrap(any, options) when is_list(options) do
{implementation, options} = Keyword.pop(options, :implementation, @implementation)
do_wrap(any, implementation, options)
end
defp do_wrap(%Slots{slots: %implementation{}} = slots, implementation, _options), do: slots
defp do_wrap(%Slots{slots: slots}, implementation, options) do
slots |> Group.flatten(options) |> do_wrap(implementation, options)
end
defp do_wrap(slots, implementation, options) do
merge(%Slots{slots: implementation.new()}, List.wrap(slots), options)
end
defimpl Enumerable do
@moduledoc false
def reduce(%Slots{slots: %_{} = slots}, acc, fun),
do: Enumerable.reduce(slots, acc, fun)
def member?(%Slots{slots: _slots}, _value), do: {:error, __MODULE__}
def count(%Slots{slots: _slots}), do: {:error, __MODULE__}
def slice(%Slots{slots: _slots}), do: {:error, __MODULE__}
end
defimpl Collectable do
@moduledoc false
alias Tempus.Slots
def into(original) do
{
original,
fn
slots, {:cont, value} -> Slots.add(slots, value)
slots, :done -> slots
_, :halt -> :ok
end
}
end
end
defimpl Inspect do
@moduledoc false
import Inspect.Algebra
def inspect(%Tempus.Slots{slots: slots}, opts) do
concat(["#𝕋<", to_doc(slots, opts), ">"])
end
end
end
