Hello, everyone,
It is necessary to implement the generation of unique meetings.
Want to replace
Enum.find(tail, &check_unique_pair(head, &1))
but I don’t know what’s best.
----migration----------
create unique_index(:"meetups", [:meetuper1, :meetuper2])
-------model---------------------------------
schema "meetups" do
field :met_at, :naive_datetime
field :meetuper1_rating, :integer
field :meetuper2_rating, :integer
field :average_rating, :float
field :is_resolved, :boolean
timestamps()
belongs_to :user1, User, foreign_key: :meetuper1
belongs_to :user2, User, foreign_key: :meetuper2
end
def active_users_query do
query = from(u in User,
where:
u.is_status == true,
select: u.id,
order_by: u.id
)
end
def unresolved_users_meetups_query() do
first_meetupers = from(u in User,
join: m1 in Meetup,
on: u.id == m1.meetuper1,
where:
m1.is_resolved == false and
(m1.meetuper1 == u.id or
m1.meetuper2 == u.id),
select: u.id,
)
second_meetupers = from(u in User,
join: m2 in Meetup,
on: u.id == m2.meetuper2,
where:
m2.is_resolved == false and
(m2.meetuper1 == u.id or
m2.meetuper2 == u.id),
select: u.id,
)
first_meetupers |> union(^second_meetupers)
end
def users_meetup_query(meetuper1, meetuper2) do
from(m in Meetup,
where:
(m.meetuper1 == ^meetuper1 and
m.meetuper2 == ^meetuper2) or
(m.meetuper1 == ^meetuper2 and
m.meetuper2 == ^meetuper1)
)
end
----context-------------------
def generete_meetups() do
active_users =
Meetup.active_users_query()
|> Repo.all()
unresolved_users_meetups =
Meetup.unresolved_users_meetups_query()
|> Repo.all()
correct_users = active_users -- unresolved_users_meetups
unique_pair = get_unique_pair(correct_users, [])
create_unique_meetups(unique_pair)
end
def get_unique_pair([head | tail] = users, meetups_list) do
case Enum.find(tail, &check_unique_pair(head, &1)) do
nil -> get_unique_pair(tail, meetups_list)
meetuper2 ->
meetups_list = meetups_list ++ [head] ++ [meetuper2]
users = users -- [head]
users = users -- [meetuper2]
get_unique_pair(users, meetups_list)
end
end
def get_unique_pair([], meetups_list) do
meetups_list
end
def check_unique_pair(meetuper1, meetuper2) do
query = Meetup.users_meetup_query(meetuper1, meetuper2)
case Repo.one(query) do
nil -> true
_ -> false
end
end
def create_unique_meetups([head | tail] = unique_pair) do
now = NaiveDateTime.utc_now()
{:ok, res} = NaiveDateTime.new(now.year, now.month, now.day, 14, 0, 0)
meetuper1 = head
[meetuper2, tail2] = tail
create_meetup([meetuper1, meetuper2], %{met_at: res})
create_unique_meetups(tail2)
end
def create_unique_meetups(single_meetuper) do
{:ok, "all meetups create"}
end
