30 lines
740 B
Elixir
30 lines
740 B
Elixir
defmodule Bones73kWeb.Pagination do
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def generate_page_list(_, total_pages) when total_pages < 5,
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do: 1..total_pages |> Enum.to_list()
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def generate_page_list(current, total_pages),
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do: first_half(1, current) ++ [current] ++ second_half(current, total_pages)
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defp first_half(first, current) do
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prev = current - 1
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cond do
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first == current -> []
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prev <= first -> [first]
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prev - first > 2 -> [first, -1, prev]
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true -> first..prev |> Enum.to_list()
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end
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end
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defp second_half(current, last) do
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next = current + 1
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cond do
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last == current -> []
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next >= last -> [last]
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last - next > 2 -> [next, -1, last]
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true -> next..last |> Enum.to_list()
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end
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end
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end
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