philomena/lib/philomena_web/markdown_renderer.ex
2022-03-24 18:44:39 +01:00

129 lines
3.5 KiB
Elixir

defmodule PhilomenaWeb.MarkdownRenderer do
alias Philomena.Markdown
alias Philomena.Images.Image
alias Philomena.Repo
import Phoenix.HTML
import Phoenix.HTML.Link
import Ecto.Query
@image_view Module.concat(["PhilomenaWeb.ImageView"])
def render_one(item, conn) do
hd(render_collection([item], conn))
end
def render_collection(collection, conn) do
representations =
collection
|> Enum.flat_map(fn %{body: text} ->
find_images(text || "")
end)
|> render_representations(conn)
Enum.map(collection, fn %{body: text} ->
Markdown.to_html(text || "", representations)
end)
end
def render_unsafe(text, conn) do
images = find_images(text)
representations = render_representations(images, conn)
Markdown.to_html_unsafe(text, representations)
end
defp find_images(text) do
Regex.scan(~r/>>(\d+)([tsp])?/, text, capture: :all_but_first)
|> Enum.map(fn matches ->
[Enum.at(matches, 0) |> String.to_integer(), Enum.at(matches, 1) || ""]
end)
|> Enum.filter(fn m -> Enum.at(m, 0) < 2_147_483_647 end)
end
defp load_images(images) do
ids = Enum.map(images, fn m -> Enum.at(m, 0) end)
Image
|> where([i], i.id in ^ids)
|> preload(tags: :aliases)
|> Repo.all()
|> Map.new(&{&1.id, &1})
end
defp link_suffix(image) do
cond do
not is_nil(image.duplicate_id) ->
" (merged)"
image.hidden_from_users ->
" (deleted)"
not image.approved ->
" (pending approval)"
true ->
""
end
end
defp render_representations(images, conn) do
loaded_images = load_images(images)
images
|> Enum.map(fn group ->
img = loaded_images[Enum.at(group, 0)]
text = "#{Enum.at(group, 0)}#{Enum.at(group, 1)}"
rendered =
cond do
img != nil ->
case group do
[_id, "p"] when not img.hidden_from_users and img.approved ->
Phoenix.View.render(@image_view, "_image_target.html",
image: img,
size: :medium,
conn: conn
)
|> safe_to_string()
[_id, "t"] when not img.hidden_from_users and img.approved ->
Phoenix.View.render(@image_view, "_image_target.html",
image: img,
size: :small,
conn: conn
)
|> safe_to_string()
[_id, "s"] when not img.hidden_from_users and img.approved ->
Phoenix.View.render(@image_view, "_image_target.html",
image: img,
size: :thumb_small,
conn: conn
)
|> safe_to_string()
[id, suffix] when not img.approved ->
">>#{img.id}#{suffix}#{link_suffix(img)}"
[_id, ""] ->
link(">>#{img.id}#{link_suffix(img)}", to: "/images/#{img.id}")
|> safe_to_string()
[_id, suffix] when suffix in ["t", "s", "p"] ->
link(">>#{img.id}#{suffix}#{link_suffix(img)}", to: "/images/#{img.id}")
|> safe_to_string()
# This condition should never trigger, but let's leave it here just in case.
[id, suffix] ->
">>#{id}#{suffix}"
end
true ->
">>#{text}"
end
[text, rendered]
end)
|> Map.new(fn [id, html] -> {id, html} end)
end
end