73 lines
2.1 KiB
Elixir
73 lines
2.1 KiB
Elixir
defmodule Frenzy.Pipeline.ScrapeStage do
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require Logger
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alias Frenzy.Pipeline.Stage
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@behaviour Stage
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@impl Stage
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def apply(_opts, %{url: url} = item_params) do
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case get_article_content(url) do
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{:ok, content} ->
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{:ok, %{item_params | content: content}}
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{:error, reason} ->
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Logger.warn("Unable to get article content for #{url}: #{reason}")
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{:ok, item_params}
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end
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end
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@impl Stage
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def validate_opts(opts), do: {:ok, opts}
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@spec get_article_content(String.t()) :: {:ok, String.t()} | {:error, String.t()}
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defp get_article_content(url) when is_binary(url) and url != "" do
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Logger.debug("Getting article from #{url}")
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url
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|> HTTPoison.get()
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|> case do
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{:ok, response} ->
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handle_response(url, response)
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{:error, %HTTPoison.Error{reason: reason}} ->
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{:error, "HTTPoison error: #{reason}"}
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end
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end
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defp get_article_content(_url), do: {:error, "URL must be a non-empty string"}
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@spec handle_response(String.t(), HTTPoison.Response.t()) ::
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{:ok, String.t()} | {:error, String.t()}
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defp handle_response(_url, %HTTPoison.Response{status_code: 200, body: body}) do
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article = Readability.article(body)
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{:ok, Readability.readable_html(article)}
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end
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defp handle_response(_url, %HTTPoison.Response{status_code: 404}) do
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{:error, "404 not found"}
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end
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defp handle_response(url, %HTTPoison.Response{status_code: status_code, headers: headers})
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when status_code in [301, 302] do
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{"Location", new_url} = Enum.find(headers, fn {name, _value} -> name == "Location" end)
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headers
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|> Enum.find(fn {name, _value} -> name == "Location" end)
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|> case do
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{"Location", new_url} ->
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Logger.debug("Got 301 redirect from #{url} to #{new_url}")
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get_article_content(new_url)
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_ ->
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{:error, "Missing Location header for redirect"}
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end
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end
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defp handle_response(_url, %HTTPoison.Response{status_code: 403}) do
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{:error, "403 Forbidden"}
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end
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defp handle_response(_url, %HTTPoison.Response{status_code: status_code} = response) do
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{:error, "No handler for response #{inspect(response)}"}
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end
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end
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