# frozen_string_literal: true

class PostReplacementProcessor
  attr_reader :post, :replacement

  def initialize(post:, replacement:)
    @post = post
    @replacement = replacement
  end

  def process!
    media_file = get_file_for_upload(replacement.replacement_url, nil, replacement.replacement_file&.tempfile)

    if Post.where.not(id: post.id).exists?(md5: media_file.md5)
      replacement.errors.add(:base, "Duplicate: post with md5 #{media_file.md5} already exists")
      return
    end

    if media_file.md5 == post.md5
      media_asset = post.media_asset
    else
      media_asset = MediaAsset.upload!(media_file)
    end

    if replacement.replacement_file.present?
      canonical_url = "file://#{replacement.replacement_file.original_filename}"
    else
      canonical_url = Sources::Strategies.find(replacement.replacement_url).canonical_url
    end

    replacement.replacement_url = canonical_url
    replacement.file_ext = media_asset.file_ext
    replacement.file_size = media_asset.file_size
    replacement.image_height = media_asset.image_height
    replacement.image_width = media_asset.image_width
    replacement.md5 = media_asset.md5

    post.md5 = media_asset.md5
    post.file_ext = media_asset.file_ext
    post.image_width = media_asset.image_width
    post.image_height = media_asset.image_height
    post.file_size = media_asset.file_size
    post.source = replacement.final_source.presence || replacement.replacement_url
    post.tag_string = replacement.tags

    rescale_notes(post)

    replacement.save!
    post.save!

    post.update_iqdb
  end

  def rescale_notes(post)
    x_scale = post.image_width.to_f  / post.image_width_was.to_f
    y_scale = post.image_height.to_f / post.image_height_was.to_f

    post.notes.each do |note|
      note.rescale!(x_scale, y_scale)
    end
  end

  def get_file_for_upload(source_url, referer_url, file)
    return MediaFile.open(file) if file.present?
    raise "No file or source URL provided" if source_url.blank?

    strategy = Sources::Strategies.find(source_url, referer_url)
    raise NotImplementedError, "No login credentials configured for #{strategy.site_name}." unless strategy.class.enabled?

    strategy.download_file!
  end
end