neiam /gitgud

defmodule GitGudWeb.ModerationComponents do
  @moduledoc """
  Renders moderation-aware bodies for issues, issue comments, PRs, and
  PR comments.

  When a row's `moderated_at` is set, its `body` has been replaced with
  a moderator note (carried on `moderation_note`). The pre-replacement
  body lives on `original_body`. We render:

    * Always: a small "Removed by moderator" banner with the note.
    * For admins + the original author: a collapsed `<details>` with
      the original body, rendered as Markdown like the live version.

  `<.moderated_body>` is the shared component used by both issue and PR
  show pages. The caller passes the schema struct, the viewer (the
  current `User` or nil), the repo (for cross-reference resolution),
  and the editor theme.
  """

  use Phoenix.Component

  import GitGudWeb.CoreComponents, only: [icon: 1]

  alias GitGud.Markdown

  attr :target, :map, required: true, doc: "issue / issue_comment / PR / pr_comment"
  attr :viewer, :map, default: nil, doc: "current user (or nil) for visibility check"
  attr :repo, :map, required: true
  attr :theme, :string, default: "onedark"
  attr :empty_text, :string, default: "No description."

  def moderated_body(assigns) do
    assigns = assign(assigns, :show_original?, can_view_original?(assigns.target, assigns.viewer))

    ~H"""
    <%= cond do %>
      <% moderated?(@target) -> %>
        <div class="rounded border border-warning/40 bg-warning/10 p-3 text-sm space-y-2">
          <p class="font-medium">
            <.icon name="hero-shield-exclamation" class="size-4 inline" /> Removed by moderator
          </p>
          <p :if={@target.moderation_note && @target.moderation_note != ""} class="opacity-80 text-xs">
            {@target.moderation_note}
          </p>
          <details :if={@show_original?} class="mt-1">
            <summary class="cursor-pointer text-xs opacity-70 hover:opacity-100">
              Show original
            </summary>
            <div class="prose max-w-none mt-2 text-sm">
              {Phoenix.HTML.raw(Markdown.to_html(@target.original_body || "", theme: @theme, repo: @repo))}
            </div>
          </details>
        </div>

      <% @target.body && @target.body != "" -> %>
        <div class="prose max-w-none">
          {Phoenix.HTML.raw(Markdown.to_html(@target.body, theme: @theme, repo: @repo))}
        </div>

      <% true -> %>
        <p class="opacity-50">{@empty_text}</p>
    <% end %>
    """
  end

  defp moderated?(%{moderated_at: ts}) when not is_nil(ts), do: true
  defp moderated?(_), do: false

  @doc """
  Visibility rule for the "Show original" toggle:
  - Admins always see it.
  - The original author sees it.
  - Everyone else: no.
  """
  def can_view_original?(_target, nil), do: false

  def can_view_original?(target, %{id: viewer_id, is_admin: is_admin}) do
    cond do
      is_admin -> true
      Map.get(target, :author_id) == viewer_id -> true
      true -> false
    end
  end

  def can_view_original?(_target, _viewer), do: false
end