# frozen_string_literal: true

#-- copyright
# OpenProject is an open source project management software.
# Copyright (C) the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2013 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See COPYRIGHT and LICENSE files for more details.
#++

class JournalsController < ApplicationController
  before_action :load_and_authorize_in_optional_project, only: [:index]
  before_action :find_journal,
                :ensure_permitted,
                :ensure_valid_for_diffing,
                only: [:diff]
  authorization_checked! :diff

  accept_key_auth :index
  menu_item :issues

  include QueriesHelper
  include SortHelper

  def index
    @query = retrieve_query(@project)
    sort_init "id", "desc"
    sort_update(@query.sortable_key_by_column_name)

    if @query.valid?
      @journals = @query.work_package_journals(order: "#{Journal.table_name}.created_at DESC",
                                               limit: 25)
    end

    respond_to do |format|
      format.atom do
        render layout: false,
               content_type: "application/atom+xml",
               locals: { title: journals_index_title,
                         journals: @journals }
      end
    end
  end

  def diff
    from, to = diff_values
    unless from || to
      return render_400 message: I18n.t(:error_journal_attribute_not_present, attribute: field_param)
    end

    @activity_page = params["activity_page"]
    @diff = Redmine::Helpers::Diff.new(to, from)

    respond_to do |format|
      format.html
      format.js do
        render partial: "diff", locals: { diff: @diff }
      end
    end
  end

  private

  def find_journal
    @journal = Journal.find(params[:id])
    @journable = @journal.journable
    @project = @journable.project
  end

  def ensure_permitted
    deny_access unless @journal.visible?(User.current)
  end

  def diff_values
    if @journal.details[field_param] in [from, to]
      [from, to]
    elsif @journal.cause_type == "import"
      imported_cause_diff_values
    end
  end

  def imported_cause_diff_values
    entries = @journal.cause_import_history
    return unless entries.is_a?(Array)

    item = entries.flat_map { |e| e["items"] || [] }
                  .find { |i| i["field"]&.parameterize&.underscore == field_param }
    return unless item

    [item["fromString"], item["toString"]]
  end

  def field_param
    @field_param ||= params[:field].parameterize.underscore
  end

  def ensure_valid_for_diffing
    case field_param
    when "description",
         "status_explanation",
         /\Aagenda_items_\d+_notes\z/
      # no additional checks
    when /\Acustom_fields_(?<cf_id>\d+)\z/
      ensure_custom_value_valid_for_diffing(Regexp.last_match(:cf_id))
    when /\Acustom_comment_(?<cf_id>\d+)\z/
      ensure_custom_comment_valid_for_diffing(Regexp.last_match(:cf_id))
    else
      render_404
    end
  end

  def ensure_custom_value_valid_for_diffing(cf_id)
    custom_field = CustomField.find_by(id: cf_id)
    # Even if the custom field is deleted
    # we will need to return 403 if the custom field class allows admin-only fields
    return render_403 if deleted_cf_forbidden?(custom_field)

    # If no admin-only field, we can allow deleted custom fields to be rendered now
    return if custom_field.nil?
    return render_403 unless custom_field.visible?(User.current, project: @journable.project)

    render_404 if custom_field.field_format != "text"
  end

  def ensure_custom_comment_valid_for_diffing(cf_id)
    custom_field = CustomField.find_by(id: cf_id)
    return render_403 if deleted_cf_forbidden?(custom_field)
    return if custom_field.nil?

    render_403 unless custom_field.visible?(User.current, project: @journable.project)
  end

  # When a CF is deleted we can no longer call visible? on it. For journables that support
  # admin-only CFs (e.g. Project), block non-admins because the deleted CF could have been admin-only.
  def deleted_cf_forbidden?(custom_field)
    custom_field.nil? &&
      @journable.admin_only_custom_fields_allowed? &&
      !User.current.admin?
  end

  def journals_index_title
    subject = @project ? @project.name : Setting.app_title
    query_name = @query.new_record? ? I18n.t(:label_changes_details) : @query.name
    "#{subject}: #{query_name}"
  end
end