# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/

class TicketsController < ApplicationController
  include CreatesTicketArticles
  include ClonesTicketArticleAttachments
  include ChecksUserAttributesByCurrentUserPermission
  include TicketStats
  include CanPaginate

  prepend_before_action -> { authorize! }, only: %i[create selector import_example import_start ticket_customer ticket_history ticket_related ticket_recent ticket_merge ticket_split]
  prepend_before_action :authentication_check

  # GET /api/v1/tickets
  def index
    paginate_with(max: 100)

    tickets = TicketPolicy::ReadScope.new(current_user).resolve
                                     .order(id: :asc)
                                     .offset(pagination.offset)
                                     .limit(pagination.limit)

    if response_expand?
      list = []
      tickets.each do |ticket|
        list.push ticket.attributes_with_association_names
      end
      render json: list, status: :ok
      return
    end

    if response_full?
      assets = {}
      item_ids = []
      tickets.each do |item|
        item_ids.push item.id
        assets = item.assets(assets)
      end
      render json: {
        record_ids: item_ids,
        assets:     assets,
      }, status: :ok
      return
    end

    render json: tickets
  end

  # GET /api/v1/tickets/1
  def show
    ticket = Ticket.find(params[:id])
    authorize!(ticket)

    if response_expand?
      result = ticket.attributes_with_association_names
      render json: result, status: :ok
      return
    end

    if response_full?
      full = Ticket.full(params[:id])
      render json: full
      return
    end

    if response_all?
      render json: ticket_all(ticket)
      return
    end

    render json: ticket
  end

  # POST /api/v1/tickets
  def create
    customer = {}
    if params[:customer].instance_of?(ActionController::Parameters)
      customer = params[:customer]
      params.delete(:customer)
    end

    clean_params = Ticket.association_name_to_id_convert(params)

    # overwrite params
    if !current_user.permissions?('ticket.agent')
      %i[owner owner_id customer customer_id organization organization_id preferences].each do |key|
        clean_params.delete(key)
      end
      clean_params[:customer_id] = current_user.id
    end

    # The parameter :customer_id is 'abused' in cases where it is not an integer, but a string like
    #   'guess:customers.email@domain.com' which implies that the customer should be looked up.
    if clean_params[:customer_id].is_a?(String) && clean_params[:customer_id] =~ %r{^guess:(.+?)$}
      email_address = $1
      email_address_validation = EmailAddressValidation.new(email_address)
      if !email_address_validation.valid_format?
        render json: { error: "Invalid email '#{email_address}' of customer" }, status: :unprocessable_entity
        return
      end
      local_customer = User.find_by(email: email_address.downcase)
      if !local_customer
        role_ids = Role.signup_role_ids
        local_customer = User.create(
          firstname: '',
          lastname:  '',
          email:     email_address,
          password:  '',
          active:    true,
          role_ids:  role_ids,
        )
      end
      clean_params[:customer_id] = local_customer.id
    end

    # try to create customer if needed
    if clean_params[:customer_id].blank? && customer.present?
      check_attributes_by_current_user_permission(customer)
      clean_customer = User.association_name_to_id_convert(customer)
      local_customer = nil
      if !local_customer && clean_customer[:id].present?
        local_customer = User.find_by(id: clean_customer[:id])
      end
      if !local_customer && clean_customer[:email].present?
        local_customer = User.find_by(email: clean_customer[:email].downcase)
      end
      if !local_customer && clean_customer[:login].present?
        local_customer = User.find_by(login: clean_customer[:login].downcase)
      end
      if !local_customer
        role_ids = Role.signup_role_ids
        local_customer = User.new(clean_customer)
        local_customer.role_ids = role_ids
        local_customer.save!
      end
      clean_params[:customer_id] = local_customer.id
    end

    clean_params = Ticket.param_cleanup(clean_params, true)
    clean_params[:screen] = 'create_middle'
    ticket = Ticket.new(clean_params)
    authorize!(ticket, :create?)

    # check if article is given
    if !params[:article]
      render json: { error: 'article hash is missing' }, status: :unprocessable_entity
      return
    end

    # create ticket
    ticket.save!
    ticket.with_lock do

      # create tags if given
      if params[:tags].present?
        tags = params[:tags].split(',')
        tags.each do |tag|
          ticket.tag_add(tag)
        end
      end

      # create mentions if given
      if params[:mentions].present?
        authorize!(Mention.new, :create?)
        Array(params[:mentions]).each do |user_id|
          Mention.where(mentionable: ticket, user_id: user_id).first_or_create(mentionable: ticket, user_id: user_id)
        end
      end

      # create article if given
      if params[:article]
        article_create(ticket, params[:article])
      end
    end
    # create links (e. g. in case of ticket split)
    # links: {
    #   Ticket: {
    #     parent: [ticket_id1, ticket_id2, ...]
    #     normal: [ticket_id1, ticket_id2, ...]
    #     child: [ticket_id1, ticket_id2, ...]
    #   },
    # }
    if params[:links].present?
      link = params[:links].permit!.to_h
      raise Exceptions::UnprocessableEntity, 'Invalid link structure' if !link.is_a? Hash

      link.each do |target_object, link_types_with_object_ids|
        raise Exceptions::UnprocessableEntity, 'Invalid link structure (Object)' if !link_types_with_object_ids.is_a? Hash

        link_types_with_object_ids.each do |link_type, object_ids|
          raise Exceptions::UnprocessableEntity, 'Invalid link structure (Object->LinkType)' if !object_ids.is_a? Array

          object_ids.each do |local_object_id|
            link = Link.add(
              link_type:                link_type,
              link_object_target:       target_object,
              link_object_target_value: local_object_id,
              link_object_source:       'Ticket',
              link_object_source_value: ticket.id,
            )
          end
        end
      end
    end

    if response_expand?
      result = ticket.reload.attributes_with_association_names
      render json: result, status: :created
      return
    end

    if response_full?
      full = Ticket.full(ticket.id)
      render json: full, status: :created
      return
    end

    if response_all?
      render json: ticket_all(ticket.reload), status: :created
      return
    end

    render json: ticket.reload.attributes_with_association_ids, status: :created
  end

  # PUT /api/v1/tickets/1
  def update
    ticket = Ticket.find(params[:id])
    authorize!(ticket, :follow_up?)
    authorize!(ticket)

    clean_params = Ticket.association_name_to_id_convert(params)
    clean_params = Ticket.param_cleanup(clean_params, true)

    # only apply preferences changes (keep not updated keys/values)
    clean_params = ticket.param_preferences_merge(clean_params)
    clean_params[:screen] = 'edit'

    # disable changes on ticket number
    clean_params.delete('number')

    # overwrite params
    if !current_user.permissions?('ticket.agent')
      %i[owner owner_id customer customer_id organization organization_id preferences].each do |key|
        clean_params.delete(key)
      end
    end

    ticket.with_lock do
      ticket.update!(clean_params)
      if params[:article].present?
        article_create(ticket, params[:article])
      end
    end

    if response_expand?
      result = ticket.reload.attributes_with_association_names
      render json: result, status: :ok
      return
    end

    if response_full?
      full = Ticket.full(params[:id])
      render json: full, status: :ok
      return
    end

    if response_all?
      render json: ticket_all(ticket.reload), status: :ok
      return
    end

    render json: ticket.reload.attributes_with_association_ids, status: :ok
  end

  # DELETE /api/v1/tickets/1
  def destroy
    ticket = Ticket.find(params[:id])
    authorize!(ticket)

    ticket.destroy!

    head :ok
  end

  # GET /api/v1/ticket_customer
  # GET /api/v1/tickets_customer
  def ticket_customer

    # return result
    result = Ticket::ScreenOptions.list_by_customer(
      current_user: current_user,
      customer_id:  params[:customer_id],
      limit:        15,
    )
    render json: result
  end

  # GET /api/v1/ticket_history/1
  def ticket_history

    # get ticket data
    ticket = Ticket.find(params[:id])
    authorize!(ticket, :show?)

    # get history of ticket
    render json: ticket.history_get(true)
  end

  # GET /api/v1/ticket_related/1
  def ticket_related

    ticket = Ticket.find(params[:ticket_id])
    assets = ticket.assets({})

    tickets = TicketPolicy::ReadScope.new(current_user).resolve
                                     .where(
                                       customer_id: ticket.customer_id,
                                       state_id:    Ticket::State.by_category(:open).select(:id),
                                     )
                                     .where.not(id: ticket.id)
                                     .order(created_at: :desc)
                                     .limit(6)

    # if we do not have open related tickets, search for any tickets
    tickets ||= TicketPolicy::ReadScope.new(current_user).resolve
                                       .where(customer_id: ticket.customer_id)
                                       .where.not(state_id: Ticket::State.by_category(:merged).pluck(:id))
                                       .where.not(id: ticket.id)
                                       .order(created_at: :desc)
                                       .limit(6)

    # get related assets
    ticket_ids_by_customer = []
    tickets.each do |ticket_list|
      ticket_ids_by_customer.push ticket_list.id
      assets = ticket_list.assets(assets)
    end

    ticket_ids_recent_viewed = []
    recent_views = RecentView.list(current_user, 8, 'Ticket')
    recent_views.each do |recent_view|
      next if recent_view.object.name != 'Ticket'
      next if recent_view.o_id == ticket.id

      ticket_ids_recent_viewed.push recent_view.o_id
      recent_view_ticket = Ticket.find(recent_view.o_id)
      assets = recent_view_ticket.assets(assets)
    end

    # return result
    render json: {
      assets:                   assets,
      ticket_ids_by_customer:   ticket_ids_by_customer,
      ticket_ids_recent_viewed: ticket_ids_recent_viewed,
    }
  end

  # GET /api/v1/ticket_recent
  def ticket_recent
    ticket_ids = RecentView.list(current_user, 10, Ticket.name).map(&:o_id)
    tickets    = ticket_ids.map { |elem| Ticket.lookup(id: elem) }
    assets     = ApplicationModel::CanAssets.reduce(tickets)

    render json: {
      assets:                   assets,
      ticket_ids_recent_viewed: ticket_ids
    }
  end

  # PUT /api/v1/ticket_merge/1/1
  def ticket_merge

    # check target ticket
    target_ticket = Ticket.find_by(number: params[:target_ticket_number])
    if !target_ticket
      render json: {
        result:  'failed',
        message: 'No such target ticket number!',
      }
      return
    end
    authorize!(target_ticket, :update?)

    # check source ticket
    source_ticket = Ticket.find_by(id: params[:source_ticket_id])
    if !source_ticket
      render json: {
        result:  'failed',
        message: 'No such source ticket!',
      }
      return
    end
    authorize!(source_ticket, :update?)

    # merge ticket
    source_ticket.merge_to(
      ticket_id:     target_ticket.id,
      created_by_id: current_user.id,
    )

    # return result
    render json: {
      result:        'success',
      target_ticket: target_ticket.attributes,
      source_ticket: source_ticket.attributes,
    }
  end

  # GET /api/v1/ticket_split
  def ticket_split
    ticket = Ticket.find(params[:ticket_id])
    authorize!(ticket, :show?)
    assets = ticket.assets({})

    article = Ticket::Article.find(params[:article_id])
    authorize!(article.ticket, :show?)
    assets = article.assets(assets)

    render json: {
      assets:      assets,
      attachments: article_attachments_clone(article),
    }
  end

  # GET /api/v1/ticket_create
  def ticket_create

    # get attributes to update
    attributes_to_change = Ticket::ScreenOptions.attributes_to_change(
      view:         'ticket_create',
      screen:       'create_middle',
      current_user: current_user,
    )
    render json: attributes_to_change
  end

  # GET /api/v1/tickets/search
  def search

    # permit nested conditions
    if params[:condition]
      params.require(:condition).permit!
    end

    paginate_with(max: 200, default: 50)

    query = params[:query]
    if query.respond_to?(:permit!)
      query = query.permit!.to_h
    end

    # build result list
    tickets = Ticket.search(
      query:        query,
      condition:    params[:condition].to_h,
      limit:        pagination.limit,
      offset:       pagination.offset,
      order_by:     params[:order_by],
      sort_by:      params[:sort_by],
      current_user: current_user,
    )

    if response_expand?
      list = []
      tickets.each do |ticket|
        list.push ticket.attributes_with_association_names
      end
      render json: list, status: :ok
      return
    end

    assets = {}
    ticket_result = []
    tickets.each do |ticket|
      ticket_result.push ticket.id
      assets = ticket.assets(assets)
    end

    # return result
    render json: {
      tickets:       ticket_result,
      tickets_count: tickets.count,
      assets:        assets,
    }
  end

  # GET /api/v1/tickets/selector
  def selector
    ticket_count, tickets = Ticket.selectors(params[:condition], limit: 6, execution_time: true)

    assets = {}
    ticket_ids = []
    tickets&.each do |ticket|
      ticket_ids.push ticket.id
      assets = ticket.assets(assets)
    end

    # return result
    render json: {
      ticket_ids:   ticket_ids,
      ticket_count: ticket_count || 0,
      assets:       assets,
    }
  end

  # GET /api/v1/ticket_stats
  def stats

    if !params[:user_id] && !params[:organization_id]
      raise 'Need user_id or organization_id as param'
    end

    # lookup open user tickets
    limit            = 100
    assets           = {}

    user_tickets = {}
    if params[:user_id]
      user = User.lookup(id: params[:user_id])
      if !user
        raise "No such user with id #{params[:user_id]}"
      end

      conditions = {
        closed_ids: {
          'ticket.state_id'    => {
            operator: 'is',
            value:    Ticket::State.by_category(:closed).pluck(:id),
          },
          'ticket.customer_id' => {
            operator: 'is',
            value:    user.id,
          },
        },
        open_ids:   {
          'ticket.state_id'    => {
            operator: 'is',
            value:    Ticket::State.by_category(:open).pluck(:id),
          },
          'ticket.customer_id' => {
            operator: 'is',
            value:    user.id,
          },
        },
      }
      conditions.each do |key, local_condition|
        user_tickets[key] = ticket_ids_and_assets(local_condition, current_user, limit, assets)
      end

      # generate stats by user
      condition = {
        'tickets.customer_id' => user.id,
      }
      user_tickets[:volume_by_year] = ticket_stats_last_year(condition)

    end

    # lookup open org tickets
    org_tickets = {}
    if params[:organization_id].present?
      organization = Organization.lookup(id: params[:organization_id])
      if !organization
        raise "No such organization with id #{params[:organization_id]}"
      end

      conditions = {
        closed_ids: {
          'ticket.state_id'        => {
            operator: 'is',
            value:    Ticket::State.by_category(:closed).pluck(:id),
          },
          'ticket.organization_id' => {
            operator: 'is',
            value:    organization.id,
          },
        },
        open_ids:   {
          'ticket.state_id'        => {
            operator: 'is',
            value:    Ticket::State.by_category(:open).pluck(:id),
          },
          'ticket.organization_id' => {
            operator: 'is',
            value:    organization.id,
          },
        },
      }
      conditions.each do |key, local_condition|
        org_tickets[key] = ticket_ids_and_assets(local_condition, current_user, limit, assets)
      end

      # generate stats by org
      condition = {
        'tickets.organization_id' => organization.id,
      }
      org_tickets[:volume_by_year] = ticket_stats_last_year(condition)
    end

    # return result
    render json: {
      user:         user_tickets,
      organization: org_tickets,
      assets:       assets,
    }
  end

  # @path    [GET] /tickets/import_example
  #
  # @summary          Download of example CSV file.
  # @notes            The requester have 'admin' permissions to be able to download it.
  # @example          curl -u 'me@example.com:test' http://localhost:3000/api/v1/tickets/import_example
  #
  # @response_message 200 File download.
  # @response_message 403 Forbidden / Invalid session.
  def import_example
    csv_string = Ticket.csv_example(
      col_sep: ',',
    )
    send_data(
      csv_string,
      filename:    'example.csv',
      type:        'text/csv',
      disposition: 'attachment'
    )

  end

  # @path    [POST] /tickets/import
  #
  # @summary          Starts import.
  # @notes            The requester have 'admin' permissions to be create a new import.
  # @example          curl -u 'me@example.com:test' -F 'file=@/path/to/file/tickets.csv' 'https://your.zammad/api/v1/tickets/import?try=true'
  # @example          curl -u 'me@example.com:test' -F 'file=@/path/to/file/tickets.csv' 'https://your.zammad/api/v1/tickets/import'
  #
  # @response_message 201 Import started.
  # @response_message 403 Forbidden / Invalid session.
  def import_start
    if Setting.get('import_mode') != true
      raise 'Only can import tickets if system is in import mode.'
    end

    string = params[:data]
    if string.blank? && params[:file].present?
      string = params[:file].read.force_encoding('utf-8')
    end
    raise Exceptions::UnprocessableEntity, 'No source data submitted!' if string.blank?

    result = Ticket.csv_import(
      string:       string,
      parse_params: {
        col_sep: params[:col_sep] || ',',
      },
      try:          params[:try],
    )
    render json: result, status: :ok
  end

  private

  def ticket_all(ticket)

    # get attributes to update
    attributes_to_change = Ticket::ScreenOptions.attributes_to_change(
      current_user: current_user,
      ticket:       ticket,
      screen:       'edit',
    )

    # get related users
    assets = attributes_to_change[:assets]
    assets = ticket.assets(assets)

    # get related users
    article_ids = []
    ticket.articles.each do |article|
      next if !authorized?(article, :show?)

      article_ids.push article.id
      assets = article.assets(assets)
    end

    # get links
    links = Link.list(
      link_object:       'Ticket',
      link_object_value: ticket.id,
      user:              current_user,
    )

    assets = Link.reduce_assets(assets, links)

    # get tags
    tags = ticket.tag_list

    # get mentions
    mentions = Mention.where(mentionable: ticket).order(created_at: :desc)
    mentions.each do |mention|
      assets = mention.assets(assets)
    end

    # return result
    {
      ticket_id:          ticket.id,
      ticket_article_ids: article_ids,
      assets:             assets,
      links:              links,
      tags:               tags,
      mentions:           mentions.pluck(:id),
      form_meta:          attributes_to_change[:form_meta],
    }
  end

end