class MailingsController < ApplicationController
  before_action :require_current_project!
  before_action :set_mailing, only: %i[show edit update destroy queue cancel test_send test_preview refresh_recipients update_recipients preview]
  before_action :load_form_collections, only: %i[new create edit update]

  def index
    redirect_to dashboard_mailings_path
  end

  def dashboard
    @page_title = "Invii email"
    @mailings = Mailing.for_project(current_project).includes(:mail_identity).recent
    @mail_identities_count = MailIdentity.active.count
    @active_mailings = @mailings.select(&:sending?)
    @paused_mailings = @active_mailings.select { |mailing| mailing.next_send_at.present? && mailing.next_send_at > Time.current }
    @completed_today = @mailings.count { |mailing| mailing.sent? && mailing.completed_at&.to_date == Time.zone.today }
    @failed_open = @mailings.sum(&:failed_count)
  end

  def new
    @page_title = "Nuovo invio"
    template = MailTemplate.for_project(current_project).order(:name).first
    identity = MailIdentity.active.ordered.first
    @mailing = Mailing.new(
      project: current_project,
      mail_template: template,
      mail_identity: identity,
      audience: "to_send",
      interval_seconds: 0,
      send_window_start_minutes: 10 * 60,
      send_window_end_minutes: 18 * 60,
      ab_assignment: "from_record",
      name: "Invio #{l(Time.zone.today)}",
      subject: template&.subject,
      body_html: template&.body_html
    )
  end

  def create
    @mailing = Mailing.new(mailing_params)
    @mailing.project = current_project
    apply_template_if_needed
    if @mailing.save
      @mailing.rebuild_recipients!
      redirect_to @mailing, notice: "Bozza creata. Controlla i destinatari e poi invia."
    else
      @page_title = "Nuovo invio"
      render :new, status: :unprocessable_entity
    end
  end

  def show
    @page_title = @mailing.name
    @recipients = @mailing.mailing_recipients.includes(:organization, :contact).ordered
    @preview_recipient = preview_recipient
    @preview_variant = preview_variant
    context = @preview_recipient&.merge_context || { project: current_project, ab_variant: @preview_variant }
    @preview_html = MailMerge.render(@mailing.body_for(@preview_variant), **context)
    @preview_subject = MailMerge.render(@mailing.subject_for(@preview_variant), **context)
    assign_test_preview
  end

  def edit
    unless @mailing.editable?
      redirect_to @mailing, alert: "Questo invio non è più modificabile."
      return
    end
    @page_title = "Modifica invio"
  end

  def update
    unless @mailing.editable?
      redirect_to @mailing, alert: "Questo invio non è più modificabile."
      return
    end

    @mailing.assign_attributes(mailing_params)
    apply_template_if_needed
    if @mailing.save
      rebuild_recipients_if_needed
      redirect_to @mailing, notice: "Invio aggiornato."
    else
      @page_title = "Modifica invio"
      render :edit, status: :unprocessable_entity
    end
  end

  def destroy
    unless @mailing.draft?
      redirect_to dashboard_mailings_path, alert: "Puoi eliminare solo le bozze."
      return
    end

    @mailing.destroy!
    redirect_to dashboard_mailings_path, notice: "Invio eliminato."
  end

  def refresh_recipients
    unless @mailing.editable?
      redirect_to @mailing, alert: "Destinatari bloccati: l'invio è già partito."
      return
    end

    @mailing.rebuild_recipients!
    redirect_to @mailing, notice: "Lista destinatari aggiornata."
  end

  def update_recipients
    unless @mailing.editable?
      redirect_to @mailing, alert: "Non puoi più cambiare i destinatari."
      return
    end

    selected = Array(params[:pending_ids]).map(&:to_i)
    @mailing.mailing_recipients.where.not(status: %w[sent queued]).find_each do |recipient|
      if selected.include?(recipient.id) && recipient.email_ok?
        recipient.update!(status: "pending", skip_reason: nil)
      else
        reason = recipient.email_ok? ? "escluso dal check" : (recipient.skip_reason.presence || "email non valida")
        recipient.update!(status: "skipped", skip_reason: reason)
      end
    end
    redirect_to @mailing, notice: "Selezione destinatari salvata."
  end

  def queue
    unless @mailing.draft? || @mailing.sending?
      redirect_to @mailing, alert: "Questo invio è già stato concluso."
      return
    end
    unless @mailing.tested?
      redirect_to @mailing, alert: "Prima di autorizzare l'invio di massa, manda una email di prova con dati di test."
      return
    end

    @mailing.queue_send!
    redirect_to dashboard_mailings_path, notice: queue_notice(@mailing)
  rescue StandardError => e
    redirect_to @mailing, alert: e.message
  end

  def cancel
    unless @mailing.sending?
      redirect_to @mailing, alert: "Solo un invio in corso può essere fermato."
      return
    end

    pending = @mailing.pending_count + @mailing.queued_count
    @mailing.cancel_send!
    redirect_to dashboard_mailings_path,
                notice: "Invio fermato. #{@mailing.sent_count} già inviate, #{pending} annullate in coda."
  rescue StandardError => e
    redirect_to @mailing, alert: e.message
  end

  def test_send
    assign_test_preview
    to = @test_to.to_s.strip
    unless to.match?(URI::MailTo::EMAIL_REGEXP)
      redirect_to @mailing, alert: "Inserisci un indirizzo email valido per la prova."
      return
    end

    html = @test_preview_html
    subject = "[TEST#{@mailing.ab_test? ? " #{@test_variant}" : ""}] #{@test_preview_subject}"
    recipient = Mailings::TestRecipient.new(mailing: @mailing, email: to)
    CampaignMailer.outreach(recipient, html: html, subject: subject).deliver_now
    @mailing.update!(test_sent_at: Time.current, test_sent_to: to)
    redirect_to @mailing, notice: "Prova inviata subito a #{to}. Controlla l'output e, se è corretto, autorizza l'invio di massa."
  rescue StandardError => e
    redirect_to @mailing, alert: "Invio di prova non riuscito: #{e.message}"
  end

  def test_preview
    assign_test_preview
  end

  def preview
    redirect_to mailing_path(@mailing, recipient_id: params[:recipient_id])
  end

  private

  def set_mailing
    @mailing = Mailing.for_project(current_project).find(params[:id])
  end

  def load_form_collections
    @mail_identities = MailIdentity.active.ordered
    @mail_templates = MailTemplate.for_project(current_project)
  end

  def mailing_params
    params.require(:mailing).permit(
      :name, :mail_identity_id, :mail_template_id, :mail_template_b_id, :audience,
      :subject, :body_html, :subject_b, :body_html_b, :ab_test, :ab_assignment,
      :interval_seconds, :send_window_enabled, :send_window_start_tod, :send_window_end_tod, files: []
    )
  end

  def queue_notice(mailing)
    pause = mailing.interval_seconds.positive? ? " con pausa di #{mailing.interval_seconds}s" : ""
    if mailing.send_window_enabled? && mailing.next_send_at && mailing.next_send_at > Time.current
      "Invio avviato. La prima email partirà #{I18n.l(mailing.next_send_at, format: :long)} (fascia #{mailing.send_window_label}#{pause})."
    else
      "Invio avviato. Le email partono in background#{pause}."
    end
  end

  def apply_template_if_needed
    copy_template_if_blank(params.dig(:mailing, :mail_template_id), :subject, :body_html)
    copy_template_if_blank(params.dig(:mailing, :mail_template_b_id), :subject_b, :body_html_b)
  end

  def copy_template_if_blank(template_id, subject_attr, body_attr)
    return if template_id.blank?

    template = MailTemplate.for_project(current_project).find_by(id: template_id)
    return unless template

    @mailing.public_send("#{subject_attr}=", template.subject) if @mailing.public_send(subject_attr).blank?
    @mailing.public_send("#{body_attr}=", template.body_html) if @mailing.public_send(body_attr).blank?
  end

  def rebuild_recipients_if_needed
    return unless @mailing.editable?
    return unless @mailing.saved_change_to_audience? || @mailing.saved_change_to_ab_test? || @mailing.saved_change_to_ab_assignment?

    @mailing.rebuild_recipients!
  end

  def preview_recipient
    if params[:recipient_id].present?
      @mailing.mailing_recipients.find_by(id: params[:recipient_id])
    else
      @mailing.mailing_recipients.pending.ordered.first || @mailing.mailing_recipients.ordered.first
    end
  end

  def preview_variant
    requested = params[:variant].to_s.upcase
    return requested if requested.in?(%w[A B])
    return "A" unless @mailing.ab_test?

    preview_recipient&.ab_variant.presence_in(%w[A B]) || "A"
  end

  def assign_test_preview
    @test_to = test_send_params[:to].presence || current_user.email
    @test_variant = test_send_params[:variant].to_s.upcase.presence_in(%w[A B]) || preview_variant
    @test_vars = default_test_vars.merge(test_vars_params)
    extras = @test_vars
    @test_preview_html = MailMerge.render(@mailing.body_for(@test_variant), extras: extras, project: current_project, ab_variant: @test_variant)
    @test_preview_subject = MailMerge.render(@mailing.subject_for(@test_variant), extras: extras, project: current_project, ab_variant: @test_variant)
  end

  def default_test_vars
    source = preview_recipient
    if source
      MailMerge.variables_for(**source.merge_context.merge(ab_variant: preview_variant))
    else
      MailMerge.catalog.keys.index_with { "" }
    end
  end

  def test_send_params
    params.permit(:to, :variant, :recipient_id)
  end

  def test_vars_params
    raw = params[:vars]
    return {} unless raw.respond_to?(:to_unsafe_h) || raw.is_a?(Hash)

    allowed = MailMerge.catalog.keys
    hash = raw.respond_to?(:to_unsafe_h) ? raw.to_unsafe_h : raw
    hash.stringify_keys.slice(*allowed).transform_values { |value| value.to_s }
  end
end