import type { Core } from '@strapi/strapi';

import { DEFAULT_EMAIL_TEMPLATES, type EmailTemplateKey } from './email-template-defaults';
import { buildBilingualMail, trySendMail } from './event-mail';
import type { PlaceholderValues } from './email-templates';

const PARTNER_CONTENT = new Set([
  'api::resource.resource',
  'api::news-article.news-article',
  'api::activity.activity',
  'api::event.event',
  'api::opportunity.opportunity',
]);
const NOTIFIABLE_ACTIONS = new Set(['create', 'update', 'publish']);
const REVIEW_RETURN_STATUSES = new Set(['changes-requested', 'rejected']);
const LOG_PREFIX = '[partner-review-mail]';
type PartnerReviewTemplateKey = Extract<
  EmailTemplateKey,
  'partner-review-submitted' | 'partner-review-decision' | 'partner-review-published'
>;

type ReviewDocument = {
  documentId?: string;
  title?: string;
  slug?: string;
  reviewStatus?: string | null;
  reviewFeedback?: string | null;
  submittedByAdminUserId?: number | null;
};
type AdminUser = {
  id: number;
  email?: string | null;
  isActive?: boolean;
  roles?: Array<{ code?: string }>;
};

const readResultDocumentId = (value: unknown): string | undefined => {
  if (!value || typeof value !== 'object') return undefined;
  const documentId = (value as { documentId?: unknown }).documentId;
  return typeof documentId === 'string' && documentId.length > 0 ? documentId : undefined;
};

const readDocument = async (
  strapi: Core.Strapi,
  uid: string,
  documentId: string,
  locale: string | undefined,
  status: 'draft' | 'published' = 'draft'
): Promise<ReviewDocument | null> => {
  try {
    return (await strapi.documents(uid as never).findOne({
      documentId,
      ...(locale ? { locale } : {}),
      status,
    })) as ReviewDocument | null;
  } catch (error) {
    strapi.log.warn(`${LOG_PREFIX} could not read ${uid} ${documentId}: ${String(error)}`);
    return null;
  }
};

const getReviewerRecipients = async (strapi: Core.Strapi): Promise<string[]> => {
  const configured = (process.env.PARTNER_REVIEW_NOTIFICATION_EMAILS ?? '')
    .split(',')
    .map((address) => address.trim())
    .filter(Boolean);
  if (configured.length > 0) return [...new Set(configured)];

  const admins = (await strapi.db.query('admin::user').findMany({
    select: ['id', 'email', 'isActive'],
    populate: { roles: { select: ['code'] } },
  })) as AdminUser[];

  return [
    ...new Set(
      admins
        .filter(
          (admin) => admin.isActive !== false && admin.roles?.some((role) => role.code === 'strapi-super-admin')
        )
        .map((admin) => admin.email?.trim())
        .filter((email): email is string => Boolean(email))
    ),
  ];
};

const getSubmitter = async (strapi: Core.Strapi, id: number): Promise<AdminUser | null> =>
  (await strapi.db.query('admin::user').findOne({
    where: { id },
    select: ['id', 'email', 'isActive'],
  })) as AdminUser | null;

const ENTRY_TYPE_LABELS: Record<string, { ar: string; en: string }> = {
  resource: { ar: 'مورد', en: 'resource' },
  'news-article': { ar: 'مقال إخباري', en: 'news article' },
  activity: { ar: 'نشاط', en: 'activity' },
  event: { ar: 'فعالية', en: 'event' },
  opportunity: { ar: 'فرصة', en: 'opportunity' },
};

const entryLabel = (uid: string, document: ReviewDocument | null | undefined, locale: 'ar' | 'en'): string => {
  const title = document?.title?.trim() || document?.slug?.trim();
  const typeSlug = uid.split('.')[1] ?? 'content';
  const type = ENTRY_TYPE_LABELS[typeSlug]?.[locale] ?? (locale === 'ar' ? 'محتوى' : typeSlug.replace(/-/g, ' '));
  if (title) return `${type}: ${title}`;
  return locale === 'ar' ? `عنصر من نوع ${type}` : `a ${type} entry`;
};

const buildReviewMail = (
  key: PartnerReviewTemplateKey,
  vars: { ar: PlaceholderValues; en: PlaceholderValues }
): ReturnType<typeof buildBilingualMail> => {
  const template = DEFAULT_EMAIL_TEMPLATES[key];
  return buildBilingualMail({
    subjectAr: template.ar.subject,
    subjectEn: template.en.subject,
    bodyAr: template.ar.body,
    bodyEn: template.en.body,
    vars,
  });
};

const sendReviewNotification = async (
  strapi: Core.Strapi,
  to: string[],
  mail: ReturnType<typeof buildBilingualMail>
): Promise<void> => {
  if (to.length === 0) {
    strapi.log.warn(`${LOG_PREFIX} no recipient configured for: ${mail.subject}`);
    return;
  }

  await Promise.all(
    to.map((address) =>
      trySendMail(strapi, { to: address, ...mail }).then((sent) => {
        if (sent) strapi.log.info(`${LOG_PREFIX} sent "${mail.subject}" to ${address}.`);
      })
    )
  );
};

const notifyAfterSave = async ({
  strapi,
  uid,
  action,
  documentId,
  locale,
  before,
}: {
  strapi: Core.Strapi;
  uid: string;
  action: string;
  documentId: string;
  locale?: string;
  before: ReviewDocument | null;
}): Promise<void> => {
  const after = await readDocument(strapi, uid, documentId, locale, action === 'publish' ? 'published' : 'draft');
  if (!after) return;

  const submitterId = after.submittedByAdminUserId;
  if (typeof submitterId !== 'number') return;

  const labelAr = entryLabel(uid, after, 'ar');
  const labelEn = entryLabel(uid, after, 'en');

  if (
    (action === 'create' && after.reviewStatus === 'pending') ||
    (action === 'update' && before?.reviewStatus !== 'pending' && after.reviewStatus === 'pending')
  ) {
    const recipients = await getReviewerRecipients(strapi);
    await sendReviewNotification(
      strapi,
      recipients,
      buildReviewMail('partner-review-submitted', {
        ar: { label: labelAr },
        en: { label: labelEn },
      })
    );
    return;
  }

  if (
    action === 'update' &&
    after.reviewStatus &&
    REVIEW_RETURN_STATUSES.has(after.reviewStatus) &&
    (before?.reviewStatus !== after.reviewStatus || before?.reviewFeedback !== after.reviewFeedback)
  ) {
    const submitter = await getSubmitter(strapi, submitterId);
    if (!submitter?.email || submitter.isActive === false) {
      strapi.log.warn(`${LOG_PREFIX} no active partner author email for admin user ${submitterId}.`);
      return;
    }

    const decisionEn = after.reviewStatus === 'rejected' ? 'rejected' : 'changes requested';
    const decisionAr = after.reviewStatus === 'rejected' ? 'الرفض' : 'طلب إجراء تغييرات';
    const feedback = after.reviewFeedback?.trim();
    await sendReviewNotification(
      strapi,
      [submitter.email],
      buildReviewMail('partner-review-decision', {
        ar: {
          label: labelAr,
          decision: decisionAr,
          feedback: feedback || '(لم تُقدَّم ملاحظات للمراجعة.)',
        },
        en: {
          label: labelEn,
          decision: decisionEn,
          feedback: feedback || '(No review feedback was provided.)',
        },
      })
    );
    return;
  }

  if (action === 'publish') {
    const submitter = await getSubmitter(strapi, submitterId);
    if (!submitter?.email || submitter.isActive === false) {
      strapi.log.warn(`${LOG_PREFIX} no active partner author email for admin user ${submitterId}.`);
      return;
    }

    await sendReviewNotification(
      strapi,
      [submitter.email],
      buildReviewMail('partner-review-published', {
        ar: { label: labelAr },
        en: { label: labelEn },
      })
    );
  }
};

/** Notify reviewers and partner authors after persisted workflow transitions. */
export const registerPartnerReviewNotifications = (strapi: Core.Strapi): void => {
  strapi.documents.use(async (context, next) => {
    if (!PARTNER_CONTENT.has(context.uid) || !NOTIFIABLE_ACTIONS.has(context.action)) return next();

    const requestContext = strapi.requestContext.get();
    if (!requestContext?.state?.user || !requestContext.request.path.startsWith('/content-manager/')) {
      return next();
    }

    const params = context.params as { documentId?: string; locale?: string };
    const before =
      params.documentId && (context.action === 'update' || context.action === 'publish')
        ? await readDocument(strapi, context.uid, params.documentId, params.locale)
        : null;
    const result = await next();
    const documentId = params.documentId ?? readResultDocumentId(result);
    if (!documentId) return result;

    // Run after Strapi has persisted the draft or review decision. Delivery
    // failures are logged and never roll back a successful content save.
    void notifyAfterSave({
      strapi,
      uid: context.uid,
      action: context.action,
      documentId,
      locale: params.locale,
      before,
    }).catch((error) => {
      strapi.log.error(`${LOG_PREFIX} notification failed for ${context.uid} ${documentId}: ${String(error)}`);
    });

    return result;
  });
};