Salon/docs/execplans/arabic-localization.md

# Arabic Localization Readiness (ar-sa First)

This ExecPlan is a living document. The sections `Progress`, `Surprises & Discoveries`, `Decision Log`, and `Outcomes & Retrospective` must be kept up to date as work proceeds.

The requirements for ExecPlans live in `PLANS.md` at the repository root. This document must be maintained in accordance with that file.

## Purpose / Big Picture

After this change, the codebase has localization foundations in place: locale selection, right-to-left layout support, and a user language preference in the backend. Arabic is treated as a first-class locale for structure and behavior, but full translation coverage is intentionally deferred until core backend flows stabilize. You can see it working by starting the backend and frontend, switching the language to Arabic, and observing RTL layout, the page `dir="rtl"`, and the API responding with the correct `Content-Language` when sending `Accept-Language: ar-sa`.

## Progress

- [x] (2026-02-27 00:00Z) Created initial ExecPlan for Arabic localization readiness.
- [x] (2026-02-28 12:00Z) Added backend locale settings, LocaleMiddleware, user language preference, and user locale middleware.
- [x] (2026-02-28 12:10Z) Wrapped backend user-facing strings for future translation (no full catalog yet).
- [x] (2026-02-28 12:20Z) Added frontend i18n, RTL support, language persistence, and minimal seed translations.
- [x] (2026-02-28 12:30Z) Added targeted backend and frontend tests for locale selection and RTL behavior.
- [x] (2026-02-28 12:40Z) Updated documentation and risks for staged localization.

## Surprises & Discoveries

- Observation: None yet.
  Evidence: No implementation work has started.

## Decision Log

- Decision: Use `ar-sa` as the default locale with English as a fallback.
  Rationale: The product is KSA-focused and Arabic should be primary while keeping English for mixed audiences.
  Date/Author: 2026-02-27, Codex
- Decision: Implement localization foundations now and defer full translation coverage.
  Rationale: Early i18n plumbing avoids future refactors, while delaying full translation prevents churn as features evolve.
  Date/Author: 2026-02-28, Codex
- Decision: Use lower-case `ar-sa` for locale identifiers in code and storage.
  Rationale: Django language codes are lower-case; standardizing avoids mismatches between backend and frontend.
  Date/Author: 2026-02-28, Codex
- Decision: Persist user language preference on the `User` model and fall back to `Accept-Language` for anonymous requests.
  Rationale: This provides consistent localized behavior for logged-in users while respecting browser preferences for guests.
  Date/Author: 2026-02-27, Codex
- Decision: Localize both backend API messages and frontend UI strings.
  Rationale: A partial localization would create mismatched language experiences and confuse users.
  Date/Author: 2026-02-27, Codex
- Decision: Use `i18next` + `react-i18next` with a small custom locale selection helper rather than a detection plugin.
  Rationale: The project is small and can avoid extra dependencies while still meeting locale selection requirements.
  Date/Author: 2026-02-27, Codex

## Outcomes & Retrospective

Localization foundations are now in place across backend and frontend, with user preference support, RTL layout, minimal Arabic strings, and basic tests. Full translation coverage and broader RTL QA remain as future work once core flows stabilize.

## Context and Orientation

The backend is a Django + DRF app in `backend/` with settings in `backend/salon_api/settings.py`. The frontend is a Vite + React app in `frontend/` with the entrypoint at `frontend/src/main.jsx` and global styles in `frontend/src/styles.css`. Localization foundations now exist: Django `LocaleMiddleware` is configured and `apps/accounts/middleware.py` applies user preferences, while the frontend initializes `i18next` in `frontend/src/i18n/index.js` and sets `lang`/`dir` on the root element. User-facing strings have begun to be wrapped for translation, but full Arabic translation coverage remains pending.

## Plan of Work

First, add Django locale support. Update `backend/salon_api/settings.py` to define `LANGUAGE_CODE="ar-sa"`, `LANGUAGES` with Arabic and English, `LOCALE_PATHS` pointing to `backend/locale`, and add `django.middleware.locale.LocaleMiddleware` to `MIDDLEWARE` after `SessionMiddleware`. Create `backend/apps/accounts/middleware.py` with `UserLocaleMiddleware` that activates `request.user.preferred_language` after `AuthenticationMiddleware` and sets the response `Content-Language` header. Add a `preferred_language` field to `backend/apps/accounts/models.py` and expose it via `backend/apps/accounts/serializers.py` so `/api/auth/me/` can read and update it.

Next, wrap all user-facing backend strings in translation wrappers. Use `from django.utils.translation import gettext_lazy as _` in serializers and models, and `gettext` in runtime view responses. Cover custom messages in `apps/accounts`, `apps/bookings`, `apps/payments`, and `apps/salons`. Do not translate the backend catalog yet; full Arabic API messages are a later milestone once core flows stabilize. Update or add tests that confirm language selection by user preference and `Accept-Language` headers.

Then, add frontend localization. Introduce an `frontend/src/i18n/` module that sets up `i18next` with `en` and `ar-sa` resource files. Update `frontend/src/main.jsx` to initialize i18n before rendering `App`, set `document.documentElement.lang` and `dir` whenever language changes, and persist the selected locale to local storage. Update `frontend/src/api/client.js` to include the `Accept-Language` header using the active locale. Replace hard-coded UI strings in `frontend/src/App.jsx` with `t(...)` keys and add minimal Arabic translations for the current UI.

Finally, make the UI RTL-safe. Update `frontend/src/styles.css` to use logical properties (`margin-inline`, `padding-inline`, `text-align: start`) where relevant, add `:dir(rtl)` overrides for layout if needed, and add an Arabic-capable font such as `Noto Sans Arabic` to the font stack. Validate end-to-end behavior by running the backend and frontend, switching language, and confirming the UI renders RTL and API responses match the selected locale. Full translation coverage remains a later milestone.

## Concrete Steps

Run these commands from the repository root (`/home/kopernikus/kshkool/Salon`).

1. Add backend locale middleware, settings, and `preferred_language` field, then create a migration.
    - Update `backend/salon_api/settings.py`, `backend/apps/accounts/models.py`, and add `backend/apps/accounts/middleware.py`.
    - Run:
        python3 backend/manage.py makemigrations accounts

2. (Deferred) Generate and compile Arabic translations for the backend when full translation coverage is ready.
    - Run:
        python3 backend/manage.py makemessages -l ar --ignore frontend --ignore node_modules
        python3 backend/manage.py compilemessages
    - Edit `backend/locale/ar/LC_MESSAGES/django.po` to translate the newly wrapped strings.

3. Add frontend i18n resources and wire them into the app.
    - Update `frontend/package.json`, `frontend/src/main.jsx`, `frontend/src/api/client.js`, `frontend/src/App.jsx`, and create `frontend/src/i18n/index.js` plus translation JSON files.

4. Run tests and verify behavior.
    - Backend:
        python3 -m pytest
    - Frontend:
        cd frontend
        npm run test

## Validation and Acceptance

Backend acceptance is achieved when `Accept-Language` and user preference change the response language header. For example, an OTP error should carry `Content-Language: ar-sa` even if the message text remains English until translations are added:

    $ curl -s -H "Accept-Language: ar-sa" -X POST http://localhost:8000/api/auth/otp/request/ -H "Content-Type: application/json" -d '{"phone_number":"123","channel":"sms"}'
    {"phone_number":["Phone number is required"]}

Frontend acceptance is achieved when the page renders Arabic text, the root element uses `dir="rtl"`, and the UI remains readable. You should be able to toggle language, reload, and still see Arabic due to stored preference. Running `npm run dev` and visiting the page should show Arabic UI strings when the selected locale is `ar-sa`.

## Idempotence and Recovery

The locale settings and middleware changes are safe to apply multiple times. Translation commands can be rerun; `makemessages` updates catalogs and `compilemessages` rebuilds `.mo` files. If a translation file is corrupted, re-run `makemessages` and re-apply translations. The migration adding `preferred_language` is additive and reversible via standard Django migration rollback.

## Artifacts and Notes

Expected header behavior after implementing locale selection:

    Content-Language: ar-sa

Example local storage entry for the frontend:

    localStorage["locale"] = "ar-sa"

## Interfaces and Dependencies

Add backend localization dependencies by using Django’s built-in translation system and middleware (`django.middleware.locale.LocaleMiddleware`) and a new `apps.accounts.middleware.UserLocaleMiddleware` to enforce user preference. The `User` model gains a language preference field:

    preferred_language = models.CharField(max_length=10, choices=settings.LANGUAGES, default=settings.LANGUAGE_CODE)

Frontend dependencies must include `i18next` and `react-i18next`. The i18n setup should live in `frontend/src/i18n/index.js`, exporting an initialized i18n instance. The API client in `frontend/src/api/client.js` must attach `Accept-Language` to every request based on the active locale.

Plan Maintenance Note: Initial plan created on 2026-02-27 to scope Arabic localization readiness across backend and frontend. Updated on 2026-02-28 to stage localization work (foundations now, full translations later).