Translations

{
  "messages": {
    "welcome":     "¡Bienvenido a FastKit Core!",
    "hello":       "¡Hola, {name}!",
    "items_count": "Tienes {count} artículos"
  },
  "auth": {
    "login":  "Iniciar Sesión",
    "logout": "Cerrar Sesión"
  }
}

from fastkit_core.i18n import _, set_locale

# Simple translation — uses current locale
greeting = _('messages.welcome')       # "Welcome to FastKit Core!"

# With parameters
hello = _('messages.hello', name='Alice')      # "Hello, Alice!"
count = _('messages.items_count', count=5)     # "You have 5 items"

# Switch locale
set_locale('es')
greeting_es = _('messages.welcome')    # "¡Bienvenido a FastKit Core!"

# Force a specific locale regardless of current
login_fr = _('auth.login', locale='fr')        # "Connexion" (if fr.json exists)

from fastapi import Depends, Header
from fastkit_core.i18n import set_locale, _

async def detect_language(accept_language: str = Header(default='en')):
    language = accept_language.split(',')[0].split('-')[0]
    set_locale(language)
    return language

# Apply to specific routes
@app.get("/", dependencies=[Depends(detect_language)])
def root():
    return {"message": _('messages.welcome')}

# Or get locale in route for logging/response
@app.get("/users/{user_id}")
def get_user(user_id: int, lang: str = Depends(detect_language)):
    return {
        "greeting": _('auth.welcome', username=f'User {user_id}'),
        "language": lang
    }

from fastkit_core.http import success_response, NotFoundException
from fastkit_core.i18n import _

@app.post("/products", status_code=201)
def create_product(data: ProductCreate):
    product = service.create(data)
    return success_response(
        data=product.model_dump(),
        message=_('messages.product_created', name=data.name)
    )

@app.get("/products/{product_id}")
def get_product(product_id: int):
    product = service.find(product_id)
    if not product:
        raise NotFoundException(_('errors.product_not_found'))
    return success_response(data=product.model_dump())

@app.delete("/products/{product_id}", status_code=204)
def delete_product(product_id: int):
    service.delete(product_id)
    # 204 — no content, no message needed

{
  "app": {
    "name": "Gestor de Tareas"
  },
  "tasks": {
    "title":     "Tareas",
    "created":   "Tarea '{title}' creada con éxito",
    "updated":   "Tarea '{title}' actualizada",
    "deleted":   "Tarea eliminada",
    "completed": "{count} tarea(s) completada(s)",
    "empty":     "Aún no hay tareas"
  },
  "errors": {
    "task_not_found": "Tarea no encontrada",
    "unauthorized":   "No tienes autorización para realizar esta acción"
  }
}

from fastapi import FastAPI, Depends
from fastkit_core.http import (
    success_response, paginated_response,
    NotFoundException,
    register_exception_handlers,
    LocaleMiddleware, get_pagination
)
from fastkit_core.i18n import _

app = FastAPI()
register_exception_handlers(app)
app.add_middleware(LocaleMiddleware)   # auto-detects Accept-Language

@app.get("/")
def root():
    return {"app": _('app.name'), "section": _('tasks.title')}

@app.get("/tasks")
def list_tasks(pagination: dict = Depends(get_pagination)):
    tasks, meta = service.paginate(**pagination)
    return paginated_response(
        items=[t.to_dict() for t in tasks],
        pagination=meta,
        message=_('tasks.title')
    )

@app.post("/tasks", status_code=201)
def create_task(data: TaskCreate):
    task = service.create(data)
    return success_response(
        data=task.model_dump(),
        message=_('tasks.created', title=data.title)
    )

@app.get("/tasks/{task_id}")
def get_task(task_id: int):
    task = service.find(task_id)
    if not task:
        raise NotFoundException(_('errors.task_not_found'))
    return success_response(data=task.model_dump())

@app.delete("/tasks/{task_id}", status_code=204)
def delete_task(task_id: int):
    service.delete(task_id)

# English (default)
curl http://localhost:8000/
# {"app": "Task Manager", "section": "Tasks"}

# Spanish
curl http://localhost:8000/ \
  -H "Accept-Language: es"
# {"app": "Gestor de Tareas", "section": "Tareas"}

# Create task in Spanish
curl -X POST http://localhost:8000/tasks \
  -H "Accept-Language: es" \
  -H "Content-Type: application/json" \
  -d '{"title": "Buy milk"}'
# {"success": true, "message": "Tarea 'Buy milk' creada con éxito", ...}

# Error in Spanish
curl http://localhost:8000/tasks/999 \
  -H "Accept-Language: es"
# {"success": false, "message": "Tarea no encontrada"}