// Package httpapi provides the HTTP-facing layer for the multi-tenant
// backend: auth middleware, tenant context propagation, and route
// wiring for the auth and note endpoints.
package httpapi

import (
	"context"
	"errors"
)

// Tenant carries the per-request tenant identity extracted from a
// validated JWT. It is the only thing handlers need to know about
// "who is this request for".
type Tenant struct {
	UserID string
	Email  string
}

type ctxKey struct{}

// ErrNoTenant indicates that handler code expected a tenant on the
// request context but found none. This is always a programming error
// (the route was reached without going through AuthMiddleware).
var ErrNoTenant = errors.New("httpapi: no tenant in context")

// WithTenant returns a derived context carrying t.
func WithTenant(ctx context.Context, t Tenant) context.Context {
	return context.WithValue(ctx, ctxKey{}, t)
}

// TenantFrom retrieves the tenant from ctx. Panics are avoided by
// returning ErrNoTenant when the value is missing.
func TenantFrom(ctx context.Context) (Tenant, error) {
	v, ok := ctx.Value(ctxKey{}).(Tenant)
	if !ok {
		return Tenant{}, ErrNoTenant
	}
	return v, nil
}