// SPDX-License-Identifier: GPL-3.0-or-later
/*
 * $Id: budget.h,v 1.1 2026/05/08 03:23:57 asm Exp $
 *
 * budget.h - USDA Food Pattern budget system for GNUtrition
 *
 * Copyright (C) 2026 Free Software Foundation, Inc.
 *
 * Author: Jason Self <jself@gnu.org>
 *         Anton McClure <asm@gnu.org>
 */

#ifndef BUDGET_H
#define BUDGET_H

/* Daily budget for the USDA Healthy US-Style Eating Pattern.
   Units: cup-equivalents for vegetables, fruits, dairy;
          ounce-equivalents for grains, protein; grams for oils.  */
struct daily_budget
{
  int calories;        /* kcal level  */
  double vegetables;   /* cup-eq  */
  double fruits;       /* cup-eq  */
  double grains;       /* oz-eq   */
  double dairy;        /* cup-eq  */
  double protein;      /* oz-eq   */
  double oils;         /* grams   */
};

/* Physical activity level multiplier categories.  */
enum activity_level
{
  ACTIVITY_SEDENTARY,       /* little or no exercise: 1.2   */
  ACTIVITY_LIGHT,           /* light exercise 1-3 days/wk: 1.375  */
  ACTIVITY_MODERATE,        /* moderate exercise 3-5 days/wk: 1.55  */
  ACTIVITY_VERY_ACTIVE,     /* hard exercise 6-7 days/wk: 1.725  */
  ACTIVITY_EXTRA_ACTIVE     /* very hard exercise / physical job: 1.9  */
};

/* User gender, for equations */
enum user_gender
{
  GENDER_NEUTRAL = 0,
  GENDER_FEMALE,
  GENDER_MALE
};

/* Estimate daily calorie needs using the Mifflin-St Jeor equation
   with a neutral midpoint default (-78).

   AGE_YEARS is the person's age.  HEIGHT_CM is height in centimeters.
   WEIGHT_KG is weight in kilograms.  ACTIVITY is the physical
   activity multiplier.  Returns estimated kcal/day, already rounded
   to the nearest USDA pattern level (200-kcal steps, 1000-3200).  */
int budget_estimate_calories (int age_years, double height_cm,
                              double weight_kg,
                              enum activity_level activity,
                              enum user_gender gender);

/* Round a raw calorie value to the nearest USDA Food Pattern level
   (200-kcal steps), clamped to the range 1000-3200.  */
int budget_round_to_pattern (int kcal_raw);

/* Return the daily budget for a given calorie level KCAL, using the
   USDA Healthy US-Style Eating Pattern table (Dietary Guidelines for
   Americans, 2020-2025, Appendix 3).  Supported levels are 1000 to
   3200 kcal.  Values between table entries are linearly
   interpolated; values outside the range are clamped.  */
struct daily_budget budget_for_calories (int kcal);

/* Return the standard 2,000 kcal daily budget.  */
struct daily_budget budget_get_default (void);

/* Print a budget summary to stdout, showing CONSUMED against BUDGET.  */
void budget_print (const struct daily_budget *budget,
                   const struct daily_budget *consumed);

#endif /* BUDGET_H */