import {
  BASE_DAILY_TARGETS,
  LEVEL1_NUTRITION_KEYS,
  LEVEL2_NUTRITION_KEYS,
  LEVEL3_NUTRITION_KEYS,
  NUTRIENT_META,
  USA_GOV_DGA_KEYS,
} from '@/common/constants/nutrition';
import type { Strings } from '@/common/strings/types';
import { NutrientKey, Nutrition, NutritionDisplayMode, NutritionSortMode } from '@/types/nutrition';

type NutrientStrings = Strings['nutrients'];
type NutrientStringKey = keyof Omit<NutrientStrings, 'foodGroups'>;
type FoodGroupStringKey = keyof NutrientStrings['foodGroups'];

const NUTRIENT_STRING_MAP: Partial<Record<NutrientKey, NutrientStringKey>> = {
  protein_g: 'protein',
  carbs_g: 'carbs',
  fat_g: 'fat',
  fiber_g: 'fiber',
  soluble_fiber_g: 'solubleFiber',
  insoluble_fiber_g: 'insolubleFiber',
  a_mcg: 'vitaminA',
  retinol_mcg: 'retinol',
  b1_mg: 'thiamin',
  b2_mg: 'riboflavin',
  b3_mg: 'niacin',
  b5_mg: 'pantothenicAcid',
  b6_mg: 'vitaminB6',
  b9_mcg: 'folate',
  b12_mcg: 'vitaminB12',
  c_mg: 'vitaminC',
  vitamin_d_mcg: 'vitaminD',
  e_mg: 'vitaminE',
  k_mcg: 'vitaminK',
  calcium_mg: 'calcium',
  iron_mg: 'iron',
  magnesium_mg: 'magnesium',
  zinc_mg: 'zinc',
  potassium_mg: 'potassium',
  phosphorus_mg: 'phosphorus',
  selenium_mcg: 'selenium',
  chromium_mcg: 'chromium',
  molybdenum_mcg: 'molybdenum',
  iodine_mcg: 'iodine',
  omega_3_mg: 'omega3',
  omega_6_mg: 'omega6',
  ala_mg: 'ala',
  epa_mg: 'epa',
  dha_mg: 'dha',
  dpa_mg: 'dpa',
  biotin_mcg: 'biotin',
  probiotics_cfu: 'probiotics',
  copper_mg: 'copper',
  manganese_mg: 'manganese',
  choline_mg: 'choline',
  water_ml: 'water',
  caffeine_mg: 'caffeine',
  theobromine_mg: 'theobromine',
  taurine_mg: 'taurine',
  collagen_g: 'collagen',
  coq10_mg: 'coq10',
  curcumin_mg: 'curcumin',
  creatine_g: 'creatine',
  resveratrol_mg: 'resveratrol',
  astaxanthin_mcg: 'astaxanthin',
  lycopene_mcg: 'lycopene',
  lutein_zeaxanthin_mcg: 'luteinZeaxanthin',
  beta_carotene_mcg: 'betaCarotene',
  alpha_carotene_mcg: 'alphaCarotene',
  cryptoxanthin_mcg: 'cryptoxanthin',
  anthocyanins_mg: 'anthocyanins',
  monounsaturated_fat_g: 'monounsaturatedFat',
  polyunsaturated_fat_g: 'polyunsaturatedFat',
  phytosterols_mg: 'phytosterols',
  tryptophan_mg: 'tryptophan',
  tyrosine_mg: 'tyrosine',
  valine_g: 'valine',
  glutamine_g: 'glutamine',
  betaine_mg: 'betaine',
  kcal: 'calories',
  alcohol_g: 'alcohol',
  cholesterol_mg: 'cholesterol',
  saturated_fat_g: 'saturatedFat',
  sodium_mg: 'sodium',
  sugar_g: 'sugar',
  starch_g: 'starch',
  oxalate_mg: 'oxalate',
  chloride_mg: 'chloride',
};

const FOOD_GROUP_STRING_MAP: Partial<Record<NutrientKey, FoodGroupStringKey>> = {
  usa_gov_dga_protein_g: 'proteinFoods',
  usa_gov_dga_healthy_fats_tsp_eq: 'healthyFats',
  usa_gov_dga_vegetables_cup_eq: 'vegetables',
  usa_gov_dga_fruits_cup_eq: 'fruits',
  usa_gov_dga_dairy_cup_eq: 'dairy',
  usa_gov_dga_whole_grains_oz_eq: 'wholeGrains',
  usa_gov_dga_dark_green_veg_cup_eq: 'darkGreenVegetables',
  usa_gov_dga_red_orange_veg_cup_eq: 'redOrangeVegetables',
  usa_gov_dga_beans_peas_lentils_veg_cup_eq: 'legumes',
  usa_gov_dga_starchy_veg_cup_eq: 'starchyVegetables',
  usa_gov_dga_other_veg_cup_eq: 'otherVegetables',
};

export function getNutrientLabel(key: NutrientKey, nutrients: NutrientStrings): string {
  const nutrientKey = NUTRIENT_STRING_MAP[key];
  if (nutrientKey) return nutrients[nutrientKey] as string;
  const foodGroupKey = FOOD_GROUP_STRING_MAP[key];
  if (foodGroupKey) return nutrients.foodGroups[foodGroupKey];
  return NUTRIENT_META[key].label;
}

export type NutrientsByLevel = {
  level1: NutrientKey[];
  level2: NutrientKey[];
  level3: NutrientKey[];
};

export function getNutrientsByMode(mode: NutritionDisplayMode): NutrientsByLevel {
  if (mode === 'usa_gov_dga') {
    return { level1: USA_GOV_DGA_KEYS, level2: [], level3: [] };
  }
  return {
    level1: LEVEL1_NUTRITION_KEYS,
    level2: LEVEL2_NUTRITION_KEYS,
    level3: LEVEL3_NUTRITION_KEYS,
  };
}

export function sortNutrients(
  keys: NutrientKey[],
  sortMode: NutritionSortMode,
  consumed?: Nutrition,
  target?: Nutrition
): NutrientKey[] {
  if (sortMode === 'default') {
    return [...keys].sort((a, b) => NUTRIENT_META[a].importance - NUTRIENT_META[b].importance);
  }
  if (!consumed || !target) {
    return [...keys].sort((a, b) => NUTRIENT_META[a].importance - NUTRIENT_META[b].importance);
  }
  return [...keys].sort((a, b) => {
    const fillA = (consumed[a] ?? 0) / (target[a] || 1);
    const fillB = (consumed[b] ?? 0) / (target[b] || 1);
    return fillA - fillB;
  });
}

export function sumNutrition(items: Nutrition[]): Nutrition {
  const result: Nutrition = {};
  for (const item of items) {
    for (const key of Object.keys(item) as NutrientKey[]) {
      const val = item[key];
      if (val != null) {
        result[key] = (result[key] ?? 0) + val;
      }
    }
  }
  return result;
}

export function emptyNutrition(): Nutrition {
  return {};
}

export function getDailyTargets(date: Date): Nutrition {
  const dayOfYear = Math.floor(
    (date.getTime() - new Date(date.getFullYear(), 0, 0).getTime()) / 86400000
  );
  const seed = dayOfYear * 7 + date.getFullYear();
  const result: Nutrition = {};
  for (const [key, base] of Object.entries(BASE_DAILY_TARGETS)) {
    const hash = ((seed * 31 + key.charCodeAt(0)) * 17) % 100;
    const variation = 0.9 + (hash / 100) * 0.2;
    result[key as NutrientKey] = Math.round(base * variation * 100) / 100;
  }
  return result;
}

const SCORE_NUTRIENTS: { key: NutrientKey; weight: number }[] = [
  { key: 'protein_g', weight: 12 },
  { key: 'fiber_g', weight: 10 },
  { key: 'omega_3_mg', weight: 10 },
  { key: 'vitamin_d_mcg', weight: 8 },
  { key: 'b12_mcg', weight: 7 },
  { key: 'iron_mg', weight: 7 },
  { key: 'calcium_mg', weight: 7 },
  { key: 'magnesium_mg', weight: 7 },
  { key: 'choline_mg', weight: 6 },
  { key: 'dha_mg', weight: 6 },
  { key: 'epa_mg', weight: 6 },
  { key: 'potassium_mg', weight: 5 },
  { key: 'zinc_mg', weight: 5 },
  { key: 'c_mg', weight: 5 },
  { key: 'a_mcg', weight: 5 },
  { key: 'b9_mcg', weight: 5 },
  { key: 'selenium_mcg', weight: 5 },
  { key: 'iodine_mcg', weight: 5 },
  { key: 'b6_mg', weight: 4 },
  { key: 'e_mg', weight: 4 },
  { key: 'k_mcg', weight: 4 },
  { key: 'copper_mg', weight: 4 },
  { key: 'manganese_mg', weight: 4 },
  { key: 'b1_mg', weight: 3 },
  { key: 'b2_mg', weight: 3 },
  { key: 'b3_mg', weight: 3 },
  { key: 'b5_mg', weight: 3 },
  { key: 'biotin_mcg', weight: 3 },
  { key: 'phosphorus_mg', weight: 3 },
  { key: 'chromium_mcg', weight: 3 },
  { key: 'molybdenum_mcg', weight: 3 },
  { key: 'ala_mg', weight: 3 },
  { key: 'soluble_fiber_g', weight: 3 },
  { key: 'insoluble_fiber_g', weight: 3 },
  { key: 'retinol_mcg', weight: 2 },
  { key: 'dpa_mg', weight: 2 },
  { key: 'omega_6_mg', weight: 2 },
  { key: 'monounsaturated_fat_g', weight: 2 },
  { key: 'polyunsaturated_fat_g', weight: 2 },
  { key: 'tryptophan_mg', weight: 2 },
  { key: 'tyrosine_mg', weight: 2 },
  { key: 'valine_g', weight: 2 },
  { key: 'glutamine_g', weight: 2 },
  { key: 'lycopene_mcg', weight: 2 },
  { key: 'lutein_zeaxanthin_mcg', weight: 2 },
  { key: 'beta_carotene_mcg', weight: 2 },
  { key: 'alpha_carotene_mcg', weight: 1 },
  { key: 'cryptoxanthin_mcg', weight: 1 },
  { key: 'anthocyanins_mg', weight: 2 },
  { key: 'phytosterols_mg', weight: 1 },
  { key: 'betaine_mg', weight: 1 },
  { key: 'probiotics_cfu', weight: 2 },
  { key: 'collagen_g', weight: 1 },
  { key: 'coq10_mg', weight: 1 },
  { key: 'curcumin_mg', weight: 1 },
  { key: 'creatine_g', weight: 1 },
  { key: 'resveratrol_mg', weight: 1 },
  { key: 'astaxanthin_mcg', weight: 1 },
  { key: 'water_ml', weight: 2 },
  { key: 'caffeine_mg', weight: 1 },
  { key: 'theobromine_mg', weight: 1 },
  { key: 'taurine_mg', weight: 1 },
];

const SCORE_FOOD_GROUPS: { key: NutrientKey; weight: number }[] = [
  { key: 'usa_gov_dga_vegetables_cup_eq', weight: 8 },
  { key: 'usa_gov_dga_fruits_cup_eq', weight: 5 },
  { key: 'usa_gov_dga_protein_g', weight: 5 },
  { key: 'usa_gov_dga_whole_grains_oz_eq', weight: 4 },
  { key: 'usa_gov_dga_dairy_cup_eq', weight: 3 },
  { key: 'usa_gov_dga_healthy_fats_tsp_eq', weight: 3 },
  { key: 'usa_gov_dga_dark_green_veg_cup_eq', weight: 4 },
  { key: 'usa_gov_dga_red_orange_veg_cup_eq', weight: 3 },
  { key: 'usa_gov_dga_beans_peas_lentils_veg_cup_eq', weight: 3 },
  { key: 'usa_gov_dga_starchy_veg_cup_eq', weight: 2 },
  { key: 'usa_gov_dga_other_veg_cup_eq', weight: 2 },
];

function fillRatio(consumed: number, target: number): number {
  if (target <= 0) return 0;
  const ratio = consumed / target;
  return Math.min(ratio, 1.5) / 1.5;
}

export function calculateNutritionScore(
  consumed: Nutrition,
  targets: Nutrition,
  uniqueIngredientCount: number
): number {
  const nutrientTotal = SCORE_NUTRIENTS.reduce((sum, n) => sum + n.weight, 0);
  const foodGroupTotal = SCORE_FOOD_GROUPS.reduce((sum, n) => sum + n.weight, 0);

  let nutrientScore = 0;
  for (const { key, weight } of SCORE_NUTRIENTS) {
    const c = consumed[key] ?? 0;
    const t = targets[key] ?? BASE_DAILY_TARGETS[key] ?? 1;
    nutrientScore += fillRatio(c, t) * weight;
  }
  const nutrientPct = nutrientScore / nutrientTotal;

  let foodGroupScore = 0;
  for (const { key, weight } of SCORE_FOOD_GROUPS) {
    const c = consumed[key] ?? 0;
    const t = targets[key] ?? BASE_DAILY_TARGETS[key] ?? 1;
    foodGroupScore += fillRatio(c, t) * weight;
  }
  const foodGroupPct = foodGroupScore / foodGroupTotal;

  const diversityBonus = Math.min(uniqueIngredientCount / 15, 1);

  const rawScore = nutrientPct * 45 + foodGroupPct * 45 + diversityBonus * 10;

  return Math.min(Math.max(rawScore, 0), 100);
}