import {
  RawExercise,
  Exercise,
  ExerciseSummary,
  ExerciseType,
} from '../exercises.interface';
import {
  BODY_PART_LABELS,
  EQUIPMENT_LABELS,
  MUSCLE_LABELS,
  labelOf,
} from '../data/labels';

const MEDIA_BASE_URL = (
  process.env.MEDIA_BASE_URL || 'https://cdn.jsdelivr.net/gh/hasaneyldrm/exercises-dataset@main'
).replace(/\/$/, '');

function toMediaUrl(path: string): string {
  if (!path) return '';
  if (/^https?:\/\//.test(path)) return path;
  return `${MEDIA_BASE_URL}/${path}`;
}

function deriveType(raw: RawExercise): ExerciseType {
  if (raw.body_part === 'cardio') return 'cardio';
  const hay = `${raw.name} ${raw.equipment} ${raw.category || ''}`.toLowerCase();
  const flexKeywords = ['stretch', 'yoga', 'mobility', 'pilates', 'flexibility', 'foam roll'];
  if (flexKeywords.some((k) => hay.includes(k))) return 'flexibility';
  return 'strength';
}

const TYPE_LABELS: Record<ExerciseType, string> = {
  strength: '力量',
  cardio: '有氧',
  flexibility: '柔韧',
};

export function normalize(raw: RawExercise): Exercise {
  const type = deriveType(raw);
  const zh = raw.instructions?.zh || '';
  const en = raw.instructions?.en || '';
  const zhSteps = raw.instruction_steps?.zh || [];
  const enSteps = raw.instruction_steps?.en || [];

  return {
    id: raw.id,
    name: raw.name,
    bodyPart: raw.body_part,
    bodyPartLabel: labelOf(BODY_PART_LABELS, raw.body_part),
    equipment: raw.equipment,
    equipmentLabel: labelOf(EQUIPMENT_LABELS, raw.equipment),
    target: raw.target,
    targetLabel: labelOf(MUSCLE_LABELS, raw.target),
    muscleGroup: raw.muscle_group,
    muscleGroupLabel: labelOf(MUSCLE_LABELS, raw.muscle_group),
    secondaryMuscles: raw.secondary_muscles || [],
    secondaryMusclesLabels: (raw.secondary_muscles || []).map(
      (m) => labelOf(MUSCLE_LABELS, m),
    ),
    type,
    typeLabel: TYPE_LABELS[type],
    image: toMediaUrl(raw.image),
    gifUrl: toMediaUrl(raw.gif_url),
    instructions: { zh, en },
    instructionSteps: { zh: zhSteps, en: enSteps },
    attribution: raw.attribution,
    mediaId: raw.media_id,
  };
}

export function toSummary(ex: Exercise): ExerciseSummary {
  return {
    id: ex.id,
    name: ex.name,
    bodyPart: ex.bodyPart,
    bodyPartLabel: ex.bodyPartLabel,
    equipment: ex.equipment,
    equipmentLabel: ex.equipmentLabel,
    target: ex.target,
    targetLabel: ex.targetLabel,
    type: ex.type,
    typeLabel: ex.typeLabel,
    image: ex.image,
    gifUrl: ex.gifUrl,
  };
}