/** Minimaler Snapshot einer Übung für die modulübergreifende Auswahl (filterunabhängig). */
export function snapshotExerciseForSelection(exercise) {
  if (!exercise || exercise.id == null) return null
  const id = Number(exercise.id)
  if (!Number.isFinite(id) || id < 1) return null
  return {
    id,
    title: exercise.title || '',
    summary: exercise.summary || '',
    visibility: exercise.visibility,
    status: exercise.status,
    exercise_kind: exercise.exercise_kind,
    created_by: exercise.created_by,
    focus_area: exercise.focus_area,
    focus_area_names: exercise.focus_area_names,
    style_direction_names: exercise.style_direction_names,
    training_type_names: exercise.training_type_names,
    media_count: exercise.media_count,
    variant_count: exercise.variant_count,
    media: Array.isArray(exercise.media) ? exercise.media : [],
  }
}

export function normalizeSelectedEntries(raw) {
  if (!Array.isArray(raw)) return []
  const out = []
  const seen = new Set()
  for (const item of raw) {
    const snap = snapshotExerciseForSelection(item)
    if (!snap || seen.has(snap.id)) continue
    seen.add(snap.id)
    out.push(snap)
  }
  return out
}

export function mergeSelectedWithListEntries(selectedEntries, exercises) {
  const byId = new Map()
  for (const e of exercises || []) {
    const id = Number(e?.id)
    if (Number.isFinite(id) && id > 0) byId.set(id, e)
  }
  return (selectedEntries || []).map((entry) => byId.get(Number(entry.id)) || entry)
}

export function moduleItemToPayload(row, orderIndex) {
  if ((row?.item_type || 'exercise') === 'note') {
    return {
      item_type: 'note',
      order_index: orderIndex,
      note_body: row.note_body ?? '',
    }
  }
  const eid = Number(row.exercise_id)
  if (!Number.isFinite(eid) || eid < 1) return null
  const vidRaw = row.exercise_variant_id
  const vid =
    vidRaw === '' || vidRaw == null || row.exercise_kind === 'combination'
      ? null
      : Number(vidRaw)
  return {
    item_type: 'exercise',
    order_index: orderIndex,
    exercise_id: eid,
    exercise_variant_id: Number.isFinite(vid) && vid > 0 ? vid : null,
    planned_duration_min:
      row.planned_duration_min !== '' && row.planned_duration_min != null
        ? Number(row.planned_duration_min)
        : null,
    notes: row.notes != null && String(row.notes).trim() ? String(row.notes).trim() : null,
  }
}

export function buildRowsPayload(rows) {
  return rows
    .map((row, idx) =>
      moduleItemToPayload(
        {
          ...row,
          exercise_id: row.exercise_id,
          exercise_variant_id: row.exercise_variant_id,
          planned_duration_min: row.planned_duration_min,
          notes: row.notes,
          exercise_kind: row.exercise_kind,
        },
        idx
      )
    )
    .filter(Boolean)
}