Files
erp-imprimelibros/src/main/java/com/imprimelibros/erp/datatables/DataTable.java

265 lines
9.5 KiB
Java

package com.imprimelibros.erp.datatables;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.data.domain.*;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import jakarta.persistence.criteria.*;
import java.util.*;
import java.util.function.BiConsumer;
import java.util.function.Function;
public class DataTable<T> {
/* ===== Tipos funcionales ===== */
public interface FilterHook<T> extends BiConsumer<SpecBuilder<T>, DataTablesRequest> {
}
public interface SpecBuilder<T> {
void add(Specification<T> extra);
}
/**
* Filtro custom por campo virtual: te doy (root, query, cb, value) y me
* devuelves un Predicate
*/
@FunctionalInterface
public interface FieldFilter<T> {
Predicate apply(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb, String value);
}
/**
* Orden custom por campo virtual: te doy (root, query, cb) y me devuelves la
* Expression<?> para orderBy
*/
@FunctionalInterface
public interface FieldOrder<T> {
Expression<?> apply(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb);
}
/* ===== Estado ===== */
private final JpaSpecificationExecutor<T> repo;
private final Class<T> entityClass;
private final DataTablesRequest dt;
private final List<String> searchable;
private final List<Function<T, Map<String, Object>>> adders = new ArrayList<>();
private final List<Function<Map<String, Object>, Map<String, Object>>> editors = new ArrayList<>();
private final List<FilterHook<T>> filters = new ArrayList<>();
private Specification<T> baseSpec = (root, q, cb) -> cb.conjunction();
private final ObjectMapper om = new ObjectMapper()
.registerModule(new JavaTimeModule())
.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
/** whitelist de campos ordenables “simples” (por nombre) */
private List<String> orderable = null;
/** mapas de comportamiento custom por campo */
private final Map<String, FieldOrder<T>> orderCustom = new HashMap<>();
private final Map<String, FieldFilter<T>> filterCustom = new HashMap<>();
private boolean onlyAdded = false;
/* ===== Ctor / factory ===== */
private DataTable(JpaSpecificationExecutor<T> repo, Class<T> entityClass, DataTablesRequest dt,
List<String> searchable) {
this.repo = repo;
this.entityClass = entityClass;
this.dt = dt;
this.searchable = searchable != null ? searchable : List.of();
}
public static <T> DataTable<T> of(JpaSpecificationExecutor<T> repo, Class<T> entityClass, DataTablesRequest dt,
List<String> searchable) {
return new DataTable<>(repo, entityClass, dt, searchable);
}
/* ===== Fluent API ===== */
public DataTable<T> onlyAddedColumns() {
this.onlyAdded = true;
return this;
}
/** WHERE base reusable */
public DataTable<T> where(Specification<T> spec) {
this.baseSpec = this.baseSpec.and(spec);
return this;
}
/** Campos renderizados */
public DataTable<T> add(String field, Function<T, Object> fn) {
adders.add(entity -> {
Map<String, Object> m = new HashMap<>();
m.put(field, fn.apply(entity));
return m;
});
return this;
}
public DataTable<T> addIf(boolean condition, String field, Function<T, Object> fn) {
if (condition)
return add(field, fn);
return this;
}
public DataTable<T> add(Function<T, Map<String, Object>> fn) {
adders.add(fn);
return this;
}
/** Edita/inyecta valor usando la entidad original (guardada como __entity) */
@SuppressWarnings("unchecked")
public DataTable<T> edit(String field, Function<T, Object> fn) {
editors.add(row -> {
row.put(field, fn.apply((T) row.get("__entity")));
return row;
});
return this;
}
/** Whitelist de campos simples ordenables (por nombre) */
public DataTable<T> orderable(List<String> fields) {
this.orderable = fields;
return this;
}
/** Orden custom por campo virtual (expresiones) */
public DataTable<T> orderable(String field, FieldOrder<T> orderFn) {
this.orderCustom.put(field, orderFn);
return this;
}
/** Filtro custom por campo virtual (LIKE, rangos, etc.) */
public DataTable<T> filter(String field, FieldFilter<T> filterFn) {
this.filterCustom.put(field, filterFn);
return this;
}
/** Hook para añadir Specifications extra programáticamente */
public DataTable<T> filter(FilterHook<T> hook) {
filters.add(hook);
return this;
}
/* ===== Helpers ===== */
private List<String> getOrderable() {
return (orderable == null || orderable.isEmpty()) ? this.searchable : this.orderable;
}
/* ===== Core ===== */
public DataTablesResponse<Map<String, Object>> toJson(long totalCount) {
// 1) Spec base + búsqueda (global/columnas) + hooks programáticos
Specification<T> spec = baseSpec.and(DataTablesSpecification.build(dt, searchable));
final Specification<T>[] holder = new Specification[] { spec };
// Hooks externos
filters.forEach(h -> h.accept(extra -> holder[0] = holder[0].and(extra), dt));
// 2) Filtros por columna “custom” (virtuales)
for (var col : dt.columns) {
if (col == null || !col.searchable)
continue;
if (col.name == null || col.name.isBlank())
continue;
if (!filterCustom.containsKey(col.name))
continue;
if (col.search == null || col.search.value == null || col.search.value.isBlank())
continue;
var value = col.search.value;
var filterFn = filterCustom.get(col.name);
holder[0] = holder[0].and((root, query, cb) -> {
Predicate p = filterFn.apply(root, query, cb, value);
return p != null ? p : cb.conjunction();
});
}
// 3) Orden:
// - Para campos “simples” (no custom): con Sort (Spring)
// - Para campos “custom” (virtuales/expresiones): query.orderBy(...) dentro de
// una spec
Sort sort = Sort.unsorted();
List<Sort.Order> simpleOrders = new ArrayList<>();
boolean customApplied = false;
if (!dt.order.isEmpty() && !dt.columns.isEmpty()) {
for (var o : dt.order) {
var col = dt.columns.get(o.column);
if (col == null)
continue;
String field = col.name;
if (field == null || field.isBlank())
continue;
if (!col.orderable)
continue;
if (!getOrderable().contains(field))
continue;
if (orderCustom.containsKey(field)) {
final boolean asc = !"desc".equalsIgnoreCase(o.dir);
final FieldOrder<T> orderFn = orderCustom.get(field);
// aplica el ORDER BY custom dentro de la Specification (con Criteria)
holder[0] = holder[0].and((root, query, cb) -> {
Expression<?> expr = orderFn.apply(root, query, cb);
if (expr != null) {
query.orderBy(asc ? cb.asc(expr) : cb.desc(expr));
}
return cb.conjunction();
});
customApplied = true;
} else {
// orden simple por nombre de propiedad real
simpleOrders.add(new Sort.Order(
"desc".equalsIgnoreCase(o.dir) ? Sort.Direction.DESC : Sort.Direction.ASC,
field));
}
}
}
if (!simpleOrders.isEmpty()) {
sort = Sort.by(simpleOrders);
}
// 4) Paginación (Sort para simples; custom order ya va dentro de la spec)
int page = dt.length > 0 ? dt.start / dt.length : 0;
Pageable pageable = dt.length > 0 ? PageRequest.of(page, dt.length, sort) : Pageable.unpaged();
var p = repo.findAll(holder[0], pageable);
long filtered = p.getTotalElements();
// 5) Mapeo a Map + add/edit
List<Map<String, Object>> data = new ArrayList<>();
for (T e : p.getContent()) {
Map<String, Object> row;
if (onlyAdded) {
row = new HashMap<>();
} else {
try {
row = om.convertValue(e, Map.class);
} catch (IllegalArgumentException ex) {
row = new HashMap<>();
}
}
row.put("__entity", e);
for (var ad : adders)
row.putAll(ad.apply(e));
for (var ed : editors)
ed.apply(row);
row.remove("__entity");
data.add(row);
}
return new DataTablesResponse<>(dt.draw, totalCount, filtered, data);
}
private Predicate nullSafePredicate(CriteriaBuilder cb) {
// Devuelve conjunción para no interferir con los demás predicados
return cb.conjunction();
}
}