From 23c9a70a472d5dcc9e0810d9a1b645ecd24554ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A1n=20Oliva?= <adrian.oliva@cimat.mx>
Date: Mon, 29 May 2023 00:41:26 -0600
Subject: First instance for pagination.

Setting filters and sorters and saving them on a list. Then the list can
be paginated and returned.
---
 src/main/java/com/encora/Main.java            | 62 +++++++++++++++++++++++++++
 src/main/java/com/encora/ToDosRepository.java | 13 ++++++
 2 files changed, 75 insertions(+)

(limited to 'src/main/java')

diff --git a/src/main/java/com/encora/Main.java b/src/main/java/com/encora/Main.java
index a8d86ba..5aaede6 100644
--- a/src/main/java/com/encora/Main.java
+++ b/src/main/java/com/encora/Main.java
@@ -6,6 +6,7 @@ import org.springframework.data.domain.Sort;
 import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 import java.util.Objects;
@@ -174,4 +175,65 @@ public class Main {
     public Integer giveMeLastID() {
         return toDosRepository.lastId;
     }
+
+
+    // Set filters and sorters for our to dos.
+    record filtersAndSorters (
+        toDoFilters filters,
+        SortingsFields sortField,
+        SortingOrders sortOrder
+    ) {
+
+    }
+    @CrossOrigin(origins=allowed_origin)
+    @PostMapping("/todos/setFiltSort")
+    @ResponseStatus(value=HttpStatus.OK)
+    public void setFiltersAndSorters(@RequestBody filtersAndSorters filAndSor) throws Exception {
+        // Sorting method.
+        Sort sortingMethod = Sort.by(String.valueOf(filAndSor.sortField()));
+        if (Objects.equals(String.valueOf(filAndSor.sortOrder()), "DESC")) {
+            sortingMethod = sortingMethod.descending();
+        }
+
+        // Filter to dos and then sort them.
+        toDosRepository.refreshFilteredToDos(
+                sortingMethod,
+                filAndSor.filters().name(),
+                filAndSor.filters().priority(),
+                filAndSor.filters().done()
+        );
+    }
+
+
+    // Return our todos filtered, sorted AND paginated.
+    @CrossOrigin(origins=allowed_origin)
+    @GetMapping("/todos/filtSort/{page}")
+    @ResponseStatus(value=HttpStatus.OK)
+    public List<ToDos> getFilteredToDos(@PathVariable("page") Integer page) {
+        if(page <= 0) {
+            throw new IllegalArgumentException("invalid page: " + page);
+        }
+
+        final int pageSize = 10;
+        List<ToDos> myToDos = toDosRepository.filteredToDos;
+
+        int fromIndex = (page - 1) * pageSize;
+        if (myToDos.size() <= fromIndex) {
+            return Collections.emptyList();
+        }
+
+        // toIndex exclusive
+        return myToDos.subList(fromIndex, Math.min(fromIndex + pageSize, myToDos.size()));
+    }
+
+
+    // Return how many pages after filter and sorting.
+    @CrossOrigin(origins=allowed_origin)
+    @GetMapping("/todos/filtSort/pages")
+    @ResponseStatus(value=HttpStatus.OK)
+    public Integer getNumberOfPages(@RequestBody filtersAndSorters filAndSor) {
+        // Number of items divided by page size.
+        final int pageSize = 10;
+        return (int) Math.ceil((double) toDosRepository.filteredToDos.size() / pageSize);
+    }
 }
diff --git a/src/main/java/com/encora/ToDosRepository.java b/src/main/java/com/encora/ToDosRepository.java
index 8d09d7e..a4c9a10 100644
--- a/src/main/java/com/encora/ToDosRepository.java
+++ b/src/main/java/com/encora/ToDosRepository.java
@@ -184,6 +184,19 @@ public class ToDosRepository implements JpaRepository<ToDos, Integer> {
         return comparator;
     }
 
+
+    // Filter and then sort all of our to dos.
+    public void refreshFilteredToDos(Sort sort, String name, String priority, String done) throws Exception {
+        this.filteredToDos = this.findAllWithFilter(name, priority, done);
+
+        try {
+            Comparator<ToDos> comparator = this.getToDoComparator(sort);
+            Collections.sort(this.filteredToDos, comparator);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     /*
     *         N O T   Y E T   D E F I N E D .
     */
-- 
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