From 70c617115692263c1d7bf20f83a712a204fb2e95 Mon Sep 17 00:00:00 2001
From: Chukwuma Ibezim <123107253+cibezim@users.noreply.github.com>
Date: Wed, 27 Mar 2024 16:51:44 -0400
Subject: [PATCH] feat: adds chukwumaibezim folder with CsvLoader

---
 .../factory/chukwumaibezim/CsvLoader.java     | 98 +++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 lesson_12/io/io_app/src/main/java/com/codedifferently/lesson12/factory/chukwumaibezim/CsvLoader.java

diff --git a/lesson_12/io/io_app/src/main/java/com/codedifferently/lesson12/factory/chukwumaibezim/CsvLoader.java b/lesson_12/io/io_app/src/main/java/com/codedifferently/lesson12/factory/chukwumaibezim/CsvLoader.java
new file mode 100644
index 00000000..c6f41d29
--- /dev/null
+++ b/lesson_12/io/io_app/src/main/java/com/codedifferently/lesson12/factory/chukwumaibezim/CsvLoader.java
@@ -0,0 +1,98 @@
+package com.codedifferently.lesson12.factory.mohamedibrahim;
+
+import com.codedifferently.lesson12.factory.LibraryCsvDataLoader;
+import com.codedifferently.lesson12.models.CheckoutModel;
+import com.codedifferently.lesson12.models.LibraryDataModel;
+import com.codedifferently.lesson12.models.LibraryGuestModel;
+import com.codedifferently.lesson12.models.MediaItemModel;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import org.springframework.stereotype.Service;
+
+@Service
+public class CsvLoader implements LibraryCsvDataLoader {
+
+  @Override
+  public LibraryDataModel loadData() throws IOException {
+    LibraryDataModel libraryData = new LibraryDataModel();
+
+    libraryData.guests = readGuestList("csv/guests.csv");
+    libraryData.mediaItems = readMediaItems("csv/media_items.csv");
+    libraryData.checkedOutItems = readCheckedOutByEmail("csv/checked_out_items.csv");
+
+    // Gives each guest a list of their checked out books.
+    libraryData.guests.forEach(
+        guest ->
+            guest.checkedOutItems =
+                libraryData.checkedOutItems.getOrDefault(guest.email, new ArrayList<>()));
+
+    return libraryData;
+  }
+
+  private List<MediaItemModel> readMediaItems(String path) throws IOException {
+    try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
+      return reader
+          .lines()
+          .skip(1)
+          .map(
+              line -> {
+                String[] parts = line.split(",", 8);
+                MediaItemModel item = new MediaItemModel();
+                item.type = parts[0];
+                item.id = UUID.fromString(parts[1]);
+                item.title = parts[2];
+                item.isbn = parts[3];
+                item.authors = List.of(parts[4]);
+                item.pages = parts[5].isEmpty() ? 0 : Integer.parseInt(parts[5]);
+                item.runtime = parts[6].isEmpty() ? 0 : Integer.parseInt(parts[6]);
+                item.edition = parts[7];
+                return item;
+              })
+          .collect(Collectors.toList());
+    }
+  }
+
+  private List<LibraryGuestModel> readGuestList(String path) throws IOException {
+    try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
+      return reader
+          .lines()
+          .skip(1)
+          .map(
+              line -> {
+                String[] parts = line.split(",");
+                LibraryGuestModel guest = new LibraryGuestModel();
+                guest.type = parts[0];
+                guest.name = parts[1];
+                guest.email = parts[2];
+                return guest;
+              })
+          .collect(Collectors.toList());
+    }
+  }
+
+  private Map<String, List<CheckoutModel>> readCheckedOutByEmail(String path) throws IOException {
+    try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
+      return reader
+          .lines()
+          .skip(1)
+          .map(
+              line -> {
+                String[] parts = line.split(",");
+                CheckoutModel item = new CheckoutModel();
+                item.itemId = UUID.fromString(parts[1]);
+                item.dueDate = Instant.parse(parts[2]);
+                return Map.entry(parts[0], item);
+              })
+          .collect(
+              Collectors.groupingBy(
+                  Map.Entry::getKey, Collectors.mapping(Map.Entry::getValue, Collectors.toList())));
+    }
+  }
+}