Attachments refactor (#737)

* refactor attachment code into its own file

* Add getters

* Remove custom models for each type of attachment

* Refactor existing widgets

* Fix double camera open bug

* Remove dead code

* Remove unused imports

* Refactor common code

* format

* Update release notes

lib/inventree/attachment.dart

@@ -0,0 +1,176 @@
+import "dart:io";
+
+import "package:flutter/cupertino.dart";
+import "package:flutter_tabler_icons/flutter_tabler_icons.dart";
+import "package:inventree/api.dart";
+import "package:inventree/inventree/model.dart";
+import "package:inventree/inventree/sentry.dart";
+import "package:inventree/l10.dart";
+import "package:inventree/widget/fields.dart";
+import "package:inventree/widget/snacks.dart";
+import "package:path/path.dart" as path;
+
+class InvenTreeAttachment extends InvenTreeModel {
+  // Class representing an "attachment" file
+  InvenTreeAttachment() : super();
+
+  InvenTreeAttachment.fromJson(Map<String, dynamic> json)
+    : super.fromJson(json);
+
+  @override
+  InvenTreeAttachment createFromJson(Map<String, dynamic> json) =>
+      InvenTreeAttachment.fromJson(json);
+
+  @override
+  String get URL => "attachment/";
+
+  @override
+  Map<String, Map<String, dynamic>> formFields() {
+    Map<String, Map<String, dynamic>> fields = {"link": {}, "comment": {}};
+
+    if (!hasLink) {
+      fields.remove("link");
+    }
+
+    return fields;
+  }
+
+  // The model type of the instance this attachment is associated with
+  String get modelType => getString("model_type");
+
+  // The ID of the instance this attachment is associated with
+  int get modelId => getInt("model_id");
+
+  String get attachment => getString("attachment");
+
+  bool get hasAttachment => attachment.isNotEmpty;
+
+  // Return the filename of the attachment
+  String get filename {
+    return attachment.split("/").last;
+  }
+
+  IconData get icon {
+    String fn = filename.toLowerCase();
+
+    if (fn.endsWith(".pdf")) {
+      return TablerIcons.file_type_pdf;
+    } else if (fn.endsWith(".csv")) {
+      return TablerIcons.file_type_csv;
+    } else if (fn.endsWith(".doc") || fn.endsWith(".docx")) {
+      return TablerIcons.file_type_doc;
+    } else if (fn.endsWith(".xls") || fn.endsWith(".xlsx")) {
+      return TablerIcons.file_type_xls;
+    }
+
+    // Image formats
+    final List<String> img_formats = [".png", ".jpg", ".gif", ".bmp", ".svg"];
+
+    for (String fmt in img_formats) {
+      if (fn.endsWith(fmt)) {
+        return TablerIcons.file_type_jpg;
+      }
+    }
+
+    return TablerIcons.file;
+  }
+
+  String get comment => getString("comment");
+
+  DateTime? get uploadDate {
+    if (jsondata.containsKey("upload_date")) {
+      return DateTime.tryParse((jsondata["upload_date"] ?? "") as String);
+    } else {
+      return null;
+    }
+  }
+
+  // Return a count of how many attachments exist against the specified model ID
+  Future<int> countAttachments(String modelType, int modelId) async {
+    Map<String, String> filters = {};
+
+    if (!api.supportsModernAttachments) {
+      return 0;
+    }
+
+    filters["model_type"] = modelType;
+    filters["model_id"] = modelId.toString();
+
+    return count(filters: filters);
+  }
+
+  Future<bool> uploadAttachment(
+    File attachment,
+    String modelType,
+    int modelId, {
+    String comment = "",
+    Map<String, String> fields = const {},
+  }) async {
+    // Ensure that the correct reference field is set
+    Map<String, String> data = Map<String, String>.from(fields);
+
+    String url = URL;
+
+    if (comment.isNotEmpty) {
+      data["comment"] = comment;
+    }
+
+    data["model_type"] = modelType;
+    data["model_id"] = modelId.toString();
+
+    final APIResponse response = await InvenTreeAPI().uploadFile(
+      url,
+      attachment,
+      method: "POST",
+      name: "attachment",
+      fields: data,
+    );
+
+    return response.successful();
+  }
+
+  Future<bool> uploadImage(
+    String modelType,
+    int modelId, {
+    String prefix = "InvenTree",
+  }) async {
+    bool result = false;
+
+    await FilePickerDialog.pickImageFromCamera().then((File? file) {
+      if (file != null) {
+        String dir = path.dirname(file.path);
+        String ext = path.extension(file.path);
+        String now = DateTime.now().toIso8601String().replaceAll(":", "-");
+
+        // Rename the file with a unique name
+        String filename = "${dir}/${prefix}_image_${now}${ext}";
+
+        try {
+          return file.rename(filename).then((File renamed) {
+            return uploadAttachment(renamed, modelType, modelId).then((
+              success,
+            ) {
+              result = success;
+              showSnackIcon(
+                result ? L10().imageUploadSuccess : L10().imageUploadFailure,
+                success: result,
+              );
+            });
+          });
+        } catch (error, stackTrace) {
+          sentryReportError("uploadImage", error, stackTrace);
+          showSnackIcon(L10().imageUploadFailure, success: false);
+        }
+      }
+    });
+
+    return result;
+  }
+
+  /*
+   * Download this attachment file
+   */
+  Future<void> downloadAttachment() async {
+    await InvenTreeAPI().downloadFile(attachment);
+  }
+}