From 141d999c9496ddc1c78f4b4879975cac6133f31e Mon Sep 17 00:00:00 2001
From: Adrien Hopkins <adrien.p.hopkins@gmail.com>
Date: Sat, 16 Sep 2023 15:56:07 -0500
Subject: Refactor Presenter.loadSettings

These changes should reduce nesting and increase readability.
---
 src/main/java/sevenUnitsGUI/Presenter.java | 126 +++++++++++++++++------------
 1 file changed, 74 insertions(+), 52 deletions(-)

(limited to 'src')

diff --git a/src/main/java/sevenUnitsGUI/Presenter.java b/src/main/java/sevenUnitsGUI/Presenter.java
index 2c8ae71..fb134bb 100644
--- a/src/main/java/sevenUnitsGUI/Presenter.java
+++ b/src/main/java/sevenUnitsGUI/Presenter.java
@@ -596,59 +596,69 @@ public final class Presenter {
 	 * @since 2021-12-15
 	 */
 	void loadSettings(Path settingsFile) {
-		try {
-			// read file line by line
-			final int lineNum = 0;
-			for (final String line : Files.readAllLines(settingsFile)) {
-				final int equalsIndex = line.indexOf('=');
-				if (equalsIndex == -1)
-					throw new IllegalStateException(
-							"Settings file is malformed at line " + lineNum);
-				
-				final String param = line.substring(0, equalsIndex);
-				final String value = line.substring(equalsIndex + 1);
-				
-				switch (param) {
-				// set manually to avoid the unnecessary saving of the non-manual
-				// methods
-				case "custom_dimension_file":
-					this.database.loadDimensionFile(pathFromConfig(value));
-					break;
-				case "custom_exception_file":
-					Files.lines(pathFromConfig(value))
-						.map(Presenter::withoutComments)
-						.forEach(this.metricExceptions::add);
-					break;
-				case "custom_unit_file":
-					this.database.loadUnitsFile(pathFromConfig(value));
-					break;
-				case "number_display_rule":
-					this.setDisplayRuleFromString(value);
-					break;
-				case "prefix_rule":
-					this.prefixRepetitionRule = DefaultPrefixRepetitionRule
-							.valueOf(value);
-					this.database.setPrefixRepetitionRule(this.prefixRepetitionRule);
-					break;
-				case "one_way":
-					this.oneWayConversionEnabled = Boolean.valueOf(value);
-					break;
-				case "include_duplicates":
-					this.showDuplicates = Boolean.valueOf(value);
-					break;
-				case "search_prefix_rule":
-					this.setSearchRuleFromString(value);
-					break;
-				default:
-					System.err.printf("Warning: unrecognized setting \"%s\".%n",
-							param);
-					break;
-				}
-			}
-			if (this.view.getPresenter() != null) {
-				this.updateView();
+		for (Map.Entry<String, String> setting : settingsFromFile(settingsFile)) {
+			final String value = setting.getValue();
+
+			switch (setting.getKey()) {
+			// set manually to avoid the unnecessary saving of the non-manual
+			// methods
+			case "custom_dimension_file":
+				this.database.loadDimensionFile(pathFromConfig(value));
+				break;
+			case "custom_exception_file":
+				this.loadExceptionFile(pathFromConfig(value));
+				break;
+			case "custom_unit_file":
+				this.database.loadUnitsFile(pathFromConfig(value));
+				break;
+			case "number_display_rule":
+				this.setDisplayRuleFromString(value);
+				break;
+			case "prefix_rule":
+				this.prefixRepetitionRule = DefaultPrefixRepetitionRule
+				.valueOf(value);
+				this.database.setPrefixRepetitionRule(this.prefixRepetitionRule);
+				break;
+			case "one_way":
+				this.oneWayConversionEnabled = Boolean.valueOf(value);
+				break;
+			case "include_duplicates":
+				this.showDuplicates = Boolean.valueOf(value);
+				break;
+			case "search_prefix_rule":
+				this.setSearchRuleFromString(value);
+				break;
+			default:
+				System.err.printf("Warning: unrecognized setting \"%s\".%n",
+						setting.getKey());
+				break;
 			}
-		} catch (final IOException e) {}
+		}
+
+		if (this.view.getPresenter() != null) {
+			this.updateView();
+		}
+	}
+
+	private List<Map.Entry<String, String>> settingsFromFile(Path settingsFile) {
+		try (Stream<String> lines = Files.lines(settingsFile)) {
+			return lines.map(Presenter::parseSettingLine).toList();
+		} catch (final IOException e) {
+			this.view.showErrorMessage("Settings Loading Error", "Error loading settings file.  Using default settings.");
+			return null;
+		}
+	}
+
+	private static Map.Entry<String, String> parseSettingLine(String line) {
+		final int equalsIndex = line.indexOf('=');
+		if (equalsIndex == -1)
+			throw new IllegalStateException(
+					"Settings file is malformed at line: " + line);
+
+		final String param = line.substring(0, equalsIndex);
+		final String value = line.substring(equalsIndex + 1);
+
+		return Map.entry(param, value);
 	}
 	
 	private void setSearchRuleFromString(String ruleString) {
@@ -687,6 +697,18 @@ public final class Presenter {
 		}
 	}
 
+	private void loadExceptionFile(Path exceptionFile) {
+		try (Stream<String> lines = Files.lines(exceptionFile)) {
+			lines.map(Presenter::withoutComments)
+					.forEach(this.metricExceptions::add);
+		} catch (IOException e) {
+			this.view.showErrorMessage("File Load Error",
+					"Error loading configured metric exception file \""
+							+ exceptionFile + "\": "
+							+ e.getLocalizedMessage());
+		}
+	}
+
 	/**
 	 * @return true iff the One-Way Conversion feature is available (views that
 	 *         show units as a list will have metric units removed from the From
-- 
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