Add MySQL2 library as dependency for the hazard history, rewrite to use mysql for data

README.md

@@ -120,6 +120,48 @@ The `Ground View` screen requires a Windy Webcams API key. Create a file named `
 
 You can obtain a free API key from [Windy Webcams API](https://api.windy.com/webcams).
 
+## MySQL
+
+`Hazard List` is now backed by MySQL in server mode. The UI only shows the latest 7 hazards, but the database retains full history.
+
+Set these environment variables before starting the app:
+
+```text
+WS4KP_MYSQL_HOST=127.0.0.1
+WS4KP_MYSQL_PORT=3306
+WS4KP_MYSQL_SOCKET_PATH=/var/run/mysql/mysql.sock
+WS4KP_MYSQL_USER=root
+WS4KP_MYSQL_PASSWORD=your-password
+WS4KP_MYSQL_DATABASE=ws4kp_linhanced
+```
+
+If your local MariaDB/MySQL instance is socket-only, set `WS4KP_MYSQL_SOCKET_PATH` and omit `WS4KP_MYSQL_HOST` / `WS4KP_MYSQL_PORT`.
+
+Create the required table:
+
+```sql
+CREATE TABLE hazard_history (
+    id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+    location_label VARCHAR(255) NOT NULL,
+    location_key VARCHAR(128) NOT NULL,
+    hazard_type VARCHAR(128) NOT NULL,
+    source VARCHAR(64) NOT NULL,
+    severity VARCHAR(64) DEFAULT NULL,
+    latest_hazard_id VARCHAR(255) DEFAULT NULL,
+    encountered_at DATETIME NOT NULL,
+    last_seen_at DATETIME NOT NULL,
+    ongoing TINYINT(1) NOT NULL DEFAULT 1,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+
+    PRIMARY KEY (id),
+    UNIQUE KEY uq_logical_hazard (location_key, hazard_type, source),
+    KEY idx_last_seen_at (last_seen_at),
+    KEY idx_location_key (location_key),
+    KEY idx_ongoing (ongoing)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+```
+
 ## Running Modes
 
 This fork supports two main runtime styles.
@@ -137,6 +179,7 @@ This mode includes:
 * Express server entry point
 * proxying and caching for weather/map requests
 * Fastfetch-backed Server Observations
+* MySQL-backed Hazard List history
 * better shared performance when multiple clients use the same instance
 
 ### Static Mode
@@ -154,9 +197,9 @@ Or upload the generated `dist/` directory to your web server after running:
 npm run build
 ```
 
-The static build has been adjusted so frontend-generated paths no longer assume deployment at `/`, which makes subdirectory hosting more practical. **Also, features that require a backend server like the on-disk cache, Fastfetch-backed Server Observations, LWN Linux News, and `Ground View` will not work when running the static build by itself.**
+The static build has been adjusted so frontend-generated paths no longer assume deployment at `/`, which makes subdirectory hosting more practical. **Also, features that require a backend server like the on-disk cache, Fastfetch-backed Server Observations, LWN Linux News, `Ground View`, and `Hazard List` will not work when running the static build by itself.**
 
-The public demo at [https://mentalnet.xyz/ws4kp-linhanced-demo/](https://mentalnet.xyz/ws4kp-linhanced-demo/) is intentionally served as a static build, so the `Linux News`, `Server Observations`, and `Ground View` screens will not work there.
+The public demo at [https://mentalnet.xyz/ws4kp-linhanced-demo/](https://mentalnet.xyz/ws4kp-linhanced-demo/) is intentionally served as a static build, so the `Linux News`, `Server Observations`, `Ground View`, and `Hazard List` screens will not work there.
 
 ## International Support
 

index.mjs

@@ -21,6 +21,7 @@ import cache from './proxy/cache.mjs';
 import devTools from './src/com.chrome.devtools.mjs';
 import { discoverThemes } from './src/theme-discovery.mjs';
 import { findNearestWindyWebcam, loadWindyApiKey } from './src/windy-webcams.mjs';
+import { checkHazardHistoryTable } from './src/mysql.mjs';
 import { getHistory, updateHistory } from './src/hazard-history.mjs';
 
 const execAsync = promisify(exec);
@@ -203,6 +204,12 @@ const staticOptions = {
 // Weather.gov API proxy (catch-all for any Weather.gov API endpoint)
 // Skip setting up routes for the caching proxy server in static mode
 if (!process.env?.STATIC) {
+	try {
+		await checkHazardHistoryTable();
+	} catch (error) {
+		console.error(error.message);
+	}
+
 	// Server info endpoint for fastfetch output (must be before /api/ weather proxy)
 	app.get('/api/server-info', async (req, res) => {
 		try {

package-lock.json

@@ -11,7 +11,8 @@
 			"dependencies": {
 				"dotenv": "^17.0.1",
 				"ejs": "^5.0.1",
-				"express": "^5.1.0"
+				"express": "^5.1.0",
+				"mysql2": "^3.22.1"
 			},
 			"devDependencies": {
 				"@eslint/eslintrc": "^3.3.1",
@@ -3071,6 +3072,15 @@
 				"url": "https://github.com/sponsors/ljharb"
 			}
 		},
+		"node_modules/aws-ssl-profiles": {
+			"version": "1.1.2",
+			"resolved": "https://registry.npmjs.org/aws-ssl-profiles/-/aws-ssl-profiles-1.1.2.tgz",
+			"integrity": "sha512-NZKeq9AfyQvEeNlN0zSYAaWrmBffJh3IELMZfRpJVWgrpEbtEpnjvzqBPf+mxoI287JohRDoa+/nsfqqiZmF6g==",
+			"license": "MIT",
+			"engines": {
+				"node": ">= 6.0.0"
+			}
+		},
 		"node_modules/b4a": {
 			"version": "1.8.0",
 			"resolved": "https://registry.npmjs.org/b4a/-/b4a-1.8.0.tgz",
@@ -3829,6 +3839,15 @@
 				"url": "https://github.com/sponsors/sindresorhus"
 			}
 		},
+		"node_modules/denque": {
+			"version": "2.1.0",
+			"resolved": "https://registry.npmjs.org/denque/-/denque-2.1.0.tgz",
+			"integrity": "sha512-HVQE3AAb/pxF8fQAoiqpvg9i3evqug3hoiwakOyZAwJm+6vZehbkYXZ0l4JxS+I3QxM97v5aaRNhj8v5oBhekw==",
+			"license": "Apache-2.0",
+			"engines": {
+				"node": ">=0.10"
+			}
+		},
 		"node_modules/depd": {
 			"version": "2.0.0",
 			"resolved": "https://registry.npmjs.org/depd/-/depd-2.0.0.tgz",
@@ -5094,6 +5113,15 @@
 				"url": "https://github.com/sponsors/ljharb"
 			}
 		},
+		"node_modules/generate-function": {
+			"version": "2.3.1",
+			"resolved": "https://registry.npmjs.org/generate-function/-/generate-function-2.3.1.tgz",
+			"integrity": "sha512-eeB5GfMNeevm/GRYq20ShmsaGcmI81kIX2K9XQx5miC8KdHaC6Jm0qQ8ZNeGOi7wYB8OsdxKs+Y2oVuTFuVwKQ==",
+			"license": "MIT",
+			"dependencies": {
+				"is-property": "^1.0.2"
+			}
+		},
 		"node_modules/generator-function": {
 			"version": "2.0.1",
 			"resolved": "https://registry.npmjs.org/generator-function/-/generator-function-2.0.1.tgz",
@@ -6421,6 +6449,12 @@
 				"node": ">=0.10.0"
 			}
 		},
+		"node_modules/is-property": {
+			"version": "1.0.2",
+			"resolved": "https://registry.npmjs.org/is-property/-/is-property-1.0.2.tgz",
+			"integrity": "sha512-Ks/IoX00TtClbGQr4TWXemAnktAQvYB7HzcCxDGqEZU6oCmb2INHuOoKxbtR+HFkmYWBKv/dOZtGRiAjDhj92g==",
+			"license": "MIT"
+		},
 		"node_modules/is-regex": {
 			"version": "1.2.1",
 			"resolved": "https://registry.npmjs.org/is-regex/-/is-regex-1.2.1.tgz",
@@ -6861,6 +6895,12 @@
 			"dev": true,
 			"license": "MIT"
 		},
+		"node_modules/long": {
+			"version": "5.3.2",
+			"resolved": "https://registry.npmjs.org/long/-/long-5.3.2.tgz",
+			"integrity": "sha512-mNAgZ1GmyNhD7AuqnTG3/VQ26o760+ZYBPKjPvugO8+nLbYfX6TVpJPseBvopbdY+qpZ/lKUnmEc1LeZYS3QAA==",
+			"license": "Apache-2.0"
+		},
 		"node_modules/lower-case": {
 			"version": "2.0.2",
 			"resolved": "https://registry.npmjs.org/lower-case/-/lower-case-2.0.2.tgz",
@@ -6871,6 +6911,21 @@
 				"tslib": "^2.0.3"
 			}
 		},
+		"node_modules/lru.min": {
+			"version": "1.1.4",
+			"resolved": "https://registry.npmjs.org/lru.min/-/lru.min-1.1.4.tgz",
+			"integrity": "sha512-DqC6n3QQ77zdFpCMASA1a3Jlb64Hv2N2DciFGkO/4L9+q/IpIAuRlKOvCXabtRW6cQf8usbmM6BE/TOPysCdIA==",
+			"license": "MIT",
+			"engines": {
+				"bun": ">=1.0.0",
+				"deno": ">=1.30.0",
+				"node": ">=8.0.0"
+			},
+			"funding": {
+				"type": "github",
+				"url": "https://github.com/sponsors/wellwelwel"
+			}
+		},
 		"node_modules/luxon": {
 			"version": "3.7.2",
 			"resolved": "https://registry.npmjs.org/luxon/-/luxon-3.7.2.tgz",
@@ -7037,6 +7092,40 @@
 				"node": ">= 10.13.0"
 			}
 		},
+		"node_modules/mysql2": {
+			"version": "3.22.1",
+			"resolved": "https://registry.npmjs.org/mysql2/-/mysql2-3.22.1.tgz",
+			"integrity": "sha512-48+9UXehKyxxiP2pqCxUq+MSFvX+v41jwsSpFDQO/jAoFuAELutBGJUhWJnDbe82/OBlIhSBMC82WeonmznT/Q==",
+			"license": "MIT",
+			"dependencies": {
+				"aws-ssl-profiles": "^1.1.2",
+				"denque": "^2.1.0",
+				"generate-function": "^2.3.1",
+				"iconv-lite": "^0.7.2",
+				"long": "^5.3.2",
+				"lru.min": "^1.1.4",
+				"named-placeholders": "^1.1.6",
+				"sql-escaper": "^1.3.3"
+			},
+			"engines": {
+				"node": ">= 8.0"
+			},
+			"peerDependencies": {
+				"@types/node": ">= 8"
+			}
+		},
+		"node_modules/named-placeholders": {
+			"version": "1.1.6",
+			"resolved": "https://registry.npmjs.org/named-placeholders/-/named-placeholders-1.1.6.tgz",
+			"integrity": "sha512-Tz09sEL2EEuv5fFowm419c1+a/jSMiBjI9gHxVLrVdbUkkNUUfjsVYs9pVZu5oCon/kmRh9TfLEObFtkVxmY0w==",
+			"license": "MIT",
+			"dependencies": {
+				"lru.min": "^1.1.0"
+			},
+			"engines": {
+				"node": ">=8.0.0"
+			}
+		},
 		"node_modules/natural-compare": {
 			"version": "1.4.0",
 			"resolved": "https://registry.npmjs.org/natural-compare/-/natural-compare-1.4.0.tgz",
@@ -8379,6 +8468,21 @@
 				"node": ">= 10.13.0"
 			}
 		},
+		"node_modules/sql-escaper": {
+			"version": "1.3.3",
+			"resolved": "https://registry.npmjs.org/sql-escaper/-/sql-escaper-1.3.3.tgz",
+			"integrity": "sha512-BsTCV265VpTp8tm1wyIm1xqQCS+Q9NHx2Sr+WcnUrgLrQ6yiDIvHYJV5gHxsj1lMBy2zm5twLaZao8Jd+S8JJw==",
+			"license": "MIT",
+			"engines": {
+				"bun": ">=1.0.0",
+				"deno": ">=2.0.0",
+				"node": ">=12.0.0"
+			},
+			"funding": {
+				"type": "github",
+				"url": "https://github.com/mysqljs/sql-escaper?sponsor=1"
+			}
+		},
 		"node_modules/statuses": {
 			"version": "2.0.2",
 			"resolved": "https://registry.npmjs.org/statuses/-/statuses-2.0.2.tgz",

package.json

@@ -56,6 +56,7 @@
 	"dependencies": {
 		"dotenv": "^17.0.1",
 		"ejs": "^5.0.1",
-		"express": "^5.1.0"
+		"express": "^5.1.0",
+		"mysql2": "^3.22.1"
 	}
 }

server/scripts/modules/hazards.mjs

@@ -285,7 +285,7 @@ class Hazards extends WeatherDisplay {
 				id: hazard.id,
 				hazardType: hazard.properties?.event || 'Unknown',
 				severity: hazard.properties?.severity || 'Unknown',
-				source: hazard.properties?.senderName?.includes('NOAA') ? 'noaa' : 'derived',
+				source: String(hazard.id || '').startsWith('derived-') ? 'derived' : 'noaa',
 			}));
 
 			// Send to backend

src/hazard-history.mjs

@@ -1,141 +1,24 @@
-/**
+import { getPool } from './mysql.mjs';
- * Hazard History persistence module
- * Tracks the last 7 hazard alerts encountered by this server instance
- */
 
-import { readFile, writeFile, mkdir } from 'fs/promises';
-import path from 'path';
-
-const HISTORY_FILE = path.resolve('./data/hazard-history.json');
 const MAX_HISTORY_ENTRIES = 7;
 
-/**
+const toIsoString = (value) => {
- * Ensure the cache directory exists
+	if (!value) return null;
- */
+	const date = value instanceof Date ? value : new Date(value);
-const ensureCacheDir = async () => {
+	return Number.isNaN(date.getTime()) ? null : date.toISOString();
-	const cacheDir = path.dirname(HISTORY_FILE);
-	try {
-		await mkdir(cacheDir, { recursive: true });
-	} catch (error) {
-		// Directory may already exist
-	}
 };
 
-/**
+const mapRowToHistoryEntry = (row) => ({
- * Load hazard history from disk
+	location: row.location_label,
- * @returns {Array} Array of hazard history entries
+	locationKey: row.location_key,
- */
+	hazardType: row.hazard_type,
-const loadHistory = async () => {
+	source: row.source,
-	try {
+	severity: row.severity,
-		await ensureCacheDir();
+	latestHazardId: row.latest_hazard_id,
-		const data = await readFile(HISTORY_FILE, 'utf8');
+	encounteredAt: toIsoString(row.encountered_at),
-		const parsed = JSON.parse(data);
+	lastSeenAt: toIsoString(row.last_seen_at),
-		return Array.isArray(parsed) ? parsed : [];
+	ongoing: Boolean(row.ongoing),
-	} catch (error) {
+});
-		// File doesn't exist or is corrupted, return empty array
-		return [];
-	}
-};
-
-/**
- * Save hazard history to disk
- * @param {Array} history - Array of hazard history entries
- */
-const saveHistory = async (history) => {
-	try {
-		await ensureCacheDir();
-		await writeFile(HISTORY_FILE, JSON.stringify(history, null, '\t'));
-	} catch (error) {
-		console.error('Failed to save hazard history:', error.message);
-	}
-};
-
-const isCoordinateLocationKey = (value) => /^-?\d+(?:\.\d+)?,-?\d+(?:\.\d+)?$/.test(value ?? '');
-
-/**
- * Generate a stable identity for a hazard entry.
- * This intentionally ignores upstream alert ids so alert revisions
- * continue updating the same logical history row.
- * @param {string} locationKey - Stable location key
- * @param {string} hazardType - Hazard/event name
- * @param {string} source - Hazard source
- * @returns {string} Stable identity key
- */
-const generateKey = (locationKey, hazardType, source) => `${locationKey}::${hazardType}::${source}`;
-
-const normalizeTimestamp = (value, fallback) => {
-	const date = new Date(value);
-	return Number.isNaN(date.getTime()) ? fallback : date.toISOString();
-};
-
-const isSameLogicalHazard = (left, right) => left.location === right.location
-	&& left.hazardType === right.hazardType
-	&& left.source === right.source;
-
-const isSameRequestedLocation = (entry, location, locationKey) => {
-	if (locationKey && entry.locationKey === locationKey) return true;
-	return entry.location === location;
-};
-
-const upgradeEntryLocationKey = (entry, location, locationKey) => {
-	if (!locationKey || entry.locationKey === locationKey) return entry;
-	return {
-		...entry,
-		location,
-		locationKey,
-		key: generateKey(locationKey, entry.hazardType, entry.source),
-	};
-};
-
-const mergeEntries = (existing, incoming) => {
-	const existingEncountered = normalizeTimestamp(existing.encounteredAt, incoming.encounteredAt);
-	const incomingEncountered = normalizeTimestamp(incoming.encounteredAt, existing.encounteredAt);
-	const existingLastSeen = normalizeTimestamp(existing.lastSeenAt, incoming.lastSeenAt);
-	const incomingLastSeen = normalizeTimestamp(incoming.lastSeenAt, existing.lastSeenAt);
-	const keepIncomingLocationKey = isCoordinateLocationKey(incoming.locationKey) && !isCoordinateLocationKey(existing.locationKey);
-	const latestHazardId = new Date(incomingLastSeen) >= new Date(existingLastSeen)
-		? (incoming.latestHazardId ?? existing.latestHazardId)
-		: (existing.latestHazardId ?? incoming.latestHazardId);
-
-	return {
-		...existing,
-		location: keepIncomingLocationKey ? incoming.location : (existing.location || incoming.location),
-		locationKey: keepIncomingLocationKey ? incoming.locationKey : (existing.locationKey || incoming.locationKey),
-		key: keepIncomingLocationKey ? incoming.key : existing.key,
-		encounteredAt: new Date(existingEncountered) <= new Date(incomingEncountered) ? existingEncountered : incomingEncountered,
-		lastSeenAt: new Date(existingLastSeen) >= new Date(incomingLastSeen) ? existingLastSeen : incomingLastSeen,
-		ongoing: Boolean(existing.ongoing || incoming.ongoing),
-		severity: incoming.severity || existing.severity,
-		source: incoming.source || existing.source,
-		latestHazardId,
-	};
-};
-
-const normalizeHistory = (history = []) => {
-	const normalized = [];
-
-	for (const rawEntry of history) {
-		if (!rawEntry?.hazardType || !rawEntry?.source) continue;
-		const locationKey = rawEntry.locationKey || rawEntry.location;
-		const entry = {
-			...rawEntry,
-			locationKey,
-			key: generateKey(locationKey, rawEntry.hazardType, rawEntry.source),
-			encounteredAt: normalizeTimestamp(rawEntry.encounteredAt, new Date().toISOString()),
-			lastSeenAt: normalizeTimestamp(rawEntry.lastSeenAt ?? rawEntry.encounteredAt, new Date().toISOString()),
-			latestHazardId: rawEntry.latestHazardId ?? rawEntry.hazardId ?? rawEntry.id ?? rawEntry.key,
-		};
-
-		const existingIndex = normalized.findIndex((candidate) => candidate.key === entry.key || isSameLogicalHazard(candidate, entry));
-		if (existingIndex >= 0) {
-			normalized[existingIndex] = mergeEntries(normalized[existingIndex], entry);
-		} else {
-			normalized.push(entry);
-		}
-	}
-
-	return normalized;
-};
 
 /**
  * Format location label from weather parameters
@@ -147,120 +30,114 @@ const normalizeHistory = (history = []) => {
  */
 const formatLocation = (city, state, country, countryCode) => {
 	const cleanCity = city?.trim() || 'Unknown';
-	
+
-	// US locations: "City, State"
 	if (countryCode === 'US' || countryCode === 'USA') {
 		const cleanState = state?.trim();
 		return cleanState ? `${cleanCity}, ${cleanState}` : cleanCity;
 	}
-	
+
-	// Non-US locations: "City, Country"
 	const cleanCountry = country?.trim();
 	return cleanCountry ? `${cleanCity}, ${cleanCountry}` : cleanCity;
 };
 
-/**
+const getHistory = async () => {
- * Update hazard history with current active hazards for a location
+	const [rows] = await getPool().query(
- * @param {Object} payload - Request payload
+		`SELECT
- * @param {string} payload.location - Formatted location label (for display)
+			location_label,
- * @param {string} payload.locationKey - Stable location key from lat/lon (for matching)
+			location_key,
- * @param {Array} payload.hazards - Array of active hazards
+			hazard_type,
- * @returns {Array} Updated history
+			source,
- */
+			severity,
-const updateHistory = async (payload) => {
+			latest_hazard_id,
-	const { location, locationKey, hazards = [] } = payload;
+			encountered_at,
-	
+			last_seen_at,
-	// Load existing history
+			ongoing
-	let history = normalizeHistory(await loadHistory());
+		FROM hazard_history
-	const now = new Date().toISOString();
+		ORDER BY last_seen_at DESC
-	
+		LIMIT ?`,
-	// Use locationKey for matching if provided, fall back to location for backward compatibility
+		[MAX_HISTORY_ENTRIES],
-	const matchKey = locationKey || location;
+	);
-	
-	// Create a set of active hazard identities for this location
-	const activeKeys = new Set(hazards.map((hazard) => generateKey(matchKey, hazard.hazardType, hazard.source)));
-	
-	// Mark previously ongoing hazards for this location as ended if no longer active
-	history = history.map((entry) => {
-		if (!isSameRequestedLocation(entry, location, locationKey)) return entry;
 
-		const upgradedEntry = upgradeEntryLocationKey(entry, location, locationKey);
+	return rows.map(mapRowToHistoryEntry);
-		
-		// If this entry is ongoing but not in the current active set, mark it as ended
-		if (upgradedEntry.ongoing && !activeKeys.has(upgradedEntry.key)) {
-			return {
-				...upgradedEntry,
-				ongoing: false,
-				lastSeenAt: now,
-			};
-		}
-		return upgradedEntry;
-	});
-	
-	// Add or update active hazards
-	hazards.forEach((hazard) => {
-		const key = generateKey(matchKey, hazard.hazardType, hazard.source);
-		const existingIndex = history.findIndex((entry) => entry.key === key);
-		
-		if (existingIndex >= 0) {
-			// Update existing entry
-			history[existingIndex] = {
-				...history[existingIndex],
-				lastSeenAt: now,
-				ongoing: true,
-				// Update severity if it changed
-				severity: hazard.severity || history[existingIndex].severity,
-				latestHazardId: hazard.id,
-			};
-		} else {
-			// Create new entry
-			history.push({
-				key,
-				location,
-				locationKey: matchKey,
-				hazardType: hazard.hazardType,
-				encounteredAt: now,
-				lastSeenAt: now,
-				ongoing: true,
-				severity: hazard.severity,
-				source: hazard.source,
-				latestHazardId: hazard.id,
-			});
-		}
-	});
-
-	history = normalizeHistory(history);
-	
-	// Sort by lastSeenAt descending (newest first)
-	history.sort((a, b) => new Date(b.lastSeenAt) - new Date(a.lastSeenAt));
-	
-	// Trim to max entries
-	if (history.length > MAX_HISTORY_ENTRIES) {
-		history = history.slice(0, MAX_HISTORY_ENTRIES);
-	}
-	
-	// Save updated history
-	await saveHistory(history);
-	
-	return history;
 };
 
-/**
+const updateHistory = async (payload) => {
- * Get current hazard history
+	const { location, locationKey, hazards = [] } = payload;
- * @returns {Array} Current history entries
+	const validHazards = hazards.filter((hazard) => hazard?.hazardType && hazard?.source);
- */
+	const pool = getPool();
-const getHistory = async () => {
+	const connection = await pool.getConnection();
-	const history = normalizeHistory(await loadHistory());
+
-	// Ensure sorted by lastSeenAt descending
+	try {
-	return history.sort((a, b) => new Date(b.lastSeenAt) - new Date(a.lastSeenAt));
+		await connection.beginTransaction();
+
+		if (validHazards.length === 0) {
+			await connection.execute(
+				`UPDATE hazard_history
+				SET ongoing = 0,
+				    last_seen_at = UTC_TIMESTAMP()
+				WHERE location_key = ?
+				  AND ongoing = 1`,
+				[locationKey],
+			);
+		} else {
+			const keepClauses = validHazards.map(() => '(hazard_type = ? AND source = ?)').join(' OR ');
+			const keepParams = validHazards.flatMap((hazard) => [hazard.hazardType, hazard.source]);
+
+			await connection.execute(
+				`UPDATE hazard_history
+				SET ongoing = 0,
+				    last_seen_at = UTC_TIMESTAMP()
+				WHERE location_key = ?
+				  AND ongoing = 1
+				  AND NOT (${keepClauses})`,
+				[locationKey, ...keepParams],
+			);
+		}
+
+		for (const hazard of validHazards) {
+			await connection.execute(
+				`INSERT INTO hazard_history (
+					location_label,
+					location_key,
+					hazard_type,
+					source,
+					severity,
+					latest_hazard_id,
+					encountered_at,
+					last_seen_at,
+					ongoing
+				) VALUES (?, ?, ?, ?, ?, ?, UTC_TIMESTAMP(), UTC_TIMESTAMP(), 1)
+				ON DUPLICATE KEY UPDATE
+					location_label = VALUES(location_label),
+					severity = VALUES(severity),
+					latest_hazard_id = VALUES(latest_hazard_id),
+					last_seen_at = UTC_TIMESTAMP(),
+					ongoing = 1`,
+				[
+					location,
+					locationKey,
+					hazard.hazardType,
+					hazard.source,
+					hazard.severity ?? null,
+					hazard.id ?? null,
+				],
+			);
+		}
+
+		await connection.commit();
+	} catch (error) {
+		await connection.rollback();
+		throw error;
+	} finally {
+		connection.release();
+	}
+
+	return getHistory();
 };
 
 export {
-	loadHistory,
-	saveHistory,
-	updateHistory,
-	getHistory,
 	formatLocation,
-	generateKey,
+	getHistory,
 	MAX_HISTORY_ENTRIES,
+	updateHistory,
 };

src/mysql.mjs

@@ -0,0 +1,66 @@
+import mysql from 'mysql2/promise';
+
+let pool;
+
+const getConfig = () => {
+	const {
+		WS4KP_MYSQL_HOST = '127.0.0.1',
+		WS4KP_MYSQL_PORT = '3306',
+		WS4KP_MYSQL_USER,
+		WS4KP_MYSQL_PASSWORD,
+		WS4KP_MYSQL_DATABASE,
+		WS4KP_MYSQL_SOCKET_PATH,
+	} = process.env;
+
+	if (!WS4KP_MYSQL_USER || !WS4KP_MYSQL_PASSWORD || !WS4KP_MYSQL_DATABASE) {
+		throw new Error('Missing MySQL configuration. Set WS4KP_MYSQL_USER, WS4KP_MYSQL_PASSWORD, and WS4KP_MYSQL_DATABASE.');
+	}
+
+	const config = {
+		user: WS4KP_MYSQL_USER,
+		password: WS4KP_MYSQL_PASSWORD,
+		database: WS4KP_MYSQL_DATABASE,
+		waitForConnections: true,
+		connectionLimit: 10,
+		queueLimit: 0,
+	};
+
+	if (WS4KP_MYSQL_SOCKET_PATH) {
+		config.socketPath = WS4KP_MYSQL_SOCKET_PATH;
+	} else {
+		config.host = WS4KP_MYSQL_HOST;
+		config.port = Number(WS4KP_MYSQL_PORT);
+	}
+
+	return config;
+};
+
+const getPool = () => {
+	if (!pool) {
+		pool = mysql.createPool(getConfig());
+	}
+	return pool;
+};
+
+const checkHazardHistoryTable = async () => {
+	const config = getConfig();
+	const [rows] = await getPool().query(
+		`SELECT 1
+		FROM information_schema.tables
+		WHERE table_schema = ?
+		  AND table_name = 'hazard_history'
+		LIMIT 1`,
+		[config.database],
+	);
+
+	if (rows.length === 0) {
+		throw new Error(`Hazard history database table 'hazard_history' is missing in database '${config.database}'. Run the documented CREATE TABLE statement before using Hazard List.`);
+	}
+
+	return true;
+};
+
+export {
+	checkHazardHistoryTable,
+	getPool,
+};