From 9edae1959117fa175d17c3b07303c9f8a37d05e8 Mon Sep 17 00:00:00 2001
From: Stephan Richter <s.richter@srsoftware.de>
Date: Thu, 11 Sep 2025 21:15:01 +0200
Subject: [PATCH] started code to rebuid the wiki tables

---
 .../de/srsoftware/umbrella/wiki/SqliteDb.java | 92 ++++++++++++++++++-
 1 file changed, 91 insertions(+), 1 deletion(-)

diff --git a/wiki/src/main/java/de/srsoftware/umbrella/wiki/SqliteDb.java b/wiki/src/main/java/de/srsoftware/umbrella/wiki/SqliteDb.java
index 2427621..4b0a437 100644
--- a/wiki/src/main/java/de/srsoftware/umbrella/wiki/SqliteDb.java
+++ b/wiki/src/main/java/de/srsoftware/umbrella/wiki/SqliteDb.java
@@ -3,6 +3,7 @@ package de.srsoftware.umbrella.wiki;
 import de.srsoftware.tools.jdbc.Condition;
 import de.srsoftware.tools.jdbc.Query;
 import de.srsoftware.umbrella.core.BaseDb;
+import de.srsoftware.umbrella.core.model.Hash;
 import de.srsoftware.umbrella.core.model.Permission;
 import de.srsoftware.umbrella.core.model.WikiPage;
 
@@ -19,7 +20,7 @@ import static de.srsoftware.umbrella.core.exceptions.UmbrellaException.notFound;
 import static de.srsoftware.umbrella.core.model.Permission.EDIT;
 import static de.srsoftware.umbrella.core.model.Permission.READ_ONLY;
 import static de.srsoftware.umbrella.wiki.Constants.*;
-import static java.lang.System.Logger.Level.ERROR;
+import static java.lang.System.Logger.Level.*;
 import static java.text.MessageFormat.format;
 
 public class SqliteDb extends BaseDb implements WikiDb {
@@ -37,11 +38,56 @@ public class SqliteDb extends BaseDb implements WikiDb {
 			case 0:
 				createPagesTable();
 				createPagesUsersTable();
+			case 1:
+				/*
+				The old structure was:
+				Pages
+				| id (String) | version (int) | content (String) |
+
+				Page_Users
+				| page_id (String) | user_id (long) | permission (long) |
+
+				This poses a problem whenever a page is renamed:
+				On that occasion, all corresponding entries in the Page_Users table (and tags and notes) need to be updated!
+
+				So the transformation went to the following structure:
+				Pages
+				| id (long) | title (String) | version (int) | content (String) |
+
+				Page_Users
+				| page_id (long) | user_id (long) | permission (long) |
+
+				With this structure we have stable ids even when a page is renamed!
+				 */
+				var newPages = TABLE_PAGES+"_new";
+				var newUsers = TABLE_PAGES_USERS+"_new";
+				createNewTables(newPages, newUsers);
+				transferValues(newPages, newUsers);
+				//dropOldTables();
+				//moveNewTables();
 		}
 
 		return setCurrentVersion(1);
 	}
 
+	private void createNewTables(String newPages, String newUsers) {
+		var pages = "CREATE TABLE IF NOT EXISTS {0} ( {1} INT NOT NULL, {2} INT NOT NULL, {3} VARCHAR(255) NOT NULL, {4} TEXT NOT NULL, PRIMARY KEY({1},{2}))";
+		var users = "CREATE TABLE IF NOT EXISTS {0} ( {1} INT NOT NULL, {2} INT NOT NULL, {3} INT NOT NULL, PRIMARY KEY({1}, {2}))";
+
+		try {
+			var stmt = db.prepareStatement(format(pages, newPages, ID, VERSION, TITLE, CONTENT));
+			stmt.execute();
+			stmt.close();
+
+			stmt = db.prepareStatement(format(users, newUsers, PAGE_ID, USER_ID, PERMISSIONS));
+			stmt.execute();
+			stmt.close();
+		} catch (SQLException e) {
+			LOG.log(ERROR, ERROR_FAILED_CREATE_TABLE, newPages, e);
+			throw new RuntimeException(e);
+		}
+	}
+
 	private void createPagesTable() {
 		var sql = "CREATE TABLE IF NOT EXISTS {0} ( {1} VARCHAR(255) NOT NULL, {2} INT NOT NULL, {3} TEXT NOT NULL, PRIMARY KEY({1},{2}))";
 		try {
@@ -103,6 +149,50 @@ public class SqliteDb extends BaseDb implements WikiDb {
 		}
 	}
 
+	private void transferValues(String newTable, String newUsers) {
+		var pageMap = new HashMap<String,Long>(); // map from old IDs to new IDs
+		try {
+			Long id = 0L;
+			String lastTitle = null;
+			var rs = select("MAX(ID)").from(newTable).limit(1).exec(db);
+			if (rs.next()) id = rs.getLong(1);
+			rs.close();
+
+			rs = select(ALL).from(TABLE_PAGES).sort(ID).exec(db);
+
+			while (rs.next()){
+				var title   = rs.getString(ID);
+				var version = rs.getInt(VERSION);
+				var content = rs.getString(CONTENT);
+				if (!title.equals(lastTitle)) {
+					pageMap.put(lastTitle = title,++id);
+					LOG.log(DEBUG,"Transferring \"{0}\" to new table with id = {1}",title,id);
+				}
+				insertInto(newTable,ID,VERSION,TITLE,CONTENT).values(id,version,title,content).execute(db).close();
+			}
+
+			rs.close();
+
+			rs = select(ALL).from(TABLE_PAGES_USERS).sort(PAGE_ID).exec(db);
+			while (rs.next()){
+				var userId = rs.getLong(USER_ID);
+				var title = rs.getString(PAGE_ID);
+				var perm   = rs.getInt(PERMISSIONS);
+				id = pageMap.get(title);
+				if (id == null){
+					LOG.log(WARNING,"Found reference to non-existing page ({0}) in {1} – skipping transfer of permission",title,TABLE_PAGES_USERS);
+					continue;
+				}
+				insertInto(newUsers,PAGE_ID,USER_ID,PERMISSIONS).values(id,userId,perm).execute(db).close();
+			}
+			rs.close();
+		} catch (SQLException e) {
+			LOG.log(ERROR,"Failed to transfer entries from {0} → {0}_new!",TABLE_PAGES,e);
+			throw new RuntimeException(e);
+
+		}
+	}
+
 	private int wikiPermissionCode(Permission perm){
 		return switch (perm){
 			case READ_ONLY -> 1;