implement /database and /database/query

Content.Tests/DMProject/Tests/Database/clear.dm

@@ -0,0 +1,19 @@
+/proc/RunTest()
+	var/database/db = new("clear.db")
+
+	var/database/query/query = new("invalid command text")
+	query.Clear()
+
+	// Add with no parameters does nothing
+	query.Add()
+
+	// Execute without a command does nothing
+	query.Execute()
+
+	// and shouldn't report an error
+	ASSERT(!query.Error())
+
+	del(query)
+	del(db)
+
+	fdel("clear.db")

Content.Tests/DMProject/Tests/Database/error.dm

@@ -0,0 +1,13 @@
+/proc/RunTest()
+	var/database/db = new("database.db")
+
+	var/database/query/query = new("I am the greatest SQL query writer of all time.")
+	query.Execute(db)
+
+	ASSERT(query.Error() == 1)
+	ASSERT(length(query.ErrorMsg()) > 1)
+
+	ASSERT(db.Error() == 1)
+	ASSERT(length(db.ErrorMsg()) > 1)
+
+	fdel("database.db")

Content.Tests/DMProject/Tests/Database/new_empty.dm

@@ -0,0 +1,7 @@
+// RUNTIME ERROR
+
+/proc/RunTest()
+	var/database/db = new()
+	var/database/query/query = new("CREATE TABLE foobar (id int)")
+
+	query.Execute(db)

Content.Tests/DMProject/Tests/Database/no_entries.dm

@@ -0,0 +1,15 @@
+/proc/RunTest()
+	var/database/db = new("noentries.db")
+
+	var/database/query/query = new("CREATE TABLE foobar (id int)")
+	query.Execute(db)
+
+	query.Add("SELECT * FROM foobar")
+	query.Execute(db)
+	query.NextRow()
+
+	query.GetRowData()
+
+	ASSERT(query.Error() && query.ErrorMsg())
+
+	fdel("noentries.db")

Content.Tests/DMProject/Tests/Database/open_and_open.dm

@@ -0,0 +1,22 @@
+/proc/RunTest()
+	var/database/db = new("foo.db")
+
+	var/database/query/query = new("CREATE TABLE foo (id int)")
+	query.Execute(db)
+
+	query.Add("INSERT INTO foo VALUES (1)")
+	query.Execute(db)
+
+	ASSERT(query.RowsAffected() == 1)
+
+	db.Open("bar.db")
+	query.Add("CREATE TABLE bar (id int)")
+	query.Execute(db)
+
+	query.Add("INSERT INTO bar VALUES (1)")
+	query.Execute(db)
+
+	ASSERT(query.RowsAffected() == 1)
+
+	fdel("foo.db")
+	fdel("bar.db")

Content.Tests/DMProject/Tests/Database/read.dm

@@ -0,0 +1,54 @@
+/proc/RunTest()	
+	var/database/db = new("database.db")
+
+	var/database/query/query = new("CREATE TABLE test (id int, name string, points float)")
+	query.Execute(db)
+
+	query.Add("INSERT INTO test VALUES (?, ?, ?)", 1, "foo", 1.5)
+	query.Execute(db)
+
+	ASSERT(query.RowsAffected() == 1)
+
+	query.Add("SELECT * FROM test WHERE id = ?", 1)
+	query.Execute(db)
+	query.NextRow()
+
+	var/list/assoc = query.GetRowData()
+	ASSERT(length(assoc) == 3)
+
+	ASSERT(assoc["id"] == 1)
+	ASSERT(assoc["name"] == "foo")
+	ASSERT(assoc["points"] == 1.5)
+
+	ASSERT(query.GetColumn(0) == 1)
+	ASSERT(query.GetColumn(1) == "foo")
+	ASSERT(query.GetColumn(2) == 1.5)
+
+	var/list/columns = query.Columns()	
+	ASSERT(columns[1] == "id")
+	ASSERT(columns[2] == "name")
+	ASSERT(columns[3] == "points")
+
+	ASSERT(query.Columns(0) == "id")
+	ASSERT(query.Columns(1) == "name")
+	ASSERT(query.Columns(2) == "points")
+
+	ASSERT(!query.Columns(10))
+
+	ASSERT(query.Error() && query.ErrorMsg())
+
+	query.Close()
+	db.Close()
+
+	db.Open("database.db")
+
+	query.Add("SELECT * FROM test WHERE id = ?", 1)
+	query.Execute(db)
+	query.NextRow()
+
+	ASSERT(query.GetColumn(0) == 1)
+
+	ASSERT(!query.GetColumn(10))
+	ASSERT(query.Error() && query.ErrorMsg())
+
+	fdel("database.db")

Content.Tests/DMProject/Tests/Database/too_many_or_few_params.dm

@@ -0,0 +1,14 @@
+/proc/RunTest()
+	var/database/db = new("params.db")
+
+	var/database/query/query = new("CREATE TABLE test (id int)", 1, "foo", 1.5)
+	query.Execute(db)
+
+	ASSERT(!query.Error()) // no error for too many parameters
+
+	query.Add("INSERT INTO test VALUES (?, ?, ?)", 1)
+	query.Execute(db)
+
+	ASSERT(query.Error()) // but there is an error for too few parameters
+
+	fdel("params.db")

OpenDreamRuntime/Objects/DreamObjectTree.cs

@@ -33,6 +33,8 @@
     public TreeEntry Matrix { get; private set; }
     public TreeEntry Exception { get; private set; }
     public TreeEntry Savefile { get; private set; }
+    public TreeEntry Database { get; private set; }
+    public TreeEntry DatabaseQuery { get; private set; }
     public TreeEntry Regex { get; private set; }
     public TreeEntry Filter { get; private set; }
     public TreeEntry Icon { get; private set; }
@@ -139,6 +141,10 @@
             return CreateList();
         if (type == Savefile)
             return new DreamObjectSavefile(Savefile.ObjectDefinition);
+        if (type == Database)
+            return new DreamObjectDatabase(Database.ObjectDefinition);
+        if (type == DatabaseQuery)
+            return new DreamObjectDatabaseQuery(DatabaseQuery.ObjectDefinition);
         if (type.ObjectDefinition.IsSubtypeOf(Matrix))
             return new DreamObjectMatrix(type.ObjectDefinition);
         if (type.ObjectDefinition.IsSubtypeOf(Sound))
@@ -275,6 +281,8 @@
         Matrix = GetTreeEntry("/matrix");
         Exception = GetTreeEntry("/exception");
         Savefile = GetTreeEntry("/savefile");
+        Database = GetTreeEntry("/database");
+        DatabaseQuery = GetTreeEntry("/database/query");
         Regex = GetTreeEntry("/regex");
         Filter = GetTreeEntry("/dm_filter");
         Icon = GetTreeEntry("/icon");

OpenDreamRuntime/Objects/Types/DreamObjectDatabase.cs

@@ -0,0 +1,82 @@
+using System.Data;
+using Microsoft.Data.Sqlite;
+using OpenDreamRuntime.Procs;
+
+namespace OpenDreamRuntime.Objects.Types;
+
+public sealed class DreamObjectDatabase(DreamObjectDefinition objectDefinition) : DreamObject(objectDefinition) {
+    private SqliteConnection? _connection;
+
+    private string? _errorMessage;
+    private int? _errorCode;
+
+    public override void Initialize(DreamProcArguments args) {
+        base.Initialize(args);
+
+        if (!args.GetArgument(0).TryGetValueAsString(out var filename)) {
+            return;
+        }
+
+        Open(filename);
+    }
+
+    protected override void HandleDeletion() {
+        Close();
+        base.HandleDeletion();
+    }
+
+    /// <summary>
+    /// Establish the connection to our SQLite database
+    /// </summary>
+    /// <param name="filename">The path to the SQLite file</param>
+    public void Open(string filename) {
+
+        if (_connection?.State == ConnectionState.Open) {
+            Close();
+        }
+
+        _connection = new SqliteConnection($"Data Source={filename};Mode=ReadWriteCreate");
+
+        try {
+            _connection.Open();
+        } catch (SqliteException exception) {
+            Logger.GetSawmill("opendream.db").Error($"Failed to open database {filename} - {exception}");
+        }
+    }
+
+    /// <summary>
+    /// Attempts to get the current connection to the SQLite database, if it is open
+    /// </summary>
+    /// <param name="connection">Variable to be populated with the connection.</param>
+    /// <returns>Boolean of the success of the operation.</returns>
+    public bool TryGetConnection(out SqliteConnection? connection) {
+        if (_connection?.State == ConnectionState.Open) {
+            connection = _connection;
+            return true;
+        }
+
+        connection = null;
+        return false;
+    }
+
+    public void SetError(int code, string message) {
+        _errorCode = code;
+        _errorMessage = message;
+    }
+
+    public int? GetErrorCode() {
+        return _errorCode;
+    }
+
+    public string? GetErrorMessage() {
+        return _errorMessage;
+    }
+
+    /// <summary>
+    /// Closes the current SQLite connection, if it is established.
+    /// </summary>
+    public void Close() {
+        _connection?.Close();
+    }
+
+}