19 open tx close early

// open/tx lifecycle API — ground truth for korulang.org phantom explorer

const std = @import("std");

const Connection = struct { handle: i32 };
const Transaction = struct { conn_handle: i32 };

~pub tor open { connstr: string }
| connected *Connection<connected!>
| connection-failed

~proc open|zig {
    _ = connstr;
    const c = std.heap.page_allocator.create(Connection) catch unreachable;
    c.* = Connection{ .handle = 42 };
    return .{ .connected = c };
}

~pub tor tx.begin { conn: *Connection<!connected|!active> } -> *Transaction<started!>

~proc tx.begin|zig {
    const t = std.heap.page_allocator.create(Transaction) catch unreachable;
    t.* = Transaction{ .conn_handle = conn.handle };
    return t;
}

~pub tor tx.exec { tx: *Transaction<!started|!active>, sql: string } -> *Transaction<active!>

~proc tx.exec|zig {
    std.debug.print("Executing: {s}\n", .{sql});
    return tx;
}

~pub tor tx.commit { tx: *Transaction<!active> } -> *Connection<active!>

~proc tx.commit|zig {
    std.debug.print("COMMIT\n", .{});
    const c = std.heap.page_allocator.create(Connection) catch unreachable;
    c.* = Connection{ .handle = tx.conn_handle };
    std.heap.page_allocator.destroy(tx);
    return c;
}

~pub tor tx.rollback { tx: *Transaction<!active> } -> *Connection<active!>

~proc tx.rollback|zig {
    std.debug.print("ROLLBACK\n", .{});
    const c = std.heap.page_allocator.create(Connection) catch unreachable;
    c.* = Connection{ .handle = tx.conn_handle };
    std.heap.page_allocator.destroy(tx);
    return .{ .rolled_back = c };
}

~pub tor close { conn: *Connection<!active> }

~proc close|zig {
    std.debug.print("Connection closed\n", .{});
    std.heap.page_allocator.destroy(conn);
}