use layers for Cache, Robots and WebBotAuth

src/network/layer/WebBotAuthLayer.zig

@@ -0,0 +1,52 @@
+// Copyright (C) 2023-2026  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const log = @import("../../log.zig");
+
+const URL = @import("../../browser/URL.zig");
+const WebBotAuth = @import("../WebBotAuth.zig");
+const Context = @import("../../browser/HttpClient.zig").Context;
+const Request = @import("../../browser/HttpClient.zig").Request;
+const Layer = @import("../../browser/HttpClient.zig").Layer;
+
+const WebBotAuthLayer = @This();
+
+next: Layer = undefined,
+
+pub fn layer(self: *WebBotAuthLayer) Layer {
+    return .{
+        .ptr = self,
+        .vtable = &.{ .request = request },
+    };
+}
+
+fn request(ptr: *anyopaque, ctx: Context, req: Request) anyerror!void {
+    const self: *WebBotAuthLayer = @ptrCast(@alignCast(ptr));
+    var our_req = req;
+
+    const wba = ctx.network.web_bot_auth orelse @panic("WebBotAuthLayer shouldn't be active without WebBotAuth");
+
+    const arena = try ctx.network.app.arena_pool.acquire(.small, "WebBotAuthLayer");
+    defer ctx.network.app.arena_pool.release(arena);
+
+    const authority = URL.getHost(req.url);
+    try wba.signRequest(arena, &our_req.headers, authority);
+
+    return self.next.request(ctx, our_req);
+}