From eefdecb1e9f38f6af8dd28ca3b586438b53669e8 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Tue, 6 Dec 2022 13:48:09 -0300
Subject: [PATCH] use request uri and regex to choose callbacks

---
 main.lua                        | 42 +++++++++++++++++++++------------
 scripts/webfinger_allowlist.lua |  6 ++++-
 2 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/main.lua b/main.lua
index ed7677f..e514ab3 100644
--- a/main.lua
+++ b/main.lua
@@ -12,33 +12,45 @@ function log(msg)
 end
 
 local WANTED_SCRIPTS = {
-    'scripts.webfinger_allowlist'
+    ['scripts.webfinger_allowlist'] = {accounts = {"example@example.com"}}
 }
 
 local compiled_chain = {}
 
-for _, module_name in pairs(WANTED_SCRIPTS) do
-    log('load module', module_name)
-    mod = require(module_name)
-    log('load module', mod)
-    table.insert(compiled_chain, mod)
+for module_name, module_config in pairs(WANTED_SCRIPTS) do
+    module = require(module_name)
+    table.insert(compiled_chain, {module, module_config})
 end
 
 local function onRequest()
+    local request_uri = ngx.var.uri
+
+    -- find out which modules to call based on their regexes
+    local callbacks_to_call = {}
+    for _, filter in ipairs(compiled_chain) do
+        local module, module_config = filter[1], filter[2]
+
+        for callback_regex, callback_function in pairs(module.callbacks) do
+            local match, error = ngx.re.match(request_uri, callback_regex)
+            if match then
+                table.insert(callbacks_to_call, {callback_function, module_config})
+            end
+        end
+    end
+
     log('AWOOOOGA')
 
-   for _,mod in ipairs(compiled_chain) do
-       log(mod)
-       local mod_config = {accounts = {"a@a.com"}}
-       local result, body = mod.callback(mod_config)
-       log(result)
-       log(body)
-       if not result then
+    for _,tuple in ipairs(callbacks_to_call) do
+        local callback_function, config = tuple[1], tuple[2]
+        local result, body = callback_function(config)
+        log(result)
+        log(body)
+        if not result then
             ngx.status = 400
             ngx.say(body or "request denied")
             ngx.exit(400)
-       end
-   end
+        end
+    end
 end
 
 return onRequest
diff --git a/scripts/webfinger_allowlist.lua b/scripts/webfinger_allowlist.lua
index c036494..bb6c561 100644
--- a/scripts/webfinger_allowlist.lua
+++ b/scripts/webfinger_allowlist.lua
@@ -6,6 +6,11 @@ function webfingerCallback(cfg)
 
     local resource = args['resource']
     if resource ~= nil then
+      -- TODO this is O(n) but we can make it O(1) by doing a funny and making
+      -- cfg.accounts be transformed into keys in a table
+      --
+      -- this would require us to do some setup() callback as well as
+      -- the request() callback
       for _, account in ipairs(cfg.accounts) do
         if resource == account then
           return true
@@ -27,7 +32,6 @@ return {
     Useful for small instances.
     ]],
     apiVersion=1,
-    callback=webfingerCallback,
     callbacks = {
         ['/.well-known/webfinger'] = webfingerCallback
     },