From f10b5fda7f24f72ea51672f64c2d838a58c92b50 Mon Sep 17 00:00:00 2001
From: Ben Sima <ben@bensima.com>
Date: Fri, 19 Dec 2025 23:35:21 -0500
Subject: Omni/Ava/Web: refactor to use Servant and Lucid

Matches the patterns used in Omni/Jr/Web.
---
 Omni/Ava/Web.hs | 245 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 122 insertions(+), 123 deletions(-)

(limited to 'Omni/Ava/Web.hs')

diff --git a/Omni/Ava/Web.hs b/Omni/Ava/Web.hs
index f9dd7cd..c1eaa48 100644
--- a/Omni/Ava/Web.hs
+++ b/Omni/Ava/Web.hs
@@ -1,4 +1,6 @@
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE NoImplicitPrelude #-}
 
 -- | Web server for Ava trace viewer.
@@ -8,6 +10,9 @@
 -- : out omni-ava-web
 -- : dep warp
 -- : dep wai
+-- : dep servant-server
+-- : dep servant-lucid
+-- : dep lucid
 -- : dep http-types
 -- : dep aeson
 -- : dep text
@@ -23,14 +28,13 @@ where
 
 import Alpha
 import qualified Data.Aeson as Aeson
-import qualified Data.ByteString.Lazy as LBS
 import qualified Data.Text as Text
-import qualified Data.Text.Encoding as Encoding
 import qualified Database.SQLite.Simple as SQL
-import qualified Network.HTTP.Types as HTTP
-import qualified Network.Wai as Wai
+import qualified Lucid
 import qualified Network.Wai.Handler.Warp as Warp
 import qualified Omni.Ava.Trace as Trace
+import Servant
+import qualified Servant.HTML.Lucid as Lucid
 
 main :: IO ()
 main = putText "Use Omni.Ava for the main entry point"
@@ -44,126 +48,121 @@ startWebServer port dbPath = do
   SQL.withConnection dbPath Trace.initTraceDb
   Warp.run port (app dbPath)
 
-app :: FilePath -> Wai.Application
-app dbPath request respond = do
-  case Wai.pathInfo request of
-    ["trace", tid] -> serveTracePage dbPath tid request respond
-    ["api", "trace", tid] -> serveTraceJson dbPath tid request respond
-    ["health"] -> respond <| Wai.responseLBS HTTP.status200 [(HTTP.hContentType, "text/plain")] "ok"
-    _ -> respond <| Wai.responseLBS HTTP.status404 [(HTTP.hContentType, "text/plain")] "Not found"
-
-serveTracePage :: FilePath -> Text -> Wai.Request -> (Wai.Response -> IO Wai.ResponseReceived) -> IO Wai.ResponseReceived
-serveTracePage dbPath tid _req respond = do
-  SQL.withConnection dbPath <| \conn -> do
-    maybeRec <- Trace.getTrace conn tid
-    case maybeRec of
-      Nothing -> respond <| Wai.responseLBS HTTP.status404 [(HTTP.hContentType, "text/plain")] "Trace not found"
-      Just rec -> do
-        html <- renderTraceHtml rec
-        respond <| Wai.responseLBS HTTP.status200 [(HTTP.hContentType, "text/html; charset=utf-8")] (LBS.fromStrict <| Encoding.encodeUtf8 html)
-
-serveTraceJson :: FilePath -> Text -> Wai.Request -> (Wai.Response -> IO Wai.ResponseReceived) -> IO Wai.ResponseReceived
-serveTraceJson dbPath tid _req respond = do
-  SQL.withConnection dbPath <| \conn -> do
-    maybeRec <- Trace.getTrace conn tid
-    case maybeRec of
-      Nothing -> respond <| Wai.responseLBS HTTP.status404 [(HTTP.hContentType, "application/json")] "{\"error\":\"not found\"}"
-      Just rec -> do
-        let json = Aeson.encode rec
-        respond <| Wai.responseLBS HTTP.status200 [(HTTP.hContentType, "application/json")] json
-
-renderTraceHtml :: Trace.TraceRecord -> IO Text
-renderTraceHtml rec =
-  pure
-    <| Text.replace "{{trace_id}}" (Trace.trcId rec)
-    <| Text.replace "{{tool_name}}" (Trace.trcToolName rec)
-    <| Text.replace "{{created_at}}" (Trace.trcCreatedAt rec)
-    <| Text.replace "{{duration_ms}}" (tshow <| Trace.trcDurationMs rec)
-    <| Text.replace "{{input_json}}" (escapeHtml <| Trace.trcInput rec)
-    <| Text.replace "{{output_json}}" (escapeHtml <| Trace.trcOutput rec)
-    <| traceTemplate
-
--- | Escape HTML special characters
-escapeHtml :: Text -> Text
-escapeHtml =
-  Text.replace "&" "&amp;"
-    <. Text.replace "<" "&lt;"
-    <. Text.replace ">" "&gt;"
-    <. Text.replace "\"" "&quot;"
-
--- | Embedded trace HTML template
-traceTemplate :: Text
-traceTemplate =
+type API =
+  "trace" :> Capture "id" Text :> Get '[Lucid.HTML] TracePage
+    :<|> "api" :> "trace" :> Capture "id" Text :> Get '[JSON] Aeson.Value
+    :<|> "health" :> Get '[PlainText] Text
+
+api :: Proxy API
+api = Proxy
+
+app :: FilePath -> Application
+app dbPath = serve api (server dbPath)
+
+server :: FilePath -> Server API
+server dbPath =
+  tracePageHandler dbPath
+    :<|> traceJsonHandler dbPath
+    :<|> healthHandler
+
+healthHandler :: Servant.Handler Text
+healthHandler = pure "ok"
+
+tracePageHandler :: FilePath -> Text -> Servant.Handler TracePage
+tracePageHandler dbPath tid = do
+  maybeRec <- liftIO <| SQL.withConnection dbPath <| \conn -> Trace.getTrace conn tid
+  case maybeRec of
+    Nothing -> throwError err404
+    Just rec -> pure (TracePage rec)
+
+traceJsonHandler :: FilePath -> Text -> Servant.Handler Aeson.Value
+traceJsonHandler dbPath tid = do
+  maybeRec <- liftIO <| SQL.withConnection dbPath <| \conn -> Trace.getTrace conn tid
+  case maybeRec of
+    Nothing -> throwError err404
+    Just rec -> pure (Aeson.toJSON rec)
+
+-- | Wrapper for trace page rendering
+newtype TracePage = TracePage Trace.TraceRecord
+
+instance Lucid.ToHtml TracePage where
+  toHtmlRaw = Lucid.toHtml
+  toHtml (TracePage rec) =
+    Lucid.doctypehtml_ <| do
+      Lucid.head_ <| do
+        Lucid.meta_ [Lucid.charset_ "utf-8"]
+        Lucid.meta_ [Lucid.name_ "viewport", Lucid.content_ "width=device-width, initial-scale=1"]
+        Lucid.title_ <| Lucid.toHtml ("Trace: " <> Trace.trcToolName rec)
+        Lucid.style_ traceStyles
+      Lucid.body_ <| do
+        Lucid.h1_ <| Lucid.toHtml (Trace.trcToolName rec)
+        Lucid.p_ [Lucid.class_ "meta"] <| do
+          Lucid.toHtml (Trace.trcCreatedAt rec)
+          " · "
+          Lucid.toHtml (tshow (Trace.trcDurationMs rec) <> "ms")
+
+        Lucid.div_ [Lucid.class_ "section", Lucid.id_ "input-section"] <| do
+          Lucid.div_ [Lucid.class_ "section-header"] <| do
+            "Input"
+            Lucid.button_ [Lucid.class_ "copy-btn", Lucid.data_ "target" "input-content"] "Copy"
+          Lucid.div_ [Lucid.class_ "section-content", Lucid.id_ "input-content"]
+            <| Lucid.pre_
+            <| Lucid.toHtml (Trace.trcInput rec)
+
+        Lucid.div_ [Lucid.class_ "section", Lucid.id_ "output-section"] <| do
+          Lucid.div_ [Lucid.class_ "section-header"] <| do
+            "Output"
+            Lucid.button_ [Lucid.class_ "copy-btn", Lucid.data_ "target" "output-content"] "Copy"
+          Lucid.div_ [Lucid.class_ "section-content", Lucid.id_ "output-content"]
+            <| Lucid.pre_
+            <| Lucid.toHtml (Trace.trcOutput rec)
+
+        Lucid.p_ [Lucid.class_ "footer"] <| Lucid.toHtml ("Trace ID: " <> Trace.trcId rec)
+
+        Lucid.script_ traceScript
+
+traceStyles :: Text
+traceStyles =
   Text.unlines
-    [ "<!DOCTYPE html>",
-      "<html lang=\"en\">",
-      "<head>",
-      "  <meta charset=\"utf-8\">",
-      "  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">",
-      "  <title>Trace: {{tool_name}}</title>",
-      "  <style>",
-      "    :root { --bg: #1a1a2e; --fg: #eee; --accent: #4a9eff; --code-bg: #0d0d1a; }",
-      "    @media (prefers-color-scheme: light) {",
-      "      :root { --bg: #fff; --fg: #222; --accent: #0066cc; --code-bg: #f5f5f5; }",
-      "    }",
-      "    * { box-sizing: border-box; }",
-      "    body { font-family: system-ui, sans-serif; background: var(--bg); color: var(--fg); padding: 1rem; margin: 0; max-width: 100%; }",
-      "    h1 { font-size: 1.25rem; margin: 0 0 0.5rem; }",
-      "    .meta { font-size: 0.875rem; opacity: 0.7; margin-bottom: 1rem; }",
-      "    .section { margin: 1rem 0; border: 1px solid var(--accent); border-radius: 8px; overflow: hidden; }",
-      "    .section-header { padding: 0.75rem 1rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; background: var(--code-bg); }",
-      "    .section-header::before { content: '▼'; margin-right: 0.5rem; transition: transform 0.2s; }",
-      "    .section.collapsed .section-header::before { transform: rotate(-90deg); }",
-      "    .section-content { padding: 1rem; display: block; overflow-x: auto; background: var(--code-bg); }",
-      "    .section.collapsed .section-content { display: none; }",
-      "    pre { margin: 0; white-space: pre-wrap; word-break: break-word; font-size: 0.875rem; font-family: ui-monospace, monospace; }",
-      "    .copy-btn { background: var(--accent); color: white; border: none; padding: 0.25rem 0.5rem; border-radius: 4px; cursor: pointer; font-size: 0.75rem; }",
-      "    .copy-btn:hover { opacity: 0.8; }",
-      "    .footer { font-size: 0.75rem; opacity: 0.5; margin-top: 2rem; text-align: center; }",
-      "  </style>",
-      "</head>",
-      "<body>",
-      "  <h1>{{tool_name}}</h1>",
-      "  <p class=\"meta\">{{created_at}} · {{duration_ms}}ms</p>",
-      "",
-      "  <div class=\"section\" id=\"input-section\">",
-      "    <div class=\"section-header\">",
-      "      Input",
-      "      <button class=\"copy-btn\" data-target=\"input-content\">Copy</button>",
-      "    </div>",
-      "    <div class=\"section-content\" id=\"input-content\"><pre>{{input_json}}</pre></div>",
-      "  </div>",
-      "",
-      "  <div class=\"section\" id=\"output-section\">",
-      "    <div class=\"section-header\">",
-      "      Output",
-      "      <button class=\"copy-btn\" data-target=\"output-content\">Copy</button>",
-      "    </div>",
-      "    <div class=\"section-content\" id=\"output-content\"><pre>{{output_json}}</pre></div>",
-      "  </div>",
-      "",
-      "  <p class=\"footer\">Trace ID: {{trace_id}}</p>",
-      "",
-      "  <script>",
-      "    document.querySelectorAll('.section-header').forEach(header => {",
-      "      header.addEventListener('click', (e) => {",
-      "        if (e.target.classList.contains('copy-btn')) return;",
-      "        header.parentElement.classList.toggle('collapsed');",
-      "      });",
-      "    });",
+    [ ":root { --bg: #1a1a2e; --fg: #eee; --accent: #4a9eff; --code-bg: #0d0d1a; }",
+      "@media (prefers-color-scheme: light) {",
+      "  :root { --bg: #fff; --fg: #222; --accent: #0066cc; --code-bg: #f5f5f5; }",
+      "}",
+      "* { box-sizing: border-box; }",
+      "body { font-family: system-ui, sans-serif; background: var(--bg); color: var(--fg); padding: 1rem; margin: 0; max-width: 100%; }",
+      "h1 { font-size: 1.25rem; margin: 0 0 0.5rem; }",
+      ".meta { font-size: 0.875rem; opacity: 0.7; margin-bottom: 1rem; }",
+      ".section { margin: 1rem 0; border: 1px solid var(--accent); border-radius: 8px; overflow: hidden; }",
+      ".section-header { padding: 0.75rem 1rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; background: var(--code-bg); }",
+      ".section-header::before { content: '▼'; margin-right: 0.5rem; transition: transform 0.2s; }",
+      ".section.collapsed .section-header::before { transform: rotate(-90deg); }",
+      ".section-content { padding: 1rem; display: block; overflow-x: auto; background: var(--code-bg); }",
+      ".section.collapsed .section-content { display: none; }",
+      "pre { margin: 0; white-space: pre-wrap; word-break: break-word; font-size: 0.875rem; font-family: ui-monospace, monospace; }",
+      ".copy-btn { background: var(--accent); color: white; border: none; padding: 0.25rem 0.5rem; border-radius: 4px; cursor: pointer; font-size: 0.75rem; }",
+      ".copy-btn:hover { opacity: 0.8; }",
+      ".footer { font-size: 0.75rem; opacity: 0.5; margin-top: 2rem; text-align: center; }"
+    ]
+
+traceScript :: Text
+traceScript =
+  Text.unlines
+    [ "document.querySelectorAll('.section-header').forEach(header => {",
+      "  header.addEventListener('click', (e) => {",
+      "    if (e.target.classList.contains('copy-btn')) return;",
+      "    header.parentElement.classList.toggle('collapsed');",
+      "  });",
+      "});",
       "",
-      "    document.querySelectorAll('.copy-btn').forEach(btn => {",
-      "      btn.addEventListener('click', () => {",
-      "        const targetId = btn.getAttribute('data-target');",
-      "        const text = document.getElementById(targetId).querySelector('pre').textContent;",
-      "        navigator.clipboard.writeText(text).then(() => {",
-      "          const orig = btn.textContent;",
-      "          btn.textContent = 'Copied!';",
-      "          setTimeout(() => btn.textContent = orig, 1500);",
-      "        });",
-      "      });",
+      "document.querySelectorAll('.copy-btn').forEach(btn => {",
+      "  btn.addEventListener('click', () => {",
+      "    const targetId = btn.getAttribute('data-target');",
+      "    const text = document.getElementById(targetId).querySelector('pre').textContent;",
+      "    navigator.clipboard.writeText(text).then(() => {",
+      "      const orig = btn.textContent;",
+      "      btn.textContent = 'Copied!';",
+      "      setTimeout(() => btn.textContent = orig, 1500);",
       "    });",
-      "  </script>",
-      "</body>",
-      "</html>"
+      "  });",
+      "});"
     ]
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