;; Async IO demo — Phase 5 client-side rendering with IO primitives.
;;
;; This component calls `highlight` inline — an IO primitive that runs
;; server-side Python. When rendered on the server, it executes
;; synchronously. When rendered client-side, the async renderer proxies
;; the call via /sx/io/highlight and awaits the result.
;;
;; `highlight` returns SxExpr — SX source with colored spans — which the
;; evaluator renders as DOM. The same SxExpr flows through the IO proxy:
;; server serializes → client parses → async renderer renders to DOM.
;;
;; Open browser console and look for:
;;   "sx:route client+async"  — async render with IO proxy
;;   "sx:io registered N proxied primitives" — IO proxy initialization

(defcomp ()
  (div (~tw :tokens "space-y-8")
    (div (~tw :tokens "border-b border-stone-200 pb-6")
      (h1 (~tw :tokens "text-2xl font-bold text-stone-900") "Async IO Demo")
      (p (~tw :tokens "mt-2 text-stone-600")
        "This page calls " (code (~tw :tokens "bg-stone-100 px-1 rounded text-violet-700") "highlight")
        " inline — an IO primitive that returns SX source with colored spans. "
        "On the server it runs Python directly. On the client it proxies via "
        (code (~tw :tokens "bg-stone-100 px-1 rounded text-violet-700") "/sx/io/highlight")
        " and the async renderer awaits the result."))

    ;; Live syntax-highlighted code blocks — each is an IO call
    (div (~tw :tokens "space-y-6")
      (h2 (~tw :tokens "text-lg font-semibold text-stone-800") "Live IO: syntax highlighting")

      (div (~tw :tokens "rounded-lg border border-stone-200 bg-white p-5 space-y-3")
        (h3 (~tw :tokens "text-sm font-medium text-stone-500 uppercase tracking-wide") "SX component definition")
        (~docs/code :src
          (highlight "(defcomp ~async-io-demo/card (&key title subtitle &rest children)\n  (div :class \"border rounded-lg p-4 shadow-sm\"\n    (h2 :class \"text-lg font-bold\" title)\n    (when subtitle\n      (p :class \"text-stone-500 text-sm\" subtitle))\n    (div :class \"mt-3\" children)))" "lisp")))

      (div (~tw :tokens "rounded-lg border border-stone-200 bg-white p-5 space-y-3")
        (h3 (~tw :tokens "text-sm font-medium text-stone-500 uppercase tracking-wide") "Python server code")
        (~docs/code :src
          (highlight "from shared.sx.pages import mount_io_endpoint\n\n# The IO proxy serves any allowed primitive:\n# GET /sx/io/highlight?_arg0=code&_arg1=lisp\nasync def io_proxy(name):\n    result = await execute_io(name, args, kwargs, ctx)\n    return serialize(result)" "python")))

      (div (~tw :tokens "rounded-lg border border-stone-200 bg-white p-5 space-y-3")
        (h3 (~tw :tokens "text-sm font-medium text-stone-500 uppercase tracking-wide") "SX async rendering spec")
        (~docs/code :src
          (highlight ";; try-client-route reads io-deps from page registry\n(let ((io-deps (get match \"io-deps\"))\n      (has-io (and io-deps (not (empty? io-deps)))))\n  ;; Register IO deps as proxied primitives on demand\n  (when has-io (register-io-deps io-deps))\n  (if has-io\n    ;; Async render: IO primitives proxied via /sx/io/<name>\n    (do\n      (try-async-eval-content content-src env\n        (fn (rendered)\n          (when rendered\n            (swap-rendered-content target rendered pathname))))\n      true)\n    ;; Sync render: pure components, no IO\n    (let ((rendered (try-eval-content content-src env)))\n      (swap-rendered-content target rendered pathname))))" "lisp"))))

    ;; Architecture explanation
    (div (~tw :tokens "rounded-lg border border-blue-200 bg-blue-50 p-5 space-y-3")
      (h2 (~tw :tokens "text-lg font-semibold text-blue-900") "How it works")
      (ol (~tw :tokens "list-decimal list-inside text-blue-800 space-y-2 text-sm")
        (li "Server renders the page — " (code "highlight") " runs Python directly")
        (li "Client receives component definitions including " (code "~async-io-demo/content"))
        (li "On client navigation, " (code "io-deps") " list routes to async renderer")
        (li (code "register-io-deps") " ensures each IO name is proxied via " (code "registerProxiedIo"))
        (li "Proxied call: " (code "fetch(\"/sx/io/highlight?_arg0=...&_arg1=lisp\")"))
        (li "Server runs highlight, returns SX source (colored span elements)")
        (li "Client parses SX → AST, async renderer recursively renders to DOM")))

    ;; Verification instructions
    (div (~tw :tokens "rounded-lg border border-amber-200 bg-amber-50 p-4 text-sm space-y-2")
      (p (~tw :tokens "font-semibold text-amber-800") "How to verify async IO rendering")
      (ol (~tw :tokens "list-decimal list-inside text-amber-700 space-y-1")
        (li "Open the browser console (F12)")
        (li "Navigate to another page (e.g. Data Test)")
        (li "Click back to this page")
        (li "Look for: " (code (~tw :tokens "bg-amber-100 px-1 rounded") "sx:route client+async /isomorphism/async-io"))
        (li "The code blocks should render identically — same syntax highlighting")
        (li "Check Network tab: you'll see 3 requests to " (code (~tw :tokens "bg-amber-100 px-1 rounded") "/sx/io/highlight"))))))
