(in-package :passepartout)

(defvar *model-cascade-code* nil
  "Cascade for :code tasks: ((:ollama . \"model\") ...)")

(defvar *model-cascade-plan* nil
  "Cascade for :plan tasks.")

(defvar *model-cascade-chat* nil
  "Cascade for :chat tasks.")

(defvar *model-cascade-background* nil
  "Cascade for background tasks (heartbeat, delegation).")

(defvar *local-backends* '(:ollama :llama-cpp)
  "Backend keywords considered local (privacy-safe).")

(defun model-classify-complexity (text)
  "Classify TEXT into :code, :plan, or :chat."
  (let ((lower (string-downcase text)))
    (cond
      ((or (search "defun" lower) (search "defmacro" lower)
           (search "write" lower) (search "refactor" lower)
           (search "fix " lower) (search "implement" lower)
           (search "code" lower)
           (search "#+begin_src" lower))
       :code)
      ((or (search "plan" lower) (search "roadmap" lower)
           (search "strategy" lower) (search "design" lower)
           (search "architecture" lower))
       :plan)
      (t :chat))))

(defun model-cascade-find (cascade backend)
  "Find first (PROVIDER . MODEL) in CASCADE matching BACKEND."
  (assoc backend cascade
         :test (lambda (a b) (string-equal (string a) (string b)))))

(defun model-select (backend context)
  "Select model for BACKEND given CONTEXT signal.
Returns model name or :skip."
  (let* ((payload (getf context :payload))
         (text (or (getf payload :text) ""))
         (sensor (getf payload :sensor))
         (has-personal (and (boundp '*dispatcher-privacy-tags*)
                            (some (lambda (tag) (search tag text))
                                  (symbol-value '*dispatcher-privacy-tags*))))
         (is-local (member backend *local-backends*)))
    ;; Privacy: skip cloud backends for personal content
    (when (and has-personal (not is-local))
      (log-message "MODEL-ROUTER: Skipping ~a (personal content)" backend)
      (return-from model-select :skip))
    ;; Quadrant: background tasks use background cascade
    (if (member sensor '(:heartbeat :delegation :tool-output :loop-error))
        (let ((entry (car (or *model-cascade-background*
                              '((:ollama . "phi-2"))))))
          (cdr entry))
        ;; Foreground: classify complexity, use slot cascade
        (let* ((slot (model-classify-complexity text))
               (cascade (case slot
                          (:code *model-cascade-code*)
                          (:plan *model-cascade-plan*)
                          (t *model-cascade-chat*)))
               (entry (model-cascade-find
                       (or cascade '((:ollama . "qwen2.5:14b"))) backend)))
          (if entry (cdr entry) :skip)))))

(defun model-router-init ()
  "Read env vars and wire model-select into *model-selector*."
  (flet ((parse-cascade (str)
           (when (and str (> (length str) 0))
             (let ((*read-eval* nil))
               (read-from-string str)))))
    (setf *model-cascade-code* (parse-cascade (uiop:getenv "MODEL_CASCADE_CODE"))
          *model-cascade-plan* (parse-cascade (uiop:getenv "MODEL_CASCADE_PLAN"))
          *model-cascade-chat* (parse-cascade (uiop:getenv "MODEL_CASCADE_CHAT"))
          *model-cascade-background* (parse-cascade (uiop:getenv "MODEL_CASCADE_BACKGROUND"))
          *local-backends* (let ((env (uiop:getenv "LOCAL_BACKENDS")))
                             (if env
                                 (mapcar (lambda (s) (intern (string-upcase (string-trim " " s)) :keyword))
                                         (uiop:split-string env :separator '(#\,)))
                                 '(:ollama :llama-cpp)))))
    (setf *model-selector* #'model-select)
    (log-message "MODEL-ROUTER: Initialized, selector=~a" *model-selector*))

(defskill :passepartout-model-router
  :priority 250
  :trigger (lambda (ctx) (declare (ignore ctx)) nil))

(model-router-init)