(defparameter *provider-configs*
  '((:ollama     . (:base-url nil          :key-env nil           :default-model "llama3"))
    (:openrouter . (:base-url "https://openrouter.ai/api/v1" :key-env "OPENROUTER_API_KEY" :default-model "openrouter/auto"))
    (:openai     . (:base-url "https://api.openai.com/v1"    :key-env "OPENAI_API_KEY"     :default-model "gpt-4o-mini"))
    (:anthropic  . (:base-url "https://api.anthropic.com/v1" :key-env "ANTHROPIC_API_KEY"  :default-model "claude-3-5-sonnet-20241022"))
    (:groq       . (:base-url "https://api.groq.com/openai/v1" :key-env "GROQ_API_KEY"     :default-model "llama-3.1-70b-versatile"))
    (:gemini     . (:base-url "https://generativelanguage.googleapis.com/v1beta/openai" :key-env "GEMINI_API_KEY" :default-model "gemini-2.0-flash"))
    (:deepseek   . (:base-url "https://api.deepseek.com/v1"  :key-env "DEEPSEEK_API_KEY"  :default-model "deepseek-chat"))
    (:nvidia     . (:base-url "https://integrate.api.nvidia.com/v1" :key-env "NVIDIA_API_KEY" :default-model "meta/llama-3.1-405b-instruct"))))

(defun provider-config (provider)
  "Returns the configuration plist for a provider keyword."
  (cdr (assoc provider *provider-configs*)))

(defun provider-available-p (provider)
  "Checks if a provider is configured. Ollama is always considered available."
  (let* ((config (provider-config provider))
         (key-env (getf config :key-env))
         (base-url (getf config :base-url)))
    (cond ((eq provider :ollama) t)
          (key-env (let ((key (uiop:getenv key-env))) (and key (> (length key) 0))))
          (base-url t))))

(defun provider-openai-request (prompt system-prompt &key model (provider :ollama))
  "Executes a request against any OpenAI-compatible API endpoint."
  (let* ((config (provider-config provider))
         (base-url (getf config :base-url))
         (key-env (getf config :key-env))
         (default-model (getf config :default-model))
         (api-key (when key-env (uiop:getenv key-env)))
         (model-id (or model default-model))
         (url (if (eq provider :ollama)
                  (format nil "http://~a/v1/chat/completions" (or (uiop:getenv "OLLAMA_HOST") "localhost:11434"))
                  (format nil "~a/chat/completions" base-url)))
         (headers `(("Content-Type" . "application/json")
                    ,@(when api-key `(("Authorization" . ,(format nil "Bearer ~a" api-key))))
                    ,@(when (eq provider :openrouter)
                        `(("HTTP-Referer" . "https://github.com/amrgharbeia/passepartout")
                          ("X-Title" . "Passepartout")))))
         (body (cl-json:encode-json-to-string
                `((model . ,model-id)
                  (messages . (( (role . "system") (content . ,system-prompt) )
                               ( (role . "user") (content . ,prompt) )))))))
    (handler-case
        (let* ((response (dex:post url :headers headers :content body :connect-timeout 10 :read-timeout 60))
               (json (cl-json:decode-json-from-string response))
               (choices (cdr (assoc :choices json)))
               (first-choice (car choices))
               (message (cdr (assoc :message first-choice)))
               (content (cdr (assoc :content message))))
          (if content
              (list :status :success :content content)
              (list :status :error :message (format nil "~a: No content in response (~s)" provider json))))
      (error (c)
        (list :status :error :message (format nil "~a Failure: ~a" provider c))))))

(defun provider-register-all ()
  "Scans environment variables and registers all available LLM backends."
  (dolist (entry *provider-configs*)
    (let ((provider (car entry)))
      (when (provider-available-p provider)
        (log-message "LLM BACKEND: Registering provider ~a" provider)
        (register-probabilistic-backend provider
          (lambda (prompt system-prompt &key model)
            (provider-openai-request prompt system-prompt :model model :provider provider)))))))

(defun provider-cascade-initialize ()
  "Reads PROVIDER_CASCADE from env and sets *provider-cascade*."
  (let ((cascade-str (uiop:getenv "PROVIDER_CASCADE")))
    (if cascade-str
        (setf *provider-cascade*
              (mapcar (lambda (s) (intern (string-upcase (string-trim '(#\Space) s)) :keyword))
                      (uiop:split-string cascade-str :separator '(#\,))))
        (setf *provider-cascade* (mapcar #'car *provider-configs*)))))

(provider-register-all)
(provider-cascade-initialize)

(defskill :passepartout-gateway-provider
  :priority 50
  :trigger (lambda (ctx) (declare (ignore ctx)) nil))