(require 'json)

(require 'ai-code-mcp-http-server)

(require 'ai-code-mcp-server)

(defgroup ai-code-mcp-agent nil

"Agent adapters for AI Code MCP tools."

:group 'tools

:prefix "ai-code-mcp-agent-")

(defcustom ai-code-mcp-agent-enabled-backends '(codex open-interpreter github-copilot-cli claude-code)

"Backends that should receive automatic Emacs MCP integration."

:type '(repeat symbol)

:group 'ai-code-mcp-agent)

(defcustom ai-code-mcp-agent-token-lifetime-seconds (* 24 60 60)

"Lifetime of a per-launch MCP bearer token in seconds."

:type 'positive-integer

:group 'ai-code-mcp-agent)

(defconst ai-code-mcp-agent--server-name "emacs_tools"

"Server name used in backend MCP config overrides.")

(defconst ai-code-mcp-agent--token-environment-variable

"AI_CODE_MCP_BEARER_TOKEN"

"Child-process environment variable that carries the MCP bearer token.")

(defconst ai-code-mcp-agent--status-buffer-name "*AI Code MCP Status*"

"Buffer name used to display MCP status to users.")

(defvar-local ai-code-mcp-agent--backend nil

"Backend symbol attached to the current agent buffer.")

(defvar-local ai-code-mcp-agent--session-id nil

"Session id attached to the current agent buffer.")

(defvar-local ai-code-mcp-agent--server-url nil

"MCP server URL attached to the current agent buffer.")

(defun ai-code-mcp-agent-buffer-status (&optional buffer)

"Return MCP status for BUFFER or the current buffer."

(with-current-buffer (or buffer (current-buffer))

(when ai-code-mcp-agent--session-id

(list :backend ai-code-mcp-agent--backend

:session-id ai-code-mcp-agent--session-id

:server-url ai-code-mcp-agent--server-url))))

(defun ai-code-mcp-agent-show-buffer-status (&optional buffer)

"Display MCP status for BUFFER or the current buffer."

(interactive)

(let ((status (ai-code-mcp-agent-buffer-status buffer)))

(if (not status)

(message "No MCP session is attached to the current buffer.")

(with-help-window ai-code-mcp-agent--status-buffer-name

(princ (ai-code-mcp-agent--format-status status))))

status))

(defun ai-code-mcp-agent--format-status (status)

"Return a display string for MCP STATUS."

(concat

"AI Code MCP Status\n\n"

(format "Backend: %s\n" (plist-get status :backend))

(format "Session ID: %s\n" (plist-get status :session-id))

(format "Server URL: %s\n" (plist-get status :server-url))))

(defun ai-code-mcp-agent-prepare-launch (backend working-dir argv)

"Return MCP launch metadata for BACKEND, WORKING-DIR, and ARGV."

(when (memq backend ai-code-mcp-agent-enabled-backends)

(ai-code-mcp-builtins-setup)

(let* ((port (ai-code-mcp-http-server-ensure))

(session-id (ai-code-mcp-agent--make-session-id backend))

(token (ai-code-mcp--random-secret))

(url (ai-code-mcp-agent--make-server-url port))

(launch-metadata

(ai-code-mcp-agent--inject-argv backend argv url

ai-code-mcp-agent--token-environment-variable))

(runtime-files (plist-get launch-metadata :runtime-files)))

(ai-code-mcp-register-session

session-id working-dir (current-buffer)

(list :backend backend

:state 'pending

:tool-profile ai-code-mcp-default-tool-profile

:token token

:expires-at

(time-add (current-time)

(seconds-to-time

ai-code-mcp-agent-token-lifetime-seconds))))

(list :argv (plist-get launch-metadata :argv)

:env-vars

(list (format "%s=%s"

ai-code-mcp-agent--token-environment-variable

token))

:mcp-session-id session-id

:mcp-server-url url

:cleanup-fn

(ai-code-mcp-agent--make-cleanup-function

session-id runtime-files)

:post-start-fn (lambda (buffer _process _instance-name)

(ai-code-mcp-agent--record-buffer-session

buffer backend session-id url))))))

(defun ai-code-mcp-agent--make-cleanup-function (session-id runtime-files)

"Return a repeat-safe cleanup function for SESSION-ID and RUNTIME-FILES.

(let ((remaining-files (copy-sequence runtime-files))

(unregistered nil))

(lambda ()

(let (failed-files)

(dolist (path remaining-files)

(when (stringp path)

(condition-case err

(when (file-exists-p path)

(delete-file path))

(error

(push path failed-files)

(display-warning

'ai-code-mcp-agent

(format "Failed to delete runtime file %s: %s"

path (error-message-string err)))))))

(setq remaining-files (nreverse failed-files)))

(unless unregistered

(ai-code-mcp-unregister-session session-id)

(setq unregistered t)

(when (zerop (ai-code-mcp-session-count))

(ai-code-mcp-http-server-stop))))))

(defun ai-code-mcp-agent--make-session-id (backend)

"Create a fresh session id for BACKEND."

(format "%s-%s-%d"

(symbol-name backend)

(format-time-string "%Y%m%d%H%M%S")

(random 1000000)))

(defun ai-code-mcp-agent--make-server-url (port)

"Build the shared MCP server endpoint for PORT.

(format "http://127.0.0.1:%d/mcp" port))

(defun ai-code-mcp-agent--record-buffer-session (buffer backend session-id url)

"Record BUFFER session for BACKEND, SESSION-ID, and URL."

(ai-code-mcp-attach-agent-buffer session-id buffer)

(with-current-buffer buffer

(setq-local ai-code-mcp-agent--backend backend

ai-code-mcp-agent--session-id session-id

ai-code-mcp-agent--server-url url)))

(defun ai-code-mcp-agent-refresh-source-context (agent-buffer source-buffer)

"Refresh AGENT-BUFFER's MCP prompt origin from SOURCE-BUFFER."

(when (and (buffer-live-p agent-buffer)

(buffer-live-p source-buffer))

(let ((session-id

(buffer-local-value 'ai-code-mcp-agent--session-id agent-buffer)))

(when session-id

(ai-code-mcp-update-source-context session-id source-buffer)))))

(defun ai-code-mcp-agent--inject-argv (backend argv url token-env-var)

"Return launch metadata after injecting URL and TOKEN-ENV-VAR into ARGV for BACKEND."

(pcase backend

((or 'codex 'open-interpreter)

(let ((config-override

(format "mcp_servers.%s={ url = %s, bearer_token_env_var = %s }"

ai-code-mcp-agent--server-name

(json-encode url)

(json-encode token-env-var))))

(list :argv (append argv (list "-c" config-override)))))

('github-copilot-cli

(let ((config-json (ai-code-mcp-agent--copilot-config-json url token-env-var)))

(list :argv

(append argv (list "--additional-mcp-config" config-json)))))

('claude-code

(let ((config-file (ai-code-mcp-agent--claude-code-config-file url token-env-var)))

(list :argv (append argv (list "--mcp-config" config-file))

:runtime-files (list config-file))))

(_ (list :argv argv))))

(defun ai-code-mcp-agent--authorization-template (token-env-var)

"Return an Authorization header template for TOKEN-ENV-VAR."

(format "Bearer ${%s}" token-env-var))

(defun ai-code-mcp-agent--copilot-config-json (url token-env-var)

"Return a Copilot MCP config for URL using TOKEN-ENV-VAR."

(json-encode

`((mcpServers

. ((,ai-code-mcp-agent--server-name

. ((type . "http")

(url . ,url)

(headers

. ((Authorization

. ,(ai-code-mcp-agent--authorization-template

token-env-var))))

(tools . ["*"]))))))))

(defun ai-code-mcp-agent--claude-code-config-file (url token-env-var)

"Write a Claude MCP config for URL using TOKEN-ENV-VAR and return its path."

(let ((config-file (make-temp-file "ai-code-mcp-claude-code-" nil ".json")))

(with-temp-file config-file

(insert (json-encode

`((mcpServers

. ((,ai-code-mcp-agent--server-name

. ((type . "http")

(url . ,url)

(headers

. ((Authorization

. ,(ai-code-mcp-agent--authorization-template

token-env-var))))))))))))

config-file))

(provide 'ai-code-mcp-agent)