;;; noise-new-chat.el --- Start new conversations from contacts -*- lexical-binding: t; -*-

;;; Commentary:

;; Provides `noise-new-chat' — start a new conversation by searching
;; contacts with minibuffer completion.  Contacts are synced from
;; signal-cli via the listContacts JSON-RPC method and cached in the
;; local SQLite database.

;;; Code:

(require 'noise-rpc)
(require 'noise-db)
(require 'cl-lib)

(declare-function noise-chat-list--render "noise-chat-list")

;;;###autoload
(defun noise-new-chat ()
  "Start a new conversation by searching contacts.
Syncs contacts from signal-cli when the local database has none.
Candidates match on both name and phone number."
  (interactive)
  (noise-db-init)
  (unless (noise-db-get-all-contacts)
    (noise-new-chat-sync-contacts))
  (let* ((contacts (noise-db-get-all-contacts))
         (collection (mapcar (lambda (c)
                               (cons (noise-new-chat--candidate c) c))
                             contacts)))
    (unless collection
      (user-error "No contacts found. Is signal-cli synced?"))
    (let* ((choice (completing-read "New chat with: " collection nil t))
           (contact (cdr (assoc choice collection))))
      (when contact
        (noise-new-chat-with-contact (gethash "id" contact)
                                     (gethash "name" contact))))))

;;;###autoload
(defun noise-new-chat-sync-contacts ()
  "Fetch contacts from signal-cli and store them in the local database.
Returns the number of contacts synced."
  (interactive)
  (noise-db-init)
  (let ((contacts (noise-rpc-call-for-account "listContacts"))
        (count 0))
    (seq-do
     (lambda (c)
       (when-let ((id (noise-new-chat--contact-id c)))
         (noise-db-upsert-contact
          id
          :name (noise-new-chat--contact-name c)
          :color (noise-new-chat--field c "color")
          :profile-name (noise-new-chat--profile-name c))
         (cl-incf count)))
     contacts)
    (when (called-interactively-p 'interactive)
      (message "Synced %d contacts from signal-cli" count))
    count))

(defun noise-new-chat-with-contact (contact-id name)
  "Open (creating if needed) a direct conversation with CONTACT-ID.
NAME is used as the conversation name for a new conversation.
The conversation ID for a direct chat is the contact ID itself."
  (unless (noise-db-get-conversation contact-id)
    (noise-db-upsert-conversation contact-id
                                  :type "direct"
                                  :name (if (and name (not (string-empty-p name)))
                                            name
                                          contact-id)
                                  :members (list contact-id)))
  (when-let ((buf (get-buffer "*signal*")))
    (with-current-buffer buf
      (noise-chat-list--render)))
  ;; Conversation buffers are not implemented yet; land on the chat list.
  (message "Conversation with %s ready (conversation buffer not yet implemented)"
           (or name contact-id)))

(defun noise-new-chat--candidate (contact)
  "Format CONTACT (a hash table from noise-db) as a completion candidate.
Includes the phone number so completion can match on it."
  (let ((id (gethash "id" contact))
        (name (gethash "name" contact)))
    (if (or (null name) (string-empty-p name) (string= name id))
        id
      (format "%s  (%s)" name id))))

(defun noise-new-chat--field (obj key)
  "Get KEY from hash table OBJ, treating JSON null as nil."
  (when obj
    (let ((v (gethash key obj)))
      (unless (eq v :null) v))))

(defun noise-new-chat--contact-id (contact)
  "Extract the contact ID from a signal-cli CONTACT object.
Prefers the phone number, falling back to the UUID."
  (or (noise-new-chat--field contact "number")
      (noise-new-chat--field contact "uuid")))

(defun noise-new-chat--profile-name (contact)
  "Extract the profile display name from a signal-cli CONTACT object."
  (when-let ((profile (noise-new-chat--field contact "profile")))
    (let ((full (string-trim
                 (concat (or (noise-new-chat--field profile "givenName") "")
                         " "
                         (or (noise-new-chat--field profile "familyName") "")))))
      (unless (string-empty-p full) full))))

(defun noise-new-chat--contact-name (contact)
  "Pick the best display name for a signal-cli CONTACT object.
Prefers the local contact name, then the profile name, then the
username, then the phone number."
  (or (let ((name (noise-new-chat--field contact "name")))
        (and name (not (string-empty-p name)) name))
      (noise-new-chat--profile-name contact)
      (noise-new-chat--field contact "username")
      (noise-new-chat--contact-id contact)))

(provide 'noise-new-chat)
;;; noise-new-chat.el ends here