(defun my-chronometrist-query-to-string (predicate)
 "Query Chronometrist database for records matching PREDICATE.
Return a string containing the human-readable duration and the
number of matching records."
 (cl-loop with dates
 with match-count = 0
 for plists being the hash-values of (chronometrist-to-hash-table (chronometrist-active-backend))
 using (hash-keys date-iso)
 sum
 (cl-loop for plist in plists
 when (funcall predicate plist)
 sum (chronometrist-interval plist) into sec
 and do (cl-pushnew date-iso dates :test #'equal)
 and do (cl-incf match-count)
 finally return sec) into seconds
 finally return
 (format "%s, over %s days. (%s matches)"
 (format-seconds "%Y, %D, %H, %M, and %S%z" seconds)
 (length dates)
 match-count)))
(my-chronometrist-query-to-string
 (lambda (plist)
 (equal (plist-get plist :project) "osm-ea")))
(my-chronometrist-query-to-string
 (lambda (plist)
 (and (equal (plist-get plist :name) "Programming")
 (equal (plist-get plist :component) "Common Lisp port"))))
(my-chronometrist-query-to-string
 (lambda (plist)
 (and (equal (plist-get plist :name) "Programming")
 (or (equal (plist-get plist :project) "osm-dm")))))
(my-chronometrist-query-to-string
 (lambda (plist)
 (and (equal (plist-get plist :name) "Programming")
 (equal (plist-get plist :project) "osm-dm-cli"))))
(my-chronometrist-query-to-string
 (lambda (plist)
 (and (equal (plist-get plist :name) "Programming")
 (or (equal (plist-get plist :project) "osm-dm")
 (equal (plist-get plist :project) "osm-dm-cli")))))
(my-chronometrist-query-to-string
 (lambda (plist)
 (let ((song (plist-get plist :song)))
 (and
 (equal (plist-get song :name) "कोई हमें बताएगा क्या?")
 (or (and (equal (plist-get plist :name) "Composing")
 (member 'accompaniment (plist-get plist :tags)))
 (equal (plist-get plist :name) "Sequencing"))))))
(my-chronometrist-query-to-string
 (lambda (plist)
 (let ((song (plist-get plist :song)))
 (and
 (equal (plist-get song :name) "आदि काल से आज तलक")
 (or (and (equal (plist-get plist :name) "Composing")
 (member 'accompaniment (plist-get plist :tags)))
 (equal (plist-get plist :name) "Sequencing"))))))

(defun my-chronometrist-query-to-buffer (predicate)
 "Return all records matching PREDICATE as a list of plists."
 (cl-loop for plist in (chronometrist-to-list (chronometrist-active-backend))
 with count = 0
 when (funcall predicate plist)
 collect
 (let* ((plist (copy-list plist))
 (interval-seconds (chronometrist-interval plist))
 (start (plist-get plist :start)))
 (plist-put plist :duration (ts-human-format-duration interval-seconds))
 (plist-put plist :date (seq-take start 10))
 (chronometrist-plist-remove plist :start :stop))))
(my-chronometrist-query-to-buffer
 (lambda (plist)
 (equal (plist-get plist :project) "StreetComplete")))

(cl-loop with task = "Exercise"
 for plist in (chronometrist-to-list (chronometrist-active-backend))
 when (equal (plist-get plist :name) task)
 collect (chronometrist-plist-key-values plist) into key-values
 finally do
 (let ((buffer (get-buffer-create (generate-new-buffer-name "chronometrist-query"))))
 (with-current-buffer buffer
 (->> (cl-remove-duplicates key-values)
 (seq-filter #'identity)
 (format "%S")
 (insert))
 (emacs-lisp-mode)
 (switch-to-buffer buffer))))

(cl-loop with start = (parse-iso8601-time-string "2021年12月13日T00:00:00+05:30")
 with buffer = (get-buffer-create "*chronometrist-query*")
 with output
 for plists being the hash-values of (chronometrist-to-hash-table (chronometrist-active-backend))
 using (hash-keys date-iso)
 when
 ;; create a list of strings for each date on which I ran
 (cl-loop with first-line = t
 with date = (parse-iso8601-time-string (concat date-iso "T00:00:00+05:30"))
 for plist in plists
 when (and (plist-get plist :running)
 (or (time-less-p start date)
 (time-equal-p start date)))
 collect
 (let* ((plist (copy-list plist))
 (duration-seconds (chronometrist-interval plist))
 (start (plist-get plist :start))
 (distance (plist-get plist :running))
 (distance-int (car distance))
 (distance-km (/ (float distance-int) 1000))
 (duration-hours (/ (float duration-seconds) 60 60))
 (distance-string (format "% 4s %s" distance-int (cdr distance)))
 (speed-string (format "%.2f" (/ distance-km duration-hours))))
 (format "%s%s in % 5s (% 5s kmph)\n"
 (if (not first-line)
 (make-string (+ 3 (length date-iso)) ?\s)
 (setq first-line nil)
 (concat date-iso " - "))
 distance-string
 (format-seconds "%m:%02s" duration-seconds)
 speed-string)))
 collect it into lists
 ;; Add indices for each date, and indentation when there are >1
 ;; instances of running in a date
 finally do
 (setq output
 (cl-loop for list in (reverse lists)
 count list into index
 concat
 (let* ((index-string (format "%2s. " index))
 (indent (if (> (length list) 1)
 (make-string (length index-string) ?\s)
 "")))
 (concat index-string (first list) indent
 (mapconcat #'identity (rest list) indent)))))
 (with-current-buffer buffer
 (erase-buffer)
 (insert output)
 (text-mode)
 (switch-to-buffer-other-window buffer)))