tt

   1 #! /usr/bin/env racket
   2 ; vim: filetype=racket
   3
   4 ; TODO write
   5 ; TODO caching (use cache by default, unless explicitly asked for update)
   6 ; TODO timeline limits
   7 ; TODO user-defined feed sets (a la twitter lists)
   8 ; TODO feed set operations
   9 ; TODO timeline as a result of a query (feed set op + filter expressions)
  10 ; TODO named timelines
  11 ; TODO CLI params
  12 ; TODO config files
  13 ; TODO highlight mentions
  14 ; TODO filter on mentions
  15 ; TODO highlight hashtags
  16 ; TODO filter on hashtags
  17 ; TODO hashtags as channels? initial hashtag special?
  18 ; TODO query language
  19 ; TODO concurrency
  20 ; TODO console logger colors by level ('error)
  21 ; TODO file logger ('debug)
  22 ; TODO commands:
  23 ; - r | read
  24 ;   - see timeline ops above
  25 ; - w | write
  26 ;   - nick expand to URI
  27 ; - q | query
  28 ;   - see timeline ops above
  29 ;   - see hashtag and channels above
  30 ; TODO user-agent format: <client>/<version> (+<source.url>; @<source.nick>)
  31 ;   - requires configurability
  32 ;   - ref: https://twtxt.readthedocs.io/en/latest/user/discoverability.html
  33
  34 #lang racket
  35
  36 (require racket/date)
  37
  38 (require http-client)
  39 (require rfc3339-old)
  40
  41 (struct msg  (tm_epoch tm_rfc3339 nick text))
  42 (struct feed (nick uri))
  43
  44 (define (msg-print odd m)
  45   (printf "~a \033[1;37m<~a>\033[0m \033[0;~am~a\033[0m~n"
  46           (date->string (seconds->date [msg-tm_epoch m]) #t)
  47           [msg-nick m]
  48           [if odd 36 33]
  49           [msg-text m]))
  50
  51 (define re-msg-begin
  52   ; TODO Zulu offset. Maybe in several formats. Which ones?
  53   (pregexp "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}"))
  54
  55 (define (str->msg nick str)
  56   (if (not (regexp-match? re-msg-begin str))
  57     (begin
  58       (log-debug "Non-msg line from nick:~a, line:~a" nick str)
  59       #f)
  60     (let ([toks (string-split str (regexp "\t+"))])
  61       (if (not (= 2 (length toks)))
  62         (begin
  63           (log-warning "Invalid msg line from nick:~a, msg:~a" nick str)
  64           #f)
  65         (let*
  66           ([tm_rfc3339 (list-ref toks 0)]
  67            [tok_text   (list-ref toks 1)]
  68            [t (string->rfc3339-record tm_rfc3339)]
  69            ; TODO handle tz offset
  70            [tm_epoch (find-seconds [rfc3339-record:second t]
  71                                    [rfc3339-record:minute t]
  72                                    [rfc3339-record:hour   t]
  73                                    [rfc3339-record:mday   t]
  74                                    [rfc3339-record:month  t]
  75                                    [rfc3339-record:year   t])])
  76           (msg tm_epoch tm_rfc3339 nick tok_text))))))
  77
  78 (define (str->lines str)
  79   (string-split str (regexp "[\r\n]+")))
  80
  81 (define (str->msgs nick str)
  82   (filter-map (λ (line) (str->msg nick line)) (str->lines str)))
  83
  84 (define (uri-fetch uri)
  85   (log-info "GET ~a" uri)
  86   (define resp (http-get uri))
  87   (define status (http-response-code resp))
  88   (define body (http-response-body resp))
  89   (log-debug "finished GET ~a status:~a  body length:~a"
  90              uri status (string-length body))
  91   ; TODO Handle redirects
  92   (if (= status 200) body (raise status)))
  93
  94 (define (timeline-print timeline)
  95   (for ([msg timeline]
  96         [i   (in-naturals)])
  97     (msg-print (odd? i) msg)))
  98
  99 (define (feed->msgs feed)
 100   (log-info "downloading feed nick:~a uri:~a"
 101             (feed-nick feed)
 102             (feed-uri feed))
 103   (with-handlers
 104     ([exn:fail:network?
 105        (λ (e)
 106           (log-error "network error nick:~a uri:~a  exn:~a"
 107                      (feed-nick feed)
 108                      (feed-uri feed)
 109                      e)
 110           #f)]
 111      [integer?
 112        (λ (status)
 113           (log-error "http error nick:~a uri:~a  status:~a"
 114                      (feed-nick feed)
 115                      (feed-uri feed)
 116                      status)
 117           #f)])
 118     (str->msgs [feed-nick feed] [uri-fetch (feed-uri feed)])))
 119
 120 ; TODO timeline contract : time-sorted list of messages
 121 (define (timeline feeds)
 122   (sort (append* (filter-map feed->msgs feeds))
 123         (λ (a b) [< (msg-tm_epoch a) (msg-tm_epoch b)])))
 124
 125 (define (we-are-twtxt)
 126   (let* ([uri
 127            "https://raw.githubusercontent.com/mdom/we-are-twtxt/master/we-are-twtxt.txt"]
 128          [payload
 129            (uri-fetch uri)]
 130          [lines
 131            (str->lines payload)]
 132          [feeds
 133            (map (λ (line)
 134                    ; TODO validation
 135                    (define toks (string-split line))
 136                    (feed
 137                      [list-ref toks 0]
 138                      [list-ref toks 1]))
 139                 lines)])
 140     feeds))
 141
 142 (define (setup-logging)
 143   (define logger (make-logger #f #f 'debug #f))
 144   (define log-chan (make-log-receiver logger 'debug))
 145   (void (thread (λ ()
 146                    [date-display-format 'iso-8601]
 147                    [let loop ()
 148                      (define data  (sync log-chan))
 149                      (define level (vector-ref data 0))
 150                      (define msg   (vector-ref data 1))
 151                      (define ts    (date->string (current-date) #t))
 152                      (eprintf "~a [~a] ~a~n" ts level msg)
 153                      (loop)])))
 154   (current-logger logger))
 155
 156 (define (main)
 157   (setup-logging)
 158   (current-http-response-auto #f)
 159   (current-http-user-agent "xandkar/tt 0.0.0")
 160   (date-display-format 'rfc2822)
 161
 162   (define feeds (we-are-twtxt))
 163   (timeline-print (timeline feeds)))
 164
 165 (main)