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 alt timeline formats: irc-like | email-like
  12 ;
  13 ; - irc-like:
  14 ;       <timestamp> <nick> <msg><lf>
  15 ;
  16 ; - email-like:
  17 ;       <timestamp>
  18 ;       <nick> <uri>
  19 ;       <msg>
  20 ;       <lf><lf>
  21 ;
  22 ; TODO CLI params
  23 ; TODO config files
  24 ; TODO parse mentions:
  25 ; - @<source.nick source.url> | @<source.url>
  26 ; TODO highlight mentions
  27 ; TODO filter on mentions
  28 ; TODO highlight hashtags
  29 ; TODO filter on hashtags
  30 ; TODO hashtags as channels? initial hashtag special?
  31 ; TODO query language
  32 ; TODO concurrency
  33 ; TODO console logger colors by level ('error)
  34 ; TODO file logger ('debug)
  35 ; TODO commands:
  36 ; - r | read
  37 ;   - see timeline ops above
  38 ; - w | write
  39 ;   - arg or stdin
  40 ;   - nick expand to URI
  41 ; - q | query
  42 ;   - see timeline ops above
  43 ;   - see hashtag and channels above
  44 ; - d | download
  45 ; - u | upload
  46 ;   - calls user-configured command to upload user's own feed file to their server
  47 ; TODO user-agent format: <client>/<version> (+<source.url>; @<source.nick>)
  48 ;   - requires configurability
  49 ;   - ref: https://twtxt.readthedocs.io/en/latest/user/discoverability.html
  50
  51 #lang racket
  52
  53 (require racket/date)
  54
  55 (require http-client)
  56 (require rfc3339-old)
  57
  58 (struct msg  (tm_epoch tm_rfc3339 nick text))
  59 (struct feed (nick uri))
  60
  61 (define (msg-print odd m)
  62   (printf "~a \033[1;37m<~a>\033[0m \033[0;~am~a\033[0m~n"
  63           (date->string (seconds->date [msg-tm_epoch m]) #t)
  64           [msg-nick m]
  65           [if odd 36 33]
  66           [msg-text m]))
  67
  68 (define re-msg-begin
  69   ; TODO Zulu offset. Maybe in several formats. Which ones?
  70   (pregexp "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}"))
  71
  72 (define (str->msg nick str)
  73   (if (not (regexp-match? re-msg-begin str))
  74     (begin
  75       (log-debug "Non-msg line from nick:~a, line:~a" nick str)
  76       #f)
  77     (let ([toks (string-split str (regexp "\t+"))])
  78       (if (not (= 2 (length toks)))
  79         (begin
  80           (log-warning "Invalid msg line from nick:~a, msg:~a" nick str)
  81           #f)
  82         (let*
  83           ([tm_rfc3339 (list-ref toks 0)]
  84            [tok_text   (list-ref toks 1)]
  85            [t (string->rfc3339-record tm_rfc3339)]
  86            ; TODO handle tz offset
  87            [tm_epoch (find-seconds [rfc3339-record:second t]
  88                                    [rfc3339-record:minute t]
  89                                    [rfc3339-record:hour   t]
  90                                    [rfc3339-record:mday   t]
  91                                    [rfc3339-record:month  t]
  92                                    [rfc3339-record:year   t])])
  93           (msg tm_epoch tm_rfc3339 nick tok_text))))))
  94
  95 (define (str->lines str)
  96   (string-split str (regexp "[\r\n]+")))
  97
  98 (define (str->msgs nick str)
  99   (filter-map (λ (line) (str->msg nick line)) (str->lines str)))
 100
 101 (define (uri-fetch uri)
 102   (log-info "GET ~a" uri)
 103   (define resp (http-get uri))
 104   (define status (http-response-code resp))
 105   (define body (http-response-body resp))
 106   (log-debug "finished GET ~a status:~a  body length:~a"
 107              uri status (string-length body))
 108   ; TODO Handle redirects
 109   (if (= status 200) body (raise status)))
 110
 111 (define (timeline-print timeline)
 112   (for ([msg timeline]
 113         [i   (in-naturals)])
 114     (msg-print (odd? i) msg)))
 115
 116 (define (feed->msgs feed)
 117   (log-info "downloading feed nick:~a uri:~a"
 118             (feed-nick feed)
 119             (feed-uri feed))
 120   (with-handlers
 121     ([exn:fail:network?
 122        (λ (e)
 123           (log-error "network error nick:~a uri:~a  exn:~a"
 124                      (feed-nick feed)
 125                      (feed-uri feed)
 126                      e)
 127           #f)]
 128      [integer?
 129        (λ (status)
 130           (log-error "http error nick:~a uri:~a  status:~a"
 131                      (feed-nick feed)
 132                      (feed-uri feed)
 133                      status)
 134           #f)])
 135     (str->msgs [feed-nick feed] [uri-fetch (feed-uri feed)])))
 136
 137 ; TODO timeline contract : time-sorted list of messages
 138 (define (timeline feeds)
 139   (sort (append* (filter-map feed->msgs feeds))
 140         (λ (a b) [< (msg-tm_epoch a) (msg-tm_epoch b)])))
 141
 142 (define (we-are-twtxt)
 143   (let* ([uri
 144            "https://raw.githubusercontent.com/mdom/we-are-twtxt/master/we-are-twtxt.txt"]
 145          [payload
 146            (uri-fetch uri)]
 147          [lines
 148            (str->lines payload)]
 149          [feeds
 150            (map (λ (line)
 151                    ; TODO validation
 152                    (define toks (string-split line))
 153                    (feed
 154                      [list-ref toks 0]
 155                      [list-ref toks 1]))
 156                 lines)])
 157     feeds))
 158
 159 (define (setup-logging)
 160   (define logger (make-logger #f #f 'debug #f))
 161   (define log-chan (make-log-receiver logger 'debug))
 162   (void (thread (λ ()
 163                    [date-display-format 'iso-8601]
 164                    [let loop ()
 165                      (define data  (sync log-chan))
 166                      (define level (vector-ref data 0))
 167                      (define msg   (vector-ref data 1))
 168                      (define ts    (date->string (current-date) #t))
 169                      (eprintf "~a [~a] ~a~n" ts level msg)
 170                      (loop)])))
 171   (current-logger logger))
 172
 173 (define (main)
 174   (setup-logging)
 175   (current-http-response-auto #f)
 176   (current-http-user-agent "xandkar/tt 0.0.0")
 177   (date-display-format 'rfc2822)
 178
 179   (define feeds (we-are-twtxt))
 180   (timeline-print (timeline feeds)))
 181
 182 (main)