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