Session 事件流

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304run_session_turn() (
  local session_id="$1"
  local user_text="$2"
  local stream_dir
  local stream_pipe=""
  local stream_error
  local stream_pid=""
  local stream_number=0
  local stream_ready=false
  local seen_ids_file
  local events_payload
  local turn_done=false
  local result_code=1
  local message_count=0
  local reconnect_count=0
  local max_reconnects="${ARK_MAX_SSE_RECONNECTS:-3}"
  local max_history_pages="${ARK_MAX_HISTORY_PAGES:-100}"
  local line
  local data

  : "${ARK_BASE_URL:?Set ARK_BASE_URL before calling run_session_turn}"
  : "${ARK_API_KEY:?Set ARK_API_KEY before calling run_session_turn}"
  : "${session_id:?Pass a Session ID as the first argument}"
  : "${user_text:?Pass a user message as the second argument}"
  command -v curl >/dev/null || {
    printf 'curl is required.\n' >&2
    return 1
  }
  command -v jq >/dev/null || {
    printf 'jq is required.\n' >&2
    return 1
  }
  [[ $max_reconnects =~ ^[0-9]+$ ]] || {
    printf 'ARK_MAX_SSE_RECONNECTS must be a non-negative integer.\n' >&2
    return 1
  }
  [[ $max_history_pages =~ ^[1-9][0-9]*$ ]] || {
    printf 'ARK_MAX_HISTORY_PAGES must be a positive integer.\n' >&2
    return 1
  }

  stream_dir=$(mktemp -d) || {
    printf 'Failed to create a temporary directory for the SSE stream.\n' >&2
    return 1
  }
  stream_error="$stream_dir/stream-error.log"
  seen_ids_file="$stream_dir/seen-event-ids"
  : >"$stream_error"
  : >"$seen_ids_file"

  stop_stream() {
    exec 3<&- || true
    if [[ -n $stream_pid ]] && kill -0 "$stream_pid" 2>/dev/null; then
      kill "$stream_pid" 2>/dev/null || true
    fi
    if [[ -n $stream_pid ]]; then
      wait "$stream_pid" 2>/dev/null || true
    fi
    if [[ -n $stream_pipe ]]; then
      rm -f "$stream_pipe"
    fi
    stream_pid=""
    stream_pipe=""
  }

  cleanup_stream() {
    stop_stream
    rm -rf "$stream_dir"
  }
  trap cleanup_stream EXIT

  start_stream() {
    stop_stream
    stream_number=$((stream_number + 1))
    stream_pipe="$stream_dir/events-$stream_number"
    stream_ready=false

    if ! mkfifo "$stream_pipe"; then
      printf 'Failed to create the SSE pipe at %s.\n' "$stream_pipe" >&2
      return 1
    fi

    curl -sS -N --fail-with-body --max-time 600 \
      "$ARK_BASE_URL/sessions/$session_id/events/stream" \
      -H "Authorization: Bearer $ARK_API_KEY" \
      -H "Accept: text/event-stream" >"$stream_pipe" 2>>"$stream_error" &
    stream_pid=$!
    exec 3<"$stream_pipe"

    while IFS= read -r line <&3; do
      line=${line%$'\r'}
      if [[ $line == ": ready" ]]; then
        stream_ready=true
        break
      fi
    done

    if [[ $stream_ready != true ]]; then
      printf 'SSE stream closed before it was ready.\n' >&2
      if [[ -s $stream_error ]]; then
        tail -n 1 "$stream_error" >&2
      fi
      return 1
    fi
  }

  event_seen() {
    local event_id="$1"
    [[ -n $event_id ]] && grep -Fqx -- "$event_id" "$seen_ids_file"
  }

  remember_event() {
    local event_id="$1"
    if [[ -n $event_id ]] && ! event_seen "$event_id"; then
      printf '%s\n' "$event_id" >>"$seen_ids_file"
    fi
  }

  process_event() {
    local event_json="$1"
    local event_id
    local event_type
    local stop_reason
    local retry_status
    local pending_ids

    event_id=$(jq -r '.id // empty' <<<"$event_json" 2>/dev/null || true)
    if event_seen "$event_id"; then
      return 0
    fi
    remember_event "$event_id"

    event_type=$(jq -r '.type // empty' <<<"$event_json" 2>/dev/null || true)
    case "$event_type" in
      agent.message)
        jq -r '.content[]? | select(.type == "text") | .text' <<<"$event_json"
        message_count=$((message_count + 1))
        ;;
      agent.tool_use | agent.mcp_tool_use | agent.custom_tool_use)
        printf '[tool] %s\n' "$(jq -r '.name // .type' <<<"$event_json")"
        ;;
      session.error)
        retry_status=$(jq -r '.error.retry_status.type // empty' <<<"$event_json")
        printf '[error] %s: %s\n' \
          "$(jq -r '.error.type // "unknown_error"' <<<"$event_json")" \
          "$(jq -r '.error.message // "No error message returned."' <<<"$event_json")" >&2
        case "$retry_status" in
          retrying)
            printf '[session] The service is retrying automatically.\n' >&2
            ;;
          exhausted)
            printf '[session] Retries were exhausted for this turn.\n' >&2
            ;;
          terminal)
            printf '[session] The Session cannot continue after this error.\n' >&2
            ;;
          *)
            printf '[session] Unknown error retry status: %s\n' "$retry_status" >&2
            result_code=4
            turn_done=true
            ;;
        esac
        ;;
      session.status_rescheduled)
        printf '[session] The Session was rescheduled; continue waiting.\n' >&2
        ;;
      session.status_idle)
        stop_reason=$(jq -r '.stop_reason.type // empty' <<<"$event_json")
        case "$stop_reason" in
          end_turn)
            if ((message_count == 0)); then
              printf 'The turn ended without an agent.message event.\n' >&2
              result_code=5
            else
              printf '[session] end_turn\n' >&2
              result_code=0
            fi
            turn_done=true
            ;;
          requires_action)
            pending_ids=$(jq -r '.stop_reason.event_ids // [] | join(",")' <<<"$event_json")
            printf '[session] requires_action: %s\n' "$pending_ids" >&2
            result_code=2
            turn_done=true
            ;;
          retries_exhausted)
            printf '[session] retries_exhausted\n' >&2
            result_code=3
            turn_done=true
            ;;
          *)
            printf 'Unknown session.status_idle stop_reason: %s\n' "$stop_reason" >&2
            result_code=5
            turn_done=true
            ;;
        esac
        ;;
      session.status_terminated)
        printf '[session] terminated\n' >&2
        result_code=4
        turn_done=true
        ;;
    esac
  }

  read_history() {
    local mode="$1"
    local page=""
    local page_count=0
    local response
    local event_json

    while :; do
      page_count=$((page_count + 1))
      if ((page_count > max_history_pages)); then
        printf 'History recovery exceeded %s pages.\n' "$max_history_pages" >&2
        return 1
      fi

      if [[ -n $page ]]; then
        response=$(curl -sS --fail-with-body --get \
          "$ARK_BASE_URL/sessions/$session_id/events" \
          -H "Authorization: Bearer $ARK_API_KEY" \
          --data-urlencode "limit=200" \
          --data-urlencode "order=asc" \
          --data-urlencode "page=$page") || return 1
      else
        response=$(curl -sS --fail-with-body --get \
          "$ARK_BASE_URL/sessions/$session_id/events" \
          -H "Authorization: Bearer $ARK_API_KEY" \
          --data-urlencode "limit=200" \
          --data-urlencode "order=asc") || return 1
      fi

      while IFS= read -r event_json; do
        [[ -n $event_json ]] || continue
        if [[ $mode == "seed" ]]; then
          remember_event "$(jq -r '.id // empty' <<<"$event_json")"
        else
          process_event "$event_json"
          [[ $turn_done == true ]] && break
        fi
      done < <(jq -c '.data[]?' <<<"$response")

      [[ $turn_done == true ]] && return 0
      page=$(jq -r '.next_page // empty' <<<"$response")
      [[ -n $page ]] || return 0
    done
  }

  if ! start_stream; then
    return 1
  fi

  # Mark existing history so reconnect recovery only emits this turn.
  if ! read_history seed; then
    printf 'Failed to read the Session history before sending the message.\n' >&2
    return 1
  fi

  events_payload=$(jq -n --arg text "$user_text" \
    '{events: [{type: "user.message", content: [{type: "text", text: $text}]}]}')

  curl -sS --fail-with-body \
    "$ARK_BASE_URL/sessions/$session_id/events" \
    -H "Authorization: Bearer $ARK_API_KEY" \
    -H "Content-Type: application/json" \
    -d "$events_payload" >/dev/null || return 1

  while [[ $turn_done != true ]]; do
    while IFS= read -r line <&3; do
      line=${line%$'\r'}
      if [[ $line == ": server draining, reconnect" ]]; then
        break
      fi
      [[ $line == data:* ]] || continue
      data=${line#data:}
      data=${data# }
      process_event "$data"
      [[ $turn_done == true ]] && break
    done

    [[ $turn_done == true ]] && break
    if ((reconnect_count >= max_reconnects)); then
      printf 'SSE reconnect limit reached before the turn finished.\n' >&2
      return 1
    fi

    reconnect_count=$((reconnect_count + 1))
    printf '[session] Reconnecting SSE and recovering history (%s/%s).\n' \
      "$reconnect_count" "$max_reconnects" >&2

    # Open the replacement stream first, then recover the disconnect window.
    if ! start_stream; then
      return 1
    fi
    if ! read_history recover; then
      printf 'Failed to recover Session history after reconnecting.\n' >&2
      return 1
    fi
  done

  return "$result_code"
)