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| 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 | 'use client' /** * Generic SSE streaming chat hook for character conversations. * * Handles message state, open/close, SSE stream parsing, abort control, * tool call continuation, and error fallbacks. The consumer provides: * - chatEndpoint: API route URL * - buildRequestBody: serializes domain-specific context into the POST body * - canvasRef: optional canvas for screenshot capture * - tools/onToolCall: optional tool support for author mode */ import { useState, useCallback, useRef } from 'react' import type { ChatMessage } from './types' import { captureScreenshot } from './captureScreenshot' import { useConversationCompaction, type CompactionState } from './useConversationCompaction' import type { RealtimeTool } from '@/lib/voice/types' export interface UseCharacterChatOptions { /** API endpoint for chat streaming */ chatEndpoint: string /** Build the request body from current messages + optional screenshot. */ buildRequestBody: ( messages: Array<{ role: string; content: string; toolCallId?: string }>, screenshot: string | undefined ) => Record<string, unknown> /** Canvas ref for screenshot capture (optional) */ canvasRef?: React.RefObject<HTMLCanvasElement | null> /** Called after a user message is added to the chat (e.g. for async markup). */ onUserMessageAdded?: (messageId: string, content: string) => void /** Tools available for the model to call. When set, tool call SSE events are parsed. */ tools?: RealtimeTool[] /** Handle a tool call from the model. Returns the tool result (JSON-serializable). */ onToolCall?: (name: string, args: Record<string, unknown>) => Promise<unknown> } export interface UseCharacterChatReturn { messages: ChatMessage[] isStreaming: boolean sendMessage: (text: string) => void /** Cold-start the conversation: Euclid speaks first with no visible user message. */ coldStart: () => void /** Inject an external message (e.g., voice transcript) into the conversation. */ addMessage: (msg: ChatMessage) => void /** Insert a message before any trailing event messages (use for speech that started before events arrived). */ addMessageBeforeTrailingEvents: (msg: ChatMessage) => void /** Replace all trailing event messages with this one, or remove them if null. */ setTrailingEvent: (msg: ChatMessage | null) => void /** Update the content of an existing message by ID (used for async markup). */ updateMessageContent: (id: string, content: string) => void isOpen: boolean open: () => void close: () => void /** Conversation compaction state — used by voice to get compacted history. */ compaction: CompactionState & { compactForVoice: (messages: ChatMessage[]) => string isSummarizingRef: React.RefObject<boolean> manualCompactUpTo: (index: number) => void } } let nextId = 0 export function generateId(): string { return `msg-${Date.now()}-${nextId++}` } /** Describe a tool call for display in chat. */ function describeToolAction(name: string, args: Record<string, unknown>): string { switch (name) { case 'place_point': return `Place point${args.label ? ` ${args.label}` : ''} at (${args.x}, ${args.y})` case 'postulate_1': return `Post.1: Segment ${args.from_label}${args.to_label}` case 'postulate_2': return `Post.2: Extend ${args.base_label}${args.through_label}` case 'postulate_3': return `Post.3: Circle centered at ${args.center_label} through ${args.radius_point_label}` case 'mark_intersection': return `Intersection of ${args.of_a} and ${args.of_b}` case 'apply_proposition': return `I.${args.prop_id}: Apply to ${args.input_labels}` case 'declare_equality': return `${args.statement}` case 'declare_angle_equality': return `${args.statement}` case 'undo_last': return 'Undo last action' case 'highlight': return `Highlight ${args.entity_type} ${args.labels}` default: return `${name}(${JSON.stringify(args).slice(0, 60)})` } } interface ToolCallEvent { callId: string name: string arguments: Record<string, unknown> } export function useCharacterChat(options: UseCharacterChatOptions): UseCharacterChatReturn { const { chatEndpoint, buildRequestBody, canvasRef, onUserMessageAdded, tools, onToolCall } = options const [messages, setMessages] = useState<ChatMessage[]>([]) const [isStreaming, setIsStreaming] = useState(false) const [isOpen, setIsOpen] = useState(false) const abortRef = useRef<AbortController | null>(null) // Refs for tool continuation — we need stable references for the async loop const toolsRef = useRef(tools) toolsRef.current = tools const onToolCallRef = useRef(onToolCall) onToolCallRef.current = onToolCall const buildRequestBodyRef = useRef(buildRequestBody) buildRequestBodyRef.current = buildRequestBody const messagesRef = useRef(messages) messagesRef.current = messages // Async conversation compaction — summarizes old messages in the background const compaction = useConversationCompaction(messages) const compactForApiRef = useRef(compaction.compactForApi) compactForApiRef.current = compaction.compactForApi const open = useCallback(() => setIsOpen(true), []) const close = useCallback(() => setIsOpen(false), []) const addMessage = useCallback((msg: ChatMessage) => { setMessages((prev) => [...prev, msg]) }, []) const addMessageBeforeTrailingEvents = useCallback((msg: ChatMessage) => { setMessages((prev) => { // Find where trailing event messages start let i = prev.length while (i > 0 && prev[i - 1].isEvent) i-- // Insert before the trailing events return [...prev.slice(0, i), msg, ...prev.slice(i)] }) }, []) const setTrailingEvent = useCallback((msg: ChatMessage | null) => { setMessages((prev) => { // Strip all trailing event messages let i = prev.length while (i > 0 && prev[i - 1].isEvent) i-- return msg ? [...prev.slice(0, i), msg] : prev.slice(0, i) }) }, []) const updateMessageContent = useCallback((id: string, content: string) => { setMessages((prev) => prev.map((m) => (m.id === id ? { ...m, content } : m))) }, []) /** * Shared streaming logic: fires the API request and streams deltas. * Returns collected tool calls (if any) so the caller can handle continuation. */ const streamResponseAsync = useCallback( async ( body: Record<string, unknown>, assistantMsgId: string, abortController: AbortController ): Promise<ToolCallEvent[]> => { const toolCalls: ToolCallEvent[] = [] try { console.log('[character-chat] fetching stream...') const res = await fetch(chatEndpoint, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body), signal: abortController.signal, }) console.log('[character-chat] response status: %d, ok: %s', res.status, res.ok) if (!res.ok) { const err = await res.json().catch(() => ({ error: 'Unknown error' })) console.error('[character-chat] API error:', err) setMessages((prev) => { const updated = [...prev] const last = updated[updated.length - 1] if (last.id === assistantMsgId) { updated[updated.length - 1] = { ...last, content: err.error || 'I cannot respond right now. Try again.', } } return updated }) return [] } const reader = res.body?.getReader() if (!reader) { console.error('[character-chat] no reader from response body') return [] } console.log('[character-chat] got reader, starting stream...') const decoder = new TextDecoder() let buffer = '' while (true) { const { done, value } = await reader.read() if (done) break buffer += decoder.decode(value, { stream: true }) const lines = buffer.split('\n') buffer = lines.pop() ?? '' for (const line of lines) { if (!line.startsWith('data: ')) continue const data = line.slice(6).trim() if (data === '[DONE]') continue try { const event = JSON.parse(data) as { text?: string error?: string toolCall?: ToolCallEvent } if (event.error) { setMessages((prev) => { const updated = [...prev] const last = updated[updated.length - 1] if (last.id === assistantMsgId) { updated[updated.length - 1] = { ...last, content: event.error!, isError: true, } } return updated }) } else if (event.toolCall) { toolCalls.push(event.toolCall) } else if (event.text) { setMessages((prev) => { const updated = [...prev] const last = updated[updated.length - 1] if (last.id === assistantMsgId) { updated[updated.length - 1] = { ...last, content: last.content + event.text, } } return updated }) } } catch { // Skip malformed JSON } } } } catch (err) { if ((err as Error).name === 'AbortError') return [] console.error('[character-chat] Stream error:', err) setMessages((prev) => { const updated = [...prev] const last = updated[updated.length - 1] if (last.id === assistantMsgId && !last.content) { updated[updated.length - 1] = { ...last, content: 'I cannot respond right now. Try again.', } } return updated }) } return toolCalls }, [chatEndpoint] ) /** * Execute tool calls from the model, add action messages, and send continuation. * Loops until the model produces text output (no more tool calls) or max iterations. */ const handleToolContinuation = useCallback( async ( initialToolCalls: ToolCallEvent[], apiMessages: Array<{ role: string; content: string; toolCallId?: string }>, abortController: AbortController, screenshot: string | undefined ) => { let pendingToolCalls = initialToolCalls let iteration = 0 const MAX_ITERATIONS = 10 while (pendingToolCalls.length > 0 && iteration < MAX_ITERATIONS) { iteration++ console.log( '[character-chat] tool continuation iteration %d, %d tool calls', iteration, pendingToolCalls.length ) // Execute each tool call and collect results const toolResults: Array<{ callId: string name: string arguments: Record<string, unknown> result: unknown }> = [] for (const tc of pendingToolCalls) { // Add tool action message to chat const actionDesc = describeToolAction(tc.name, tc.arguments) const actionMsg: ChatMessage = { id: generateId(), role: 'assistant', content: actionDesc, timestamp: Date.now(), isToolAction: true, } setMessages((prev) => [...prev, actionMsg]) // Execute the tool let result: unknown = { success: false, error: 'No tool handler' } if (onToolCallRef.current) { try { result = await onToolCallRef.current(tc.name, tc.arguments) } catch (err) { result = { success: false, error: String(err) } } } toolResults.push({ callId: tc.callId, name: tc.name, arguments: tc.arguments, result }) } // Build continuation messages: include both the tool calls and their results. // The Responses API requires a function_call item for each function_call_output. const toolMessages: Array<{ role: string content: string toolCallId?: string toolCallName?: string toolCallArgs?: string }> = [] for (const tr of toolResults) { // The function_call item (assistant called a tool) toolMessages.push({ role: 'assistant_tool_call', content: '', toolCallId: tr.callId, toolCallName: tr.name, toolCallArgs: JSON.stringify(tr.arguments), }) // The function_call_output item (tool result) toolMessages.push({ role: 'tool', content: JSON.stringify(tr.result), toolCallId: tr.callId, }) } const continuationMessages = [...apiMessages, ...toolMessages] // Create a new assistant message for the continuation response const continuationMsgId = generateId() const continuationMsg: ChatMessage = { id: continuationMsgId, role: 'assistant', content: '', timestamp: Date.now(), } setMessages((prev) => [...prev, continuationMsg]) // Send continuation request const body = buildRequestBodyRef.current(continuationMessages, screenshot) pendingToolCalls = await streamResponseAsync(body, continuationMsgId, abortController) // Update apiMessages for potential next iteration apiMessages = continuationMessages } if (iteration >= MAX_ITERATIONS) { console.warn('[character-chat] max tool continuation iterations reached') } }, [streamResponseAsync] ) const sendMessage = useCallback( (text: string) => { if (!text.trim()) return if (abortRef.current) { abortRef.current.abort() } const userMsg: ChatMessage = { id: generateId(), role: 'user', content: text.trim(), timestamp: Date.now(), } const assistantMsg: ChatMessage = { id: generateId(), role: 'assistant', content: '', timestamp: Date.now(), } setMessages((prev) => [...prev, userMsg, assistantMsg]) setIsStreaming(true) onUserMessageAdded?.(userMsg.id, userMsg.content) const abortController = new AbortController() abortRef.current = abortController const screenshot = canvasRef?.current ? (captureScreenshot(canvasRef.current) ?? undefined) : undefined const apiMessages = compaction.compactForApi([...messages, userMsg]) const body = buildRequestBody(apiMessages, screenshot) console.log( '[character-chat] sendMessage: endpoint=%s, messageCount=%d, hasScreenshot=%s', chatEndpoint, apiMessages.length, !!screenshot ) // Stream response and handle tool calls const run = async () => { try { const toolCalls = await streamResponseAsync(body, assistantMsg.id, abortController) if (toolCalls.length > 0 && onToolCallRef.current) { await handleToolContinuation(toolCalls, apiMessages, abortController, screenshot) } } finally { // Only clear streaming if we're still the active request // (a newer sendMessage may have replaced us via abort) if (abortRef.current === abortController) { setIsStreaming(false) } } } run() }, [ messages, chatEndpoint, buildRequestBody, canvasRef, compaction.compactForApi, streamResponseAsync, handleToolContinuation, onUserMessageAdded, ] ) const coldStart = useCallback(() => { // Allow cold-start if no real conversation has happened (events are OK) const hasConversation = messages.some((m) => !m.isEvent) if (isStreaming || hasConversation) return if (abortRef.current) { abortRef.current.abort() } // Hidden user message — sent to API but not shown in chat UI const hiddenUserMsg: ChatMessage = { id: generateId(), role: 'user', content: '[The student has just opened the chat. Proactively help them — assess where they are in the construction and tell them what to do next. Do NOT greet them or introduce yourself.]', timestamp: Date.now(), } const assistantMsg: ChatMessage = { id: generateId(), role: 'assistant', content: '', timestamp: Date.now(), } // Keep existing event messages, append the assistant response setMessages((prev) => [...prev, assistantMsg]) setIsStreaming(true) const abortController = new AbortController() abortRef.current = abortController const screenshot = canvasRef?.current ? (captureScreenshot(canvasRef.current) ?? undefined) : undefined // Include existing events + hidden prompt so the API sees construction history const eventMessages = compaction.compactForApi(messages) const apiMessages = [...eventMessages, { role: 'user', content: hiddenUserMsg.content }] const body = buildRequestBody(apiMessages, screenshot) console.log( '[character-chat] coldStart: endpoint=%s, events=%d, hasScreenshot=%s', chatEndpoint, eventMessages.length, !!screenshot ) const run = async () => { try { const toolCalls = await streamResponseAsync(body, assistantMsg.id, abortController) if (toolCalls.length > 0 && onToolCallRef.current) { await handleToolContinuation(toolCalls, apiMessages, abortController, screenshot) } } finally { if (abortRef.current === abortController) { setIsStreaming(false) } } } run() }, [ isStreaming, messages, chatEndpoint, buildRequestBody, canvasRef, streamResponseAsync, handleToolContinuation, compaction.compactForApi, ]) return { messages, isStreaming, sendMessage, coldStart, addMessage, addMessageBeforeTrailingEvents, setTrailingEvent, updateMessageContent, isOpen, open, close, compaction: { headSummary: compaction.headSummary, coversUpTo: compaction.coversUpTo, compactForVoice: compaction.compactForVoice, isSummarizingRef: compaction.isSummarizingRef, manualCompactUpTo: compaction.manualCompactUpTo, }, } } |