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Diffstat (limited to 'src/background/translation-service.js')
| -rw-r--r-- | src/background/translation-service.js | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/src/background/translation-service.js b/src/background/translation-service.js new file mode 100644 index 0000000..f443237 --- /dev/null +++ b/src/background/translation-service.js @@ -0,0 +1,319 @@ +/** + * Translation service (background): shared translation pipeline. + * + * Both entry points use this module so there is exactly one request + * generation / streaming / state implementation: + * - content script (runtime.Port streaming, Design.md §8) + * - context menu / popup (translation state, Design.md §9.2) + * + * No PDF-specific translation engine exists; `source` is metadata only. + */ + +import { getSettings, saveSettings } from './settings-service.js'; +import { TranslationSession } from './translation-session.js'; +import { chatStream, listModels } from './ollama-client.js'; +import { buildSystemPrompt } from '../shared/prompt.js'; +import { buildOptions, toApiThinking, sanitizeSettings, defaultSettings } from '../shared/settings-schema.js'; +import { BG_TO_CONTENT, MAX_SELECTION_LENGTH, ERROR_CODES } from '../shared/constants.js'; + +const session = new TranslationSession(); + +/** User-facing messages per error code (kept minimal; no stack traces). */ +const ERROR_MESSAGES = { + [ERROR_CODES.INVALID_REQUEST]: '要求が不正です。', + [ERROR_CODES.TEXT_EMPTY]: '選択文字列が空です。', + [ERROR_CODES.TEXT_TOO_LONG]: `選択文字列が長すぎます（上限 ${MAX_SELECTION_LENGTH} 文字）。`, + [ERROR_CODES.OLLAMA_UNAVAILABLE]: 'Ollamaに接続できません。Ollamaが起動しているか確認してください。', + [ERROR_CODES.MODEL_NOT_FOUND]: '指定されたモデルが見つかりません。設定画面でモデルを選び直してください。', + [ERROR_CODES.INVALID_SETTINGS]: '設定値が不正です。設定画面を確認してください。', + [ERROR_CODES.REQUEST_ABORTED]: '翻訳を中断しました。', + [ERROR_CODES.STREAM_ERROR]: '翻訳中にエラーが発生しました。', + [ERROR_CODES.UNKNOWN_ERROR]: '不明なエラーが発生しました。' +}; + +const NO_MODEL_MESSAGE = 'モデルが設定されていません。ツールバーアイコンまたは設定画面でモデルを選択してください。'; + +/** + * Background translation state (Design.md §9.2). Shared by popup and + * menu-controller; the popup reads it via GET_POPUP_STATE. + * @type {{requestId: string|null, sourceText: string, translatedText: string, + * status: string, model: string, error: string|null, startedAt: number|null, + * source: string}} + */ +const state = { + requestId: null, + sourceText: '', + translatedText: '', + status: 'idle', + model: '', + error: null, + startedAt: null, + source: '' +}; + +/** + * @returns {object} a copy of the current translation state. + */ +export function getTranslationState() { + return { ...state, translatedText: state.translatedText }; +} + +/** + * Reset the shared state for a new request. + * @param {string} requestId + * @param {string} text validated source text + * @param {string} source 'content' | 'context-menu' + */ +function beginState(requestId, text, source) { + state.requestId = requestId; + state.sourceText = text; + state.translatedText = ''; + state.status = 'starting'; + state.model = ''; + state.error = null; + state.startedAt = Date.now(); + state.source = source; +} + +/** + * Validate an untrusted selection string (content script or + * menus.selectionText - both are untrusted, Security.md §7.4). + * @param {*} text + * @returns {{ok: true, text: string}|{ok: false, code: string}} + */ +export function validateSelectionText(text) { + if (typeof text !== 'string') { + return { ok: false, code: ERROR_CODES.INVALID_REQUEST }; + } + const trimmed = text.trim(); + if (trimmed.length === 0) { + return { ok: false, code: ERROR_CODES.TEXT_EMPTY }; + } + // Strip control characters except tab/newline/CR. + const cleaned = trimmed.replace(/[\u0000-\u0008\u000B\u000C\u000E-\u001F\u007F]/g, ''); + if (cleaned.length === 0) { + return { ok: false, code: ERROR_CODES.TEXT_EMPTY }; + } + if (cleaned.length > MAX_SELECTION_LENGTH) { + return { ok: false, code: ERROR_CODES.TEXT_TOO_LONG }; + } + return { ok: true, text: cleaned }; +} + +/** + * @param {string} code + * @returns {string} user-facing message for the code + */ +export function messageForCode(code) { + return ERROR_MESSAGES[code] || ERROR_MESSAGES[ERROR_CODES.UNKNOWN_ERROR]; +} + +/** + * Ensure a model is configured before translating. On a fresh install the + * user may translate straight from a context menu without ever opening the + * settings UI, so storage.model would still be ''. In that case pick the + * first model reported by the running Ollama (best-effort, one attempt per + * runTranslation call) and persist it so the choice is visible in the UI. + * This mirrors the popup/options auto-select behavior so every path agrees. + * @param {object} browserApi injectable for tests + * @returns {Promise<{settings: object, error: string|null}>} + */ +async function ensureModelConfigured(browserApi) { + let settings = await getSettings(browserApi); + if (settings.model) { + return { settings, error: null }; + } + try { + const models = await listModels(settings.ollamaHost); + if (models.length > 0) { + const merged = sanitizeSettings({ ...settings, model: models[0] }); + await saveSettings(merged, browserApi); + settings = merged; + return { settings, error: null }; + } + return { settings, error: NO_MODEL_MESSAGE }; + } catch (error) { + // Ollama unreachable while listing models: report a clear error. + const code = (error && error.code) || ERROR_CODES.OLLAMA_UNAVAILABLE; + return { settings, error: messageForCode(code) }; + } +} + +/** + * Popup state subscribers. The popup connects a 'popup-state' port and + * receives the shared state after every change, so an open popup shows + * live streaming progress even for sink-less (context-menu) requests. + * @type {Set<object>} + */ +const popupPorts = new Set(); + +/** + * Register a popup port for live state broadcasts. + * @param {object} port runtime.Port (name 'popup-state') + */ +export function addPopupPort(port) { + popupPorts.add(port); + try { + port.postMessage({ type: 'popup-state', state: getTranslationState() }); + } catch { + // ignore + } +} + +/** + * Unregister a popup port. + * @param {object} port + */ +export function removePopupPort(port) { + popupPorts.delete(port); +} + +/** + * Broadcast the current state to every connected popup port. + */ +function broadcastState() { + for (const port of popupPorts) { + try { + port.postMessage({ type: 'popup-state', state: getTranslationState() }); + } catch { + popupPorts.delete(port); + } + } +} + +/** + * Run one translation and notify a sink with started/chunk/completed/error. + * + * The sink is an object with an optional postMessage(message) method. The + * content-script port is one sink; the popup state is updated internally and + * broadcast to connected popups so they can render live progress. + * + * @param {object} params + * @param {string} params.text validated source text + * @param {string} params.requestId + * @param {string} params.source 'content' | 'context-menu' + * @param {object|null} [params.sink] optional message sink (port-like) + * @returns {Promise<void>} + */ +export async function runTranslation({ text, requestId, source, sink = null, browserApi = null }) { + let settings = await getSettings(browserApi); + + if (!settings.enabled) { + state.status = 'error'; + state.error = messageForCode(ERROR_CODES.INVALID_REQUEST); + broadcastState(); + postToSink(sink, { type: BG_TO_CONTENT.ERROR, requestId, code: ERROR_CODES.INVALID_REQUEST, message: state.error }); + return; + } + + // Fresh-install path: pick the first model from the running Ollama so a + // user who never opened the settings UI can still translate. + const ensured = await ensureModelConfigured(browserApi); + if (ensured.error) { + state.status = 'error'; + state.error = ensured.error; + broadcastState(); + postToSink(sink, { type: BG_TO_CONTENT.ERROR, requestId, code: ERROR_CODES.INVALID_SETTINGS, message: ensured.error }); + return; + } + settings = ensured.settings; + + // Registering the new request aborts any previous one. + const controller = session.start(requestId, sink); + + beginState(requestId, text, source); + state.model = settings.model; + broadcastState(); + + postToSink(sink, { type: BG_TO_CONTENT.STARTED, requestId, model: settings.model }); + + try { + await chatStream({ + host: settings.ollamaHost, + model: settings.model, + messages: [ + { role: 'system', content: buildSystemPrompt(settings) }, + { role: 'user', content: text } + ], + think: toApiThinking(settings), + options: buildOptions(settings), + signal: controller.signal, + onChunk: (content) => { + // Drop chunks if a newer request took over. + if (!session.isActive(requestId)) return; + if (content) { + state.translatedText += content; + state.status = 'streaming'; + broadcastState(); + } + postToSink(sink, { type: BG_TO_CONTENT.CHUNK, requestId, text: content }); + } + }); + if (session.isActive(requestId)) { + state.status = 'completed'; + broadcastState(); + postToSink(sink, { type: BG_TO_CONTENT.COMPLETED, requestId }); + } + } catch (error) { + const code = (error && error.code) || ERROR_CODES.UNKNOWN_ERROR; + if (code === ERROR_CODES.REQUEST_ABORTED) { + // Reported by TranslationSession.abortActive() to the old sink; the + // shared state marks it cancelled so the popup can show it. + state.status = 'cancelled'; + state.error = messageForCode(code); + broadcastState(); + } else if (session.isActive(requestId)) { + state.status = 'error'; + // Fall back to the code's base message when the detail is empty or + // judged non-user-facing by detailForUser(). + const detail = detailForUser(error); + state.error = detail ? `${messageForCode(code)}\n(${detail})` : messageForCode(code); + broadcastState(); + postToSink(sink, { type: BG_TO_CONTENT.ERROR, requestId, code, detail: state.error }); + } + } finally { + session.clear(requestId); + } +} + +/** + * Build a short, user-safe detail string from an error. Low-level exception + * text and full server responses are not shown unbounded: keep the message + * short and drop anything that looks like an internal URL or a huge blob. + * @param {*} error + * @returns {string} '' when there is nothing worth showing + */ +function detailForUser(error) { + const base = messageForCode(ERROR_CODES.UNKNOWN_ERROR); + const raw = error && error.message ? String(error.message) : ''; + if (!raw) return ''; + // Skip raw network errors that leak no useful info beyond the code. + if (/failed to fetch|networkerror|load failed/i.test(raw)) return ''; + // Strip URLs (internal host names should not be echoed to the UI). + const cleaned = raw.replace(/\bhttps?:\/\/\S+/gi, '').trim(); + if (!cleaned) return ''; + // Drop obviously non-user-facing payloads (full JSON responses etc.). + if (cleaned.startsWith('{') || cleaned.startsWith('[')) return ''; + const short = cleaned.length > 120 ? `${cleaned.slice(0, 120)}…` : cleaned; + return `${short}`; +} + +/** + * @param {object|null} sink + * @param {object} message + */ +function postToSink(sink, message) { + if (!sink) return; + try { + sink.postMessage(message); + } catch { + // sink may be disconnected (e.g. popup closed) + } +} + +/** @returns {TranslationSession} the shared session (for tests / cancel). */ +export function getSession() { + return session; +} + +export { ERROR_MESSAGES, NO_MODEL_MESSAGE };
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