import {createSseParser, parseSseData, SseParseError} from "./sse.js";

// A Response body is single-use. Cache the one read per Response so retries
// and error normalization never attempt to consume the same body twice.
const responseTextCache = new WeakMap();

export class ApiError extends Error {
    constructor(message, {status = 0, code = "REQUEST_FAILED", requestId = null, ...details} = {}) { super(message); this.name = "ApiError"; this.status = status; this.code = code; this.requestId = requestId; this.details = details; }
    toJSON() { return {...this.details, error: this.message, status: this.status, code: this.code, requestId: this.requestId}; }
}
function requestScope({signal, timeoutMs = 30000} = {}) { const controller = new AbortController(); const abort = () => controller.abort(new ApiError("Request cancelled.", {code: "ABORTED"})); if (signal?.aborted) abort(); else signal?.addEventListener("abort", abort, {once: true}); const timer = timeoutMs > 0 ? setTimeout(() => controller.abort(new ApiError("Request timed out. Please try again.", {code: "TIMEOUT"})), timeoutMs) : null; return {signal: controller.signal, close() { clearTimeout(timer); signal?.removeEventListener("abort", abort); }}; }
function abortable(operation, signal) {
    if (signal.aborted) return Promise.reject(signal.reason);
    return new Promise((resolve, reject) => {
        const abort = () => { signal.removeEventListener("abort", abort); reject(signal.reason); };
        signal.addEventListener("abort", abort, {once: true});
        let result;
        try { result = operation(); } catch (error) { reject(error); return; }
        Promise.resolve(result).then(resolve, reject).finally(() => signal.removeEventListener("abort", abort));
    });
}
function responseError(response, payload = {}, fallback = "", code = "") { const details = payload && typeof payload === "object" ? payload : {}; const error = details.error; return new ApiError(typeof error === "string" ? error : error?.message || fallback || `HTTP ${response.status} ${response.statusText}`.trim(), {...details, status: response.ok && Number.isInteger(details.status) && details.status >= 400 ? details.status : response.status, code: details.code || error?.code || code || `HTTP_${response.status}`, requestId: details.requestId || response.headers.get("X-Request-ID") || null}); }
async function readResponseText(response, signal) {
    let textPromise = responseTextCache.get(response);
    if (!textPromise) {
        textPromise = Promise.resolve().then(() => response.text());
        responseTextCache.set(response, textPromise);
    }
    return abortable(() => textPromise, signal);
}
async function readJson(response, signal) { const text = await readResponseText(response, signal); let payload; if (text.trim()) { try { payload = JSON.parse(text); } catch { if (response.ok) throw responseError(response, {}, "Invalid JSON response.", "INVALID_RESPONSE"); } } if (!response.ok) throw responseError(response, payload); return payload ?? {}; }
function normalizeError(error, scope, response) { const failure = scope.signal.aborted ? scope.signal.reason : error; if (failure instanceof ApiError) { if (!failure.status && response) failure.status = response.status; failure.requestId ||= response?.headers.get("X-Request-ID") || null; return failure; } return new ApiError(response ? failure?.message || "Response could not be read." : "Network error - please try again.", {status: response?.status || 0, code: response ? "INVALID_RESPONSE" : "NETWORK_ERROR", requestId: response?.headers.get("X-Request-ID") || null}); }
const transient = e => e?.status === 408 || e?.status === 425 || e?.status === 429 || e?.status >= 500 || e?.code === "NETWORK_ERROR" || e?.code === "TIMEOUT";
const pause = (ms, signal) => new Promise((resolve, reject) => { const timer = setTimeout(resolve, ms); signal?.addEventListener("abort", () => { clearTimeout(timer); reject(signal.reason); }, {once: true}); });
function filenameFromDisposition(value) { const encoded = value?.match(/filename\*=UTF-8''([^;]+)/i)?.[1]; const plain = value?.match(/filename="?([^";]+)"?/i)?.[1]; try { return decodeURIComponent(encoded || plain || ""); } catch { return plain || null; } }
async function bufferedRequest(url, {method, body, headers}, options = {}, asBlob = false) { const scope = requestScope(options); const maxRetries = method === "GET" ? Math.max(0, options.retries ?? 2) : 0; try { for (let attempt = 0; ; attempt += 1) { let response; try { response = await abortable(() => fetch(url, {method, credentials: "same-origin", headers, body, signal: scope.signal}), scope.signal); if (!asBlob || !response.ok) return await readJson(response, scope.signal); const blob = await abortable(() => response.blob(), scope.signal); return {blob, filename: filenameFromDisposition(response.headers.get("Content-Disposition")), contentType: response.headers.get("Content-Type") || blob.type || "application/octet-stream", size: Number(response.headers.get("Content-Length")) || blob.size}; } catch (error) { const failure = normalizeError(error, scope, response); if (attempt < maxRetries && transient(failure) && !scope.signal.aborted) { await pause(Math.min(8000, 250 * 2 ** attempt), scope.signal); continue; } return failure.toJSON(); } } } finally { scope.close(); } }
export function request(url, data, method = "POST", options = {}) { return bufferedRequest(url, {method, headers: {"Accept": "application/json", "Content-Type": "application/json"}, body: data == null ? undefined : JSON.stringify(data)}, options); }
export async function requestResult(url, data, method = "POST", options = {}) { const value = await request(url, data, method, options); return value?.error ? {ok: false, data: null, error: new ApiError(value.error, value)} : {ok: true, data: value, error: null}; }
export async function requestOrThrow(url, data, method = "POST", options = {}) { const result = await requestResult(url, data, method, options); if (!result.ok) throw result.error; return result.data; }
export const multipart = (url, form, options = {}) => bufferedRequest(url, {method: "POST", headers: {"Accept": "application/json"}, body: form}, {timeoutMs: 120000, ...options});
export const download = (url, options = {}) => bufferedRequest(url, {method: "GET", headers: {"Accept": "*/*"}}, {timeoutMs: 120000, ...options}, true);
export const get = (url, options) => request(url, null, "GET", options); export const post = (url, data, options) => request(url, data, "POST", options); export const put = (url, data, options) => request(url, data, "PUT", options); export const del = (url, options) => request(url, null, "DELETE", options);
export async function stream(url, data, handlers = {}, options = {}) { if (options && typeof options.addEventListener === "function") options = {signal: options}; const scope = requestScope({timeoutMs: 660000, ...options}); let response; let reader; let terminal = false; try { response = await abortable(() => fetch(url, {method: "POST", credentials: "same-origin", headers: {"Accept": "text/event-stream, application/json", "Content-Type": "application/json"}, body: JSON.stringify(data || {}), signal: scope.signal}), scope.signal); if (!response.ok) await readJson(response, scope.signal); if (!response.body) throw responseError(response, {}, "Missing response stream.", "INVALID_RESPONSE"); reader = response.body.getReader(); const parser = createSseParser({onComment: handlers.onComment, onRetry: handlers.onRetry}); const decoder = new TextDecoder(); const consume = events => { for (const event of events) { let payload; try { payload = parseSseData(event); } catch (error) { throw new SseParseError(error.message, {cause: error, event}); } if (!payload || typeof payload !== "object" || Array.isArray(payload)) throw new SseParseError("Invalid response stream.", {event}); const name = event.event; const fields = {status: "status", done: "reply", error: "error", replace: "text"}; if (fields[name] && typeof payload[fields[name]] !== "string") throw new SseParseError(`Invalid ${name} event payload.`, {event}); if (name === "chunk" && typeof (payload.chunk ?? payload.fullReply) !== "string") throw new SseParseError("Invalid chunk event payload.", {event}); if (name === "thinking" && typeof (payload.chunk ?? payload.fullThinking) !== "string") throw new SseParseError("Invalid thinking event payload.", {event}); if (name === "replace" && !["reply", "thinking"].includes(payload.target)) throw new SseParseError("Invalid replacement stream.", {event}); if (name === "error") throw responseError(response, payload, "Streaming request failed.", "STREAM_ERROR"); const handler = {chunk: "onChunk", thinking: "onThinking", status: "onStatus", replace: "onReplace", done: "onDone"}[name]; if (handler) handlers[handler]?.(payload); else if (name !== "message") handlers.onUnknown?.(event, payload); if (name === "done") { terminal = true; break; } } }; while (!terminal) { const {value, done} = await abortable(() => reader.read(), scope.signal); if (done) break; consume(parser.push(decoder.decode(value, {stream: true}))); } consume(parser.finish()); if (!terminal) throw responseError(response, {}, "Response was interrupted. Please try again.", "STREAM_INTERRUPTED"); } catch (error) { const failure = normalizeError(error, scope, response); const reconnectAttempt = options._reconnectAttempt || 0; if (options.reconnect === true && reconnectAttempt < (options.maxReconnects ?? 3) && transient(failure) && !scope.signal.aborted) { await pause(Math.min(8000, options.reconnectDelayMs ?? 500 * 2 ** reconnectAttempt), scope.signal); return stream(url, data, handlers, {...options, _reconnectAttempt: reconnectAttempt + 1}); } if (handlers.onError) handlers.onError(failure.toJSON()); else throw failure; } finally { scope.close(); if (reader) { void reader.cancel().catch(() => {}); reader.releaseLock(); } } }