/**
 * Copyright (c) Microsoft Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { WebSocketTransport } from '../transport';
export class Chat {
    _history = [];
    _connectionPromise;
    _chatSinks = new Map();
    _wsEndpoint;
    constructor(wsEndpoint) {
        this._wsEndpoint = wsEndpoint;
    }
    clearHistory() {
        this._history = [];
    }
    async post(prompt) {
        await this._append('user', prompt);
        let text = await asString(await this._post());
        if (text.startsWith('```json') && text.endsWith('```'))
            text = text.substring('```json'.length, text.length - '```'.length);
        for (let i = 0; i < 3; ++i) {
            try {
                return JSON.parse(text);
            }
            catch (e) {
                await this._append('user', String(e));
            }
        }
        throw new Error('Failed to parse response: ' + text);
    }
    async _append(user, content) {
        this._history.push({ user, content });
    }
    async _connection() {
        if (!this._connectionPromise) {
            this._connectionPromise = WebSocketTransport.connect(undefined, this._wsEndpoint).then(transport => {
                return new Connection(transport, (method, params) => this._dispatchEvent(method, params), () => { });
            });
        }
        return this._connectionPromise;
    }
    _dispatchEvent(method, params) {
        if (method === 'chatChunk') {
            const { chatId, chunk } = params;
            const chunkSink = this._chatSinks.get(chatId);
            chunkSink(chunk);
            if (!chunk)
                this._chatSinks.delete(chatId);
        }
    }
    async _post() {
        const connection = await this._connection();
        const result = await connection.send('chat', { history: this._history });
        const { chatId } = result;
        const { iterable, addChunk } = iterablePump();
        this._chatSinks.set(chatId, addChunk);
        return iterable;
    }
}
export async function asString(stream) {
    let result = '';
    for await (const chunk of stream)
        result += chunk;
    return result;
}
function iterablePump() {
    let controller;
    const stream = new ReadableStream({ start: c => controller = c });
    const iterable = (async function* () {
        const reader = stream.getReader();
        while (true) {
            const { done, value } = await reader.read();
            if (done)
                break;
            yield value;
        }
    })();
    return {
        iterable,
        addChunk: chunk => {
            if (chunk)
                controller.enqueue(chunk);
            else
                controller.close();
        }
    };
}
class Connection {
    _transport;
    _lastId = 0;
    _closed = false;
    _pending = new Map();
    _onEvent;
    _onClose;
    constructor(transport, onEvent, onClose) {
        this._transport = transport;
        this._onEvent = onEvent;
        this._onClose = onClose;
        this._transport.onmessage = this._dispatchMessage.bind(this);
        this._transport.onclose = this._close.bind(this);
    }
    send(method, params) {
        const id = this._lastId++;
        const message = { id, method, params };
        this._transport.send(message);
        return new Promise((resolve, reject) => {
            this._pending.set(id, { resolve, reject });
        });
    }
    _dispatchMessage(message) {
        if (message.id === undefined) {
            this._onEvent(message.method, message.params);
            return;
        }
        const callback = this._pending.get(message.id);
        this._pending.delete(message.id);
        if (!callback)
            return;
        if (message.error) {
            callback.reject(new Error(message.error.message));
            return;
        }
        callback.resolve(message.result);
    }
    _close() {
        this._closed = true;
        this._transport.onmessage = undefined;
        this._transport.onclose = undefined;
        for (const { reject } of this._pending.values())
            reject(new Error('Connection closed'));
        this._onClose();
    }
    isClosed() {
        return this._closed;
    }
    close() {
        if (!this._closed)
            this._transport.close();
    }
}
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