import { LLMOrbiter, OpenRouterProvider } from 'libllmorbiter';
import * as db from '../db/modelconversation.js';
import { getStore } from '../db/store.js';
import env from '../config/env.js';
import { emit as emitCompanyEvent } from '../api/sse.js';
import { readFileSync, writeFileSync, mkdirSync } from 'fs';
import { resolve, dirname, extname } from 'path';
import { fileURLToPath } from 'url';
import { randomUUID } from 'node:crypto';
import { buildSystemPrompt } from './prompts.js';
import { createDashbackRequestTool } from '../tools/dashback-request.js';
import { createAskUserTool } from '../tools/ask-user.js';
import { createJavascriptExecuteTool } from '../tools/javascript.js';
import { createResetVfsTool } from '../tools/reset-vfs.js';
import { resolveVfsRoot, prepareVfs, getMimeType } from '../tools/vfs.js';
import { createApiSuggestionsOrIssuesTool } from '../tools/apisuggestionsorissues.js';
import { createFindFilesTool } from '../tools/find-files.js';
import { createReadFileTool } from '../tools/read-file.js';
import { createPatchTool } from '../tools/patch.js';
import { createRmTool } from '../tools/rm.js';
import { createSearchImagesTool } from '../tools/search-images.js';
import { createAnalyzeImageTool } from '../tools/analyze-image.js';
import { createEditImageTool } from '../tools/edit-image.js';
import { createWebSearchTool } from '../tools/web-search.js';
import { createSearchWebPriceTool } from '../tools/search-web-price.js';
import { createUrlGetTool } from '../tools/url-get.js';
import { createPdfReadTool } from '../tools/pdf-read.js';
import { createSearchArticlesTool } from '../tools/search-articles.js';
import { createEanChecksumTool } from '../tools/ean-checksum.js';
import { createNetGrossCalcTool } from '../tools/net-gross-calc.js';
import { createSetUserRouteTool } from '../tools/set-user-route.js';
import { createDraftDeliveryManifestTool } from '../tools/draft-delivery-manifest.js';
import { createSubagentTool } from '../tools/subagent.js';
import { resolveOpenRouterKey, resolveDefaultModel, resolveModelReasoning, RETIRED_MODELS, hasConfiguredOpenRouterKey } from '../tools/llm-key.js';

// #region Constants

const KEEP_ALIVE_MS = 20_000;

// #endregion


// #region Message Helpers

/**
 * Per-conversation manager. Owns the SSE subscribers of one conversation and
 * runs the LLM (via LLMOrbiter) for each posted user message.
 *
 * Persistence: the database holds the transcript (`modelmessage`) and a binary
 * `idle`/`busy` state. The finer SSE states (`thinking`, `working`, `done`)
 * and the streamed `delta` chunks are SSE-only.
 */
function parseUtcDate(val) {
    if (!val) return new Date();
    if (val instanceof Date) return isNaN(val.getTime()) ? new Date() : val;
    if (typeof val === 'string') {
        const s = val.trim();
        if (/^\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}:\d{2}/.test(s) && !s.endsWith('Z') && !/[+-]\d{2}(:?\d{2})?$/.test(s)) {
            const parsed = new Date(s.replace(' ', 'T') + 'Z');
            if (!isNaN(parsed.getTime())) return parsed;
        }
        const parsed = new Date(s);
        if (!isNaN(parsed.getTime())) return parsed;
    }
    return new Date();
}

export function formatTimePrefix(createdDate) {
    const d = parseUtcDate(createdDate);
    const parts = new Intl.DateTimeFormat('en-GB', {
        timeZone: 'Europe/Berlin',
        hour: '2-digit',
        minute: '2-digit',
        hour12: false,
        timeZoneName: 'short',
    }).formatToParts(d);
    const hour = parts.find((p) => p.type === 'hour')?.value.padStart(2, '0') || '00';
    const minute = parts.find((p) => p.type === 'minute')?.value.padStart(2, '0') || '00';
    let tz = parts.find((p) => p.type === 'timeZoneName')?.value || 'MEST';
    if (tz === 'CEST') tz = 'MEST';
    else if (tz === 'CET') tz = 'MET';
    return `[${hour}:${minute}${tz}] `;
}

export function parseIncomingUserMessage({ message, attachments: directAttachments, content: directContent } = {}) {
    let text = '';
    const attachments = Array.isArray(directAttachments) ? [...directAttachments] : [];

    const tryParseJson = (str) => {
        if (typeof str !== 'string') return null;
        const trimmed = str.trim();
        if ((trimmed.startsWith('{') && trimmed.endsWith('}')) || (trimmed.startsWith('[') && trimmed.endsWith(']'))) {
            try {
                return JSON.parse(trimmed);
            } catch {
                return null;
            }
        }
        return null;
    };

    let candidate = message !== undefined ? message : directContent;

    if (typeof candidate === 'string') {
        const parsed = tryParseJson(candidate);
        if (parsed && typeof parsed === 'object') {
            candidate = parsed;
        } else {
            text = candidate;
        }
    }

    if (candidate && typeof candidate === 'object' && !Array.isArray(candidate)) {
        if (typeof candidate.content === 'string') {
            const innerParsed = tryParseJson(candidate.content);
            if (innerParsed && typeof innerParsed === 'object') {
                if (typeof innerParsed.content === 'string') {
                    text = innerParsed.content;
                }
                if (Array.isArray(innerParsed.attachments)) {
                    attachments.push(...innerParsed.attachments);
                }
            } else {
                text = candidate.content;
            }
        } else if (typeof candidate.message === 'string') {
            const innerParsed = tryParseJson(candidate.message);
            if (innerParsed && typeof innerParsed === 'object') {
                if (typeof innerParsed.content === 'string') {
                    text = innerParsed.content;
                }
                if (Array.isArray(innerParsed.attachments)) {
                    attachments.push(...innerParsed.attachments);
                }
            } else {
                text = candidate.message;
            }
        }

        if (Array.isArray(candidate.attachments)) {
            attachments.push(...candidate.attachments);
        }
    }

    const uniqueAttachments = [];
    const seen = new Set();
    for (const att of attachments) {
        if (!att || typeof att !== 'object') continue;
        const key = att.id || `${att.name || att.filename}_${att.size || ''}`;
        if (!seen.has(key)) {
            seen.add(key);
            uniqueAttachments.push(att);
        }
    }

    return {
        content: String(text || '').trim(),
        attachments: uniqueAttachments,
    };
}

export function cleanUserMessageContent(rawContent) {
    if (!rawContent || typeof rawContent !== 'string') return '';
    if (rawContent.includes('"attachments"') && (rawContent.trim().startsWith('{') || rawContent.includes('{"content"'))) {
        try {
            const parsed = parseIncomingUserMessage({ message: rawContent });
            if (parsed.attachments.length > 0) {
                const tags = parsed.attachments.map((att) => {
                    const name = (att.name || att.filename || 'attachment').replace(/^.*[\\\/]/, '').replace(/[\0\r\n"]/g, '').trim() || 'attachment';
                    const mime = att.mimeType || att.type || getMimeType(name);
                    const vfsRelPath = `attachments/${name}`;
                    const formatAttr = (val) => String(val).includes(' ') ? `"${val}"` : String(val);
                    return `[ATTACHMENT name=${formatAttr(name)} path=${formatAttr(vfsRelPath)} type=${formatAttr(mime)}]`;
                });
                const prefix = tags.join(' ');
                return parsed.content ? `${prefix}\n\n${parsed.content}` : prefix;
            }
            if (parsed.content) return parsed.content;
        } catch {
            // keep rawContent if parsing fails
        }
    }
    return rawContent;
}

export function historyToLlmMessages(history) {
    const messages = [];
    for (const m of history) {
        if (m.role === 'usage' || m.role === 'reasoning') continue;
        let payload;
        try {
            payload = typeof m.message === 'string' ? JSON.parse(m.message) : m.message;
        } catch {
            payload = { content: m.message };
        }
        if (m.role === 'user') {
            const rawContent = payload.content ?? (typeof m.message === 'string' ? m.message : '');
            const cleanedContent = cleanUserMessageContent(rawContent);
            const timePrefix = formatTimePrefix(m.created_at);
            const content = /^\s*\[\d{2}:\d{2}[A-Za-z]+\]\s*/.test(cleanedContent)
                ? cleanedContent
                : `${timePrefix}${cleanedContent}`;
            messages.push({ role: 'user', content });
        } else if (m.role === 'assistant') {
            messages.push({
                role: 'assistant',
                content: payload.content ?? null,
                ...(Array.isArray(payload.tool_calls) && payload.tool_calls.length > 0 ? { tool_calls: payload.tool_calls } : {}),
            });
        } else if (m.role === 'tool') {
            const toolCallId = payload.tool_call_id ?? '';
            const toolName = payload.name ?? '';
            const toolParams = payload.parameters ?? payload.arguments ?? '{}';
            const prevMsg = messages[messages.length - 1];
            if (!prevMsg || prevMsg.role !== 'assistant' || !prevMsg.tool_calls) {
                messages.push({
                    role: 'assistant',
                    content: null,
                    tool_calls: [{
                        id: toolCallId,
                        type: 'function',
                        function: {
                            name: toolName,
                            arguments: typeof toolParams === 'string' ? toolParams : JSON.stringify(toolParams),
                        },
                    }],
                });
            } else if (!prevMsg.tool_calls.some((tc) => tc.id === toolCallId)) {
                prevMsg.tool_calls.push({
                    id: toolCallId,
                    type: 'function',
                    function: {
                        name: toolName,
                        arguments: typeof toolParams === 'string' ? toolParams : JSON.stringify(toolParams),
                    },
                });
            }
            messages.push({
                role: 'tool',
                tool_call_id: toolCallId,
                content: typeof payload.content === 'string' ? payload.content : JSON.stringify(payload.content ?? ''),
                ...(toolName ? { name: toolName } : {}),
            });
        }
    }
    return messages;
}

// #endregion

// #region ConversationManager

export class ConversationManager {
    /**
     * @param {number} conversationId
     * @param {{ companyId: number, googleAuthId: number }} meta
     */
    constructor(conversationId, { companyId, googleAuthId }) {
        this.conversationId = conversationId;
        this.companyId = companyId;
        this.googleAuthId = googleAuthId;
        /** @type {Set<{ res: import('express').Response, keepAlive: NodeJS.Timeout }>} */
        this.subscribers = new Set();
        /** @type {LLMOrbiter|null} */
        this.orbiter = null;
        this.destroyed = false;
        this.isProcessing = false;
    }

    // #region Subscription & Broadcast

    /**
     * Broadcast an SSE event to all subscribers of this conversation.
     * @param {string} event
     * @param {object} data
     */
    broadcast(event, data) {
        if (this.destroyed) return;
        const payload = `event: ${event}\ndata: ${JSON.stringify(data)}\n\n`;
        for (const client of this.subscribers) {
            if (!client.res.writableEnded && !client.res.destroyed) {
                client.res.write(payload);
            }
        }
    }

    /**
     * Add an SSE subscriber for this conversation.
     * @param {import('express').Response} res
     * @param {import('express').Request} [req]
     * @returns {() => void} unsubscribe
     */
    subscribe(res, req) {
        req?.socket?.setTimeout(0);
        res.setTimeout?.(0);

        res.writeHead(200, {
            'Content-Type': 'text/event-stream',
            'Cache-Control': 'no-cache, no-transform',
            'Connection': 'keep-alive',
            'X-Accel-Buffering': 'no',
        });
        res.flushHeaders?.();
        res.write(': ping\n\n');

        const client = {
            res,
            keepAlive: setInterval(() => {
                if (res.writableEnded || res.destroyed) return;
                res.write(': heartbeat\n\n');
            }, KEEP_ALIVE_MS),
        };
        this.subscribers.add(client);

        const unsubscribe = () => {
            clearInterval(client.keepAlive);
            this.subscribers.delete(client);
        };

        res.on('close', unsubscribe);
        req?.on('close', unsubscribe);
        return unsubscribe;
    }

    // #endregion

    // #region Attachments

    /**
     * Saves attachments sent with a user message to the company's VFS
     * under `attachments/<filename>` and registers them in `modelvfs`.
     *
     * @param {number} googleAuthId
     * @param {Array<object>} attachments
     * @returns {Promise<Array<string>>} Array of `[ATTACHMENT name= path= type=]` tags
     */
    async saveAttachmentsToVfs(googleAuthId, attachments) {
        if (!Array.isArray(attachments) || attachments.length === 0) return [];

        let vfsRoot;
        try {
            vfsRoot = await prepareVfs({ googleAuthId });
        } catch (err) {
            console.error(`[ConversationManager ${this.conversationId}] prepareVfs error:`, err);
            return [];
        }

        const store = await getStore();
        const attachmentsDir = resolve(vfsRoot, 'attachments');
        try {
            mkdirSync(attachmentsDir, { recursive: true });
        } catch (err) {
            console.error(`[ConversationManager ${this.conversationId}] failed to create attachments directory:`, err);
        }

        const tags = [];
        const usedNames = new Set();

        for (const att of attachments) {
            if (!att || typeof att !== 'object') continue;

            const rawName = (att.name || att.filename || `attachment-${Date.now()}`).replace(/^.*[\\\/]/, '');
            const cleanName = rawName.replace(/[\0\r\n"]/g, '').trim() || 'attachment';

            let finalName = cleanName;
            let counter = 1;
            const ext = extname(cleanName);
            const base = ext ? cleanName.slice(0, -ext.length) : cleanName;
            while (usedNames.has(finalName.toLowerCase())) {
                counter++;
                finalName = `${base}_${counter}${ext}`;
            }
            usedNames.add(finalName.toLowerCase());

            let fileBuffer = null;
            if (att.dataUrl && typeof att.dataUrl === 'string') {
                const commaIdx = att.dataUrl.indexOf(',');
                if (commaIdx !== -1) {
                    const metaPart = att.dataUrl.slice(0, commaIdx);
                    const dataPart = att.dataUrl.slice(commaIdx + 1);
                    if (metaPart.includes(';base64')) {
                        fileBuffer = Buffer.from(dataPart, 'base64');
                    } else {
                        fileBuffer = Buffer.from(decodeURIComponent(dataPart), 'utf8');
                    }
                }
            }
            if (!fileBuffer && att.textContent != null) {
                fileBuffer = Buffer.from(String(att.textContent), 'utf8');
            }
            if (!fileBuffer && att.content != null) {
                fileBuffer = Buffer.isBuffer(att.content) ? att.content : Buffer.from(String(att.content));
            }

            let mime = att.mimeType || att.type || '';
            if (!mime && att.dataUrl && typeof att.dataUrl === 'string') {
                const match = att.dataUrl.match(/^data:([^;,]+)/);
                if (match) mime = match[1];
            }
            if (!mime) {
                mime = getMimeType(finalName);
            }

            const vfsRelPath = `attachments/${finalName}`;
            const diskPath = resolve(vfsRoot, vfsRelPath);

            if (fileBuffer) {
                try {
                    writeFileSync(diskPath, fileBuffer);
                } catch (err) {
                    console.error(`[ConversationManager ${this.conversationId}] failed to write attachment disk file:`, err);
                }
            }

            const formatAttr = (val) => String(val).includes(' ') ? `"${val}"` : String(val);
            tags.push(`[ATTACHMENT name=${formatAttr(finalName)} path=${formatAttr(vfsRelPath)} type=${formatAttr(mime)}]`);
        }

        return tags;
    }

    // #endregion

    // #region Message Handlers

    /**
     * Handle an incoming user message.
     * 1. Extracts text content and saves any attachments into the company VFS (`attachments/`).
     * 2. Prefixes user message with `[ATTACHMENT name= path= type=]` tags.
     * 3. Persists the user message (DB refuses unless `idle`).
     * 4. Broadcasts it, marks the conversation `busy` (DB) and `thinking` (SSE).
     * 5. Starts the LLM run in the background; the HTTP request returns immediately.
     *
     * @param {number} googleAuthId
     * @param {{ message?: any, attachments?: Array<object>, content?: any }} input
     * @returns {Promise<object>} The created user message
     * @throws {Error} 'Conversation is not idle' while a run is active.
     */
    async handleUserMessage(googleAuthId, { message, attachments, content }) {
        if (this.isProcessing) throw new Error('Conversation is not idle');
        this.isProcessing = true;

        let userMsg;
        try {
            const parsed = parseIncomingUserMessage({ message, attachments, content });
            if (!parsed.content && parsed.attachments.length === 0) {
                throw new Error('Message required');
            }

            let finalMessage = parsed.content;

            if (parsed.attachments.length > 0) {
                const tags = await this.saveAttachmentsToVfs(googleAuthId, parsed.attachments);
                if (tags.length > 0) {
                    const prefix = tags.join(' ');
                    finalMessage = parsed.content ? `${prefix}\n\n${parsed.content}` : prefix;
                }
            }

            const payload = JSON.stringify({ content: finalMessage });
            userMsg = await db.addMessage(googleAuthId, this.conversationId, { message: payload, role: 'user' });
            await db.setState(googleAuthId, this.conversationId, 'busy');
        } catch (err) {
            this.isProcessing = false;
            throw err;
        }

        this.broadcast('state', { state: 'thinking' });
        emitCompanyEvent('modelconversation', { companyId: this.companyId });

        this.runGeneration(googleAuthId).catch((err) => {
            console.error(`[ConversationManager ${this.conversationId}] unexpected generation error:`, err);
        });

        return userMsg;
    }

    /**
     * Handle an incoming tool response message (e.g. from the user answering ask_user).
     * 1. Persists the tool response message (DB refuses unless `idle`).
     * 2. Broadcasts it, marks the conversation `busy` (DB) and `working` (SSE).
     * 3. Starts the LLM run in the background; the HTTP request returns immediately.
     *
     * @param {number} googleAuthId
     * @param {{ tool_call_id: string, content?: any, answer?: any }} input
     * @returns {Promise<object>} The created tool message
     * @throws {Error} 'Conversation is not idle' while a run is active.
     */
    async handleToolMessage(googleAuthId, { tool_call_id, content, answer, name }) {
        if (!tool_call_id) throw new Error('tool_call_id is required');
        if (this.isProcessing) throw new Error('Conversation is not idle');
        this.isProcessing = true;

        let toolMsg;
        try {
            const rawContent = content !== undefined
                ? (typeof content === 'string' ? content : JSON.stringify(content))
                : JSON.stringify({ answer: answer ?? '' });
            const payload = JSON.stringify({
                content: rawContent,
                tool_call_id,
                name: name || 'ask_user',
            });
            toolMsg = await db.addMessage(googleAuthId, this.conversationId, { message: payload, role: 'tool' });
            await db.setState(googleAuthId, this.conversationId, 'busy');

        } catch (err) {
            this.isProcessing = false;
            throw err;
        }

        this.broadcast('state', { state: 'working' });
        emitCompanyEvent('modelconversation', { companyId: this.companyId });

        this.runGeneration(googleAuthId).catch((err) => {
            console.error(`[ConversationManager ${this.conversationId}] unexpected generation error:`, err);
        });

        return toolMsg;
    }

    // #endregion

    // #region Run
    /**
     * Run the LLM over the stored transcript, stream the answer over SSE,
     * persist reasoning, tool calls, and assistant messages, then return to `idle`.
     * @param {number} googleAuthId
     */
    async runGeneration(googleAuthId) {
        let error = null;

        try {
            const conversation = await db.get(googleAuthId, this.conversationId);
            if (conversation.provider !== 'openrouter') {
                throw new Error(`Unsupported provider: ${conversation.provider}`);
            }
            // Fall back to the configured default when the stored model is missing, blank, or
            // retired. If the stored model was defaulted to the free model and the company now has
            // a custom key configured, transition to the configured paid default model.
            const defaultModel = await resolveDefaultModel(googleAuthId);
            const hasCustomKey = await hasConfiguredOpenRouterKey(googleAuthId);
            const storedModel = typeof conversation.model === 'string' ? conversation.model.trim() : '';
            const model = (!storedModel || RETIRED_MODELS.has(storedModel) || (storedModel === env.openrouterFreeModel && (hasCustomKey || defaultModel !== env.openrouterFreeModel)))
                ? defaultModel
                : storedModel;
            const apiKey = await resolveOpenRouterKey(googleAuthId);

            // Transcript comes from the database (includes user, assistant, tool, reasoning).
            const history = await db.listMessages(googleAuthId, this.conversationId);

            // Resolve the VFS root so the prompt can list the company's SKILL files. A failure
            // here must not abort the turn — the prompt simply falls back to "no skills".
            let vfsRoot = null;
            try {
                vfsRoot = await resolveVfsRoot(googleAuthId);
            } catch (err) {
                console.warn('conversation: could not resolve VFS root for skill index:', err.message);
            }

            const messages = [
                { role: 'system', content: await buildSystemPrompt(vfsRoot, googleAuthId) },
                ...historyToLlmMessages(history),
            ];

            let text = '';
            let currentReasoning = '';

            this.orbiter = new LLMOrbiter(new OpenRouterProvider({ apiKey, apiUrl: env.openrouterApiUrl }), {
                onStatus: (status, meta) => {
                    this.broadcast('state', { state: status, ...(meta || {}) });
                },
                onReasoning: (reasoning) => {
                    currentReasoning = reasoning;
                    this.broadcast('reasoning', { text: reasoning });
                },
                onContent: (chunk) => {
                    text += chunk;
                    this.broadcast('delta', { delta: chunk, text });
                },
                onAssistantMessage: async ({ content, tool_calls, reasoning_details, reasoning }) => {
                    const plain = (reasoning || currentReasoning.trim() || reasoning_details?.find((d) => d?.type === 'reasoning.summary')?.summary || '').trim();
                    const encrypted = reasoning_details?.find((d) => d?.type === 'reasoning.encrypted')?.data || '';
                    currentReasoning = '';

                    if (plain || encrypted) {
                        try {
                            await db.addMessage(googleAuthId, this.conversationId, {
                                role: 'reasoning',
                                message: JSON.stringify({ plain, encrypted }),
                            });
                        } catch (err) {
                            console.error(`[ConversationManager ${this.conversationId}] failed to save reasoning message:`, err);
                        }
                    }

                    const trimmedContent = (content || text).trim();
                    const hasToolCalls = Array.isArray(tool_calls) && tool_calls.length > 0;
                    if (trimmedContent || hasToolCalls) {
                        try {
                            await db.addMessage(googleAuthId, this.conversationId, {
                                role: 'assistant',
                                message: JSON.stringify({
                                    content: trimmedContent,
                                    ...(hasToolCalls ? { tool_calls } : {}),
                                }),
                            });
                            text = '';
                            emitCompanyEvent('modelconversation', { companyId: this.companyId });
                        } catch (err) {
                            console.error(`[ConversationManager ${this.conversationId}] failed to save assistant message:`, err);
                        }
                    }
                },
                onToolCall: async ({ name, args, id, callItem }) => {
                    const rawArgs = callItem?.function?.arguments || (typeof args === 'string' ? args : JSON.stringify(args || {}));
                    console.log(`[conversation ${this.conversationId}] tool call: ${name} args=${rawArgs}`);
                    this.broadcast('state', {
                        state: 'toolcall',
                        id: id || callItem?.id || '',
                        name,
                        arguments: rawArgs,
                        content: rawArgs,
                    });
                },
                onToolResult: async ({ name, result, id, callItem }) => {
                    const rawArgs = callItem?.function?.arguments || '';
                    this.broadcast('state', {
                        state: 'toolcall',
                        id: id || callItem?.id || '',
                        name,
                        arguments: rawArgs,
                        content: rawArgs,
                        result,
                    });
                    try {
                        await db.addMessage(googleAuthId, this.conversationId, {
                            role: 'tool',
                            message: JSON.stringify({
                                name,
                                parameters: rawArgs,
                                content: typeof result === 'string' ? result : JSON.stringify(result),
                                tool_call_id: id || callItem?.id || '',
                            }),
                        });
                        emitCompanyEvent('modelconversation', { companyId: this.companyId });
                    } catch (err) {
                        console.error(`[ConversationManager ${this.conversationId}] failed to save tool result message:`, err);
                    }
                },
                onToolError: async ({ name, error, id, callItem }) => {
                    console.error(`[ConversationManager ${this.conversationId}] Tool "${name}" errored:`, error);
                    const rawArgs = callItem?.function?.arguments || '';
                    this.broadcast('state', {
                        state: 'toolcall',
                        id: id || callItem?.id || '',
                        name,
                        arguments: rawArgs,
                        content: rawArgs,
                        error: String(error),
                    });
                    try {
                        await db.addMessage(googleAuthId, this.conversationId, {
                            role: 'tool',
                            message: JSON.stringify({
                                name,
                                parameters: rawArgs,
                                content: `Tool error [${name}]: ${error}`,
                                tool_call_id: id || callItem?.id || '',
                            }),
                        });
                        emitCompanyEvent('modelconversation', { companyId: this.companyId });
                    } catch (err) {
                        console.error(`[ConversationManager ${this.conversationId}] failed to save tool error message:`, err);
                    }
                },
                onUsage: async (u) => {
                    if (u) {
                        this.broadcast('usage', {
                            input: u.input ?? 0,
                            cached: u.cached ?? 0,
                            output: u.output ?? 0,
                            ...(u.cost != null ? { cost: u.cost } : {}),
                        });
                        try {
                            await db.addMessage(googleAuthId, this.conversationId, {
                                role: 'usage',
                                message: JSON.stringify({
                                    input: u.input ?? 0,
                                    cached: u.cached ?? 0,
                                    output: u.output ?? 0,
                                    ...(u.cost != null ? { cost: u.cost } : {}),
                                }),
                            });
                            emitCompanyEvent('modelconversation', { companyId: this.companyId });
                        } catch (err) {
                            console.error(`[ConversationManager ${this.conversationId}] failed to save usage message:`, err);
                        }
                    }
                    // A call that consumed 0 input tokens AND produced 0 output means the
                    // provider returned nothing at all — not a real generation. LLMOrbiter
                    // treats "no content and no tool calls" as "keep looping", so several of
                    // these in a row burn iterations for nothing. Flag them loudly so the
                    // cause is visible instead of showing up as a silent weird loop.
                    if (u.input === 0 && u.output === 0) {
                        console.warn(
                            `[conversation ${this.conversationId}] EMPTY LLM RESPONSE ` +
                            `(iteration reported no usage at all). The provider returned no content ` +
                            `and no tool calls, so the orchestrator will retry. ` +
                            `If this repeats, the upstream model/API is failing — check the model id ` +
                            `and the key.`
                        );
                    }
                    console.log(
                        `[conversation ${this.conversationId}] usage: input=${u.input}, cached=${u.cached}, output=${u.output}` +
                        (u.cost != null ? `, cost=$${u.cost.toFixed(4)}` : '')
                    );
                },
                onLLMCall: (call) => {
                    console.log(
                        `[conversation ${this.conversationId}] LLM call #${call.iteration}: ` +
                        `model=${call.model}, messages=${call.messageCount}, flow=${call.messages}, ` +
                        `promptChars=${call.promptSize}`
                    );
                },
            });

            const reasoningEffort = await resolveModelReasoning(googleAuthId);
            const extraBody = reasoningEffort
                ? { reasoning: { effort: reasoningEffort } }
                : {};

            const result = await this.orbiter.run({
                messages,
                model,
                extraBody,
                tools: [
                    createDashbackRequestTool({ googleAuthId }),
                    createAskUserTool(),
                    // VFS tools take no companyId on purpose — each resolves the user's
                    // currently selected company itself, so the on-disk VFS and the database
                    // can never end up pointed at different companies.
                    createJavascriptExecuteTool({ googleAuthId }),
                    createFindFilesTool({ googleAuthId }),
                    createReadFileTool({ googleAuthId }),
                    createPatchTool({ googleAuthId }),
                    createRmTool({ googleAuthId }),
                    createSearchImagesTool({ googleAuthId }),
                    createAnalyzeImageTool({ googleAuthId, model }),
                    createEditImageTool({ googleAuthId, model }),
                    createWebSearchTool({ googleAuthId }),
                    createSearchWebPriceTool({ googleAuthId }),
                    createUrlGetTool({ googleAuthId }),
                    createPdfReadTool({ googleAuthId }),
                    createResetVfsTool({ googleAuthId }),
                    createApiSuggestionsOrIssuesTool({ googleAuthId, companyId: this.companyId }),
                    createSearchArticlesTool({ googleAuthId, companyId: this.companyId }),
                    createEanChecksumTool(),
                    createNetGrossCalcTool(),
                    createSetUserRouteTool({
                        onRoute: (route) => {
                            this.broadcast('route', { route });
                        },
                    }),
                    createDraftDeliveryManifestTool(),
                    createSubagentTool({
                        googleAuthId,
                        companyId: this.companyId,
                        conversationId: this.conversationId,
                        parentModel: model,
                        depth: 0,
                    }),
                ],
            });

            if (this.destroyed) return;

            // Log the shape of every run, including degenerate ones. When nothing comes back
            // there is nothing persisted and the UI just sits there — this line is the only
            // clue, so make it explicit about which field was empty.
            console.log(
                `[conversation ${this.conversationId}] run finished: ` +
                `iterations=${result?.iterations}, ` +
                `content=${result?.content ? `${result.content.length} chars` : 'EMPTY'}, ` +
                `toolCalls=${result?.toolResults ? Object.keys(result.toolResults).length : 0}, ` +
                `directReturn=${result?.directReturn === true}`
            );

            // Direct return (e.g. from ask_user) halts without adding an additional assistant message.
            if (result?.directReturn) {
                console.log(
                    `[conversation ${this.conversationId}] direct return halted loop: ` +
                    JSON.stringify(result.data)
                );
                return;
            }

            const content = (result.content ?? '').trim();
            const finalReasoningDetails = (Array.isArray(result.reasoning_details) && result.reasoning_details.length > 0)
                ? result.reasoning_details
                : undefined;
            const finalReasoning = result.reasoning || currentReasoning.trim() || undefined;

            // Nothing came back at all: no content, no reasoning. Surface it to the user rather
            // than silently returning to `idle` with an empty turn, which reads as a hang.
            if (!content && !finalReasoningDetails && !finalReasoning) {
                console.error(
                    `[conversation ${this.conversationId}] generation produced no content after ` +
                    `${result?.iterations ?? 0} iteration(s). The model returned neither text nor tool calls.`
                );
                error = 'The model returned an empty response. Please try again.';
            }
        } catch (err) {
            if (this.destroyed) return;
            error = err.message;
            console.error(`[ConversationManager ${this.conversationId}] generation failed:`, err);
        } finally {
            this.orbiter = null;
            this.isProcessing = false;
        }

        try {
            await db.setState(googleAuthId, this.conversationId, 'idle');
        } catch (err) {
            console.error(`[ConversationManager ${this.conversationId}] failed to reset state:`, err);
        }
        emitCompanyEvent('modelconversation', { companyId: this.companyId });
        this.broadcast('state', error ? { state: 'done', error } : { state: 'done' });
    }

    // #endregion

    // #region Teardown

    destroy() {
        this.destroyed = true;
        this.orbiter?.abort('Conversation manager closed');
        for (const client of this.subscribers) {
            clearInterval(client.keepAlive);
            if (!client.res.writableEnded && !client.res.destroyed) {
                client.res.end();
            }
        }
        this.subscribers.clear();
    }

    // #endregion
}

// #endregion

// #region Manager Registry

/** @type {Map<number, ConversationManager>} */
const activeManagers = new Map();

/**
 * Get or create an active ConversationManager for a conversation.
 * @param {number} conversationId
 * @param {{ companyId: number, googleAuthId: number }} meta
 * @returns {ConversationManager}
 */
export function getOrCreateManager(conversationId, { companyId, googleAuthId }) {
    let manager = activeManagers.get(conversationId);
    if (!manager) {
        manager = new ConversationManager(conversationId, { companyId, googleAuthId });
        activeManagers.set(conversationId, manager);
    } else {
        if (companyId) manager.companyId = companyId;
        if (googleAuthId) manager.googleAuthId = googleAuthId;
    }
    return manager;
}

/**
 * Get an active ConversationManager if one exists.
 * @param {number} conversationId
 * @returns {ConversationManager|undefined}
 */
export function getActiveManager(conversationId) {
    return activeManagers.get(conversationId);
}

/**
 * Close, destroy, and remove an active ConversationManager if one exists.
 * @param {number} conversationId
 */
export function removeManager(conversationId) {
    const manager = activeManagers.get(conversationId);
    if (manager) {
        manager.destroy();
        activeManagers.delete(conversationId);
    }
}

/**
 * Close and destroy all active conversation managers.
 */
export function closeAllManagers() {
    for (const [id, manager] of activeManagers.entries()) {
        manager.destroy();
        activeManagers.delete(id);
    }
}

// #endregion