import * as http from 'http';
import * as fs from 'fs';
import * as path from 'path';
import axios from 'axios';
import { getConfig, _getBrainDir, _isBrainDirExplicitlySet, findBrainFiles } from './utils';

export interface BridgeInterface {
    injectSystemMessage(msg: string): void;
    getHistoryText(): string;
    sendPromptFromExtension(prompt: string): void;
    brainEnabled: boolean;
    findBrainFiles(dir: string): string[];
}

export class BridgeServer {
    private server: http.Server | null = null;

    constructor(private provider: BridgeInterface) {}

    public start(port: number = 4825) {
        this.server = http.createServer((req, res) => {
            res.setHeader('Access-Control-Allow-Origin', '*');
            res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
            res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

            if (req.method === 'OPTIONS') {
                res.writeHead(200);
                res.end();
                return;
            }

            const url = req.url || '';

            if (req.method === 'GET' && url === '/ping') {
                this.handlePing(res);
            } else if (req.method === 'POST' && url === '/api/exam') {
                this.handlePost(req, res, this.processExam.bind(this));
            } else if (req.method === 'POST' && url === '/api/evaluate') {
                this.handlePost(req, res, this.processEvaluate.bind(this));
            } else if (req.method === 'GET' && url === '/api/evaluate-history') {
                this.processEvaluateHistory(res);
            } else if (req.method === 'POST' && url === '/api/brain-inject') {
                this.handlePost(req, res, this.processBrainInject.bind(this));
            } else {
                res.writeHead(404);
                res.end();
            }
        });

        this.server.listen(port, '127.0.0.1', () => {
            console.log(`[G1nation] Bridge Server active on port ${port}`);
        });
    }

    private handlePing(res: http.ServerResponse) {
        const brainDir = _getBrainDir();
        const brainCount = fs.existsSync(brainDir) ? findBrainFiles(brainDir).length : 0;
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({
            status: 'ok',
            msg: 'G1nation Bridge Ready',
            config: getConfig(),
            brain: { fileCount: brainCount, enabled: this.provider.brainEnabled }
        }));
    }

    private handlePost(req: http.IncomingMessage, res: http.ServerResponse, processor: (data: any, res: http.ServerResponse) => Promise<void>) {
        let body = '';
        req.on('data', chunk => body += chunk.toString());
        req.on('end', async () => {
            try {
                const parsed = JSON.parse(body);
                await processor(parsed, res);
            } catch (e: any) {
                res.writeHead(500, { 'Content-Type': 'application/json' });
                res.end(JSON.stringify({ error: e.message }));
            }
        });
    }

    private async processExam(data: any, res: http.ServerResponse) {
        const prompt = data.prompt || 'Automatic Prompt Received';
        this.provider.sendPromptFromExtension(`[Bridge Input] ${prompt}`);
        const result = await this.callAI(prompt);
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ success: true, rawOutput: result }));
    }

    private async processEvaluate(data: any, res: http.ServerResponse) {
        const prompt = data.prompt || '';
        this.provider.injectSystemMessage(`**[A.U Evaluation Started]**\nAnalyzing input: _"${prompt.substring(0, 60)}..."_`);
        
        const evaluationPrompt = `[EVALUATION REQUEST]\nPlease evaluate the following input and provide a score/reasoning:\n\n${prompt}`;
        const result = await this.callAI(evaluationPrompt);
        
        this.provider.injectSystemMessage(`**[Evaluation Complete]**\n${result.substring(0, 300)}...`);
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ rawOutput: result }));
    }

    private async processEvaluateHistory(res: http.ServerResponse) {
        const historyText = this.provider.getHistoryText();
        if (!historyText || historyText.length < 50) {
            res.writeHead(400, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ error: "Insufficient chat history for evaluation." }));
            return;
        }

        this.provider.injectSystemMessage(`**[History Evaluation]** Analyzing conversation flow...`);
        const historyPrompt = `Analyze this conversation history and return a JSON score for Math, Logic, Creative, and Code (0-100):\n\n${historyText.slice(-6000)}`;
        const result = await this.callAI(historyPrompt);
        
        const jsonMatch = result.match(/\{[\s\S]*?\}/);
        if (jsonMatch) {
            res.writeHead(200, { 'Content-Type': 'application/json' });
            res.end(jsonMatch[0]);
        } else {
            res.writeHead(500, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ error: "Failed to parse evaluation JSON", raw: result }));
        }
    }

    private async processBrainInject(data: any, res: http.ServerResponse) {
        const { title, markdown, prompt } = data;
        let brainDir = _getBrainDir();

        if (!fs.existsSync(brainDir)) {
            fs.mkdirSync(brainDir, { recursive: true });
        }

        const today = new Date().toISOString().split('T')[0];
        const datePath = path.join(brainDir, '00_Raw', today);
        fs.mkdirSync(datePath, { recursive: true });

        const safeTitle = title.replace(/[^a-zA-Z0-9가-힣]/gi, '_');
        const filePath = path.join(datePath, `${safeTitle}.md`);
        fs.writeFileSync(filePath, markdown, 'utf-8');

        this.provider.injectSystemMessage(`**[Brain Inject]** Knowledge captured: ${title}`);
        
        const result = await this.callAI(prompt || `Analyze this new knowledge: ${title}`);
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ success: true, rawOutput: result }));
    }

    private async callAI(prompt: string): Promise<string> {
        const config = getConfig();
        const isLMStudio = config.ollamaUrl.includes('1234') || config.ollamaUrl.includes('v1');
        const apiUrl = isLMStudio ? `${config.ollamaUrl}/v1/chat/completions` : `${config.ollamaUrl}/api/chat`;

        const payload = {
            model: config.defaultModel,
            messages: [{ role: 'user', content: prompt }],
            stream: false
        };

        const res = await axios.post(apiUrl, payload, { timeout: config.timeout });
        return isLMStudio ? (res.data.choices?.[0]?.message?.content || '') : (res.data.message?.content || '');
    }
}