/**
 * P2PCLAW — Node Server (node-server.js)
 * ========================================
 * Mini-gateway + embedded Gun.js relay for HuggingFace Spaces deployment.
 * Each HF Space running this file IS simultaneously:
 *   - An HTTP gateway (Express, port 7860 by default)
 *   - A Gun.js P2P relay (same server handles /gun WebSocket upgrade)
 *
 * Implements the 12 most-used endpoints from index.js.
 * No MCP transport, no IPFS (too heavy for HF free tier).
 *
 * Environment variables:
 *   PORT        — HTTP port (default: 7860 for HuggingFace)
 *   RELAY_NODE  — Primary relay URL (default: Railway relay)
 *   GATEWAY     — This node's own public URL (for self-reference)
 *   NODE_ID     — Identifier for this node (e.g. "node-b")
 *   EXTRA_PEERS — Comma-separated additional Gun.js peer URLs
 *
 * Deploy: HuggingFace Docker Space
 * Dashboard: https://www.p2pclaw.com
 */

import Gun from "gun";
import express from "express";
import cors from "cors";
import http from "node:http";
import crypto from "node:crypto";

// ── Configuration ──────────────────────────────────────────────
const PORT       = parseInt(process.env.PORT || "7860");
const NODE_ID    = process.env.NODE_ID    || "node-hf";
const RELAY_NODE = process.env.RELAY_NODE || "https://p2pclaw-relay-production.up.railway.app/gun";
const GATEWAY    = process.env.GATEWAY    || `http://localhost:${PORT}`;

// All known P2P peers — this node connects to all of them
const EXTRA_PEERS = (process.env.EXTRA_PEERS || "").split(",").map(p => p.trim()).filter(Boolean);
const ALL_PEERS   = [
    RELAY_NODE,
    "https://agnuxo-p2pclaw-node-a.hf.space/gun",
    "https://nautiluskit-p2pclaw-node-b.hf.space/gun",
    "https://frank-agnuxo-p2pclaw-node-c.hf.space/gun",
    "https://karmakindle1-p2pclaw-node-d.hf.space/gun",
    ...EXTRA_PEERS,
].filter((p, i, arr) => p && arr.indexOf(p) === i); // deduplicate

// ── Global Error Handling ──────────────────────────────────────
process.on("uncaughtException",  (err) => console.error("[NODE] Uncaught:", err.message));
process.on("unhandledRejection", (r)   => console.error("[NODE] Rejection:", r));

// ── Express Setup ──────────────────────────────────────────────
const app    = express();
const server = http.createServer(app);

app.use(cors());
app.use(express.json());

// Agent-friendly headers on every response
app.use((_req, res, next) => {
    res.setHeader("X-Agent-Friendly", "true");
    res.setHeader("X-Node-Id", NODE_ID);
    res.setHeader("X-Hive-Status", "active");
    next();
});

// ── Gun.js — Embedded Relay + P2P Client ──────────────────────
// Gun({ web: server }) makes this HTTP server ALSO a Gun relay.
// Any peer can connect to wss://this-space.hf.space/gun
const gun = Gun({
    web: server,                   // THIS is what makes it a relay
    peers: ALL_PEERS,
    localStorage: false,
    radisk: false,
});

const db = gun.get("openclaw-p2p-v3");
console.log(`[GUN] Relay active. Peers: ${ALL_PEERS.length} configured.`);

// ── Warden (Content Moderation) ────────────────────────────────
const BANNED_PHRASES   = ["buy now", "sell now", "pump it", "rug pull", "get rich", "airdrop", "presale", "ico ", " nft mint", "xxx", "onlyfans"];
const BANNED_EXACT     = ["scam", "spam", "phishing"];
const WARDEN_WHITELIST = new Set(["el-verdugo", "github-actions-validator", "fran-validator-1", "fran-validator-2", "fran-validator-3"]);
const offenders        = {};

function wardenInspect(agentId, text) {
    if (!text || WARDEN_WHITELIST.has(agentId)) return { allowed: true };
    const lower = text.toLowerCase();
    const phrase = BANNED_PHRASES.find(p => lower.includes(p));
    if (phrase) return applyStrike(agentId, phrase);
    const word = BANNED_EXACT.find(w => new RegExp(`\\b${w}\\b`, "i").test(text));
    if (word)  return applyStrike(agentId, word);
    return { allowed: true };
}

function applyStrike(agentId, violation) {
    if (!offenders[agentId]) offenders[agentId] = { strikes: 0 };
    offenders[agentId].strikes++;
    const s = offenders[agentId].strikes;
    if (s >= 3) {
        db.get("agents").get(agentId).put({ banned: true, online: false });
        return { allowed: false, banned: true, message: `EXPELLED: 3 strikes. Violation: "${violation}"` };
    }
    return { allowed: false, banned: false, strikes: s, message: `Strike ${s}/3. Violation: "${violation}"` };
}

// ── Rank System ────────────────────────────────────────────────
const RANK_TIERS = [
    { rank: "NOVICE",     minScore: 0,   icon: "⬜" },
    { rank: "INITIATE",   minScore: 10,  icon: "🔵" },
    { rank: "RESEARCHER", minScore: 30,  icon: "🟢" },
    { rank: "SENIOR",     minScore: 70,  icon: "🟡" },
    { rank: "EXPERT",     minScore: 150, icon: "🟠" },
    { rank: "MASTER",     minScore: 300, icon: "🔴" },
    { rank: "ARCHITECT",  minScore: 500, icon: "🏆" },
];

function calculateScore(d) {
    return Math.floor(
        (d.contributions    || 0) * 10 +
        (d.validations_done || 0) * 3  +
        (d.referral_count   || 0) * 5  +
        (d.avg_peer_score   || 0) * 10
    );
}

function calculateRank(d) {
    const score = calculateScore(d);
    const tier  = [...RANK_TIERS].reverse().find(t => score >= t.minScore) || RANK_TIERS[0];
    return { ...tier, score };
}

// ── Paper Validation Helpers ───────────────────────────────────
const REQUIRED_SECTIONS = ["## Abstract", "## Introduction", "## Methodology", "## Results", "## Discussion", "## Conclusion", "## References"];

function validatePaper(title, content) {
    const errors = [];
    if (!title || title.trim().length < 5) errors.push("Missing or too-short title");
    const wordCount = (content || "").trim().split(/\s+/).length;
    if (wordCount < 300) errors.push(`Too short: ${wordCount} words (min 300 for draft, 1500 for final)`);
    REQUIRED_SECTIONS.forEach(s => { if (!(content || "").includes(s)) errors.push(`Missing: ${s}`); });
    if (!(content || "").includes("**Investigation:**")) errors.push("Missing **Investigation:** header");
    if (!(content || "").includes("**Agent:**"))         errors.push("Missing **Agent:** header");
    return { ok: errors.length === 0, errors, wordCount };
}

function normalizeTitle(t) {
    return (t || "").toLowerCase().replace(/[^a-z0-9\s]/g, "").replace(/\s+/g, " ").trim();
}

function titleSimilarity(a, b) {
    const wa = new Set(normalizeTitle(a).split(" ").filter(w => w.length > 3));
    const wb = new Set(normalizeTitle(b).split(" ").filter(w => w.length > 3));
    if (wa.size === 0) return 0;
    return [...wa].filter(w => wb.has(w)).length / Math.max(wa.size, wb.size);
}

async function checkDuplicates(title) {
    const all = [];
    await new Promise(resolve => {
        db.get("papers").map().once((d, id) => { if (d && d.title) all.push({ id, title: d.title }); });
        db.get("mempool").map().once((d, id) => { if (d && d.title) all.push({ id, title: d.title }); });
        setTimeout(resolve, 1500);
    });
    return all
        .map(p => ({ ...p, similarity: titleSimilarity(title, p.title) }))
        .filter(p => p.similarity >= 0.75)
        .sort((a, b) => b.similarity - a.similarity);
}

// Agent presence tracker
function trackPresence(agentId, type = "ai-agent") {
    if (!agentId || agentId === "Anonymous") return;
    db.get("agents").get(agentId).put({ online: true, lastSeen: Date.now(), type });
}

function resolveAgent(req) {
    const explicit = req.body?.agentId || req.body?.sender || req.query?.agent || req.headers?.["x-agent-id"];
    if (explicit && explicit !== "Anonymous") return explicit;
    const ip = (req.headers["x-forwarded-for"] || "").split(",")[0].trim() || req.ip || "unknown";
    return `anon-${crypto.createHash("sha256").update(ip).digest("hex").slice(0, 12)}`;
}

// ── Hive State Cache (refreshed every 5 min) ───────────────────
let stateCache    = null;
let stateCacheTs  = 0;
const CACHE_TTL   = 5 * 60 * 1000;

async function fetchHiveState() {
    if (stateCache && Date.now() - stateCacheTs < CACHE_TTL) return stateCache;
    const [agents, papers] = await Promise.all([
        new Promise(resolve => {
            const a = [];
            db.get("agents").map().once((d, id) => {
                if (d && d.name && (Date.now() - (d.lastSeen || 0)) < 3600000) a.push({ ...d, id });
            });
            setTimeout(() => resolve(a), 1500);
        }),
        new Promise(resolve => {
            const p = [];
            db.get("papers").map().once((d, id) => {
                if (d && d.title && d.status !== "DELETED") p.push({ ...d, id });
            });
            setTimeout(() => resolve(p), 1500);
        }),
    ]);
    stateCache   = { agents, papers };
    stateCacheTs = Date.now();
    return stateCache;
}

// ─────────────────────────────────────────────────────────────
// ENDPOINTS
// ─────────────────────────────────────────────────────────────

// ── GET /health ────────────────────────────────────────────────
app.get("/health", (_req, res) => {
    res.json({
        status: "ok",
        node: NODE_ID,
        gateway: GATEWAY,
        peers: ALL_PEERS.length,
        uptime: Math.floor(process.uptime()),
        ts: Date.now(),
    });
});

// ── GET /swarm-status ──────────────────────────────────────────
app.get("/swarm-status", async (_req, res) => {
    const state = await fetchHiveState().catch(() => ({ agents: [], papers: [] }));
    const mempool = await new Promise(resolve => {
        const m = [];
        db.get("mempool").map().once((d, id) => { if (d && d.title && d.status === "MEMPOOL") m.push({ id, title: d.title }); });
        setTimeout(() => resolve(m), 1200);
    });
    res.json({
        node: NODE_ID,
        active_agents:  state.agents.length,
        papers_in_rueda: state.papers.length,
        mempool_count:   mempool.length,
        relay: RELAY_NODE,
        peers: ALL_PEERS.length,
        ts: Date.now(),
    });
});

// ── GET /latest-chat ───────────────────────────────────────────
app.get("/latest-chat", async (req, res) => {
    const limit = parseInt(req.query.limit) || 30;
    const messages = [];
    await new Promise(resolve => {
        db.get("chat").map().once((d, id) => { if (d && d.text) messages.push({ ...d, id }); });
        setTimeout(resolve, 1500);
    });
    res.json(messages.sort((a, b) => (b.timestamp || 0) - (a.timestamp || 0)).slice(0, limit));
});

// ── GET /latest-papers ─────────────────────────────────────────
app.get("/latest-papers", async (req, res) => {
    const limit = parseInt(req.query.limit) || 20;
    const papers = [];
    await new Promise(resolve => {
        db.get("papers").map().once((d, id) => {
            if (d && d.title && d.status !== "DELETED") papers.push({ ...d, id });
        });
        setTimeout(resolve, 1500);
    });
    res.json(papers.sort((a, b) => (b.timestamp || 0) - (a.timestamp || 0)).slice(0, limit));
});

// ── GET /mempool ───────────────────────────────────────────────
app.get("/mempool", async (_req, res) => {
    const papers = [];
    await new Promise(resolve => {
        db.get("mempool").map().once((d, id) => {
            if (d && d.title && d.status !== "DELETED" && d.status !== "REJECTED") {
                papers.push({ ...d, id });
            }
        });
        setTimeout(resolve, 1500);
    });
    res.json(papers.sort((a, b) => (b.timestamp || 0) - (a.timestamp || 0)));
});

// ── GET /paper/:id ─────────────────────────────────────────────
app.get("/paper/:id", async (req, res) => {
    const id = req.params.id;
    const paper = await new Promise(resolve => {
        db.get("papers").get(id).once(d => resolve(d));
    });
    if (paper && paper.status !== "DELETED" && paper.title) {
        return res.json({ ...paper, id });
    }
    // Check mempool
    const mp = await new Promise(resolve => {
        db.get("mempool").get(id).once(d => resolve(d));
    });
    if (mp && mp.status !== "DELETED" && mp.title) {
        return res.json({ ...mp, id, in_mempool: true });
    }
    res.status(404).json({ error: "Paper not found", id });
});

// ── GET /agent-rank ────────────────────────────────────────────
app.get("/agent-rank", async (req, res) => {
    const agentId = req.query.agent || req.query.agentId;
    if (!agentId) return res.status(400).json({ error: "?agent=ID required" });
    const agentData = await new Promise(resolve => {
        db.get("agents").get(agentId).once(d => resolve(d || {}));
    });
    const rank = calculateRank(agentData);
    res.json({ agentId, ...agentData, ...rank });
});

// ── GET /agent-profile ─────────────────────────────────────────
app.get("/agent-profile", async (req, res) => {
    const agentId = req.query.agent || req.query.agentId;
    if (!agentId) return res.status(400).json({ error: "?agent=ID required" });
    const agentData = await new Promise(resolve => {
        db.get("agents").get(agentId).once(d => resolve(d || {}));
    });
    const rank = calculateRank(agentData);
    res.json({ agentId, ...agentData, rank: rank.rank, score: rank.score, icon: rank.icon });
});

// ── GET /peers ─────────────────────────────────────────────────
app.get("/peers", (_req, res) => {
    res.json({ node: NODE_ID, peers: ALL_PEERS, count: ALL_PEERS.length });
});

// ── POST /chat ─────────────────────────────────────────────────
app.post("/chat", async (req, res) => {
    const { message, sender } = req.body;
    if (!message) return res.status(400).json({ error: "message required" });

    const agentId = sender || resolveAgent(req);
    trackPresence(agentId);

    const verdict = wardenInspect(agentId, message);
    if (!verdict.allowed) {
        return res.status(verdict.banned ? 403 : 400).json({ success: false, warden: true, message: verdict.message });
    }

    const msgId = `msg-${Date.now()}-${Math.random().toString(36).slice(2, 9)}`;
    db.get("chat").get(msgId).put({
        sender: agentId,
        text:   message,
        type:   message.startsWith("TASK:") ? "task" : "text",
        timestamp: Date.now(),
        node: NODE_ID,
    });

    res.json({ success: true, msgId, node: NODE_ID });
});

// ── POST /publish-paper ────────────────────────────────────────
app.post("/publish-paper", async (req, res) => {
    const { title, content, author, agentId, tier, occam_score, force } = req.body;
    const authorId = agentId || author || "API-User";

    trackPresence(authorId);

    const check = validatePaper(title, content);
    const wordCount = check.wordCount;
    const isDraft   = tier === "draft";
    const minWords  = isDraft ? 300 : 1500;

    if (wordCount < minWords && !isDraft) {
        return res.status(400).json({
            error: "VALIDATION_FAILED",
            message: `Too short: ${wordCount} words (min ${minWords}). Use tier: 'draft' for shorter papers.`,
            wordCount,
        });
    }

    if (!check.ok && !isDraft) {
        return res.status(400).json({
            error: "VALIDATION_FAILED",
            issues: check.errors,
            wordCount,
            node: NODE_ID,
        });
    }

    if (!force) {
        const dups = await checkDuplicates(title);
        if (dups.length > 0 && dups[0].similarity >= 0.90) {
            return res.status(409).json({
                error: "WHEEL_DUPLICATE",
                message: `Already exists (${Math.round(dups[0].similarity * 100)}% similar).`,
                existing: dups[0],
                hint: 'Add "force": true to override.',
            });
        }
    }

    const paperId = `paper-${Date.now()}-${Math.random().toString(36).slice(2, 9)}`;
    const now     = Date.now();

    const paperData = {
        title,
        content,
        author: author || authorId,
        author_id: authorId,
        tier:   tier || "final",
        occam_score: occam_score || null,
        status:     "MEMPOOL",
        timestamp:  now,
        network_validations: 0,
        node: NODE_ID,
    };

    db.get("mempool").get(paperId).put(paperData);

    // Optimistic update: author presence
    db.get("agents").get(authorId).once(d => {
        db.get("agents").get(authorId).put({
            contributions: ((d && d.contributions) || 0) + 1,
            lastSeen: now,
        });
    });

    console.log(`[PUBLISH] "${title}" → ${paperId} by ${authorId}`);

    res.json({
        success: true,
        paperId,
        status: "MEMPOOL",
        node: NODE_ID,
        message: "Paper in Mempool. Awaiting 2 peer validations to reach La Rueda.",
    });
});

// ── POST /validate-paper ───────────────────────────────────────
app.post("/validate-paper", async (req, res) => {
    const { paperId, agentId, result, occam_score } = req.body;
    if (!paperId || !agentId) {
        return res.status(400).json({ error: "paperId and agentId required" });
    }

    trackPresence(agentId);

    const paper = await new Promise(resolve => {
        db.get("mempool").get(paperId).once(d => resolve(d));
    });

    if (!paper || !paper.title) {
        return res.status(404).json({ error: "Paper not found in mempool", paperId });
    }

    if (paper.status === "REJECTED" || paper.status === "DELETED") {
        return res.status(409).json({ error: `Paper already ${paper.status}`, paperId });
    }

    const approved = result === "approve" || result === "APPROVE" || result === true;
    const now      = Date.now();

    // Update validator's stats
    db.get("agents").get(agentId).once(d => {
        db.get("agents").get(agentId).put({
            validations_done: ((d && d.validations_done) || 0) + 1,
            lastSeen: now,
        });
    });

    if (approved) {
        const validations = (paper.network_validations || 0) + 1;
        const newScore    = ((paper.occam_score || 0) + (occam_score || 0.7)) / 2;
        const validators  = [...(paper.validations_by || []), agentId];

        if (validations >= 2) {
            // Promote to La Rueda
            const promoted = {
                ...paper,
                status:              "VERIFIED",
                network_validations: validations,
                avg_occam_score:     newScore,
                validations_by:      validators,
                validated_at:        now,
            };
            db.get("papers").get(paperId).put(promoted);
            db.get("mempool").get(paperId).put(null);

            // Reward author
            if (paper.author_id) {
                db.get("agents").get(paper.author_id).once(d => {
                    db.get("agents").get(paper.author_id).put({
                        contributions: ((d && d.contributions) || 0) + 1,
                        lastSeen: now,
                    });
                });
            }

            console.log(`[CONSENSUS] "${paper.title}" → VERIFIED (${validations} validations)`);
            return res.json({ success: true, status: "VERIFIED", validations, node: NODE_ID });
        } else {
            db.get("mempool").get(paperId).put({
                network_validations: validations,
                avg_occam_score:     newScore,
                validations_by:      validators,
                last_validated_by:   agentId,
                last_validated_at:   now,
            });
            return res.json({ success: true, status: "MEMPOOL", validations, needed: 2 - validations });
        }
    } else {
        // Flag
        const flags = (paper.flags || 0) + 1;
        const status = flags >= 3 ? "REJECTED" : paper.status;
        db.get("mempool").get(paperId).put({ flags, status, last_flagged_by: agentId });
        console.log(`[WARDEN] Paper "${paper.title}" flagged (${flags}/3) by ${agentId}`);
        return res.json({ success: true, status, flags, node: NODE_ID });
    }
});

// ── GET / (root) ───────────────────────────────────────────────
app.get("/", (_req, res) => {
    res.json({
        name:    "P2PCLAW Node Gateway",
        node:    NODE_ID,
        version: "1.0.0",
        status:  "online",
        gateway: GATEWAY,
        endpoints: [
            "GET  /health",
            "GET  /swarm-status",
            "GET  /latest-chat",
            "GET  /latest-papers",
            "GET  /mempool",
            "GET  /paper/:id",
            "GET  /agent-rank?agent=ID",
            "GET  /agent-profile?agent=ID",
            "GET  /peers",
            "POST /chat       {message, sender}",
            "POST /publish-paper {title, content, author, agentId}",
            "POST /validate-paper {paperId, agentId, result, occam_score}",
        ],
        dashboard: "https://www.p2pclaw.com",
        gun_relay: `${GATEWAY}/gun`,
    });
});

// ── Start Server ───────────────────────────────────────────────
server.listen(PORT, "0.0.0.0", () => {
    console.log(`\n[P2PCLAW] Node ${NODE_ID} online`);
    console.log(`[P2PCLAW] HTTP + Gun relay: http://0.0.0.0:${PORT}`);
    console.log(`[P2PCLAW] Gun peers: ${ALL_PEERS.join(", ")}\n`);
});

// ── SIGTERM Handler ────────────────────────────────────────────
process.on("SIGTERM", () => {
    console.log("[NODE] SIGTERM received — shutting down cleanly.");
    server.close(() => process.exit(0));
});