/**
 * server.js
 * Express API server (replaces api.php + proxy_check.php)
 * All Telegram features have been removed.
 * Token-based ext login has been removed — extension works without login.
 */

const express = require("express");
const cors = require("cors");
const crypto = require("crypto");
const path = require("path");
const https = require("https");
const http = require("http");
const fs = require("fs");
const Database = require("./database");
const gitSync = require("./git-sync");

// ─── Git sync: pull data from GitHub before starting ────────────
gitSync.initSync();

const app = express();
const PORT = process.env.PORT || 7860; // 7860 = HF Spaces default
const db = new Database(path.join(__dirname, "data"));

// Middleware
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Auto-migrate / sync hit counters on startup
db.migrateOldHitCounters();
db.autoSyncHitCounters();

// ─── Helpers ────────────────────────────────────────────────────

function apiResponse(res, success, data = {}, error = null, status = 200) {
  const response = { success, ...data };
  if (error) response.error = error;
  return res.status(status).json(response);
}

function getInput(req, key, defaultVal = null) {
  return req.query[key] || req.body?.[key] || defaultVal;
}

function sanitize(input, maxLen = 500) {
  if (!input) return "";
  input = String(input)
    .trim()
    .replace(/<[^>]*>/g, "");
  return input.length > maxLen ? input.substring(0, maxLen) : input;
}

function generateToken(length = 15) {
  const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  let token = "";
  for (let i = 0; i < length; i++) {
    token += chars[crypto.randomInt(0, chars.length)];
  }
  return token;
}

function generateLicenseKey(version) {
  const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  let random = "";
  for (let i = 0; i < 20; i++) {
    random += chars[crypto.randomInt(0, chars.length)];
  }
  return `USAGI-${version.replace(/\./g, "")}-${random}`;
}

function requireToken(req, res) {
  const token = getInput(req, "token");
  if (!token) return apiResponse(res, false, {}, "Token required", 400);
  if (token.length !== 15)
    return apiResponse(res, false, {}, "Invalid token format (must be 15 chars)", 400);

  const user = db.getUserByToken(token);
  if (!user) return apiResponse(res, false, {}, "Invalid token", 401);
  if (user.banned) return apiResponse(res, false, {}, "Account suspended", 403);

  return user;
}

// ─── Feedback helpers (concurrent-safe) ──────────────────────────

const feedbackFile = path.join(__dirname, "feedback.json");

function readFeedback() {
  try {
    if (!fs.existsSync(feedbackFile)) return {};
    return JSON.parse(fs.readFileSync(feedbackFile, "utf-8")) || {};
  } catch (e) {
    return {};
  }
}

function writeFeedback(data) {
  const tmp = feedbackFile + ".tmp." + process.pid;
  try {
    fs.writeFileSync(tmp, JSON.stringify(data, null, 2), "utf-8");
    fs.renameSync(tmp, feedbackFile);
    return true;
  } catch (e) {
    try {
      fs.unlinkSync(tmp);
    } catch (_) {}
    return false;
  }
}

// ─── Routes ─────────────────────────────────────────────────────

// GET/POST actions all route through ?action=...
app.all("/api", (req, res) => {
  const action = getInput(req, "action", "");

  switch (action) {
    case "":
    case "index":
      return apiResponse(res, true, {
        service: "UsagiAutoX API",
        version: "2.5",
        status: "online",
      });

    case "health":
      return apiResponse(res, true, {
        status: "healthy",
        timestamp: new Date().toISOString(),
        data_dir_writable: true,
      });

    // ── License key check ──
    case "check-key": {
      const key = getInput(req, "key");
      if (!key) return apiResponse(res, false, {}, "License key required", 400);

      const result = db.validateLicenseKey(key);
      const latestVersion = db.getSetting("latest_version") || "1.0.7";

      if (result.valid) {
        return apiResponse(res, true, {
          valid: true,
          version: result.version || "",
          latest_version: latestVersion,
          message: "License key is valid",
        });
      } else {
        return apiResponse(
          res,
          false,
          {
            valid: false,
            latest_version: latestVersion,
            message: "Invalid or expired license key.",
          },
          null,
          403,
        );
      }
    }

    // ── Token validation ──
    case "validate": {
      const token = getInput(req, "token");
      if (!token) return apiResponse(res, false, {}, "Token required", 400);
      if (token.length !== 15)
        return apiResponse(res, false, {}, "Token must be 15 characters", 400);

      const user = db.getUserByToken(token);
      if (!user) return apiResponse(res, false, {}, "Invalid token", 401);
      if (user.banned) return apiResponse(res, false, {}, "Account suspended", 403);

      db.updateUser(user.user_id, { last_active: new Date().toISOString() });
      const counts = db.getHitCounts(user.user_id);

      return apiResponse(res, true, {
        user_id: String(user.user_id),
        username: user.username || "",
        first_name: user.first_name || "",
        pfp_url: user.pfp_url || "",
        hits: counts.user_hits,
        attempts: user.attempts || 0,
        global_hits: counts.global_hits,
        user_hits: counts.user_hits,
      });
    }

    // ── Attempt ──
    case "attempt": {
      const user = requireToken(req, res);
      if (!user.user_id) return; // response already sent
      const newAttempts = db.incrementStat(user.user_id, "attempts");
      return apiResponse(res, true, {
        user_id: String(user.user_id),
        attempts: newAttempts,
        message: "Attempt recorded",
      });
    }

    // ── Hit ──
    case "hit": {
      const user = requireToken(req, res);
      if (!user.user_id) return;

      const fullCard = getInput(req, "full_card", "");
      let currency = getInput(req, "currency", "usd");
      if (!currency || currency === "null") currency = "usd";

      if (!fullCard || fullCard === "null" || fullCard.length < 13 || !fullCard.includes("|")) {
        return apiResponse(res, false, {}, `Invalid card data: ${fullCard || "empty"}`, 400);
      }

      const rawAmount = getInput(req, "amount", "0") || "0";
      const details = {
        full_card: sanitize(fullCard, 100),
        amount: sanitize(rawAmount, 20),
        currency: sanitize(currency, 10),
        merchant: sanitize(getInput(req, "merchant", "") || "", 100),
      };

      db.incrementStat(user.user_id, "hits");
      db.addHitRecord(user.user_id, details);
      const counts = db.getHitCounts(user.user_id);

      return apiResponse(res, true, {
        user_id: String(user.user_id),
        hits: counts.user_hits,
        global_hits: counts.global_hits,
        user_hits: counts.user_hits,
        message: "Hit recorded successfully",
      });
    }

    // ── User info ──
    case "user": {
      const userId = getInput(req, "user_id");
      if (!userId) return apiResponse(res, false, {}, "User ID required", 400);
      const user = db.getUser(userId);
      if (!user) return apiResponse(res, false, {}, "User not found", 404);
      return apiResponse(res, true, {
        user_id: String(user.user_id),
        username: user.username || "",
        pfp_url: user.pfp_url || "",
        hits: user.hits || 0,
        attempts: user.attempts || 0,
      });
    }

    // ── Stats ──
    case "stats": {
      const stats = db.getGlobalStats();
      return apiResponse(res, true, {
        total_users: stats.total_users,
        total_attempts: stats.total_attempts,
        total_hits: stats.total_hits,
      });
    }

    // ── Leaderboard ──
    case "leaderboard": {
      const limit = Math.max(1, Math.min(50, parseInt(getInput(req, "limit", "10")) || 10));
      const topUsers = db.getTopUsers(limit);
      const leaderboard = topUsers.map((u, i) => ({
        rank: i + 1,
        user_id: String(u.user_id),
        username: u.username || "",
        first_name: u.first_name || "",
        pfp_url: u.pfp_url || "",
        hits: u.hits || 0,
      }));

      const reqUserId = getInput(req, "user_id");
      const reqToken = getInput(req, "token");
      let resolvedUserId = reqUserId;

      if (reqToken && reqToken.length === 15) {
        const reqUser = db.getUserByToken(reqToken);
        if (reqUser) resolvedUserId = String(reqUser.user_id);
      }

      const response = { leaderboard };
      if (resolvedUserId) {
        const myRank = db.getUserRank(resolvedUserId);
        if (myRank) response.my_rank = myRank;
      }

      return apiResponse(res, true, response);
    }

    // ── Popup dashboard stats ──
    case "popup-stats": {
      const users = db.getAllUsers();
      const hits = db.getAllHits();
      const today = new Date().toISOString().slice(0, 10);
      const weekAgo = new Date(Date.now() - 7 * 86400000).toISOString().slice(0, 10);
      let hitsToday = 0,
        hitsWeek = 0;

      for (const h of hits) {
        const d = (h.timestamp || "").slice(0, 10);
        if (d === today) hitsToday++;
        if (d >= weekAgo) hitsWeek++;
      }

      return apiResponse(res, true, {
        total_users: users.length,
        total_hits: hits.length,
        hits_today: hitsToday,
        hits_week: hitsWeek,
      });
    }

    // ── Hit counts ──
    case "hit-counts": {
      const token = getInput(req, "token");
      let userId = getInput(req, "user_id");

      if (token && token.length === 15) {
        const user = db.getUserByToken(token);
        if (user && !user.banned) userId = String(user.user_id);
      }

      const counts = db.getHitCounts(userId || null);
      return apiResponse(res, true, {
        global_hits: counts.global_hits,
        user_hits: counts.user_hits,
      });
    }

    // ── User hits history ──
    case "user-hits": {
      const user = requireToken(req, res);
      if (!user.user_id) return;
      const limit = Math.max(1, Math.min(500, parseInt(getInput(req, "limit", "50")) || 50));
      const allUserHits = db.getUserHits(user.user_id, limit);
      const totalCount = db.getUserHitsTotal(user.user_id);
      return apiResponse(res, true, {
        user_id: String(user.user_id),
        hits: allUserHits,
        total_count: totalCount,
      });
    }

    // ── Create user ──
    case "create-user": {
      const userId = getInput(req, "user_id");
      const username = sanitize(getInput(req, "username", "") || "", 100);
      const firstName = sanitize(getInput(req, "first_name", "") || "", 100);
      const pfpUrl = sanitize(getInput(req, "pfp_url", "") || "", 500);
      if (!userId) return apiResponse(res, false, {}, "User ID required", 400);

      const existing = db.getUser(userId);
      if (existing) {
        const updates = {};
        if (pfpUrl) updates.pfp_url = pfpUrl;
        if (username) updates.username = username;
        if (firstName) updates.first_name = firstName;
        if (Object.keys(updates).length) db.updateUser(userId, updates);

        return apiResponse(res, true, {
          user_id: String(existing.user_id),
          message: "User already exists",
          token: existing.token || null,
        });
      }

      const user = db.createUser({
        user_id: userId,
        username,
        first_name: firstName,
        pfp_url: pfpUrl,
      });
      return apiResponse(res, true, {
        user_id: String(user.user_id),
        message: "User created",
      });
    }

    // ── Generate token ──
    case "generate-token": {
      const userId = getInput(req, "user_id");
      const forceNew = getInput(req, "force_new", "false") === "true";
      if (!userId) return apiResponse(res, false, {}, "User ID required", 400);

      const user = db.getUser(userId);
      if (!user) return apiResponse(res, false, {}, "User not found", 404);

      if (forceNew || !user.token) {
        let token = generateToken();
        let retries = 10;
        while (db.isTokenExists(token) && retries-- > 0) {
          token = generateToken();
        }
        db.updateUser(userId, { token });
        return apiResponse(res, true, {
          user_id: String(userId),
          token,
          message: forceNew ? "Token regenerated" : "New token generated",
        });
      }

      return apiResponse(res, true, {
        user_id: String(userId),
        token: user.token,
        message: "Existing token returned",
      });
    }

    // ── BIN library ──
    case "bin-library": {
      const bins = db.getBinLibrary();
      const userId = getInput(req, "user_id");
      const allFeedback = readFeedback();
      let needsUpdate = false;

      for (const bin of bins) {
        if (!bin.id) {
          bin.id = "bin_" + Date.now() + "_" + Math.random().toString(36).substr(2, 5);
          needsUpdate = true;
        }
        const fb = allFeedback[bin.id];
        bin.likes = fb ? fb.likes || 0 : 0;
        bin.dislikes = fb ? fb.dislikes || 0 : 0;
        bin.user_vote = (userId && fb?.voters?.[userId]?.vote) || null;
      }

      if (needsUpdate) db.saveBinLibrary(bins);
      return apiResponse(res, true, { bins });
    }

    // ── BIN feedback ──
    case "bin-feedback": {
      const binId = getInput(req, "id");
      const vote = getInput(req, "vote");
      const userId = getInput(req, "user_id");
      const userName = sanitize(getInput(req, "user_name", "") || "", 100);

      if (!binId || !vote || !userId) {
        return apiResponse(res, false, {}, "ID, vote, and user_id required", 400);
      }
      if (!["like", "dislike"].includes(vote)) {
        return apiResponse(res, false, {}, 'Vote must be "like" or "dislike"', 400);
      }

      const feedback = readFeedback();
      if (!feedback[binId]) feedback[binId] = { likes: 0, dislikes: 0, voters: {} };
      if (!feedback[binId].voters) feedback[binId].voters = {};

      const previousVote = feedback[binId].voters[userId]?.vote || null;

      if (previousVote === vote) {
        return apiResponse(res, true, {
          message: "Already voted",
          likes: feedback[binId].likes,
          dislikes: feedback[binId].dislikes,
          user_vote: vote,
          id: binId,
        });
      }

      // Undo previous vote
      if (previousVote === "like") feedback[binId].likes = Math.max(0, feedback[binId].likes - 1);
      else if (previousVote === "dislike")
        feedback[binId].dislikes = Math.max(0, feedback[binId].dislikes - 1);

      // Apply new vote
      if (vote === "like") feedback[binId].likes++;
      else if (vote === "dislike") feedback[binId].dislikes++;

      feedback[binId].voters[userId] = {
        vote,
        name: userName || "Unknown",
        time: new Date().toISOString(),
      };

      writeFeedback(feedback);

      return apiResponse(res, true, {
        message: "Feedback recorded",
        likes: feedback[binId].likes,
        dislikes: feedback[binId].dislikes,
        user_vote: vote,
        id: binId,
        changed_from: previousVote,
      });
    }

    // ═══════════════════ Admin endpoints ═══════════════════

    case "admin-genkey": {
      const version = getInput(req, "version");
      if (!version) return apiResponse(res, false, {}, "Version required", 400);
      const key = generateLicenseKey(version);
      db.createLicenseKey(key, version, true);
      return apiResponse(res, true, { key, version, active: true });
    }

    case "admin-listkeys":
      return apiResponse(res, true, { keys: db.getAllLicenseKeys() });

    case "admin-revokekey": {
      const key = getInput(req, "key");
      if (!key) return apiResponse(res, false, {}, "Key required", 400);
      return db.revokeLicenseKey(key)
        ? apiResponse(res, true, { message: "Key revoked", key })
        : apiResponse(res, false, {}, "Key not found", 404);
    }

    case "admin-activatekey": {
      const key = getInput(req, "key");
      if (!key) return apiResponse(res, false, {}, "Key required", 400);
      return db.activateLicenseKey(key)
        ? apiResponse(res, true, { message: "Key activated", key })
        : apiResponse(res, false, {}, "Key not found", 404);
    }

    case "admin-deletekey": {
      const key = getInput(req, "key");
      if (!key) return apiResponse(res, false, {}, "Key required", 400);
      return db.deleteLicenseKey(key)
        ? apiResponse(res, true, { message: "Key deleted", key })
        : apiResponse(res, false, {}, "Key not found", 404);
    }

    case "admin-setsetting": {
      const name = getInput(req, "name");
      const value = getInput(req, "value");
      if (!name) return apiResponse(res, false, {}, "Setting name required", 400);
      db.setSetting(name, value);
      return apiResponse(res, true, { message: "Setting saved", name, value });
    }

    case "admin-getsettings":
      return apiResponse(res, true, { settings: db.getAllSettings() });

    case "admin-cleartokens": {
      const count = db.clearAllTokensAndStats();
      return apiResponse(res, true, { message: "Tokens and stats cleared", users_reset: count });
    }

    case "admin-cleanfakehits": {
      const deleted = db.cleanFakeHits();
      return apiResponse(res, true, { message: "Fake hits cleaned", deleted });
    }

    case "admin-resetdb": {
      if (getInput(req, "confirm") !== "yes") {
        return apiResponse(res, false, {}, "Add confirm=yes to reset database", 400);
      }
      const result = db.resetDatabase();
      return apiResponse(res, true, { message: "Database reset complete", deleted: result });
    }

    case "admin-banuser": {
      const userId = getInput(req, "user_id");
      if (!userId) return apiResponse(res, false, {}, "User ID required", 400);
      return db.updateUser(userId, { banned: true })
        ? apiResponse(res, true, { message: "User banned", user_id: userId })
        : apiResponse(res, false, {}, "User not found", 404);
    }

    case "admin-unbanuser": {
      const userId = getInput(req, "user_id");
      if (!userId) return apiResponse(res, false, {}, "User ID required", 400);
      return db.updateUser(userId, { banned: false })
        ? apiResponse(res, true, { message: "User unbanned", user_id: userId })
        : apiResponse(res, false, {}, "User not found", 404);
    }

    case "admin-allusers":
      return apiResponse(res, true, { users: db.getAllUsers() });

    case "admin-stats": {
      const users = db.getAllUsers();
      const keys = db.getAllLicenseKeys();
      const hits = db.getAllHits();
      const bins = db.getBinLibrary();

      let activeKeys = 0,
        revokedKeys = 0;
      for (const k of keys) {
        k.active !== false ? activeKeys++ : revokedKeys++;
      }

      const today = new Date().toISOString().slice(0, 10);
      const weekAgo = new Date(Date.now() - 7 * 86400000).toISOString().slice(0, 10);
      let hitsToday = 0,
        hitsWeek = 0;
      const activeToday = new Set();

      for (const h of hits) {
        const d = (h.timestamp || "").slice(0, 10);
        if (d === today) hitsToday++;
        if (d >= weekAgo) hitsWeek++;
      }
      for (const u of users) {
        if ((u.last_active || "").slice(0, 10) === today) {
          activeToday.add(u.user_id);
        }
      }

      return apiResponse(res, true, {
        stats: {
          total_users: users.length,
          active_today: activeToday.size,
          total_keys: keys.length,
          active_keys: activeKeys,
          revoked_keys: revokedKeys,
          total_hits: hits.length,
          hits_today: hitsToday,
          hits_week: hitsWeek,
          total_bins: bins.length,
        },
      });
    }

    case "admin-allhits":
      return apiResponse(res, true, { hits: db.getAllHits() });

    case "admin-addbin": {
      const site = sanitize(getInput(req, "site", "Unknown") || "Unknown", 200);
      const bin = getInput(req, "bin");
      const credit = sanitize(getInput(req, "credit", "Unknown") || "Unknown", 200);
      if (!bin) return apiResponse(res, false, {}, "BIN is required", 400);

      const newBin = {
        id: "bin_" + Date.now(),
        site,
        bin: sanitize(bin, 20),
        credit,
        likes: 0,
        dislikes: 0,
        added_at: new Date().toISOString(),
      };

      return db.addBinToLibrary(newBin)
        ? apiResponse(res, true, { message: "BIN added to library", bin: newBin })
        : apiResponse(res, false, {}, "Failed to add BIN", 500);
    }

    case "admin-removebin": {
      const binId = getInput(req, "bin_id");
      const binNumber = getInput(req, "bin");
      if (!binId && !binNumber)
        return apiResponse(res, false, {}, "BIN ID or BIN number required", 400);

      const removed = db.removeBinFromLibrary(binId, binNumber);
      return removed
        ? apiResponse(res, true, {
            message: "BIN removed from library",
            bin: removed.bin || "N/A",
            site: removed.site || "N/A",
            id: removed.id || binId,
          })
        : apiResponse(res, false, {}, "BIN not found", 404);
    }

    case "admin-rebuild-hits": {
      const result = db.rebuildHitCounters();
      return apiResponse(res, true, {
        message: "Hit counters rebuilt from users.json",
        total_hits: result.total_hits,
        users_with_hits: result.users_with_hits,
      });
    }

    case "admin-clearbin":
      return db.clearBinLibrary()
        ? apiResponse(res, true, { message: "BIN library cleared" })
        : apiResponse(res, false, {}, "Failed to clear library", 500);

    case "debug": {
      const users = db.getAllUsers();
      const hits = db.getAllHits();
      return apiResponse(res, true, {
        users_count: users.length,
        hits_count: hits.length,
        data_dir: path.join(__dirname, "data"),
        node_version: process.version,
        users,
        recent_hits: hits.slice(-5),
      });
    }

    default:
      return apiResponse(res, false, {}, `Unknown action: ${sanitize(action, 50)}`, 400);
  }
});

// ─── Proxy check endpoint (replaces proxy_check.php) ────────────

app.all("/proxy_check", async (req, res) => {
  let rawProxy = "";

  if (req.method === "POST") {
    rawProxy = req.body?.proxy || "";
  } else {
    rawProxy = req.query.proxy || "";
  }

  if (!rawProxy) {
    return res.json({ success: false, status: "fail", error: "No proxy provided" });
  }

  rawProxy = rawProxy.trim();

  try {
    const checkUrl = `https://proxyshare.com/api/check-proxy?proxy=${encodeURIComponent(rawProxy)}`;
    const response = await fetch(checkUrl, {
      headers: { Accept: "application/json" },
      signal: AbortSignal.timeout(50000),
    });

    if (!response.ok) {
      return res.json({
        success: false,
        status: "fail",
        error: `Upstream HTTP ${response.status}`,
      });
    }

    const data = await response.json();
    return res.json(data);
  } catch (e) {
    return res.json({ success: false, status: "fail", error: e.message || "Proxy check failed" });
  }
});

// ─── Start server ───────────────────────────────────────────────

app.listen(PORT, "0.0.0.0", () => {
  console.log(`✅ UsagiAutoX API running on http://0.0.0.0:${PORT}`);
  console.log(`   API endpoint:    http://localhost:${PORT}/api?action=health`);
  console.log(`   Proxy check:     http://localhost:${PORT}/proxy_check?proxy=...`);
  console.log(
    `   Git sync:        ${gitSync.isConfigured() ? "ENABLED" : "DISABLED (set GITHUB_TOKEN + GITHUB_REPO)"}`,
  );
});

// ─── Graceful shutdown: push pending data before exit ───────────
async function gracefulShutdown(signal) {
  console.log(`\n🛑 ${signal} received, syncing data...`);
  try {
    await gitSync.forceSync();
    console.log("✅ Data synced, exiting.");
  } catch (e) {
    console.error("⚠️  Final sync failed:", e.message);
  }
  process.exit(0);
}

process.on("SIGTERM", () => gracefulShutdown("SIGTERM"));
process.on("SIGINT", () => gracefulShutdown("SIGINT"));