const http = require("http");
const fs = require("fs");
const path = require("path");
const XLSX = require("xlsx");

const PORT = process.env.PORT || 3000;
const DATA_FILE = path.join(__dirname, "data.json");
const EXCEL_FILE = path.join(__dirname, "Выгрузка исполнения бюджета закупок.xlsx");

function parseExcelData() {
  try {
    if (!fs.existsSync(EXCEL_FILE)) {
      console.log("Excel файл не найден, используем существующие данные");
      return null;
    }

    const workbook = XLSX.readFile(EXCEL_FILE);
    const sheetName = workbook.SheetNames[0];
    const worksheet = workbook.Sheets[sheetName];
    const rows = XLSX.utils.sheet_to_json(worksheet, { header: 1 });

    if (rows.length < 2) return [];

    const headers = rows[0].map(h => String(h || '').trim().toLowerCase());
    
    const findColumn = (names) => {
      for (const name of names) {
        const idx = headers.findIndex(h => h.includes(name.toLowerCase()));
        if (idx !== -1) return idx;
      }
      return -1;
    };

    const articleCodeIdx = findColumn(['код статьи', 'статья', 'код']);
    const serviceNameIdx = findColumn(['наименование', 'услуг', 'работ', 'название']);
    const departmentIdx = findColumn(['подраздел', 'центр', 'департамент', 'управление']);
    const budgetSumIdx = findColumn(['бюджет', 'план', 'сумма план']);
    const executedSumIdx = findColumn(['исполн', 'факт', 'оплачено']);
    const execPercentIdx = findColumn(['исполнение', '%', 'процент']);

    const data = [];
    for (let i = 1; i < rows.length; i++) {
      const row = rows[i];
      if (!row || row.length === 0) continue;

      const budgetSum = parseFloat(String(row[budgetSumIdx] || 0).replace(/\s/g, '')) || 0;
      const executedSum = parseFloat(String(row[executedSumIdx] || 0).replace(/\s/g, '')) || 0;
      let execPercent = 0;

      if (execPercentIdx !== -1 && row[execPercentIdx]) {
        execPercent = parseFloat(String(row[execPercentIdx]).replace('%', '').replace(/\s/g, '')) || 0;
      } else if (budgetSum > 0) {
        execPercent = (executedSum / budgetSum) * 100;
      }

      const item = {
        articleCode: String(row[articleCodeIdx] || '').trim(),
        serviceName: String(row[serviceNameIdx] || '').trim(),
        department: String(row[departmentIdx] || '').trim(),
        budgetSum: budgetSum,
        executedSum: executedSum,
        execPercent: Math.round(execPercent * 100) / 100
      };

      if (item.serviceName || item.articleCode) {
        data.push(item);
      }
    }

    console.log("Обработано строк:", data.length);
    return data;
  } catch (error) {
    console.error("Ошибка при чтении Excel:", error.message);
    return null;
  }
}

function ensureDataFile() {
  if (!fs.existsSync(DATA_FILE)) {
    const data = parseExcelData();
    if (data && data.length > 0) {
      fs.writeFileSync(DATA_FILE, JSON.stringify(data, null, 2));
      console.log("Создан data.json с", data.length, "записями");
    } else {
      fs.writeFileSync(DATA_FILE, JSON.stringify([], null, 2));
    }
  }
}

function body(req) {
  return new Promise((resolve) => {
    let s = "";
    req.on("data", (c) => (s += c));
    req.on("end", () => { 
      try { 
        resolve(JSON.parse(s || "{}")); 
      } catch (_) { 
        resolve({}); 
      } 
    });
  });
}

http.createServer(async (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(204);
    return res.end();
  }

  if (req.method === "GET" && req.url === "/api/data") {
    try {
      const data = JSON.parse(fs.readFileSync(DATA_FILE, "utf8"));
      res.writeHead(200, { "Content-Type": "application/json" });
      return res.end(JSON.stringify(data));
    } catch (error) {
      res.writeHead(500, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ error: error.message }));
    }
  }

  if (req.method === "POST" && req.url === "/api/reload") {
    try {
      const data = parseExcelData();
      if (data !== null) {
        fs.writeFileSync(DATA_FILE, JSON.stringify(data, null, 2));
        res.writeHead(200, { "Content-Type": "application/json" });
        return res.end(JSON.stringify({ ok: true, count: data.length }));
      } else {
        res.writeHead(400, { "Content-Type": "application/json" });
        return res.end(JSON.stringify({ error: "Не удалось прочитать Excel файл" }));
      }
    } catch (error) {
      res.writeHead(500, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ error: error.message }));
    }
  }

  let file = req.url === "/" ? "/index.html" : req.url.split("?")[0];
  const full = path.join(__dirname, file);
  
  if (full.startsWith(__dirname) && fs.existsSync(full) && fs.statSync(full).isFile()) {
    const ext = path.extname(full);
    const type = ext === ".css" ? "text/css" : ext === ".js" ? "application/javascript" : "text/html";
    res.writeHead(200, { "Content-Type": type + "; charset=utf-8" });
    return res.end(fs.readFileSync(full));
  }

  res.writeHead(404); 
  res.end("Not found");
}).listen(PORT, () => {
  ensureDataFile();
  console.log("Сервер запущен на порту " + PORT);
});