const http = require("http");
const fs = require("fs");
const path = require("path");
const formidable = require("formidable");
const docx = require("docx");

const PORT = process.env.PORT || 3000;
const DATA = path.join(__dirname, "data.json");
const UPLOADS = path.join(__dirname, "uploads");
const OUTPUTS = path.join(__dirname, "outputs");

if (!fs.existsSync(UPLOADS)) fs.mkdirSync(UPLOADS);
if (!fs.existsSync(OUTPUTS)) fs.mkdirSync(OUTPUTS);

function readData() {
  try { return JSON.parse(fs.readFileSync(DATA, "utf8")); } catch (_) { return { inputData: null, suppliers: [], offers: [], checks: { c1: false, c2: false, c3: false }, files: [], emails: [] }; }
}
function writeData(data) {
  fs.writeFileSync(DATA, JSON.stringify(data, 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({}); } });
  });
}

function generateDocx(data) {
  const d = data;
  const prices = d.offers.map(o => Number(o.price));
  const min = prices.length ? Math.min(...prices) : 0;
  const avg = prices.length ? Math.round(prices.reduce((a,b) => a+b, 0) / prices.length) : 0;
  const minOffer = d.offers.find(o => Number(o.price) === min);
  const minSupplier = minOffer ? d.suppliers.find(x => x.id === minOffer.supplierId) : null;

  const doc = new docx.Document({
    sections: [{
      properties: {},
      children: [
        new docx.Paragraph({
          text: "МАРКЕТИНГОВОЕ ЗАКЛЮЧЕНИЕ",
          heading: docx.HeadingLevel.HEADING_1,
          alignment: docx.AlignmentType.CENTER,
          spacing: { after: 400 }
        }),
        new docx.Paragraph({
          text: "Утверждено",
          alignment: docx.AlignmentType.RIGHT,
          spacing: { after: 200 }
        }),
        new docx.Paragraph({
          text: "_______________",
          spacing: { after: 100 }
        }),
        new docx.Paragraph({
          text: '«___» __________ 2026г.',
          spacing: { after: 400 }
        }),

        new docx.Paragraph({
          text: "1. Входные данные",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        new docx.Paragraph({ text: "Код ЕНС ТРУ: " + (d.inputData?.ensCode || "—") }),
        new docx.Paragraph({ text: "Объем: " + (d.inputData?.volume || "—") }),
        new docx.Paragraph({ text: "Место поставки: " + (d.inputData?.deliveryPlace || "—") }),
        new docx.Paragraph({ text: "Техническая спецификация: " + (d.inputData?.techSpec || "—") }),

        new docx.Paragraph({
          text: "2. Список поставщиков",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        ...d.suppliers.map(s => new docx.Paragraph({
          text: `${s.name} (${s.status}, ${s.resident}) - ${s.contacts || "—"}`
        })),

        new docx.Paragraph({
          text: "3. Ценовые предложения",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        new docx.Table({
          width: { size: 100, type: docx.WidthType.PERCENTAGE },
          rows: [
            new docx.TableRow({
              children: [
                new docx.TableCell({ children: [new docx.Paragraph("Поставщик")] }),
                new docx.TableCell({ children: [new docx.Paragraph("№ запроса")] }),
                new docx.TableCell({ children: [new docx.Paragraph("Цена (тенге)")] }),
                new docx.TableCell({ children: [new docx.Paragraph("Дата")] })
              ]
            }),
            ...d.offers.map(o => {
              const s = d.suppliers.find(x => x.id === o.supplierId);
              return new docx.TableRow({
                children: [
                  new docx.TableCell({ children: [new docx.Paragraph(s ? s.name : "—")] }),
                  new docx.TableCell({ children: [new docx.Paragraph(o.requestNumber || "—")] }),
                  new docx.TableCell({ children: [new docx.Paragraph(Number(o.price).toLocaleString())] }),
                  new docx.TableCell({ children: [new docx.Paragraph(o.date || "—")] })
                ]
              });
            })
          ]
        }),

        new docx.Paragraph({
          text: "4. Проверка по ст. 31",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        new docx.Paragraph({ text: "☐ Поставщик НЕ в реестре недобросовестных: " + (d.checks.c1 ? "✓" : "☐") }),
        new docx.Paragraph({ text: "☐ НЕ в перечне терроризма/экстремизма: " + (d.checks.c2 ? "✓" : "☐") }),
        new docx.Paragraph({ text: "☐ НЕ из офшорной зоны: " + (d.checks.c3 ? "✓" : "☐") }),

        new docx.Paragraph({
          text: "5. Анализ цен",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        new docx.Paragraph({ text: "Количество предложений: " + d.offers.length }),
        new docx.Paragraph({ text: "Минимальная цена: " + min.toLocaleString() + " тенге" }),
        new docx.Paragraph({ text: "Максимальная цена: " + (Math.max(...prices) || 0).toLocaleString() + " тенге" }),
        new docx.Paragraph({ text: "Средняя цена: " + avg.toLocaleString() + " тенге" }),
        minSupplier ? new docx.Paragraph({ text: "Лучшее предложение: " + minSupplier.name + " - " + min.toLocaleString() + " тенге", shading: { fill: "d4edda" } }) : null,

        new docx.Paragraph({
          text: "6. Заключение",
          heading: docx.HeadingLevel.HEADING_2,
          spacing: { before: 200, after: 200 }
        }),
        new docx.Paragraph({
          text: "На основании цен потенциальных поставщиков/производителей определены маркетинговые цены без учета НДС (КП представлены)."
        }),
        minSupplier ? new docx.Paragraph({
          text: "РЕКОМЕНДАЦИЯ: " + minSupplier.name + " (" + minSupplier.status.toLowerCase() + ", " + minSupplier.resident.toLowerCase() + ") по цене " + min.toLocaleString() + " тенге.",
          spacing: { after: 200 }
        }) : null,

        new docx.Paragraph({ text: "Исполнитель: __________________ / _________________", spacing: { before: 400 } }),
        new docx.Paragraph({ text: "Инициатор потребности: __________________ / _________________", spacing: { before: 200 } }),
        new docx.Paragraph({ text: "Утверждено: __________________ / _________________", spacing: { before: 400, after: 200 } }),
        new docx.Paragraph({ text: '«___» __________ 2026г.', spacing: { after: 200 } })
      ].filter(Boolean)
    }]
  });

  return docx.Packer.toBuffer(doc);
}

http.createServer(async (req, res) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader("Access-Control-Allow-Methods", "GET, POST, DELETE, OPTIONS");
  res.setHeader("Access-Control-Allow-Headers", "Content-Type");
  
  if (req.method === "OPTIONS") {
    res.writeHead(200);
    return res.end();
  }

  if (req.method === "GET" && req.url === "/api/data") {
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify(readData()));
  }
  
  if (req.method === "GET" && req.url === "/api/files") {
    const data = readData();
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify(data.files || []));
  }

  if (req.method === "GET" && req.url === "/api/emails") {
    const data = readData();
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify(data.emails || []));
  }
  
  if (req.method === "POST" && req.url === "/api/upload") {
    const form = formidable({ uploadDir: UPLOADS, keepExtensions: true });
    form.parse(req, async (err, fields, files) => {
      if (err) {
        res.writeHead(500, { "Content-Type": "application/json" });
        return res.end(JSON.stringify({ error: err.message }));
      }
      const data = readData();
      const uploaded = [];
      if (files.file && Array.isArray(files.file)) {
        for (const f of files.file) {
          const fileName = Date.now() + "_" + path.basename(f.filepath);
          const newPath = path.join(UPLOADS, fileName);
          fs.renameSync(f.filepath, newPath);
          const fileRec = {
            id: Date.now() + Math.random(),
            name: f.originalFilename || fileName,
            path: "/api/files/" + fileName,
            section: fields.section ? fields.section[0] : "other",
            size: f.size,
            date: new Date().toISOString()
          };
          data.files.push(fileRec);
          uploaded.push(fileRec);
        }
      }
      writeData(data);
      res.writeHead(200, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ ok: true, files: uploaded }));
    });
    return;
  }
  
  if (req.method === "GET" && req.url.startsWith("/api/files/")) {
    const fileName = req.url.split("/")[3];
    const filePath = path.join(UPLOADS, fileName);
    if (fs.existsSync(filePath)) {
      const ext = path.extname(fileName).toLowerCase();
      const mime = ext === ".pdf" ? "application/pdf" : ext === ".docx" ? "application/vnd.openxmlformats-officedocument.wordprocessingml.document" : ext === ".xlsx" ? "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" : "application/octet-stream";
      res.writeHead(200, { "Content-Type": mime, "Content-Disposition": "attachment; filename=\"" + fileName + "\"" });
      return res.end(fs.readFileSync(filePath));
    }
    res.writeHead(404); res.end("File not found");
    return;
  }

  if (req.method === "GET" && req.url.startsWith("/api/outputs/")) {
    const fileName = req.url.split("/")[3];
    const filePath = path.join(OUTPUTS, fileName);
    if (fs.existsSync(filePath)) {
      res.writeHead(200, { "Content-Type": "application/vnd.openxmlformats-officedocument.wordprocessingml.document", "Content-Disposition": "attachment; filename=\"" + fileName + "\"" });
      return res.end(fs.readFileSync(filePath));
    }
    res.writeHead(404); res.end("File not found");
    return;
  }
  
  if (req.method === "DELETE" && req.url.startsWith("/api/files/")) {
    const fileName = req.url.split("/")[3];
    const data = readData();
    const fileRec = data.files.find(f => f.path.endsWith(fileName));
    if (fileRec) {
      const filePath = path.join(UPLOADS, fileName);
      if (fs.existsSync(filePath)) fs.unlinkSync(filePath);
      data.files = data.files.filter(f => f.path !== fileRec.path);
      writeData(data);
    }
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }

  if (req.method === "POST" && req.url === "/api/generate-docx") {
    try {
      const data = readData();
      const buffer = await generateDocx(data);
      const fileName = "MAC_" + (data.inputData?.ensCode?.replace(/[^a-zA-Z0-9]/g, "") || "otchet") + "_" + Date.now() + ".docx";
      const filePath = path.join(OUTPUTS, fileName);
      fs.writeFileSync(filePath, buffer);
      
      const fileRec = {
        id: Date.now(),
        name: fileName.replace(/_\d+\.docx$/, ".docx"),
        path: "/api/outputs/" + fileName,
        section: "Выходные документы",
        size: buffer.length,
        date: new Date().toISOString()
      };
      data.files.push(fileRec);
      writeData(data);
      
      res.writeHead(200, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ ok: true, file: fileRec }));
    } catch (e) {
      console.error("DOCX error:", e);
      res.writeHead(500, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ error: e.message }));
    }
  }

  if (req.method === "POST" && req.url === "/api/send-emails") {
    try {
      const d = await body(req);
      const data = readData();
      const inputData = data.inputData || {};
      
      const emails = [];
      for (const supplier of data.suppliers) {
        const emailData = {
          id: Date.now() + Math.random(),
          to: supplier.contacts || "",
          subject: "Запрос коммерческого предложения: " + (inputData.ensCode || "ТРУ"),
          body: `Уважаемые партнёры!\n\nПросим предоставить коммерческое предложение на поставку:\n\n` +
                `Код ЕНС: ${inputData.ensCode || "—"}\n` +
                `Объем: ${inputData.volume || "—"}\n` +
                `Место поставки: ${inputData.deliveryPlace || "—"}\n` +
                `Техническая спецификация: ${inputData.techSpec || "—"}\n\n` +
                `Просим ответить до: ${d.deadline || "укажите срок"}\n\n` +
                `С уважением,\nОтдел закупок`,
          supplierName: supplier.name,
          date: new Date().toISOString(),
          status: "Отправлено (симуляция)"
        };
        data.emails.push(emailData);
        emails.push(emailData);
      }
      writeData(data);
      
      res.writeHead(200, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ ok: true, count: emails.length, emails }));
    } catch (e) {
      res.writeHead(500, { "Content-Type": "application/json" });
      return res.end(JSON.stringify({ error: e.message }));
    }
  }
  
  if (req.method === "POST" && req.url === "/api/inputData") {
    const d = await body(req);
    const data = readData();
    data.inputData = d;
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/suppliers") {
    const s = await body(req);
    const data = readData();
    data.suppliers.push({ id: Date.now(), ...s });
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/offers") {
    const o = await body(req);
    const data = readData();
    data.offers.push({ id: Date.now(), ...o });
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/checks") {
    const c = await body(req);
    const data = readData();
    data.checks = c;
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "DELETE" && req.url.startsWith("/api/suppliers/")) {
    const id = parseInt(req.url.split("/")[3]);
    const data = readData();
    data.suppliers = data.suppliers.filter(s => s.id !== id);
    data.offers = data.offers.filter(o => o.supplierId !== id);
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "DELETE" && req.url.startsWith("/api/offers/")) {
    const id = parseInt(req.url.split("/")[3]);
    const data = readData();
    data.offers = data.offers.filter(o => o.id !== id);
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  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, () => console.log("Сервер запущен на порту " + PORT));