const { Scenes, Markup } = require('telegraf');
const Product = require('../../models/Product');
const ExcelJS = require('exceljs');
const axios = require('axios');

const inventoryScene = new Scenes.WizardScene(
    'admin_inventory',

    // Step 1: Menu
    async (ctx) => {
        // Inject i18n
        if (!ctx.i18n) {
            const User = require('../../models/User');
            const locales = require('../../locales');
            const user = await User.findOne({ id: ctx.from.id });
            const lang = (user && user.language) ? user.language : 'uz';
            ctx.i18n = locales[lang] || locales.uz;
        }

        const i18n = ctx.i18n;
        const text = i18n.admin.inv_title;
        const buttons = [
            [Markup.button.callback(i18n.admin.inv_mass_price, "mass_price_update")],
            [Markup.button.callback(i18n.admin.inv_excel, "excel_import")],
            [Markup.button.callback(i18n.admin.back, "back_dashboard")]
        ];

        if (ctx.callbackQuery) {
            await ctx.editMessageText(text, { parse_mode: 'Markdown', ...Markup.inlineKeyboard(buttons) });
        } else {
            await ctx.replyWithMarkdown(text, Markup.inlineKeyboard(buttons));
        }
        return ctx.wizard.next();
    },

    // Step 2: Handle Choice
    async (ctx) => {
        // Ensure i18n
        if (!ctx.i18n) {
            const locales = require('../../locales');
            ctx.i18n = locales.uz; // Fallback
        }
        const i18n = ctx.i18n;

        if (!ctx.callbackQuery && !ctx.message) return;

        const txt = ctx.message ? ctx.message.text : '';
        if (txt === '/start' || txt === i18n.admin.btn_reject || txt === '❌ Bekor qilish') return ctx.scene.leave();

        if (ctx.callbackQuery) {
            const data = ctx.callbackQuery.data;

            if (data === 'back_dashboard') {
                await ctx.scene.leave();
                const adminController = require('../../controllers/adminController');
                // Re-fetch user logic inside controller usually handles i18n, but here we call it directly.
                // adminController uses ctx.i18n, so it's fine.
                return adminController.showDashboard(ctx);
            }

            if (data === 'mass_price_update') {
                await ctx.reply(i18n.admin.inv_price_prompt, { parse_mode: 'Markdown', ...Markup.keyboard([[i18n.admin.btn_reject]]).resize() });
                ctx.wizard.state.action = 'mass_price';
                return ctx.wizard.next();
            }

            if (data === 'excel_import') {
                await ctx.reply(i18n.admin.inv_excel_prompt, Markup.keyboard([[i18n.admin.btn_reject]]).resize());
                ctx.wizard.state.action = 'excel_import';
                return ctx.wizard.next();
            }
        }
    },

    // Step 3: Execution
    async (ctx) => {
        // Ensure i18n
        if (!ctx.i18n) {
            const locales = require('../../locales');
            ctx.i18n = locales.uz;
        }
        const i18n = ctx.i18n;

        const txt = ctx.message ? ctx.message.text : '';
        if (txt === i18n.admin.btn_reject || txt === '❌ Bekor qilish') {
            await ctx.reply(i18n.admin.back || "Bekor qilindi.", Markup.removeKeyboard());
            await ctx.scene.leave();
            const adminController = require('../../controllers/adminController');
            return adminController.showDashboard(ctx);
        }

        // --- Mass Price Update Logic ---
        if (ctx.wizard.state.action === 'mass_price') {
            const percent = parseInt(txt);
            if (isNaN(percent) || percent === 0) {
                await ctx.reply(i18n.admin.error_num || "Error");
                return;
            }

            await ctx.reply(i18n.admin.broadcast_sending || "⏳...");
            const products = await Product.find({});
            let count = 0;

            for (let p of products) {
                try {
                    if (!p.id || !p.name) continue; // Skip invalid

                    const change = (p.price * percent) / 100;
                    p.price = Math.round(p.price + change);
                    await p.save();
                    count++;
                } catch (e) {
                    console.error("Update error:", e.message);
                }
            }

            await ctx.reply(i18n.admin.inv_updated.replace('{count}', count), { parse_mode: 'Markdown', ...Markup.removeKeyboard() });
            return ctx.scene.leave();
        }

        // --- Excel Import Logic ---
        if (ctx.wizard.state.action === 'excel_import') {
            if (!ctx.message.document) {
                await ctx.reply(i18n.admin.error || "Error");
                return;
            }

            const doc = ctx.message.document;
            if (!doc.file_name.endsWith('.xlsx')) {
                await ctx.reply("Only .xlsx");
                return;
            }

            await ctx.reply(i18n.admin.broadcast_sending || "⏳...");

            try {
                const fileLink = await ctx.telegram.getFileLink(doc.file_id);
                const response = await axios({
                    url: fileLink.href,
                    method: 'GET',
                    responseType: 'arraybuffer'
                });

                const workbook = new ExcelJS.Workbook();
                await workbook.xlsx.load(response.data);
                const worksheet = workbook.getWorksheet(1); // First sheet

                let imported = 0;
                let updated = 0;

                // Iterate rows (skip header)
                worksheet.eachRow(async (row, rowNumber) => {
                    if (rowNumber === 1) return; // Header

                    const id = row.getCell(1).value;
                    const name = row.getCell(2).value;
                    const price = row.getCell(3).value;
                    const category = row.getCell(4).value; // logic: text or id? let's assume raw text/id
                    const quantity = row.getCell(5).value;
                    const description = row.getCell(6).value;

                    if (id && name && price) {
                        const existing = await Product.findOne({ id: id });
                        if (existing) {
                            existing.name = name;
                            existing.price = price;
                            existing.category = category;
                            existing.quantity = quantity || 0;
                            existing.description = description || "";
                            await existing.save();
                            updated++;
                        } else {
                            const newProd = new Product({
                                id: id,
                                name: name,
                                price: price,
                                category: category,
                                quantity: quantity || 0,
                                description: description || ""
                            });
                            await newProd.save();
                            imported++;
                        }
                    }
                });

                await ctx.reply(`${i18n.admin.inv_import_success}\n🆕: ~${imported}\n🔄: ~${updated}`, { parse_mode: 'Markdown', ...Markup.removeKeyboard() });

                return ctx.scene.leave();

            } catch (err) {
                console.error(err);
                await ctx.reply(i18n.admin.error);
                return ctx.scene.leave();
            }
        }
    }
);

module.exports = inventoryScene;