import XLSX from 'xlsx';
import { readFileSync, existsSync } from 'fs';
import Papa from 'papaparse';

const ADS_FILE = 'Ads Weekly.xlsx';
const DATA_FILE = 'dist/Amazon-Sell-Out-2023-2025.csv'; // Need to check if this exists locally or if I need to fetch it.

async function main() {
    console.log('--- AD SPEND BY PRODUCT LINE (UK, 2026) ---');

    // 1. Build Metadata Map (ASIN -> Line) from Sales Records
    const metaMap = new Map<string, string>();

    // Check local CSV if it exists, otherwise we might need to fetch it
    const dropboxUrl = "https://www.dropbox.com/scl/fi/b9zxn4z5i7sxwfakk5g5y/Amazon-Sell-Out-2023-2025.csv?rlkey=uoto6v0mm99py8nszy8ldtez8&st=pzn1zkrg&dl=1";
    console.log('Fetching Sales data to build ASIN-Line mapping...');
    const csvResponse = await fetch(dropboxUrl);
    const csvText = await csvResponse.text();

    console.log('Parsing CSV...');
    const results = Papa.parse(csvText, { header: true, skipEmptyLines: true });
    const rows = results.data as any[];

    if (rows.length > 0) {
        console.log('CSV Columns:', Object.keys(rows[0]));
    }

    rows.forEach(r => {
        const asin = String(rowValue(r, ['CUSTOMER REFERENCE', 'ASIN'])).trim().toUpperCase();
        const line = rowValue(r, ['PRODUCT Line', 'Line']) || 'Unassigned';
        if (asin && !metaMap.has(asin)) {
            metaMap.set(asin, line);
        }
    });
    console.log(`Built mapping for ${metaMap.size} unique ASINs.`);

    // Helper to get case-insensitive row value
    function rowValue(row: any, aliases: string[]): string {
        for (const a of aliases) {
            if (row[a]) return row[a];
            const lowerA = a.toLowerCase();
            const found = Object.keys(row).find(k => k.toLowerCase() === lowerA);
            if (found) return row[found];
        }
        return '';
    }

    // 2. Parse Ads Data
    if (!existsSync(ADS_FILE)) {
        console.error(`Error: ${ADS_FILE} not found.`);
        return;
    }

    const buf = readFileSync(ADS_FILE);
    const wb = XLSX.read(buf, { type: 'buffer' });

    const spendByLine = new Map<string, number>();
    let totalUkSpend = 0;
    let foundMatches: any[] = [];

    for (const sheetName of wb.SheetNames) {
        const ws = wb.Sheets[sheetName];
        const rows: any[] = XLSX.utils.sheet_to_json(ws, { defval: '' });

        rows.forEach((r: any) => {
            const countryRaw = String(r.Country || '').toUpperCase();
            const asin = String(r.ASIN || '').trim().toUpperCase();
            const cost = parseFloat(r.Cost) || 0;
            const line = metaMap.get(asin) || 'Unassigned';

            // Still track official UK 2026 total for the summary
            if (sheetName === '2026' && (countryRaw === 'UK' || countryRaw === 'GB' || countryRaw === 'AMAZON UK' || countryRaw === 'AMAZON GB')) {
                spendByLine.set(line, (spendByLine.get(line) || 0) + cost);
                totalUkSpend += cost;
            }

            // DEBUG: Find ALL "INKEE" records anywhere that might explain the 126
            if (line.toUpperCase() === 'INKEE' && cost > 0) {
                foundMatches.push({
                    Sheet: sheetName,
                    Country: countryRaw,
                    ASIN: asin,
                    Cost: cost,
                    Week: r.Week
                });
            }
        });
    }

    console.log('\n--- ALL INKEE AD RECORDS FOUND (ANY COUNTRY/YEAR) ---');
    console.table(foundMatches.slice(0, 50)); // Showing first 50
    if (foundMatches.length > 50) console.log(`... and ${foundMatches.length - 50} more records.`);

    const totalsByGroup = foundMatches.reduce((acc, curr) => {
        const key = `${curr.Sheet} | ${curr.Country}`;
        acc[key] = (acc[key] || 0) + curr.Cost;
        return acc;
    }, {});

    console.log('\nSummary of INKEE Spend by Sheet and Country:');
    console.table(totalsByGroup);

    // 3. Output results
    console.log('\nOfficial Results for Amazon UK (2026 YTD) based on sheet "2026":');
    const sortedLines = Array.from(spendByLine.entries())
        .sort((a, b) => b[1] - a[1]);

    console.log('--------------------------------------------------');
    console.log(`${'Product Line'.padEnd(30)} | ${'Ad Spend (£)'.padStart(15)}`);
    console.log('--------------------------------------------------');
    sortedLines.forEach(([line, spend]) => {
        console.log(`${line.padEnd(30)} | ${spend.toFixed(2).padStart(15)}`);
    });
    console.log('--------------------------------------------------');
    console.log(`${'TOTAL'.padEnd(30)} | ${totalUkSpend.toFixed(2).padStart(15)}`);
}

main().catch(console.error);