const fs = require('fs');
const path = require('path');

const csvFolderPath = './csv';

// 引用符内の改行を保持したままCSVをレコード単位で分割
function splitCsvRecords(content) {
    const records = [];
    let current = '';
    let inQuotes = false;

    for (let i = 0; i < content.length; i += 1) {
        const char = content[i];
        const next = content[i + 1];

        if (char === '"') {
            if (inQuotes && next === '"') {
                current += '""';
                i += 1;
            } else {
                inQuotes = !inQuotes;
                current += char;
            }
            continue;
        }

        if (!inQuotes && (char === '\n' || char === '\r')) {
            records.push(current);
            current = '';

            // CRLFは1つの改行として扱う
            if (char === '\r' && next === '\n') {
                i += 1;
            }
            continue;
        }

        current += char;
    }

    if (current.length > 0) {
        records.push(current);
    }

    // 末尾空行由来の空レコードを除外
    while (records.length > 0 && records[records.length - 1].trim() === '') {
        records.pop();
    }

    return records;
}

// ダブルクォーテーションを含むCSV1行を解析
function parseCsvLine(line) {
    const fields = [];
    let current = '';
    let inQuotes = false;

    for (let i = 0; i < line.length; i += 1) {
        const char = line[i];

        if (char === '"') {
            // "" はエスケープされたダブルクォーテーション
            if (inQuotes && line[i + 1] === '"') {
                current += '"';
                i += 1;
            } else {
                inQuotes = !inQuotes;
            }
            continue;
        }

        if (char === ',' && !inQuotes) {
            fields.push(current);
            current = '';
            continue;
        }

        current += char;
    }

    fields.push(current);
    return fields;
}

// フィールドをCSV形式へ再構築
function toCsvLine(fields) {
    return fields
        .map(field => `"${String(field).replace(/"/g, '""')}"`)
        .join(',');
}

// CSVファイルを読み込む関数
function processCSVFiles() {
    const files = fs.readdirSync(csvFolderPath).filter(file => file.endsWith('.csv'));

    files.forEach(file => {
        const filePath = path.join(csvFolderPath, file);
        const content = fs.readFileSync(filePath, 'utf-8');
        const eol = content.includes('\r\n') ? '\r\n' : '\n';
        const records = splitCsvRecords(content);

        // ヘッダ行のみの場合
        if (records.length === 1) {
            if (file.startsWith('✕')) {
                return;
            }

            const newFileName = `✕${file}`;
            const newFilePath = path.join(csvFolderPath, newFileName);
            fs.renameSync(filePath, newFilePath);
            console.log(`Renamed: ${file} → ${newFileName}`);
            return;
        }

        // データが1行以上ある場合
        let modified = false;
        const updatedRecords = records.map((record, index) => {
            if (index === 0) return record; // ヘッダ行はスキップ

            const fields = parseCsvLine(record);
            const firstField = fields[0];

            // "（P）"と"(P)"のすべてのパターンを削除
            const patterns = ['（P）', '(P)', '（P)', '(P）'];
            let updatedField = firstField;

            patterns.forEach(pattern => {
                if (updatedField.endsWith(pattern)) {
                    updatedField = updatedField.slice(0, -pattern.length);
                    modified = true;
                }
            });

            fields[0] = updatedField;
            return toCsvLine(fields);
        });

        // 修正があった場合、ファイルを上書き
        if (modified) {
            fs.writeFileSync(filePath, updatedRecords.join(eol), 'utf-8');
            console.log(`Modified: ${file}`);
        }
    });
}

processCSVFiles();