import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';
import { dirname } from 'path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

/**
 * Vite 插件：构建时直接读取 CSV，替换代码中的 t('xxx') 为翻译文本
 * 无需生成任何中间文件，直接从 CSV 读取并替换
 * @param {object} options - 插件选项
 * @param {string} options.locale - 目标语言代码，从 vite.config.ts 传递
 */
function vitePluginTranslate(options = {}) {
	let translations = {};
	let locale = options.locale || 'en';
	
	return {
		name: 'vite-plugin-translate',
		enforce: 'pre', // 在 Vue 插件之前执行，处理原始模板
		configResolved(config) {
			// 直接读取 CSV 翻译文件（与后端共享同一数据源）
			if (locale && locale !== 'en') {
				const csvPath = path.resolve(__dirname, `../jcloud/translations/${locale}.csv`);
				if (fs.existsSync(csvPath)) {
					translations = parseCSV(csvPath);
					console.log(`[translate] Loaded ${Object.keys(translations).length} translations from ${csvPath}`);
				} else {
					console.warn(`[translate] CSV file not found: ${csvPath}, translations will not be replaced`);
				}
			}
		},
		transform(code, id) {
			// 只处理 .vue, .js, .ts 文件
			if (!/\.(vue|js|ts|jsx|tsx)$/.test(id)) {
				return null;
			}
			
			// 如果是英文，不替换
			if (locale === 'en') {
				return null;
			}
			
			// 如果翻译为空，警告但不阻止（可能 CSV 文件不存在，使用原文）
			if (Object.keys(translations).length === 0) {
				console.warn(`[translate] No translations loaded for locale: ${locale}, skipping replacement`);
				return null;
			}
			
			let replaced = code;
			const isVueFile = id.endsWith('.vue');
			
			if (isVueFile) {
				// 分离 <template> 和 <script> 部分，分别处理
				replaced = replaced.replace(
					/(<template[^>]*>)([\s\S]*?)(<\/template>)/gi,
					(templateMatch, openTag, templateContent, closeTag) => {
						// 在模板中替换 {{ $t('xxx') }} 为静态文本
						const replacedContent = templateContent.replace(
							/\{\{\s*\$t\((['"])([^'"]+)\1\)\s*\}\}/g,
							(match, quote, key) => {
								const translation = translations[key];
								if (translation) {
									return translation;
								}
								return match;
							}
						);
						return openTag + replacedContent + closeTag;
					}
				);
				
				// 替换 <script> 中的 this.$t('xxx') 为 this.$t('翻译')
				replaced = replaced.replace(
					/(<script[^>]*>)([\s\S]*?)(<\/script>)/gi,
					(scriptMatch, openTag, scriptContent, closeTag) => {
						// 在脚本中替换 $t('xxx') 为 $t('翻译')
						const replacedContent = scriptContent.replace(
							/\$t\((['"])([^'"]+)\1\)/g,
							(match, quote, key) => {
								const translation = translations[key];
								if (translation) {
									const escaped = translation
										.replace(/\\/g, '\\\\')
										.replace(/'/g, "\\'")
										.replace(/"/g, '\\"');
									return `$t(${quote}${escaped}${quote})`;
								}
								return match;
							}
						);
						return openTag + replacedContent + closeTag;
					}
				);
			} else {
				// 非 Vue 文件：替换 t('xxx') 为 '翻译'
				replaced = replaced.replace(
					/\bt\((['"])([^'"]+)\1\)/g,
					(match, quote, key) => {
						const translation = translations[key];
						if (translation) {
							const escaped = translation
								.replace(/\\/g, '\\\\')
								.replace(/'/g, "\\'")
								.replace(/"/g, '\\"');
							return quote + escaped + quote;
						}
						return match;
					}
				);
			}
			
			if (replaced !== code) {
				return {
					code: replaced,
					map: null
				};
			}
			
			return null;
		}
	};
}

/**
 * 解析 CSV 文件
 */
function parseCSV(csvPath) {
	if (!fs.existsSync(csvPath)) {
		return {};
	}
	
	const content = fs.readFileSync(csvPath, 'utf-8');
	const lines = content.split('\n');
	const translations = {};
	
	for (const line of lines) {
		const trimmed = line.trim();
		if (!trimmed || trimmed.startsWith('#')) continue;
		
		const parts = [];
		let current = '';
		let inQuotes = false;
		
		for (let i = 0; i < trimmed.length; i++) {
			const char = trimmed[i];
			if (char === '"') {
				inQuotes = !inQuotes;
			} else if (char === ',' && !inQuotes) {
				parts.push(current);
				current = '';
			} else {
				current += char;
			}
		}
		parts.push(current);
		
		if (parts.length >= 2 && parts[0] && parts[1]) {
			const key = parts[0].trim();
			const translation = parts[1].trim();
			const context = parts[2] ? parts[2].trim() : '';
			
			if (context) {
				translations[`${key}:${context}`] = translation;
			} else {
				translations[key] = translation;
			}
		}
	}
	
	return translations;
}

/**
 * HTML 转义函数
 */
function escapeHtml(text) {
	return text
		.replace(/&/g, '&amp;')
		.replace(/</g, '&lt;')
		.replace(/>/g, '&gt;')
		.replace(/"/g, '&quot;')
		.replace(/'/g, '&#39;');
}

export default vitePluginTranslate;