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

/**
 * @function ensurePathEndsWithSlash
 * @description 确保路径以斜杠结尾
 * @param {string} pathValue - 要处理的路径
 * @returns {string} 处理后的路径
 */
function ensurePathEndsWithSlash(pathValue) {
    if (!pathValue) return pathValue;
    return pathValue.endsWith('/') ? pathValue : pathValue + '/';
}

/**
 * @function validatePaths
 * @description 验证多个路径是否存在
 * @param {Object} paths - 要验证的路径对象
 * @returns {Object} 验证结果，包含每个路径的验证状态和错误信息
 */
async function validatePaths(paths) {
    const results = {};
    
    // 首先验证工作路径
    if (!paths.workPath) {
        results.workPath = {
            valid: false,
            error: '工作路径不能为空'
        };
        return results;
    }

    // 确保工作路径以斜杠结尾
    const workPath = ensurePathEndsWithSlash(paths.workPath);

    try {
        // 检查工作路径是否存在
        await fs.access(workPath);
        results.workPath = {
            valid: true,
            normalizedPath: workPath
        };
    } catch (error) {
        results.workPath = {
            valid: false,
            error: error.code === 'ENOENT' ? '工作路径不存在' : '工作路径访问错误'
        };
        return results;
    }

    // 验证模型路径和服务路径（相对于工作路径）
    const relativePaths = {
        modelsPath: paths.modelsPath,
        servicesPath: paths.servicesPath
    };

    for (const [key, pathValue] of Object.entries(relativePaths)) {
        if (!pathValue) {
            results[key] = {
                valid: false,
                error: '路径不能为空'
            };
            continue;
        }

        try {
            // 确保相对路径以斜杠结尾
            const normalizedPath = ensurePathEndsWithSlash(pathValue);
            // 拼接完整路径
            const fullPath = path.join(workPath, normalizedPath);
            // 检查路径是否存在
            await fs.access(fullPath);
            results[key] = {
                valid: true,
                normalizedPath: normalizedPath
            };
        } catch (error) {
            results[key] = {
                valid: false,
                error: error.code === 'ENOENT' ? '路径不存在' : '路径访问错误'
            };
        }
    }
    
    return results;
}

module.exports = {
    validatePaths,
    ensurePathEndsWithSlash
};