/**
 * 薪资解析工具
 * 统一处理职位薪资和期望薪资的解析逻辑
 */
class SalaryParser {
    /**
     * 解析薪资范围字符串
     * @param {string} salaryDesc - 薪资描述 (如 "15-20K", "8000-12000元")
     * @returns {{ min: number, max: number }} 薪资范围（单位：元）
     */
    static parse(salaryDesc) {
        if (!salaryDesc || typeof salaryDesc !== 'string') {
            return { min: 0, max: 0 };
        }

        // 尝试各种格式
        return this.parseK(salaryDesc)
            || this.parseYuan(salaryDesc)
            || this.parseMixed(salaryDesc)
            || { min: 0, max: 0 };
    }

    /**
     * 解析 K 格式薪资 (如 "15-20K", "8-12k")
     */
    static parseK(desc) {
        const kMatch = desc.match(/(\d+)[-~](\d+)[kK千]/);
        if (kMatch) {
            return {
                min: parseInt(kMatch[1]) * 1000,
                max: parseInt(kMatch[2]) * 1000
            };
        }
        return null;
    }

    /**
     * 解析元格式薪资 (如 "8000-12000元", "15000-20000")
     */
    static parseYuan(desc) {
        const yuanMatch = desc.match(/(\d+)[-~](\d+)元?/);
        if (yuanMatch) {
            return {
                min: parseInt(yuanMatch[1]),
                max: parseInt(yuanMatch[2])
            };
        }
        return null;
    }

    /**
     * 解析混合格式 (如 "8k-12000元")
     */
    static parseMixed(desc) {
        const mixedMatch = desc.match(/(\d+)[kK千][-~](\d+)元?/);
        if (mixedMatch) {
            return {
                min: parseInt(mixedMatch[1]) * 1000,
                max: parseInt(mixedMatch[2])
            };
        }
        return null;
    }

    /**
     * 检查职位薪资是否在期望范围内
     * @param {object} jobSalary - 职位薪资 { min, max }
     * @param {number} minExpected - 期望最低薪资
     * @param {number} maxExpected - 期望最高薪资
     */
    static isWithinRange(jobSalary, minExpected, maxExpected) {
        if (!jobSalary || jobSalary.min === 0) {
            return true; // 无法判断时默认通过
        }

        // 职位最高薪资 >= 期望最低薪资
        if (minExpected > 0 && jobSalary.max < minExpected) {
            return false;
        }

        // 职位最低薪资 <= 期望最高薪资
        if (maxExpected > 0 && jobSalary.min > maxExpected) {
            return false;
        }

        return true;
    }

    /**
     * 计算薪资匹配度（用于职位评分）
     * @param {object} jobSalary - 职位薪资
     * @param {object} expectedSalary - 期望薪资
     * @returns {number} 匹配度 0-1
     */
    static calculateMatch(jobSalary, expectedSalary) {
        if (!jobSalary || !expectedSalary || jobSalary.min === 0 || expectedSalary.min === 0) {
            return 0.5; // 无法判断时返回中性值
        }

        const jobAvg = (jobSalary.min + jobSalary.max) / 2;
        const expectedAvg = (expectedSalary.min + expectedSalary.max) / 2;

        const diff = Math.abs(jobAvg - expectedAvg);
        const range = (jobSalary.max - jobSalary.min + expectedSalary.max - expectedSalary.min) / 2;

        // 差距越小，匹配度越高
        return Math.max(0, 1 - diff / (range || 1));
    }

    /**
     * 格式化薪资显示
     * @param {object} salary - 薪资对象 { min, max }
     * @returns {string} 格式化字符串
     */
    static format(salary) {
        if (!salary || salary.min === 0) {
            return '面议';
        }

        const minK = (salary.min / 1000).toFixed(0);
        const maxK = (salary.max / 1000).toFixed(0);
        return `${minK}-${maxK}K`;
    }
}

module.exports = SalaryParser;