package com.example.demo.service;

import org.springframework.stereotype.Service;

import java.util.*;

/**
 * 统计分析服务。
 * <p>实现数据汇总、图表数据、自定义查询、报表导出及台账生成功能。</p>
 */
@Service
public class StatService {

    /**
     * 数据汇总。
     *
     * @requirement(name="数据汇总", id="SRS-F-03-001")
     * 按用户选择的维度和时间范围对业务数据进行聚合计算。
     */
    public Map<String, Object> summary(String dimension, String dateFrom, String dateTo) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("dimension", dimension != null ? dimension : "total");
        result.put("dateFrom", dateFrom != null ? dateFrom : "2026-01-01");
        result.put("dateTo", dateTo != null ? dateTo : "2026-12-31");
        result.put("totalCount", 3);
        result.put("approvedCount", 1);
        result.put("rejectedCount", 0);
        result.put("pendingCount", 1);
        result.put("draftCount", 1);
        return result;
    }

    /**
     * 图表数据。
     *
     * @requirement(name="图表展示", id="SRS-F-03-002")
     * 支持以柱状图、折线图、饼图等形式展示统计结果。
     */
    public Map<String, Object> chartData(String chartType, String dimension, String dateFrom, String dateTo) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("chartType", chartType != null ? chartType : "bar");
        result.put("dimension", dimension != null ? dimension : "businessType");
        List<Map<String, Object>> series = new ArrayList<>();
        Map<String, Object> s1 = new LinkedHashMap<>();
        s1.put("name", "请假");
        s1.put("value", 1);
        series.add(s1);
        Map<String, Object> s2 = new LinkedHashMap<>();
        s2.put("name", "报销");
        s2.put("value", 1);
        series.add(s2);
        Map<String, Object> s3 = new LinkedHashMap<>();
        s3.put("name", "采购");
        s3.put("value", 1);
        series.add(s3);
        result.put("series", series);
        return result;
    }

    /**
     * 自定义查询。
     *
     * @requirement(name="自定义查询", id="SRS-F-03-003")
     * 支持用户组合查询条件进行灵活的统计分析。
     */
    public Map<String, Object> customQuery(Map<String, String> conditions) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("conditions", conditions);
        result.put("matchedCount", 2);
        List<Map<String, Object>> records = new ArrayList<>();
        Map<String, Object> r1 = new LinkedHashMap<>();
        r1.put("businessNo", "BIZ20260001");
        r1.put("type", "leave");
        r1.put("status", "draft");
        records.add(r1);
        result.put("records", records);
        return result;
    }

    /**
     * 报表导出（模拟返回导出信息）。
     *
     * @requirement(name="报表导出", id="SRS-F-03-004")
     * 支持将统计结果以Excel和PDF格式导出为文件。
     */
    public Map<String, Object> exportReport(String format, String dateFrom, String dateTo) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("format", format != null ? format : "excel");
        result.put("fileUrl", "/download/report_" + System.currentTimeMillis() + "." + (format != null ? format : "xlsx"));
        result.put("fileSize", "15KB");
        result.put("generatedAt", java.time.LocalDateTime.now().toString().replace("T", " "));
        return result;
    }

    /**
     * 台账生成。
     *
     * @requirement(name="数据台账生成", id="SRS-F-03-005")
     * 按业务类型或时间段生成结构化的数据清单。
     */
    public Map<String, Object> generateLedger(String businessType, String dateFrom, String dateTo) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("businessType", businessType != null ? businessType : "all");
        result.put("dateFrom", dateFrom != null ? dateFrom : "2026-01-01");
        result.put("dateTo", dateTo != null ? dateTo : "2026-12-31");
        result.put("totalCount", 3);
        List<Map<String, Object>> items = new ArrayList<>();
        Map<String, Object> i1 = new LinkedHashMap<>();
        i1.put("businessNo", "BIZ20260001");
        i1.put("type", "请假");
        i1.put("applicant", "张三");
        i1.put("status", "草稿");
        items.add(i1);
        result.put("items", items);
        return result;
    }
}
