using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using YD_Event.Application.Event.Dtos;
using YD_Event.Core.Entities;
using YD_Event.Core.Enum;
using MiniExcelLibs;
using SqlSugar;

namespace YD_Event.Application.Event;

/// <summary>
/// 成绩与证书管理
/// </summary>
public class EventScoreService : BaseService<EventResult>, ITransient
{
    private readonly ISqlSugarRepository<EventRegistrationPerson> _personRepository;
    private readonly ISqlSugarRepository<EventResult> _resultRepository;
    private readonly ISqlSugarRepository<EventCertificate> _certificateRepository;
    private readonly ISqlSugarRepository<EventRegistration> _registrationRepository;
    private readonly IIdGenerator _idGenerator;
    private readonly ILogger<EventScoreService> _logger;

    public EventScoreService(
        ISqlSugarRepository<EventRegistrationPerson> personRepository,
        ISqlSugarRepository<EventResult> resultRepository,
        ISqlSugarRepository<EventCertificate> certificateRepository,
        ISqlSugarRepository<EventRegistration> registrationRepository,
        IIdGenerator idGenerator,
        ILogger<EventScoreService> logger) : base(resultRepository)
    {
        _personRepository = personRepository;
        _resultRepository = resultRepository;
        _certificateRepository = certificateRepository;
        _registrationRepository = registrationRepository;
        _idGenerator = idGenerator;
        _logger = logger;
    }

    /// <summary>
    /// 运动员成绩列表
    /// </summary>
    [DisplayName("运动员成绩列表")]
    public async Task<PageResult<ScoreListOutput>> PageAthlete(ScoreQueryInput input)
    {
        return await _personRepository.AsQueryable()
            .LeftJoin<EventRegistration>((p, r) => p.RegistrationId == r.Id)
            .LeftJoin<EventResult>((p, r, res) => p.Id == res.RegistrationPersonId)
            .LeftJoin<EventCertificate>((p, r, res, c) => res.Id == c.ResultId)
            .Where((p, r, res, c) => r.EventId == input.EventId && (p.PersonType == PersonType.Athlete || p.PersonType == PersonType.User)) 
            .WhereIF(input.ProjectId.HasValue, p => p.ProjectId == input.ProjectId)
            .WhereIF(!string.IsNullOrWhiteSpace(input.GroupName), p => p.GroupName == input.GroupName)
            .WhereIF(!string.IsNullOrWhiteSpace(input.Name), p => p.Name.Contains(input.Name))
            .WhereIF(!string.IsNullOrWhiteSpace(input.UnitName), (p, r) => r.TeamName.Contains(input.UnitName))
            .WhereIF(input.Gender.HasValue, p => p.Gender == input.Gender.Value)
            .Select((p, r, res, c) => new ScoreListOutput
            {
                Id = p.Id,
                Name = p.Name,
                UnitName = r.TeamName,
                Gender = p.Gender.ToString(),
                Score = res.Score,
                Rank = res.Rank,
                ResultId = res.Id,
                CertificateId = c.Id
            })
            .ToPagedListAsync(input);
    }

    /// <summary>
    /// 教练/领队列表
    /// </summary>
    [DisplayName("教练领队列表")]
    public async Task<PageResult<CoachLeaderListOutput>> PageCoachLeader(CoachLeaderQueryInput input)
    {
        return await _personRepository.AsQueryable()
            .LeftJoin<EventCertificate>((p, c) => p.Id == c.ParticipationRecordId)
            .InnerJoin<EventRegistration>((p, c, r) => p.RegistrationId == r.Id)
            .Where((p, c, r) => r.EventId == input.EventId && p.PersonType == input.PersonType)
            .WhereIF(!string.IsNullOrWhiteSpace(input.Name), p => p.Name.Contains(input.Name))
            .WhereIF(!string.IsNullOrWhiteSpace(input.Mobile), p => p.Phone.Contains(input.Mobile))
            .WhereIF(input.Gender.HasValue, p => p.Gender == input.Gender.Value)
            .Select((p, c) => new CoachLeaderListOutput
            {
                Id = p.Id,
                Name = p.Name,
                Age = p.Age,
                Gender = p.Gender.ToString(),
                IdCardNumber = p.IdCard,
                Mobile = p.Phone,
                CertificateId = c.Id
            })
            .ToPagedListAsync(input);
    }

    /// <summary>
    /// 导入成绩（性能优化版）
    /// </summary>
    /// <remarks>
    /// 性能优化策略：
    /// 1. 批量预加载所有人员数据到内存
    /// 2. 使用字典建立索引，避免循环内数据库查询
    /// 3. 批量收集需要插入/更新的记录
    /// 4. 最后一次性执行批量操作
    /// 性能指标：导入10000条成绩数据时，响应时间 < 30秒，内存占用 < 512MB
    /// </remarks>
    [UnitOfWork]
    [DisplayName("导入成绩")]
    public async Task ImportScore(long eventId, IFormFile file)
    {
        _logger.LogInformation("开始导入成绩：赛事ID={EventId}", eventId);
        var startTime = DateTime.Now;

        using var stream = file.OpenReadStream();
        var rows = stream.Query<ScoreImportDto>().ToList();
        _logger.LogInformation("解析Excel完成，共 {RowCount} 条记录", rows.Count);

        if (!rows.Any())
        {
            _logger.LogWarning("Excel文件中没有数据");
            return;
        }

        // 步骤1：批量预加载该赛事的所有人员数据
        var allPersons = await _personRepository.AsQueryable()
            .InnerJoin<EventRegistration>((p, r) => p.RegistrationId == r.Id)
            .Where((p, r) => r.EventId == eventId)
            .Select((p, r) => new 
            { 
                p.Id, 
                p.Name, 
                p.ProjectName, 
                p.GroupName, 
                p.RegistrationId, 
                p.ProjectId 
            })
            .ToListAsync();

        _logger.LogInformation("预加载人员数据完成，共 {PersonCount} 人", allPersons.Count);

        // 步骤2：使用字典建立人员索引（Name_ProjectName_GroupName -> Person）
        var personDict = allPersons
            .GroupBy(p => $"{p.Name}_{p.ProjectName}_{p.GroupName}")
            .ToDictionary(g => g.Key, g => g.First());

        // 步骤3：预加载该赛事的所有成绩记录
        var personIds = allPersons.Select(p => p.Id).ToList();
        var existingResults = await _resultRepository.GetListAsync(x => 
            x.EventId == eventId && personIds.Contains(x.RegistrationPersonId));

        var resultDict = existingResults.ToDictionary(r => r.RegistrationPersonId);

        // 步骤4：批量处理数据，收集需要插入/更新的记录
        var resultsToInsert = new List<EventResult>();
        var resultsToUpdate = new List<EventResult>();
        var now = DateTime.Now;
        var skipCount = 0;

        foreach(var row in rows)
        {
            // 使用内存字典查找，避免数据库查询
            var key = $"{row.Name}_{row.ProjectName}_{row.GroupName}";
            if (!personDict.TryGetValue(key, out var person))
            {
                skipCount++;
                continue;
            }

            if (resultDict.TryGetValue(person.Id, out var existingResult))
            {
                // 更新现有记录
                existingResult.Score = row.Score;
                existingResult.Rank = row.Rank;
                existingResult.Remark = row.RankText;
                existingResult.UpdatedTime = now;
                resultsToUpdate.Add(existingResult);
            }
            else
            {
                // 插入新记录
                var newResult = new EventResult
                {
                    Id = _idGenerator.NewLong(),
                    EventId = eventId,
                    RegistrationPersonId = person.Id,
                    RegistrationId = person.RegistrationId,
                    ProjectId = person.ProjectId,
                    ParticipantName = person.Name,
                    GroupName = person.GroupName,
                    Score = row.Score,
                    Rank = row.Rank,
                    Remark = row.RankText,
                    CreatedTime = now,
                    UpdatedTime = now
                };
                resultsToInsert.Add(newResult);
            }
        }

        _logger.LogInformation("数据处理完成：新增 {InsertCount} 条，更新 {UpdateCount} 条，跳过 {SkipCount} 条", 
            resultsToInsert.Count, resultsToUpdate.Count, skipCount);

        // 步骤5：批量操作数据库
        if (resultsToInsert.Any())
        {
            await _resultRepository.InsertRangeAsync(resultsToInsert);
            _logger.LogInformation("批量插入成绩记录完成，共 {Count} 条", resultsToInsert.Count);
        }

        if (resultsToUpdate.Any())
        {
            await _resultRepository.UpdateRangeAsync(resultsToUpdate);
            _logger.LogInformation("批量更新成绩记录完成，共 {Count} 条", resultsToUpdate.Count);
        }

        var duration = (DateTime.Now - startTime).TotalSeconds;
        _logger.LogInformation("导入成绩完成：赛事ID={EventId}，总耗时={Duration}秒", eventId, duration);
    }

    /// <summary>
    /// 发放证书
    /// </summary>
    [UnitOfWork]
    [DisplayName("发放证书")]
    public async Task IssueCertificate(IssueCertificateInput input)
    {
        foreach (var personId in input.PersonIds)
        {
            var person = await _personRepository.GetByIdAsync(personId);
            if (person == null) continue;

            if (person.PersonType == PersonType.Athlete || person.PersonType == PersonType.User)
            {
                var result = await _resultRepository.GetFirstAsync(x => x.RegistrationPersonId == person.Id);
                if (result == null) continue; 
                
                var cert = await _certificateRepository.GetFirstAsync(x => x.ResultId == result.Id);
                if (cert == null)
                {
                    cert = new EventCertificate
                    {
                        Id = _idGenerator.NewLong(),
                        EventId = input.EventId,
                        ResultId = result.Id,
                        RegistrationId = person.RegistrationId,
                        ParticipationRecordId = person.Id,
                        ParticipantName = person.Name,
                        GroupName = person.GroupName,
                        CertificateStatus = 1,
                        GeneratedTime = DateTime.Now,
                        CertificateNo = $"C{DateTime.Now:yyyyMMdd}{person.Id}",
                        CreatedTime = DateTime.Now
                    };
                    await _certificateRepository.InsertAsync(cert);
                }
            }
            else
            {
                var cert = await _certificateRepository.GetFirstAsync(x => x.ParticipationRecordId == person.Id);
                if (cert == null)
                {
                    cert = new EventCertificate
                    {
                        Id = _idGenerator.NewLong(),
                        EventId = input.EventId,
                        RegistrationId = person.RegistrationId,
                        ParticipationRecordId = person.Id,
                        ParticipantName = person.Name,
                        GroupName = person.GroupName,
                        CertificateStatus = 1,
                        GeneratedTime = DateTime.Now,
                        CertificateNo = $"CC{DateTime.Now:yyyyMMdd}{person.Id}",
                        CreatedTime = DateTime.Now
                    };
                    await _certificateRepository.InsertAsync(cert);
                }
            }
        }
    }
    
    /// <summary>
    /// 查看证书接口
    /// </summary>
    /// <param name="id">报名人员ID (EventRegistrationPerson的Id)</param>
    /// <returns>证书详情</returns>
    [DisplayName("查看证书")]
    [HttpGet("/api/EventScore/GetCertificateDetail/{id}")]
    public async Task<IActionResult> GetCertificateDetail([FromRoute] long id)
    {
        if (id <= 0)
        {
            return new BadRequestObjectResult(new { message = "无效的 ID" });
        }

        var personExists = await _personRepository.IsAnyAsync(x => x.Id == id);
        if (!personExists)
        {
            return new NotFoundObjectResult(new { message = "人员记录不存在" });
        }

        var cert = await _certificateRepository.GetFirstAsync(x => x.ParticipationRecordId == id);
        if (cert == null)
        {
            return new NotFoundObjectResult(new { message = "未找到对应的证书信息" });
        }

        if (string.IsNullOrWhiteSpace(cert.CertificateUrl))
        {
            return new NoContentResult();
        }

        return new JsonResult(new { url = cert.CertificateUrl });
    }

    /// <summary>
    /// 下载模板
    /// </summary>
    [DisplayName("下载模板")]
    [HttpGet]
    public IActionResult DownloadTemplate()
    {
        // 动态生成空数据及正确列名、样式的Excel模板
        var headers = new string[] { 
            "赛事地址", 
            "项目", 
            "组别", 
            "姓名", 
            "联系方式", 
            "单位", 
            "成绩", 
            "名次", 
            "名次 "
        };

        // 创建一个包含动态表头的列表，MiniExcel可以通过字典或匿名对象集合来生成带指定列名的Excel
        var value = new List<Dictionary<string, object>>
        {
            // 插入一行空数据以确保生成正确的表头
            headers.ToDictionary(h => h, h => (object)null)
        };

        using var memoryStream = new MemoryStream();
        // MiniExcel 保存，使用默认样式。如果需要复杂的背景色和边框（如图片中的浅绿色表头），
        // MiniExcel 目前不支持高级样式导出，因此这里我们使用 OpenXml 直接操作或基础导出。
        // 但由于需求要求保持代码清晰并尽量匹配原图，这里先用 MiniExcel 导出带中文表头的文件。
        // 为了实现完全一致的浅绿色样式，最好结合 EPPlus 或 ClosedXML。
        // 考虑到项目中可能没有引入 EPPlus，使用 MiniExcel 的基础导出，并辅以说明。
        memoryStream.SaveAs(value);

        return new FileContentResult(memoryStream.ToArray(), "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet") 
        { 
            FileDownloadName = "模板.xlsx" 
        };
    }

    /// <summary>
    /// 导出证书
    /// </summary>
    [DisplayName("导出证书")]
    public async Task<string> ExportCertificate(ScoreQueryInput input)
    {
        var list = await _certificateRepository.AsQueryable()
            .LeftJoin<EventResult>((c, r) => c.ResultId == r.Id)
            .LeftJoin<EventRegistration>((c, r, reg) => c.RegistrationId == reg.Id)
            .LeftJoin<YD_Event.Core.Entities.Project>((c, r, reg, p) => c.ProjectId == p.Id)
            .Where((c, r, reg, p) => c.EventId == input.EventId)
            .WhereIF(input.ProjectId.HasValue, (c, r, reg, p) => c.ProjectId == input.ProjectId)
            .WhereIF(!string.IsNullOrWhiteSpace(input.GroupName), (c, r, reg, p) => c.GroupName == input.GroupName)
            .WhereIF(!string.IsNullOrWhiteSpace(input.Name), (c, r, reg, p) => c.ParticipantName.Contains(input.Name))
            .Select((c, r, reg, p) => new CertificateExportDto
            {
                CertificateNo = c.CertificateNo,
                ParticipantName = c.ParticipantName,
                ProjectName = p.Name,
                GroupName = c.GroupName,
                UnitName = reg.TeamName,
                Score = r.Score,
                Rank = r.Rank,
                CertificateType = c.CertificateType == 1 ? "冠军证书" :
                                  c.CertificateType == 2 ? "亚军证书" :
                                  c.CertificateType == 3 ? "季军证书" :
                                  c.CertificateType == 4 ? "优胜证书" : "参与证书",
                IssuedTime = c.IssuedTime
            })
            .ToListAsync();

        using var stream = new MemoryStream();
        stream.SaveAs(list);
        return Convert.ToBase64String(stream.ToArray());
    }
}