using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Cors;
using Microsoft.AspNetCore.Mvc;
using DotNext;

namespace server.Controllers;

/// <summary>
/// 实验控制器
/// </summary>
[ApiController]
[Route("api/[controller]")]
public class ExamController : ControllerBase
{
    private static NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();

    /// <summary>
    /// 实验信息类
    /// </summary>
    public class ExamInfo
    {
        /// <summary>
        /// 实验的唯一标识符
        /// </summary>
        public required string ID { get; set; }

        /// <summary>
        /// 实验文档内容（Markdown格式）
        /// </summary>
        public required string DocContent { get; set; }

        /// <summary>
        /// 实验创建时间
        /// </summary>
        public DateTime CreatedTime { get; set; }

        /// <summary>
        /// 实验最后更新时间
        /// </summary>
        public DateTime UpdatedTime { get; set; }
    }

    /// <summary>
    /// 实验简要信息类（用于列表显示）
    /// </summary>
    public class ExamSummary
    {
        /// <summary>
        /// 实验的唯一标识符
        /// </summary>
        public required string ID { get; set; }

        /// <summary>
        /// 实验创建时间
        /// </summary>
        public DateTime CreatedTime { get; set; }

        /// <summary>
        /// 实验最后更新时间
        /// </summary>
        public DateTime UpdatedTime { get; set; }

        /// <summary>
        /// 实验标题（从文档内容中提取）
        /// </summary>
        public string Title { get; set; } = "";
    }

    /// <summary>
    /// 扫描结果类
    /// </summary>
    public class ScanResult
    {
        /// <summary>
        /// 结果消息
        /// </summary>
        public required string Message { get; set; }

        /// <summary>
        /// 更新的实验数量
        /// </summary>
        public int UpdateCount { get; set; }
    }

    /// <summary>
    /// 获取所有实验列表
    /// </summary>
    /// <returns>实验列表</returns>
    [Authorize]
    [HttpGet("list")]
    [EnableCors("Users")]
    [ProducesResponseType(typeof(ExamSummary[]), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
    public IActionResult GetExamList()
    {
        try
        {
            using var db = new Database.AppDataConnection();
            var exams = db.GetAllExams();

            var examSummaries = exams.Select(exam => new ExamSummary
            {
                ID = exam.ID,
                CreatedTime = exam.CreatedTime,
                UpdatedTime = exam.UpdatedTime,
                Title = ExtractTitleFromMarkdown(exam.DocContent)
            }).ToArray();

            logger.Info($"成功获取实验列表，共 {examSummaries.Length} 个实验");
            return Ok(examSummaries);
        }
        catch (Exception ex)
        {
            logger.Error($"获取实验列表时出错: {ex.Message}");
            return StatusCode(StatusCodes.Status500InternalServerError, $"获取实验列表失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 根据实验ID获取实验详细信息
    /// </summary>
    /// <param name="examId">实验ID</param>
    /// <returns>实验详细信息</returns>
    [Authorize]
    [HttpGet("{examId}")]
    [EnableCors("Users")]
    [ProducesResponseType(typeof(ExamInfo), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status400BadRequest)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
    public IActionResult GetExam(string examId)
    {
        if (string.IsNullOrWhiteSpace(examId))
            return BadRequest("实验ID不能为空");

        try
        {
            using var db = new Database.AppDataConnection();
            var result = db.GetExamByID(examId);

            if (!result.IsSuccessful)
            {
                logger.Error($"获取实验时出错: {result.Error.Message}");
                return StatusCode(StatusCodes.Status500InternalServerError, $"获取实验失败: {result.Error.Message}");
            }

            if (!result.Value.HasValue)
            {
                logger.Warn($"实验不存在: {examId}");
                return NotFound($"实验 {examId} 不存在");
            }

            var exam = result.Value.Value;
            var examInfo = new ExamInfo
            {
                ID = exam.ID,
                DocContent = exam.DocContent,
                CreatedTime = exam.CreatedTime,
                UpdatedTime = exam.UpdatedTime
            };

            logger.Info($"成功获取实验信息: {examId}");
            return Ok(examInfo);
        }
        catch (Exception ex)
        {
            logger.Error($"获取实验 {examId} 时出错: {ex.Message}");
            return StatusCode(StatusCodes.Status500InternalServerError, $"获取实验失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 重新扫描实验文件夹并更新数据库
    /// </summary>
    /// <returns>更新结果</returns>
    [Authorize("Admin")]
    [HttpPost("scan")]
    [EnableCors("Users")]
    [ProducesResponseType(typeof(ScanResult), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
    [ProducesResponseType(StatusCodes.Status403Forbidden)]
    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
    public IActionResult ScanExams()
    {
        try
        {
            using var db = new Database.AppDataConnection();
            var examFolderPath = Path.Combine(Directory.GetCurrentDirectory(), "exam");
            var updateCount = db.ScanAndUpdateExams(examFolderPath);

            var result = new ScanResult
            {
                Message = $"扫描完成，更新了 {updateCount} 个实验",
                UpdateCount = updateCount
            };

            logger.Info($"手动扫描实验完成，更新了 {updateCount} 个实验");
            return Ok(result);
        }
        catch (Exception ex)
        {
            logger.Error($"扫描实验时出错: {ex.Message}");
            return StatusCode(StatusCodes.Status500InternalServerError, $"扫描实验失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 从 Markdown 内容中提取标题
    /// </summary>
    /// <param name="markdownContent">Markdown 内容</param>
    /// <returns>提取的标题</returns>
    private static string ExtractTitleFromMarkdown(string markdownContent)
    {
        if (string.IsNullOrEmpty(markdownContent))
            return "";

        var lines = markdownContent.Split('\n');
        foreach (var line in lines)
        {
            var trimmedLine = line.Trim();
            if (trimmedLine.StartsWith("# "))
            {
                return trimmedLine.Substring(2).Trim();
            }
        }

        return "";
    }
}