using System.Text;
using Microsoft.Extensions.Logging;

namespace ConsoleApp2.Services;

public class ErrorRecorder
{
    private readonly string _outputDir = "./ErrorRecords";
    private readonly ILogger _logger;
    private readonly Dictionary<string, int> _logIndex = new();

    /// <summary>
    /// 当次执行标识
    /// </summary>
    private static readonly string UID = DateTime.Now.ToString("yyyy-MM-dd HH-mm-ss");

    public ErrorRecorder(ILogger<ErrorRecorder> logger)
    {
        _logger = logger;
        var dir = Path.Combine(_outputDir, UID);
        if (!Directory.Exists(dir))
        {
            Directory.CreateDirectory(dir);
        }
    }

    /// <summary>
    /// 记录已知表名发生错误的SQL
    /// </summary>
    /// <param name="commandText"></param>
    /// <param name="tableName"></param>
    /// <param name="exception"></param>
    public async Task LogErrorSqlAsync(string commandText, string tableName, Exception exception)
    {
        if (!_logIndex.TryGetValue(tableName, out var idx))
        {
            idx = 0;
            _logIndex.Add(tableName, idx);
        }
        var filePath = Path.Combine(_outputDir, UID, $"{tableName}-{idx}.errlog");
            
        if (File.Exists(filePath) && new FileInfo(filePath).Length > 10 * 1024 * 1024)
        {
            ++idx;
            _logIndex[tableName] = idx;
            filePath = Path.Combine(_outputDir, UID, $"{tableName}-{idx}.errlog");
        }
        var content = $"""
                      /* [{DateTime.Now:yyyy-MM-dd HH:mm:ss}]
                       * Error occurred when export table '{tableName}':
                       * {exception.Message}
                       */
                      
                      {commandText}


                      """;
        await File.AppendAllTextAsync(filePath, content, Encoding.UTF8);
    }

    /// <summary>
    /// 记录发生错误的SQL
    /// </summary>
    /// <param name="commandText"></param>
    /// <param name="exception"></param>
    public async Task LogErrorSqlAsync(string commandText, Exception exception)
    {
        var filePath = Path.Combine(_outputDir, UID, "UnknownTables.errlog");
        var content = $"""
                       /* [{DateTime.Now:yyyy-MM-dd HH:mm:ss}]
                        * Error occurred when export table with unknown table name:
                        * {exception.Message}
                        */
                       {commandText}
                       
                       
                       """;
        await File.AppendAllTextAsync(filePath, content, Encoding.UTF8);
    }

    public async Task LogErrorRecordsAsync(IDictionary<string, DataRecord> records, Exception exception)
    {
        var pathDict = new Dictionary<string, string>();
        foreach (var pair in records)
        {
            if(!pathDict.TryGetValue(pair.Key, out var path))
            {
                path = Path.Combine(_outputDir, UID, "ErrorRecords", $"{pair.Key}.errlog");
                pathDict.Add(pair.Key, path);
            }
            //
            await File.AppendAllTextAsync(path, string.Join(',', pair.Value.Fields));
        }
    }
    
    public void ClearErrorRecords()
    {
        _logger.LogInformation("***** Clear error records *****");
        foreach (var file in Directory.GetFiles(_outputDir, "*.errlog", SearchOption.AllDirectories))
        {
            File.Delete(file);
        }
    }
}