using BaseOUDAL;
using YLErp.Commons;

namespace YLErp.Modules.AppModule.UpgradModule
{
    /// <summary>
    /// 数据库结构及数据升级服务
    /// </summary>
    public class DbUpdateService
    {
        const int UpState_Fail = -1;
        const int UpState_Done = 1;
        const int UpState_Pending = 0;

        const string UpType_DbUpdate = "DbUpdate";
        const string ResNameSpacePrefix = "YLErp.Resources.DbUpdate.Ver";

        #region----获取资源文件列表----

        /// <summary>
        /// 获取资源文件列表
        /// </summary>
        public static List<DbUpdateDto> GetUpdateList()
        {
            var upList = new List<DbUpdateDto>();
            var assembly = typeof(YLErp.Resources.PlaceHolder).Assembly;

            foreach (var resName in assembly.GetManifestResourceNames())
            {
                //YLErp.Resources.DbUpdate.Ver_3._17.prod.sql

                if (!resName.StartsWith(ResNameSpacePrefix))
                {
                    continue;
                }

                var upkey = resName.Substring(ResNameSpacePrefix.Length, resName.Length - ResNameSpacePrefix.Length - 4);
                var strArr = upkey.Split(new[] { '.' }, StringSplitOptions.RemoveEmptyEntries);

                var version = string.Join(".", strArr.Take(strArr.Length - 1).Select(n => n.Substring(1)).ToArray());

                var dto = new DbUpdateDto
                {
                    UpKey = upkey,
                    Version = version,
                    DbSchema = strArr[^1],
                    UpResult = "未执行"
                };

                upList.Add(dto);
            }

            var dic = GetLogs();

            foreach (var dto in upList)
            {
                if (dic.TryGetValue(dto.UpKey, out var a))
                {
                    dto.UpState = a.UpState;
                    dto.UpResult = a.UpResult;
                }
            }

            return upList.OrderByDescending(x => x.Version + ".").ThenBy(n => n.DbSchema).ToList();
        }

        private static Dictionary<string, InnerDbLog> GetLogs()
        {
            InnerDbLog[] getLogs(DbSet<SysUpdateLog> dbset)
            {
                var startDate = DateTime.Today.AddMonths(-6);

                var baseQry = from a in dbset
                              where a.CreateTime > startDate && a.UpType == UpType_DbUpdate
                              select a;

                var groupQry = from a in baseQry
                               group a by a.UpKey into g
                               select new { id = g.Max(n => n.id) };

                var listQry = from g in groupQry
                              join a in baseQry on g.id equals a.id
                              select new InnerDbLog
                              {
                                  UpKey = a.UpKey,
                                  UpResult = a.UpResult,
                                  UpState = a.UpState
                              };

                return listQry.ToArray();
            }

            var list = new List<InnerDbLog>(100);

            using (var db = DbContextFactory.GetYLDbContext())
            {
                list.AddRange(getLogs(db.SysUpdateLogs));
            }

            using (var db = DbContextFactory.GetErpBaseContext())
            {
                list.AddRange(getLogs(db.SysUpdateLogs));
            }

            using (var db = DbContextFactory.GetClientDbContext(OptUserInfo.SystemUser))
            {
                list.AddRange(getLogs(db.SysUpdateLogs));
            }

            return CollectionHelper.ToDictionary2(list, n => n.UpKey, n => n, StringComparer.OrdinalIgnoreCase, useFirst: true);
        }

        #endregion

        #region----执行数据库脚本升级----

        /// <summary>
        /// 执行数据库脚本升级
        /// </summary>
        public static List<DbUpdateResult> ExecuteUpdate(IEnumerable<string> upKeyList, bool onlyUpdateDone)
        {
            var resultList = new List<DbUpdateResult>();

            var exelist = upKeyList.OrderBy(n => n.ToLowerInvariant()).ToArray();

            foreach (var upkey in exelist)
            {
                var result = InnerExecuteUpdate(upkey, onlyUpdateDone);

                resultList.Add(result);
            }

            return resultList;
        }

        /// <summary>
        /// 执行单个更新
        /// </summary>
        private static DbUpdateResult InnerExecuteUpdate(string upkey, bool onlyUpdateDone)
        {
            var result = new DbUpdateResult { UpKey = upkey, UpState = UpState_Fail };

            if (string.IsNullOrEmpty(upkey))
            {
                result.UpResult = "upkey是空值";
                return result;
            }

            result.UpState = UpState_Pending;

            var sqlText = string.Empty;

            if (onlyUpdateDone)
            {
                result.UpState = UpState_Done;
                result.UpResult = "手动更新为已执行";
            }
            else
            {
                sqlText = GetResourceContent(upkey);

                if (sqlText == null)
                {
                    result.UpState = UpState_Fail;
                    result.UpResult = "没有找到升级脚本";
                }
                else if (string.IsNullOrWhiteSpace(sqlText))
                {
                    sqlText = string.Empty;

                    result.UpState = UpState_Done;
                    result.UpResult = "升级脚本为空";
                }
            }

            using (var db = getDbContext(upkey))
            {
                if (db == null)
                {
                    result.UpResult = "未从upkey中解析出正确的数据库";
                    return result;
                }

                if (result.UpState == UpState_Pending)
                {
                    try
                    {
                        var changes = db.Database.ExecuteSqlRaw(sqlText);

                        result.UpState = UpState_Done;
                        result.UpResult = "执行成功,受影响的行数:" + changes;
                    }
                    catch (Exception ex)
                    {
                        result.UpState = UpState_Fail;
                        result.UpResult = ex.Messages();
                    }
                }

                var dblog = new SysUpdateLog()
                {
                    UpKey = upkey,
                    UpType = UpType_DbUpdate,

                    UpState = result.UpState,
                    UpResult = result.UpResult,

                    CreateTime = DateTime.Now
                };

                db.SysUpdateLogs.Add(dblog);

                db.SaveChanges();
            }

            return result;

            DBContextBase getDbContext(string upkey)
            {
                var index = upkey.LastIndexOf('.');
                var dbSchema = upkey.Substring(index + 1);

                return (dbSchema?.ToLowerInvariant()) switch
                {
                    "admin" => DbContextFactory.GetErpBaseContext(),
                    "client" => DbContextFactory.GetClientDbContext(OptUserInfo.SystemUser),
                    "prod" => DbContextFactory.GetYLDbContext(),
                    _ => null,
                };
            }
        }

        #endregion

        /// <summary>
        /// 查看数据库脚本升级内容
        /// </summary>
        public static string GetUpdateContent(IEnumerable<string> upKeyList)
        {
            if (upKeyList is null || !upKeyList.Any())
            {
                return string.Empty;
            }

            var sb = StringBuilderPool.Acquire();

            var exelist = upKeyList.OrderBy(n =>
            {
                var index = n.LastIndexOf('.');
                return n.Substring(0, index + 1);
            }).ToArray();

            foreach (var upkey in exelist)
            {
                var sqlText = GetResourceContent(upkey);

                sb.AppendLine("-- -----------------------------------------------------------")
                  .Append("-- V").Append(upkey.Replace("_", "")).AppendLine()
                  .AppendLine("-- -----------------------------------------------------------");

                if (sqlText == null)
                {
                    sb.Append("-- !!!没有找到升级脚本:").Append(upkey).AppendLine();
                }
                else
                {
                    sb.AppendLine(sqlText);
                }
            }

            return sb.Release();
        }

        /// <summary>
        /// 返回资源文件内容，如果是null表示资源不存在
        /// </summary>
        private static string GetResourceContent(string upkey)
        {
            var resName = string.Concat(ResNameSpacePrefix, upkey, ".sql");

            var assembly = typeof(Resources.PlaceHolder).Assembly;

            using var s = assembly.GetManifestResourceStream(resName);

            if (s == null)
            {
                return null;
            }

            using var sr = new StreamReader(s);

            return sr.ReadToEnd();
        }

        class InnerDbLog
        {
            public string UpKey { get; set; }

            public string UpResult { get; set; }

            public int UpState { get; set; }
        }
    }
}