using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using Autofac.Extensions.DependencyInjection;
using Infrastructure;
using Infrastructure.Utilities;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Options;
using OpenAuth.Repository;
using OpenAuth.Repository.Domain;
using OpenAuth.Repository.QueryObj;

namespace OpenAuth.App
{
    public class DbExtension
    {
        private List<DbContext> _contexts = new List<DbContext>();
        
        private IOptions<AppSetting> _appConfiguration;
        private IHttpContextAccessor _httpContextAccessor;

        public DbExtension(IOptions<AppSetting> appConfiguration, OpenAuthDBContext openAuthDbContext, IHttpContextAccessor httpContextAccessor)
        {
            _appConfiguration = appConfiguration;
            _httpContextAccessor = httpContextAccessor;
            _contexts.Add(openAuthDbContext);  //如果有多个DBContext，可以按OpenAuthDBContext同样的方式添加到_contexts中
        }

        /// <summary>
        /// 通过实体获取字段定义，因为MVC版本没有代码生成界面，只能通过这种方式
        /// </summary>
        /// <param name="moduleName">模块名称/表名</param>
        /// <returns></returns>
        [Obsolete("因为MVC版本没有代码生成界面，只能通过这种方式")]
        public List<BuilderTableColumn> GetTableColumnsFromDb(string moduleName)
        {
            var result = new List<BuilderTableColumn>();
            const string domain = "openauth.repository.domain.";
            IEntityType entity = null; 
            _contexts.ForEach(u =>
            {
                entity = u.Model.GetEntityTypes()
                    .FirstOrDefault(u => u.Name.ToLower() == domain + moduleName.ToLower());
            });
            if (entity == null)
            {
                throw new Exception($"未能找到{moduleName}对应的实体类");
            }

            foreach (var property in entity.ClrType.GetProperties())
            {
                object[] objs = property.GetCustomAttributes(typeof(DescriptionAttribute), true);
                object[] browsableObjs = property.GetCustomAttributes(typeof(BrowsableAttribute), true);
                var description = objs.Length > 0 ? ((DescriptionAttribute) objs[0]).Description : property.Name;
                if (string.IsNullOrEmpty(description)) description = property.Name;
                //如果没有BrowsableAttribute或 [Browsable(true)]表示可见，其他均为不可见，需要前端配合显示
                bool browsable = browsableObjs == null || browsableObjs.Length == 0 ||
                                 ((BrowsableAttribute) browsableObjs[0]).Browsable;
                var typeName = property.PropertyType.Name;
                if (Nullable.GetUnderlyingType(property.PropertyType) != null)
                {
                    typeName = Nullable.GetUnderlyingType(property.PropertyType).Name;
                }
                result.Add(new BuilderTableColumn
                {
                    ColumnName = property.Name,
                    TableName = moduleName,
                    Comment = description,
                    IsList = browsable,
                    ColumnType = typeName
                });
            }

            return result;
        }

        /// <summary>
        /// 获取数据库DbContext中所有的实体名称。
        /// <para>注意！并不能获取数据库中的所有表</para>
        /// </summary>
        public List<string> GetDbEntityNames()
        {
            var names = new List<string>();
            var models = _contexts.Select(u =>u.Model);

            foreach (var model in models)
            {
                // Get all the entity types information contained in the DbContext class, ...
                var entityTypes = model.GetEntityTypes();
                foreach (var entityType in entityTypes)
                {
                    var tableNameAnnotation = entityType.GetAnnotation("Relational:TableName");
                    names.Add(tableNameAnnotation.Value.ToString());
                }
            }

            return names;
        }

        /// <summary>
        /// 获取数据库表结构信息
        /// </summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public IList<SysTableColumn> GetDbTableStructure(string tableName)
        {
            var dbtype = _appConfiguration.Value.DbTypes[_httpContextAccessor.GetTenantId()];
            if (dbtype == Define.DBTYPE_MYSQL)
            {
                return GetMySqlStructure(tableName);
            }
            else if (dbtype == Define.DBTYPE_SQLSERVER)
            {
                return GetSqlServerStructure(tableName);
            }
            else if (dbtype == Define.DBTYPE_PostgreSQL)
            {
                return GetPostgreStructure(tableName);
            }
            else
            {
                return GetOracleStructure(tableName);
            }
        }

        /// <summary>
        /// 获取Oracle表结构
        /// </summary>
        private IList<SysTableColumn> GetOracleStructure(string tableName)
        {
            var sql = $@"
select utc.column_name as columnname
     , utc.data_type columntype
     , utc.data_length maxlength
     , case utc.nullable when 'N' then 0 else 1 end isnull
     , utc.data_default defaultval
     , ucc.comments ""COMMENT""
     , utc.table_name tablename
     , case utc.column_name
           when (select col.column_name
                 from user_constraints con
                    , user_cons_columns col
                 where con.constraint_name = col.constraint_name
                   and con.constraint_type = 'P'
                   and col.table_name = '{tableName}') then 1
           else 0 end as iskey
     , case
           when utc.column_name in ('CreateUserId', 'UpdateUserId', 'Id')
               then 0
           else 1
    end as isdisplay
     , case
           when data_type in ('BIT', 'BOOL') then
               'bool'
           when data_type in ('SMALLINT') then 'short'
           when data_type in ('TINYINT') then 'bool'
           when data_type in ('NUMBER', 'CHAR', 'INT', 'Year') then
               'int'
           when data_type in ('BIGINT') then
               'bigint'
           when data_type in ('FLOAT', 'DOUBLE', 'DECIMAL') then
               'decimal'
           when data_type in
                ('CHAR', 'VARCHAR', 'TINY TEXT', 'TEXT', 'MEDIUMTEXT', 'LONGTEXT', 'TINYBLOB', 'BLOB',
                 'MEDIUMBLOB', 'LONGBLOB', 'Time') then
               'string'
           when data_type in ('Date', 'DateTime', 'TIMESTAMP(6)') then
               'DateTime'
           else 'string'
    end as entitytype
from user_tab_columns utc
   , user_col_comments ucc
where utc.table_name = ucc.table_name
  and utc.column_name = ucc.column_name
  and utc.table_name = '{tableName}'
order by column_id;  ";
            
            foreach (var context in _contexts)
            {
                var columns = context.Set<SysTableColumn>().FromSqlRaw(sql);
                var columnList = columns?.ToList();
                if (columnList != null && columnList.Any())
                {
                    return columnList;
                }
            }
            
            return new List<SysTableColumn>();
        }

        /// <summary>
        /// 获取Mysql表结构信息
        /// </summary>
        private IList<SysTableColumn> GetMySqlStructure(string tableName)
        {
            var sql =  $@"SELECT  DISTINCT
                    Column_Name AS ColumnName,
                     '{ tableName}'  as tableName,
	                Column_Comment AS Comment,
                    data_type as ColumnType,
                        CASE
                          WHEN data_type IN( 'BIT', 'BOOL', 'bit', 'bool') THEN
                'bool'
		             WHEN data_type in('smallint','SMALLINT') THEN 'short'
								WHEN data_type in('tinyint','TINYINT') THEN 'bool'
                        WHEN data_type IN('MEDIUMINT','mediumint', 'int','INT','year', 'Year') THEN
                    'int'
                    WHEN data_type in ( 'BIGINT','bigint') THEN
                    'bigint'
                    WHEN data_type IN('FLOAT', 'DOUBLE', 'DECIMAL','float', 'double', 'decimal') THEN
                    'decimal'
                    WHEN data_type IN('CHAR', 'VARCHAR', 'TINY TEXT', 'TEXT', 'MEDIUMTEXT', 'LONGTEXT', 'TINYBLOB', 'BLOB', 'MEDIUMBLOB', 'LONGBLOB', 'Time','char', 'varchar', 'tiny text', 'text', 'mediumtext', 'longtext', 'tinyblob', 'blob', 'mediumblob', 'longblob', 'time') THEN
                    'string'
                    WHEN data_type IN('Date', 'DateTime', 'TimeStamp','date', 'datetime', 'timestamp') THEN
                    'DateTime' ELSE 'string'
                END AS EntityType,
	              case WHEN CHARACTER_MAXIMUM_LENGTH>8000 THEN 0 ELSE CHARACTER_MAXIMUM_LENGTH end  AS Maxlength,
            CASE
                    WHEN COLUMN_KEY = 'PRI' THEN  
                    1 ELSE 0
                END AS IsKey,
            CASE
                    WHEN Column_Name IN( 'CreateID', 'ModifyID', '' ) 
		            OR COLUMN_KEY<> '' THEN
                        0 ELSE 1
                        END AS IsDisplay,
		            1 AS IsColumnData,
                    120 AS ColumnWidth,
                    0 AS OrderNo,
                CASE
                        WHEN IS_NULLABLE = 'NO' THEN
                        0 ELSE 1
                    END AS IsNull,
	            CASE
                        WHEN COLUMN_KEY <> '' THEN
                        1 ELSE 0
                    END AS IsReadDataset
                FROM
                    information_schema.COLUMNS
                WHERE
                    table_name = '{tableName}'";

            foreach (var context in _contexts)
            {
                var columns = context.Set<SysTableColumn>().FromSqlRaw(sql);
                var columnList = columns?.ToList();
                if (columnList != null && columnList.Any())
                {
                    return columnList;
                }
            }
            
            return new List<SysTableColumn>();
            
        }
       
        
          /// <summary>
        /// 获取Mysql表结构信息
        /// </summary>
        private IList<SysTableColumn> GetPostgreStructure(string tableName)
        {
            var sql =  $@"select attr.attrelid
     , schema.nspname as schemaname
     , class.relname as tablename --表名
     , attr.attname as columnname --列名
     , attr.atttypid --类型ID
     , attr.atttypmod
     , case when con.conname is not null then 1 else 0 end as iskey --是否主键
     , case when attr.attnotnull is true then 0 else 1 end as isnull --可空
     , t.typname columntype --类型名称
     , case
           when typname in ('BIT', 'BOOL', 'bit', 'bool') then
               'bool'
           when typname in ('smallint', 'SMALLINT') then 'short'
           when typname in ('tinyint', 'TINYINT') then 'bool'
           when typname in ('int4', 'int', 'INT') then
               'int'
           when typname in ('BIGINT', 'bigint') then
               'bigint'
           when typname in ('FLOAT', 'DOUBLE', 'DECIMAL', 'float', 'double', 'decimal') then
               'decimal'
           when typname in ('varchar', 'text') then
               'string'
           when typname in ('Date', 'DateTime', 'TimeStamp', 'date', 'datetime', 'timestamp') then
               'DateTime'
           else 'string'
    end as entitytype
     , comment.description as comment
     , 1 as iscolumndata
     , case
           when t.typname = 'varchar' or t.typname = 'bpchar' then attr.atttypmod - 4
           else 10
    end as columnwidth
     , 0 as orderno
     , case
           when t.typname = 'varchar' or t.typname = 'bpchar' then attr.atttypmod - 4
           else 10
    end as maxlength
     , case
           when attname in ('createid', 'modifyid', '')
               or con.conname is null then 0
           else 1
    end as isdisplay --是否显示
from pg_catalog.pg_class class
         inner join pg_catalog.pg_attribute attr on attr.attrelid = class.oid
         left join pg_catalog.pg_constraint con
                   on con.conrelid = class.oid and attr.attnum = any (con.conkey) and con.contype = 'p'
         left join pg_catalog.pg_type t on attr.atttypid = t.oid
         inner join pg_catalog.pg_description comment
                    on comment.objoid = attr.attrelid and comment.objsubid = attr.attnum
         inner join pg_catalog.pg_namespace schema on schema.oid = class.relnamespace
where attr.attnum > 0
  and not attr.attisdropped
  and schema.nspname = 'public' -- replace 'your_schema' with your schema name
  and class.relname = '{tableName}'";

            foreach (var context in _contexts)
            {
                var columns = context.Set<SysTableColumn>().FromSqlRaw(sql);
                var columnList = columns?.ToList();
                if (columnList != null && columnList.Any())
                {
                    return columnList;
                }
            }
            
            return new List<SysTableColumn>();
            
        }
       
        
        
         /// <summary>
        /// 获取SqlServer表结构信息
        /// </summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        private IList<SysTableColumn> GetSqlServerStructure(string tableName)
        {
            var sql =  $@"
            SELECT TableName,
                LTRIM(RTRIM(ColumnName)) AS ColumnName,
                Comment,
                CASE WHEN ColumnType = 'uniqueidentifier' THEN 'guid'
                     WHEN ColumnType IN('smallint', 'INT') THEN 'int'
                     WHEN ColumnType = 'BIGINT' THEN 'long'
                     WHEN ColumnType IN('CHAR', 'VARCHAR', 'NVARCHAR',
                                          'text', 'xml', 'varbinary', 'image')
                     THEN 'string'
                     WHEN ColumnType IN('tinyint')
                     THEN 'byte'
                     WHEN ColumnType IN('bit')
                     THEN 'bool'

                     WHEN ColumnType IN('bit') THEN 'bool'
                     WHEN ColumnType IN('time', 'date', 'DATETIME', 'smallDATETIME')
                     THEN 'DateTime'
                     WHEN ColumnType IN('smallmoney', 'DECIMAL', 'numeric',
                                          'money') THEN 'decimal'
                     WHEN ColumnType = 'float' THEN 'double'
                     ELSE 'string'
                END as  EntityType,
                    ColumnType,
                    [Maxlength],
                IsKey,
                CASE WHEN ColumnName IN('CreateID', 'ModifyID', '')
                          OR IsKey = 1 THEN 0
                     ELSE 1
                END AS IsDisplay ,
				1 AS IsColumnData,

              CASE   
                     WHEN ColumnName IN('Modifier', 'Creator') THEN 130
                     WHEN[Maxlength] < 110 AND[Maxlength] > 60 THEN 120
                     WHEN[Maxlength] < 200 AND[Maxlength] >= 110 THEN 180
                     WHEN[Maxlength] > 200 THEN 220
                     ELSE 90
                   END AS ColumnWidth ,
                0 AS OrderNo,
                --CASE WHEN IsKey = 1 OR t.[IsNull]=0 THEN 0
                --     ELSE 1 END
                t.[IsNull] AS
                 [IsNull],
            CASE WHEN IsKey = 1 THEN 1 ELSE 0 END IsReadDataset,
            CASE WHEN IsKey!=1 AND t.[IsNull] = 0 THEN 0 ELSE NULL END AS EditColNo
        FROM    (SELECT obj.name AS TableName ,
                            col.name AS ColumnName ,
                            CONVERT(NVARCHAR(100),ISNULL(ep.[value], '')) AS Comment,
                            t.name AS ColumnType ,
                           CASE WHEN  col.length<1 THEN 0 ELSE  col.length END  AS[Maxlength],
                            CASE WHEN EXISTS (SELECT   1
                                               FROM dbo.sysindexes si
                                                        INNER JOIN dbo.sysindexkeys sik ON si.id = sik.id
                                                              AND si.indid = sik.indid
                                                        INNER JOIN dbo.syscolumns sc ON sc.id = sik.id
                                                              AND sc.colid = sik.colid
                                                        INNER JOIN dbo.sysobjects so ON so.name = si.name
                                                              AND so.xtype = 'PK'
                                               WHERE sc.id = col.id
                                                        AND sc.colid = col.colid)
                                 THEN 1
                                 ELSE 0
                            END AS IsKey ,
                            CASE WHEN col.isnullable = 1 THEN 1
                                 ELSE 0
                            END AS[IsNull],
                            col.colorder
                  FROM      dbo.syscolumns col
                            LEFT JOIN dbo.systypes t ON col.xtype = t.xusertype
                           INNER JOIN dbo.sysobjects obj ON col.id = obj.id

                                                            AND obj.xtype IN ( 'U','V')
                                                          --   AND obj.status >= 01
                            LEFT JOIN dbo.syscomments comm ON col.cdefault = comm.id
                            LEFT JOIN sys.extended_properties ep ON col.id = ep.major_id
                                                              AND col.colid = ep.minor_id
                                                              AND ep.name = 'MS_Description'
                            LEFT JOIN sys.extended_properties epTwo ON obj.id = epTwo.major_id
                                                              AND epTwo.minor_id = 0
                                                              AND epTwo.name = 'MS_Description'
                  WHERE obj.name =  '{ tableName}') AS t
            ORDER BY t.colorder";

            foreach (var context in _contexts)
            {
                var columns = context.Set<SysTableColumn>().FromSqlRaw(sql);
                var columnList = columns?.ToList();
                if (columnList != null && columnList.Any())
                {
                    return columnList;
                }
            }
            return new List<SysTableColumn>();
        }
    }
}