using System.Data;
using System.Text.RegularExpressions;

namespace etoy
{
    sealed class CommonTableCsvParser
    {
        // excel 上的规则
        // 默认0列为主键(long/int) 0-3行按顺序表示：字段名、数据类型、数据标签(Tag)、字段描述， 正式数据从 4行开始
        // *                        0               1               2               3               4       ....           备注
        // 0      #字段名           no             name            xxxx             yyyy                                  (‘#’开头忽略)
        // 1       #类型            int            string      repeated int    repeated CustomType
        // 2       #Tags           Tag1            Tag2         Tag1;Tag2;Tag3      Tag4                                   (';'分号隔开) 
        // 3     #字段描述         主键            名字            XXXXXXX          YYYYYY
        // 4     #正式数据

        const char TAG_SEPARATOR = ';';
        const char TAG_SEPARATOR_VALUE = ':';
        const string FIELD_REPEATED = "[]";


        public Table Parse(DataTable dt, string path)
        {
            //string tableDescription = dt.Rows[0][0].ToString().ToDescription();

            TableTag tag = GetTableTag(dt, out string tableName, path);

            Dictionary<int, FieldInfo> fieldInfos = GetFieldInfos(dt, tableName);

            var table = new Table
            {
                Path = path,
                Name = tableName,
                Description = tableName,
                TableTag = tag,
                FieldInfos = fieldInfos.Values.ToArray()
            };
            var rowOffset = 4;
            if (TryGetTableEnum(dt, fieldInfos, tableName, out var @enum))
            {
                table.tableEnum = @enum;
                rowOffset = 5;
            }
            table.Rows = GetRows(dt, fieldInfos, rowOffset);

            return table;
        }

        Dictionary<int, FieldInfo> GetFieldInfos(DataTable dt, string tableName)
        {
            int columnCount = dt.Columns.Count;
            int rowOffset = 0;

            Dictionary<int, FieldInfo> fieldInfos = new Dictionary<int, FieldInfo>();
            for (int i = 0; i < columnCount; i++)
            {
                string fieldName = dt.Rows[rowOffset][i].ToString().ToFieldName();
                if (string.IsNullOrEmpty(fieldName))
                    break;

                if (fieldName.StartsWith("#"))
                    continue;

                //const string REPEATED_STR = "repeated";
                string fieldType = dt.Rows[rowOffset + 1][i].ToString().Trim();
                bool isRepeaded = fieldType.Contains(FIELD_REPEATED);
                if (isRepeaded) fieldType = fieldType.Substring(0, fieldType.IndexOf(FIELD_REPEATED)).Trim();

                string tags = dt.Rows[rowOffset + 2][i].ToString().ToTags();
                string description = dt.Rows[rowOffset + 3][i].ToString().ToDescription();


                FieldInfo field = new FieldInfo();
                field.Column = i;
                field.FieldName = fieldName;
                field.FieldType = fieldType;
                field.IsRepeated = isRepeaded;
                field.Description = description;
                field.Tags = tags;
                field.TagInfos = GetFieldTagInfos(rowOffset + 2, i, tags, tableName);
                fieldInfos[i] = field;
            }

            return fieldInfos;
        }

        FieldTagInfo[] GetFieldTagInfos(int excelRow, int excelCol, string tags, string tableName)
        {
            if (string.IsNullOrEmpty(tags))
                return new FieldTagInfo[0];

            string[] fieldTags = tags.Split(TAG_SEPARATOR);
            if (fieldTags.Length > 0)
            {
                List<FieldTagInfo> result = new List<FieldTagInfo>();
                for (int i = 0, length = fieldTags.Length; i < length; i++)
                {
                    string[] kv = fieldTags[i].Split(TAG_SEPARATOR_VALUE);
                    if (kv.Length == 1)
                    {
                        bool valid = Enum.TryParse<FieldTag>(kv[0], true, out var fieldTag);
                        if (!valid)
                        { // tag字段只写了 'c'或's'或'sc'
                            if (kv[0].Contains('c', StringComparison.OrdinalIgnoreCase) || kv[0].Contains('s', StringComparison.OrdinalIgnoreCase)){
                                result.Add(new FieldTagInfo()
                                {
                                    Key = FieldTag.Output,
                                    Value = kv[0]
                                });
                            }
                            else 
                                throw new Exception($"配置表({tableName}) 不支持该Tag格式: [{tags}], 应满足以下格式: [Tag1Key:Tag1Value;Tag2Key:Tag2Value] (行: {excelRow}, 列: {excelCol})");
                        }
                        else
                        {
                            FieldTagInfo info = new FieldTagInfo();
                            info.Key = fieldTag;
                            info.Value = null;
                            result.Add(info);
                        }
                    }
                    else if (kv.Length == 2)
                    {
                        bool valid = Enum.TryParse<FieldTag>(kv[0], true, out var fieldTag);
                        if (!valid)
                            throw new Exception($"配置表({tableName}) 不支持该Tag格式: [{tags}], 应满足以下格式: [Tag1Key:Tag1Value;Tag2Key:Tag2Value] (行: {excelRow}, 列: {excelCol})");

                        FieldTagInfo info = new FieldTagInfo();
                        info.Key = fieldTag;
                        info.Value = kv[1];
                        result.Add(info);
                    }
                    else
                        throw new Exception($"配置表({tableName}) 不支持该Tag格式: [{tags}], 应满足以下格式: [Tag1Key:Tag1Value;Tag2Key:Tag2Value] (行: {excelRow}, 列: {excelCol})");
                }
                return result.ToArray();
            }
            return new FieldTagInfo[0];
        }
        Regex _enumRegex = new Regex(@"enum{name:(\w+)\s*?;\s*?key:(\w+)\s*?;\s*?value:(\w+)\s*?;\s*?summary:(\w+)\s*?;\s*?}");
        bool TryGetTableEnum(DataTable dt, Dictionary<int, FieldInfo> fieldInfos, string tableName, out TableEnum tableEnum)
        {
            // 第5行第一列
            var cellVal = dt.Rows[4][0].ToString().ToCellValue();
            var match = _enumRegex.Match(cellVal);
            if (match.Success)
            {
                var name = match.Groups[1].Value;
                var key = match.Groups[2].Value;
                var value = match.Groups[3].Value;
                var summary = match.Groups[4].Value;
                var fieldNames = new HashSet<string>();
                foreach(var fieldInfo in  fieldInfos.Values)
                {
                    if (fieldInfo.IsRepeated)
                        continue;
                    fieldNames.Add(fieldInfo.FieldName);
                }
                if (!fieldNames.Contains(key))
                {
                    throw new Exception($"配置表({tableName}) 枚举类型字段名错误(行:5,列:1): {cellVal}");
                }
                if (!fieldNames.Contains(value))
                {
                    throw new Exception($"配置表({tableName}) 枚举值字段名错误(行:5,列:1): {cellVal}");
                }
                if (!fieldNames.Contains(summary))
                {
                    throw new Exception($"配置表({tableName}) 枚举说明字段名错误(行:5,列:1): {cellVal}");
                }
                tableEnum = new TableEnum()
                {
                    name = name,
                    key = key,
                    value = value,
                    summary = summary,
                };
                return true;
            }
            tableEnum = null;
            return false;
        }
        List<Row> GetRows(DataTable dt, Dictionary<int, FieldInfo> fieldInfos, int rowOffset = 4)
        {
            int rowCount = dt.Rows.Count;
            int columnCount = dt.Columns.Count;

            List<Row> rows = new List<Row>();

            for (int i = rowOffset; i < rowCount; i++)
            {
                int emptyCount = 0;
                List<Cell> cells = new List<Cell>();
                for (int j = 0; j < columnCount; j++)
                {
                    if (fieldInfos.TryGetValue(j, out var fieldInfo))
                    {
                        var value = dt.Rows[i][j].ToString().ToCellValue();
                        if (string.IsNullOrEmpty(value))
                            emptyCount++;

                        // last set value
                        cells.Add(new Cell
                        {
                            Row = i,
                            Column = j,
                            Value = value,
                            FieldInfo = fieldInfo
                        });
                    }
                }

                //-------------------------------------------
                //     过滤掉【全部为空】的情况 (#:filter field)
                //-------------------------------------------
                //  a   b   c   d   #e  #f
                //  *   *   *   *   *   *
                //  *   *   *   *   *   *
                // [             ]  *   *
                // [    filter   ]  *   *
                // [             ]  *   *
                //-------------------------------------------
                if (emptyCount < cells.Count)
                {
                    cells.Sort((a, b) => a.Column.CompareTo(b.Column));
                    Row row = new Row();
                    row.Cells = cells;
                    rows.Add(row);
                }
            }
            return rows;
        }


        TableTag GetTableTag(DataTable dt, out string newName, string path)
        {
            string tableName = string.Empty;
            //if (dt.Columns.Count > 2)
            //{
            //    _ = dt.Rows[0][1].ToString();//表名
            //    tableName = dt.Rows[0][2].ToString().ToTableName();
            //}
            tableName = string.IsNullOrEmpty(tableName) ? Path.GetFileNameWithoutExtension(path).ToTableName() : tableName;
            const string C = "c_";
            const string S = "s_";
            const string E = "e_";

            if (tableName.StartsWith(C))
            {
                newName = tableName.Substring(C.Length);
                return TableTag.Client;
            }

            if (tableName.StartsWith(S))
            {
                newName = tableName.Substring(S.Length);
                return TableTag.Server;
            }

            if (tableName.StartsWith(E))
            {
                newName = tableName.Substring(E.Length);
                return TableTag.Editor;
            }

            newName = tableName;
            return TableTag.All;
        }
    }
}