using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json;
using AnalyticsDAL.CustomCode.DataSource;
using AnalyticsDAL.DTO.AnalysisAggregation.V1;
using AnalyticsDAL.DTO.BICatalog;
using AnalyticsDAL.DTO.DataSource;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Report;
using GB5Shared.ExcelExport;

namespace AnalyticsDAL.CustomCode.ApiDataset
{
    public class ApiDatasetDAL : IApiDatasetDAL
    {
        private readonly IDataSourceDAL _dataSourceDAL;
        private readonly IExcelExport _excelExport;

        public ApiDatasetDAL(IDataSourceDAL dataSourceDAL, IExcelExport excelExport)
        {
            _dataSourceDAL = dataSourceDAL;
            _excelExport = excelExport;
        }

        public async Task<List<Dictionary<string, object?>>> FetchRowsAsync(
            DatasetResolutionDTO resolution,
            AnalysisQueryDefinition definition,
            LoginDTO login,
            CancellationToken ct)
        {
            if (resolution.DataSourceId is not int dataSourceId)
                throw new InvalidOperationException("ApiService dataset resolution is missing DataSourceId.");
            if (string.IsNullOrWhiteSpace(resolution.ResourcePath))
                throw new InvalidOperationException("ApiService dataset resolution is missing ResourcePath.");

            var json = await _dataSourceDAL.GetDataSource(dataSourceId, login, ct).ConfigureAwait(false);
            var dataSource = JsonSerializer.Deserialize<DataSourceDTO>(json)
                ?? throw new InvalidOperationException($"DataSource {dataSourceId} could not be resolved.");

            if (dataSource.DataSourceType != 4) // 4 = RestAPI, per MDATASOURCE.DATASOURCETYPE
                throw new InvalidOperationException(
                    $"DataSource {dataSourceId} is not a RestAPI-type source (DataSourceType={dataSource.DataSourceType}).");

            // HOSTNAME holds the API base URL for RestAPI-type sources (a convention, not a
            // dedicated column — MDATASOURCE has no URL-specific field; see the plan's
            // "to verify before implementing" note for MDATASOURCE's actual column list).
            var baseUrl = dataSource.HostName?.TrimEnd('/') ?? string.Empty;
            var resourcePath = resolution.ResourcePath!.TrimStart('/');
            var fullUri = string.IsNullOrEmpty(baseUrl) ? resolution.ResourcePath! : $"{baseUrl}/{resourcePath}";

            var reportCallingDTO = new ReportCallingDTO
            {
                ReportUri = fullUri,
                CriteriaDTO = BuildCriteriaDTO(definition)
            };

            var rows = new List<Dictionary<string, object?>>();
            await foreach (var row in _excelExport.ReportURICalling(reportCallingDTO, login, ct).WithCancellation(ct).ConfigureAwait(false))
                rows.Add(row);

            return rows;
        }

        private static CriteriaDTO BuildCriteriaDTO(AnalysisQueryDefinition definition)
        {
            var attributeCriteria = definition.Filters.Select(f => new AttributesCriteriaDTO
            {
                FieldName = f.Field,
                OperationType = f.Operator,
                FieldValue = f.Values.Length > 0 ? f.Values[0] : null,
                InArray = f.Values,
                JoinType = CriteriaDTO.AttributeJoinOperationType.And
            }).ToList();

            return new CriteriaDTO
            {
                SectionCriteriaList = new List<SectionCriteriaDTO>
                {
                    new SectionCriteriaDTO
                    {
                        SectionId = 0,
                        OperationType = CriteriaDTO.SectionOperationType.And,
                        AttributesCriteriaList = attributeCriteria
                    }
                }
            };
        }
    }
}