using System;
using System.Globalization;
using System.Text.Json;
using GB5Shared.DTO.Framework.Criteria;
using TMSDAL.DTO.Reports;

namespace TMSBLL.Reports
{
    // Shared CriteriaDTO -> TmsReportCriteria parsing for every TMS Reports-family endpoint --
    // mirrors AccountsBLL.AccountReports.AccountReportCriteriaParser's shape/conventions exactly so
    // the wire format (SectionCriteriaList -> AttributesCriteriaList -> FieldName/FieldValue) behaves
    // identically across modules.
    public static class TmsReportCriteriaParser
    {
        public static TmsReportCriteria Parse(CriteriaDTO criteriaDTO)
        {
            var result = new TmsReportCriteria();

            if (criteriaDTO?.SectionCriteriaList == null)
                return result;

            foreach (var section in criteriaDTO.SectionCriteriaList)
            {
                if (section?.AttributesCriteriaList == null) continue;

                foreach (var attr in section.AttributesCriteriaList)
                {
                    if (attr.FieldValue == null) continue;
                    var field = attr.FieldName?.ToLowerInvariant() ?? string.Empty;

                    switch (field)
                    {
                        case "fromdate":
                            result.FromDate = ParseDate(attr.FieldValue);
                            break;
                        case "todate":
                            result.ToDate = ParseDate(attr.FieldValue);
                            break;
                        case "trainingdomainid":
                            result.TrainingDomainId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "departmentid":
                            result.DepartmentId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "programmeid":
                            result.ProgrammeId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "instanceid":
                            result.InstanceId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "trainerid":
                            result.TrainerId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "employeeid":
                            result.EmployeeId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "vendorid":
                            result.VendorId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "venueid":
                            result.VenueId = ParseInt(attr.FieldValue, -1);
                            break;
                        case "mandatoryonly":
                            result.MandatoryOnly = ParseInt(attr.FieldValue, 0);
                            break;
                        case "rollingwindowdays":
                            result.RollingWindowDays = ParseInt(attr.FieldValue, 0);
                            break;
                    }
                }
            }

            return result;
        }

        private static DateTime? ParseDate(object fieldValue)
        {
            var raw = RawString(fieldValue);
            if (string.IsNullOrWhiteSpace(raw)) return null;
            if (long.TryParse(raw, out var epoch))
                return DateTimeOffset.FromUnixTimeMilliseconds(epoch).UtcDateTime;
            return DateTime.TryParse(raw, null, DateTimeStyles.None, out var dt) ? dt : null;
        }

        private static int ParseInt(object fieldValue, int fallback)
        {
            var raw = RawString(fieldValue);
            return int.TryParse(raw, out var v) ? v : fallback;
        }

        private static string RawString(object fieldValue)
        {
            return fieldValue is JsonElement je
                ? (je.ValueKind == JsonValueKind.Number ? je.GetRawText() : je.GetString() ?? string.Empty)
                : fieldValue?.ToString() ?? string.Empty;
        }
    }
}