package report

import (
	"context"

	"fmt"

	"github.com/SamuelTariku/FortuneBet-Backend/internal/domain"
	"go.uber.org/zap"
)

type EventIntervalRow struct {
	Period         string `csv:"Period"`
	TotalEvents    int64  `csv:"Total Events"`
	ActiveEvents   int64  `csv:"Active Events"`
	InActiveEvents int64  `csv:"In-Active Events"`
	FeaturedEvents int64  `csv:"Featured Events"`
	Leagues        int64  `csv:"Leagues"`
	Pending        int64  `csv:"Pending"`
	InPlay         int64  `csv:"In-Play"`
	ToBeFixed      int64  `csv:"To-Be-Fixed"`
	Ended          int64  `csv:"Ended"`
	Postponed      int64  `csv:"Postponed"`
	Cancelled      int64  `csv:"Cancelled"`
	Walkover       int64  `csv:"Walkover"`
	Interrupted    int64  `csv:"Interrupted"`
	Abandoned      int64  `csv:"Abandoned"`
	Retired        int64  `csv:"Retired"`
	Suspended      int64  `csv:"Suspended"`
	DecidedByFA    int64  `csv:"Decided-By-FA"`
	Removed        int64  `csv:"Removed"`
}

func (s *Service) GenerateEventIntervalReport(ctx context.Context, request domain.ReportRequestDetail) (string, error) {
	// Only a super-admin is allowed to generate this type of report
	if request.RequesterRole.Valid && request.RequesterRole.Value != domain.RoleSuperAdmin {
		s.mongoLogger.Error("[GenerateEventIntervalReport] Unauthorized user report")
		return "", ErrUnauthorizedUserReport
	}

	if request.Metadata.Interval == nil {
		s.mongoLogger.Error("[GenerateEventIntervalReport] Metadata interval is empty")
		return "", domain.ErrInvalidInterval
	}

	interval, err := domain.ParseDateInterval(*request.Metadata.Interval)
	if err != nil {
		s.mongoLogger.Error("[GenerateEventIntervalReport] Failed to parse date interval",
			zap.String("interval", *request.Metadata.Interval),
			zap.Error(err),
		)
		return "", domain.ErrInvalidInterval
	}

	stats, err := s.statService.GetTotalEventStatsByInterval(ctx, domain.EventStatsByIntervalFilter{
		Interval: domain.ValidDateInterval{
			Value: interval,
			Valid: true,
		},
	})
	if err != nil {
		s.mongoLogger.Error("[GenerateEventIntervalReport] Failed to fetch event stats",
			zap.String("interval", string(interval)),
			zap.Error(err),
		)
		return "", fmt.Errorf("fetching event stats: %w", err)
	}

	var rows [][]string
	var headers []string
	for _, stat := range stats {
		endDate, err := domain.GetEndDateFromInterval(interval, stat.Date)
		if err != nil {
			s.mongoLogger.Error("[GenerateEventIntervalReport] Failed to get end date from interval",
				zap.String("interval", string(interval)),
				zap.Error(err),
			)
			return "", fmt.Errorf("invalid interval end date: %w", err)
		}

		period := fmt.Sprintf("%s to %s",
			stat.Date.Format("2006-01-02"),
			endDate.Format("2006-01-02"),
		)

		r := EventIntervalRow{
			Period:         period,
			TotalEvents:    stat.EventCount,
			ActiveEvents:   stat.TotalActiveEvents,
			InActiveEvents: stat.TotalInActiveEvents,
			FeaturedEvents: stat.TotalFeaturedEvents,
			Leagues:        stat.TotalLeagues,
			Pending:        stat.Pending,
			InPlay:         stat.InPlay,
			ToBeFixed:      stat.ToBeFixed,
			Ended:          stat.Ended,
			Postponed:      stat.Postponed,
			Cancelled:      stat.Cancelled,
			Walkover:       stat.Walkover,
			Interrupted:    stat.Interrupted,
			Abandoned:      stat.Abandoned,
			Retired:        stat.Retired,
			Suspended:      stat.Suspended,
			DecidedByFA:    stat.DecidedByFa,
			Removed:        stat.Removed,
		}

		if headers == nil {
			headers, _ = StructToCSVRow(r)
			rows = append(rows, headers)
		}

		_, row := StructToCSVRow(r)
		rows = append(rows, row)
	}

	return s.WriteCSV(rows, "event_interval")
}