package report

import (
	"context"

	"errors"
	"fmt"

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

var (
	ErrInvalidInterval = errors.New("invalid interval provided")
)

func (s *Service) GenerateEventIntervalReport(ctx context.Context, request domain.ReportRequestDetail) (string, error) {
	if request.Metadata.Interval == nil {
		s.mongoLogger.Error("[GenerateEventIntervalReport] Metadata interval is empty")
		return "", 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 "", 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)
	}

	rows := [][]string{{
		"Period", "Total Events", "Active Events", "In-Active Events", "Featured Events", "Leagues",
		"Pending", "In-Play", "To-Be-Fixed", "Ended", "Postponed", "Cancelled", "Walkover",
		"Interrupted", "Abandoned", "Retired", "Suspended", "Decided-By-FA", "Removed",
	}}

	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"),
		)

		rows = append(rows, []string{
			period,
			fmt.Sprint(stat.EventCount),
			fmt.Sprint(stat.TotalActiveEvents),
			fmt.Sprint(stat.TotalInActiveEvents),
			fmt.Sprint(stat.TotalFeaturedEvents),
			fmt.Sprint(stat.TotalLeagues),
			fmt.Sprint(stat.Pending),
			fmt.Sprint(stat.InPlay),
			fmt.Sprint(stat.ToBeFixed),
			fmt.Sprint(stat.Ended),
			fmt.Sprint(stat.Postponed),
			fmt.Sprint(stat.Cancelled),
			fmt.Sprint(stat.Walkover),
			fmt.Sprint(stat.Interrupted),
			fmt.Sprint(stat.Abandoned),
			fmt.Sprint(stat.Retired),
			fmt.Sprint(stat.Suspended),
			fmt.Sprint(stat.DecidedByFa),
			fmt.Sprint(stat.Removed),
		})
	}

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