package service

import (
	"context"
	"fmt"
	"time"

	"github.com/Caknoooo/go-gin-clean-starter/modules/sequence/repository"
	pkgdto "github.com/Caknoooo/go-gin-clean-starter/pkg/dto"
	"github.com/Caknoooo/go-gin-clean-starter/pkg/utils"
	"gorm.io/gorm"
)

type SequenceService interface {
	GenerateNumber(ctx context.Context, clientId string, config pkgdto.SequenceConfig) (string, error)
	GenerateNumberWithPeriod(ctx context.Context, clientId string, config pkgdto.SequenceConfig, suffix string) (string, error)
	GenerateNumberWithSuffix(ctx context.Context, clientId string, config pkgdto.SequenceConfig, suffix string) (string, error)
	GetNextSequence(ctx context.Context, clientId string, config pkgdto.SequenceConfig) (int, error)
	GenerateDocumentNumber(ctx context.Context, clientId string, docType string, config pkgdto.SequenceConfig) (string, error)
}

type sequenceService struct {
	db           *gorm.DB
	sequenceRepo repository.SequenceRepository
}

func NewSequenceService(sequenceRepo repository.SequenceRepository, db *gorm.DB) SequenceService {
	return &sequenceService{
		sequenceRepo: sequenceRepo,
		db:           db,
	}
}

// GenerateNumberWithSuffix implements SequenceService.
func (s *sequenceService) GenerateNumberWithSuffix(ctx context.Context, clientId string, config pkgdto.SequenceConfig, suffix string) (string, error) {
	period := config.Period
	seq, err := s.sequenceRepo.GetOrCreateSequence(ctx, s.db, clientId, config.EntityType, period)
	if err != nil {
		return "", err
	}
	seq.CurrentSeq++
	if err := s.sequenceRepo.UpdateSequence(ctx, s.db, seq); err != nil {
		return "", err
	}
	refNum := fmt.Sprintf("%s-%s-%04d", config.Prefix, suffix, seq.CurrentSeq)
	return refNum, nil
}

func (s *sequenceService) GenerateNumber(ctx context.Context, clientId string, config pkgdto.SequenceConfig) (string, error) {
	period := config.Period
	if period == "" {
		period = "-"
	}
	seq, err := s.sequenceRepo.GetOrCreateSequence(ctx, s.db, clientId, config.EntityType, period)
	if err != nil {
		return "", err
	}
	seq.CurrentSeq++
	if err := s.sequenceRepo.UpdateSequence(ctx, s.db, seq); err != nil {
		return "", err
	}
	refNum := fmt.Sprintf("%s-%04d", config.Prefix, seq.CurrentSeq)
	return refNum, nil
}

func (s *sequenceService) GenerateNumberWithPeriod(ctx context.Context, clientId string, config pkgdto.SequenceConfig, suffix string) (string, error) {
	if config.Period == "" {
		config.Period = time.Now().Format("0601")
	}
	period := config.Period
	seq, err := s.sequenceRepo.GetOrCreateSequence(ctx, s.db, clientId, config.EntityType, period)
	if err != nil {
		return "", err
	}
	seq.CurrentSeq++
	if err := s.sequenceRepo.UpdateSequence(ctx, s.db, seq); err != nil {
		return "", err
	}
	refNum := fmt.Sprintf("%s-%s-%s-%04d", config.Prefix, suffix, period, seq.CurrentSeq)
	return refNum, nil
}

func (s *sequenceService) GetNextSequence(ctx context.Context, clientId string, config pkgdto.SequenceConfig) (int, error) {
	period := config.Period
	if period == "" {
		period = "-"
	}
	seq, err := s.sequenceRepo.GetOrCreateSequence(ctx, s.db, clientId, config.EntityType, period)
	if err != nil {
		return 0, err
	}
	seq.CurrentSeq++
	if err := s.sequenceRepo.UpdateSequence(ctx, s.db, seq); err != nil {
		return 0, err
	}
	return seq.CurrentSeq, nil
}

func (s *sequenceService) GenerateDocumentNumber(ctx context.Context, clientId string, docType string, config pkgdto.SequenceConfig) (string, error) {
	// Ambil nama client berdasarkan clientId
	var client struct {
		Name string
	}
	if err := s.db.Table("m_clients").Select("name").Where("id = ?", clientId).First(&client).Error; err != nil {
		return "", fmt.Errorf("client not found")
	}
	if client.Name == "" {
		return "", fmt.Errorf("client name is empty")
	}

	initials := utils.GetInitials(client.Name)
	
	// Ambil sequence dari sequence service
	seqNum, err := s.GetNextSequence(ctx, clientId, config)
	if err != nil {
		return "", err
	}

	docNum := fmt.Sprintf("%s-%s-%04d", docType, initials, seqNum)
	return docNum, nil
}