package mysql

import (
	"context"
	"errors"
	"time"

	"gorm.io/gorm"

	"wucher/internal/domain/land"
	"wucher/internal/shared/pkg/sortkey"
	"wucher/internal/transport/http/dto"
)

type LandRepository struct {
	db *gorm.DB
}

func NewLandRepository(db *gorm.DB) *LandRepository {
	return &LandRepository{db: db}
}

func (r *LandRepository) Create(ctx context.Context, row *land.Land) error {
	requestedIsActive := row.IsActive
	db := r.db.WithContext(ctx)
	if err := db.Create(row).Error; err != nil {
		return err
	}
	return db.Model(&land.Land{}).Where("id = ?", row.ID).UpdateColumn("is_active", requestedIsActive).Error
}

func (r *LandRepository) Update(ctx context.Context, row *land.Land) error {
	return r.db.WithContext(ctx).Save(row).Error
}

func (r *LandRepository) Delete(ctx context.Context, id []byte, deletedBy []byte) error {
	if err := ensureNoReferenceBeforeDelete(ctx, r.db, "lands", id); err != nil {
		return err
	}
	now := time.Now().UTC()
	updates := map[string]any{
		"deleted_at": now,
		"deleted_by": deletedBy,
		"updated_by": deletedBy,
	}
	return mapDeleteConstraintError(r.db.WithContext(ctx).
		Model(&land.Land{}).
		Where("id = ? AND deleted_at IS NULL", id).
		Updates(updates).Error)
}

func (r *LandRepository) GetByID(ctx context.Context, id []byte) (*land.Land, error) {
	var row land.Land
	err := r.db.WithContext(ctx).Where("id = ? AND deleted_at IS NULL", id).First(&row).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, nil
	}
	return &row, err
}

func (r *LandRepository) List(ctx context.Context, filter, sort string, limit, offset int) ([]land.Land, int64, error) {
	var rows []land.Land
	var total int64

	base := r.db.WithContext(ctx).Model(&land.Land{}).Where("deleted_at IS NULL")
	if filter != "" {
		like := "%" + filter + "%"
		base = base.Where("(name LIKE ? OR land_iso_code LIKE ?)", like, like)
	}

	query := base
	if sort != "" {
		query = query.Order(sort)
	} else {
		for _, clause := range sortkey.ActivePositiveSortClauses("lands", "is_active", "sortkey", "name", false) {
			query = query.Order(clause)
		}
	}
	if err := base.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	if limit > 0 {
		query = query.Limit(limit).Offset(offset)
	}
	if err := query.Find(&rows).Error; err != nil {
		return nil, 0, err
	}

	return rows, total, nil
}

func (r *LandRepository) GetByIDView(ctx context.Context, id []byte) (*dto.LandView, error) {
	row, err := r.GetByID(ctx, id)
	if err != nil || row == nil {
		return nil, err
	}
	views, err := r.buildViews(ctx, []land.Land{*row})
	if err != nil {
		return nil, err
	}
	if len(views) == 0 {
		return nil, nil
	}
	return &views[0], nil
}

func (r *LandRepository) ListView(ctx context.Context, filter, sort string, limit, offset int) ([]dto.LandView, int64, error) {
	rows, total, err := r.List(ctx, filter, sort, limit, offset)
	if err != nil {
		return nil, 0, err
	}
	views, err := r.buildViews(ctx, rows)
	if err != nil {
		return nil, 0, err
	}
	return views, total, nil
}

type landFederalStateRow struct {
	ID     []byte `gorm:"column:id"`
	Name   string `gorm:"column:name"`
	LandID []byte `gorm:"column:land_id"`
}

func (r *LandRepository) attachFederalStates(ctx context.Context, rows []land.Land) (map[string][]dto.LandFederalStateView, error) {
	if len(rows) == 0 {
		return map[string][]dto.LandFederalStateView{}, nil
	}

	landIDs := make([][]byte, 0, len(rows))
	for i := range rows {
		if len(rows[i].ID) == 0 {
			continue
		}
		landIDs = append(landIDs, rows[i].ID)
	}
	if len(landIDs) == 0 {
		return map[string][]dto.LandFederalStateView{}, nil
	}

	var states []landFederalStateRow
	if err := r.db.WithContext(ctx).
		Table("federal_states").
		Select("id, name, land_id").
		Where("deleted_at IS NULL AND land_id IN ?", landIDs).
		Order("name ASC").
		Find(&states).Error; err != nil {
		return nil, err
	}

	grouped := make(map[string][]dto.LandFederalStateView, len(landIDs))
	for i := range states {
		s := states[i]
		key := string(s.LandID)
		grouped[key] = append(grouped[key], dto.LandFederalStateView{
			ID:   append([]byte(nil), s.ID...),
			Name: s.Name,
		})
	}
	return grouped, nil
}

func (r *LandRepository) buildViews(ctx context.Context, rows []land.Land) ([]dto.LandView, error) {
	if len(rows) == 0 {
		return []dto.LandView{}, nil
	}
	federalStatesByLandID, err := r.attachFederalStates(ctx, rows)
	if err != nil {
		return nil, err
	}

	views := make([]dto.LandView, 0, len(rows))
	for i := range rows {
		key := string(rows[i].ID)
		list := federalStatesByLandID[key]
		views = append(views, dto.LandView{
			Row:               rows[i],
			FederalStateTotal: len(list),
			FederalStateList:  list,
		})
	}
	return views, nil
}