package repository

import (
	"context"
	"permission/reborn/domain/entity"
	"permission/reborn/domain/errors"
	"permission/reborn/domain/repository"

	"gorm.io/gorm"
)

type roleRepository struct {
	db *gorm.DB
}

// NewRoleRepository 建立角色 Repository
func NewRoleRepository(db *gorm.DB) repository.RoleRepository {
	return &roleRepository{db: db}
}

func (r *roleRepository) Create(ctx context.Context, role *entity.Role) error {
	if err := role.Validate(); err != nil {
		return errors.Wrap(errors.ErrCodeInvalidInput, "invalid role data", err)
	}

	if err := r.db.WithContext(ctx).Create(role).Error; err != nil {
		return errors.Wrap(errors.ErrCodeDBQuery, "failed to create role", err)
	}
	return nil
}

func (r *roleRepository) Update(ctx context.Context, role *entity.Role) error {
	if err := role.Validate(); err != nil {
		return errors.Wrap(errors.ErrCodeInvalidInput, "invalid role data", err)
	}

	result := r.db.WithContext(ctx).
		Model(&entity.Role{}).
		Where("uid = ? AND status != ?", role.UID, entity.StatusDeleted).
		Updates(map[string]interface{}{
			"name":   role.Name,
			"status": role.Status,
		})

	if result.Error != nil {
		return errors.Wrap(errors.ErrCodeDBQuery, "failed to update role", result.Error)
	}

	if result.RowsAffected == 0 {
		return errors.ErrRoleNotFound
	}

	return nil
}

func (r *roleRepository) Delete(ctx context.Context, uid string) error {
	result := r.db.WithContext(ctx).
		Model(&entity.Role{}).
		Where("uid = ?", uid).
		Update("status", entity.StatusDeleted)

	if result.Error != nil {
		return errors.Wrap(errors.ErrCodeDBQuery, "failed to delete role", result.Error)
	}

	if result.RowsAffected == 0 {
		return errors.ErrRoleNotFound
	}

	return nil
}

func (r *roleRepository) Get(ctx context.Context, id int64) (*entity.Role, error) {
	var role entity.Role
	err := r.db.WithContext(ctx).
		Where("id = ? AND status != ?", id, entity.StatusDeleted).
		First(&role).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.ErrRoleNotFound
		}
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get role", err)
	}

	return &role, nil
}

func (r *roleRepository) GetByUID(ctx context.Context, uid string) (*entity.Role, error) {
	var role entity.Role
	err := r.db.WithContext(ctx).
		Where("uid = ? AND status != ?", uid, entity.StatusDeleted).
		First(&role).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, errors.ErrRoleNotFound
		}
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get role by uid", err)
	}

	return &role, nil
}

func (r *roleRepository) GetByUIDs(ctx context.Context, uids []string) ([]*entity.Role, error) {
	if len(uids) == 0 {
		return []*entity.Role{}, nil
	}

	var roles []*entity.Role
	err := r.db.WithContext(ctx).
		Where("uid IN ? AND status != ?", uids, entity.StatusDeleted).
		Find(&roles).Error

	if err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to get roles by uids", err)
	}

	return roles, nil
}

func (r *roleRepository) List(ctx context.Context, filter repository.RoleFilter) ([]*entity.Role, error) {
	query := r.buildQuery(ctx, filter)

	var roles []*entity.Role
	if err := query.Find(&roles).Error; err != nil {
		return nil, errors.Wrap(errors.ErrCodeDBQuery, "failed to list roles", err)
	}

	return roles, nil
}

func (r *roleRepository) Page(ctx context.Context, filter repository.RoleFilter, page, size int) ([]*entity.Role, int64, error) {
	query := r.buildQuery(ctx, filter)

	// 計算總數
	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, 0, errors.Wrap(errors.ErrCodeDBQuery, "failed to count roles", err)
	}

	// 分頁查詢
	var roles []*entity.Role
	offset := (page - 1) * size
	if err := query.Offset(offset).Limit(size).Find(&roles).Error; err != nil {
		return nil, 0, errors.Wrap(errors.ErrCodeDBQuery, "failed to page roles", err)
	}

	return roles, total, nil
}

func (r *roleRepository) Exists(ctx context.Context, uid string) (bool, error) {
	var count int64
	err := r.db.WithContext(ctx).
		Model(&entity.Role{}).
		Where("uid = ? AND status != ?", uid, entity.StatusDeleted).
		Count(&count).Error

	if err != nil {
		return false, errors.Wrap(errors.ErrCodeDBQuery, "failed to check role exists", err)
	}

	return count > 0, nil
}

func (r *roleRepository) NextID(ctx context.Context) (int64, error) {
	var role entity.Role
	err := r.db.WithContext(ctx).
		Order("id DESC").
		Limit(1).
		First(&role).Error

	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return 1, nil
		}
		return 0, errors.Wrap(errors.ErrCodeDBQuery, "failed to get next id", err)
	}

	return role.ID + 1, nil
}

func (r *roleRepository) buildQuery(ctx context.Context, filter repository.RoleFilter) *gorm.DB {
	query := r.db.WithContext(ctx).
		Model(&entity.Role{}).
		Where("status != ?", entity.StatusDeleted)

	if filter.ClientID > 0 {
		query = query.Where("client_id = ?", filter.ClientID)
	}

	if filter.UID != "" {
		query = query.Where("uid = ?", filter.UID)
	}

	if filter.Name != "" {
		query = query.Where("name LIKE ?", "%"+filter.Name+"%")
	}

	if filter.Status != nil {
		query = query.Where("status = ?", *filter.Status)
	}

	return query
}