package customerverification

import (
	"context"
	"errors"

	"github.com/google/uuid"
	"gorm.io/gorm"
)

var ErrNotFound = errors.New("verification not found")

type Repository interface {
	Upsert(ctx context.Context, v *CustomerVerification) error
	FindByUserID(ctx context.Context, userID uuid.UUID) (*CustomerVerification, error)
	FindByID(ctx context.Context, id uuid.UUID) (*CustomerVerification, error)
	List(ctx context.Context, status string) ([]*CustomerVerification, error)
	UpdateStatus(ctx context.Context, id uuid.UUID, status, adminNote string) (*CustomerVerification, error)
}

type gormRepository struct {
	db *gorm.DB
}

func NewRepository(db *gorm.DB) Repository {
	return &gormRepository{db: db}
}

// Upsert inserts a new submission or overwrites the customer's existing one
// (a resubmission after rejection reuses the same row, reset to pending).
func (r *gormRepository) Upsert(ctx context.Context, v *CustomerVerification) error {
	existing, err := r.FindByUserID(ctx, v.UserID)
	if errors.Is(err, ErrNotFound) {
		return r.db.WithContext(ctx).Create(v).Error
	}
	if err != nil {
		return err
	}
	v.ID = existing.ID
	v.CreatedAt = existing.CreatedAt
	return r.db.WithContext(ctx).Save(v).Error
}

func (r *gormRepository) FindByUserID(ctx context.Context, userID uuid.UUID) (*CustomerVerification, error) {
	var v CustomerVerification
	err := r.db.WithContext(ctx).Where("user_id = ?", userID).First(&v).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	return &v, nil
}

func (r *gormRepository) FindByID(ctx context.Context, id uuid.UUID) (*CustomerVerification, error) {
	var v CustomerVerification
	err := r.db.WithContext(ctx).Where("id = ?", id).First(&v).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	return &v, nil
}

func (r *gormRepository) List(ctx context.Context, status string) ([]*CustomerVerification, error) {
	q := r.db.WithContext(ctx).Order("created_at asc")
	if status != "" {
		q = q.Where("status = ?", status)
	}
	var list []*CustomerVerification
	if err := q.Find(&list).Error; err != nil {
		return nil, err
	}
	return list, nil
}

func (r *gormRepository) UpdateStatus(ctx context.Context, id uuid.UUID, status, adminNote string) (*CustomerVerification, error) {
	res := r.db.WithContext(ctx).Model(&CustomerVerification{}).Where("id = ?", id).Updates(map[string]any{
		"status":     status,
		"admin_note": adminNote,
	})
	if res.Error != nil {
		return nil, res.Error
	}
	if res.RowsAffected == 0 {
		return nil, ErrNotFound
	}
	return r.FindByID(ctx, id)
}