package models

import (
	"errors"
	"fmt"
	"time"

	"gorm.io/gorm"
)

// CertificationPhoto table.
type CertificationPhoto struct {
	ID                uint64 `gorm:"primaryKey"`
	UserID            uint64 `gorm:"uniqueIndex"`
	Filename          string
	Filesize          int64
	Status            CertificationPhotoStatus
	AdminComment      string
	SecondaryNeeded   bool   // a secondary form of ID has been requested
	SecondaryFilename string // photo ID upload
	SecondaryVerified bool   // mark true when ID checked so original can be deleted
	IPAddress         string // the IP they uploaded the photo from
	CreatedAt         time.Time
	UpdatedAt         time.Time
}

type CertificationPhotoStatus string

const (
	CertificationPhotoNeeded   CertificationPhotoStatus = "needed"
	CertificationPhotoPending  CertificationPhotoStatus = "pending"
	CertificationPhotoApproved CertificationPhotoStatus = "approved"
	CertificationPhotoRejected CertificationPhotoStatus = "rejected"

	// If a photo is pending approval but the admin wants to engage the
	// secondary check (prompt user for a photo ID upload)
	CertificationPhotoSecondary CertificationPhotoStatus = "secondary"
)

// GetCertificationPhoto retrieves the user's record from the DB or upserts their initial record.
func GetCertificationPhoto(userID uint64) (*CertificationPhoto, error) {
	p := &CertificationPhoto{}
	result := DB.Where("user_id = ?", userID).First(&p)
	if result.Error == gorm.ErrRecordNotFound {
		p = &CertificationPhoto{
			UserID: userID,
			Status: CertificationPhotoNeeded,
		}
		result = DB.Create(p)
		return p, result.Error
	}
	return p, result.Error
}

// CertifiedSince retrieve's the last updated date of the user's certification photo, if approved.
//
// This incurs a DB query for their cert photo.
func (u *User) CertifiedSince() (time.Time, error) {
	if !u.Certified {
		return time.Time{}, errors.New("user is not certified")
	}

	cert, err := GetCertificationPhoto(u.ID)
	if err != nil {
		return time.Time{}, err
	}

	if cert.Status != CertificationPhotoApproved {
		return time.Time{}, fmt.Errorf("cert photo status is: %s (expected 'approved')", cert.Status)
	}

	return cert.UpdatedAt, nil
}

// CertificationPhotosNeedingApproval returns a pager of the pictures that require admin approval.
func CertificationPhotosNeedingApproval(status CertificationPhotoStatus, pager *Pagination) ([]*CertificationPhoto, error) {
	var p = []*CertificationPhoto{}

	query := DB.Where(
		"status = ?",
		status,
	).Order(
		pager.Sort,
	)

	// Get the total count.
	query.Model(&CertificationPhoto{}).Count(&pager.Total)

	result := query.Offset(
		pager.GetOffset(),
	).Limit(pager.PerPage).Find(&p)

	return p, result.Error
}

// CountCertificationPhotosNeedingApproval gets the count of pending photos for admin alert.
func CountCertificationPhotosNeedingApproval() int64 {
	var count int64
	DB.Where("status = ?", CertificationPhotoPending).Model(&CertificationPhoto{}).Count(&count)
	return count
}

// Save photo.
func (p *CertificationPhoto) Save() error {
	result := DB.Save(p)
	return result.Error
}

// Delete the DB entry.
func (p *CertificationPhoto) Delete() error {
	return DB.Delete(p).Error
}