package models

import (
	"errors"
	"time"

	"gorm.io/gorm"
)

// BookingStatus represents the possible states of a booking
type BookingStatus string

const (
	BookingStatusScheduled BookingStatus = "scheduled"
	BookingStatusCompleted BookingStatus = "completed"
	BookingStatusCancelled BookingStatus = "cancelled"
)

// PaymentStatus represents the possible states of a payment
type PaymentStatus string

const (
	PaymentStatusPending   PaymentStatus = "pending"
	PaymentStatusSucceeded PaymentStatus = "succeeded"
	PaymentStatusFailed    PaymentStatus = "failed"
	PaymentStatusRefunded  PaymentStatus = "refunded"
)

// Booking represents a scheduled meeting
type Booking struct {
	gorm.Model
	UserID        uint          `json:"user_id" gorm:"not null;index" validate:"required"`
	User          User          `json:"user" gorm:"foreignKey:UserID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
	ScheduledAt   time.Time     `json:"scheduled_at" gorm:"not null;index" validate:"required"`
	Duration      int           `json:"duration" gorm:"default:60;check:duration > 0" validate:"min=15,max=480"` // minutes, 15min to 8hrs
	Status        BookingStatus `json:"status" gorm:"default:'scheduled';size:20" validate:"required,oneof=scheduled completed cancelled"`
	JitsiRoomID   string        `json:"jitsi_room_id" gorm:"size:255;index"`
	JitsiRoomURL  string        `json:"jitsi_room_url" gorm:"size:500"`
	PaymentID     string        `json:"payment_id" gorm:"size:255;index"`
	PaymentStatus PaymentStatus `json:"payment_status" gorm:"size:20" validate:"omitempty,oneof=pending succeeded failed refunded"`
	Amount        float64       `json:"amount" gorm:"type:decimal(10,2);check:amount >= 0" validate:"min=0"`
	Notes         string        `json:"notes" gorm:"type:text"`
}

// BeforeCreate is a GORM hook that runs before creating a booking record
func (b *Booking) BeforeCreate(tx *gorm.DB) error {
	// Validate that the scheduled time is in the future
	if b.ScheduledAt.Before(time.Now()) {
		return errors.New("booking cannot be scheduled in the past")
	}

	// Set default status if not provided
	if b.Status == "" {
		b.Status = BookingStatusScheduled
	}

	// Set default duration if not provided
	if b.Duration == 0 {
		b.Duration = 60
	}

	return nil
}

// BeforeUpdate is a GORM hook that runs before updating a booking record
func (b *Booking) BeforeUpdate(tx *gorm.DB) error {
	// Prevent updating completed bookings
	if b.Status == BookingStatusCompleted {
		return errors.New("cannot modify completed bookings")
	}

	return nil
}

// CanBeCancelled checks if the booking can be cancelled
func (b *Booking) CanBeCancelled() bool {
	return b.Status == BookingStatusScheduled && b.ScheduledAt.After(time.Now().Add(24*time.Hour))
}

// CanBeRescheduled checks if the booking can be rescheduled
func (b *Booking) CanBeRescheduled() bool {
	return b.Status == BookingStatusScheduled && b.ScheduledAt.After(time.Now().Add(2*time.Hour))
}

// IsUpcoming checks if the booking is scheduled for the future
func (b *Booking) IsUpcoming() bool {
	return b.Status == BookingStatusScheduled && b.ScheduledAt.After(time.Now())
}