package paypalsdk

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"time"
)

const (
	// APIBaseSandBox points to the sandbox (for testing) version of the API
	APIBaseSandBox = "https://api.sandbox.paypal.com"

	// APIBaseLive points to the live version of the API
	APIBaseLive = "https://api.paypal.com"

	// RequestNewTokenBeforeExpiresIn is used by SendWithAuth and try to get new Token when it's about to expire
	RequestNewTokenBeforeExpiresIn = time.Duration(60) * time.Second
)

// Possible values for `no_shipping` in InputFields
//
// https://developer.paypal.com/docs/api/payment-experience/#definition-input_fields
const (
	NoShippingDisplay      uint = 0
	NoShippingHide         uint = 1
	NoShippingBuyerAccount uint = 2
)

// Possible values for `address_override` in InputFields
//
// https://developer.paypal.com/docs/api/payment-experience/#definition-input_fields
const (
	AddrOverrideFromFile uint = 0
	AddrOverrideFromCall uint = 1
)

// Possible values for `landing_page_type` in FlowConfig
//
// https://developer.paypal.com/docs/api/payment-experience/#definition-flow_config
const (
	LandingPageTypeBilling string = "Billing"
	LandingPageTypeLogin   string = "Login"
)

// Possible value for `allowed_payment_method` in PaymentOptions
//
// https://developer.paypal.com/docs/api/payments/#definition-payment_options
const (
	AllowedPaymentUnrestricted         string = "UNRESTRICTED"
	AllowedPaymentInstantFundingSource string = "INSTANT_FUNDING_SOURCE"
	AllowedPaymentImmediatePay         string = "IMMEDIATE_PAY"
)

type (
	// JSONTime overrides MarshalJson method to format in ISO8601
	JSONTime time.Time

	// Address struct
	Address struct {
		Line1       string `json:"line1"`
		Line2       string `json:"line2,omitempty"`
		City        string `json:"city"`
		CountryCode string `json:"country_code"`
		PostalCode  string `json:"postal_code,omitempty"`
		State       string `json:"state,omitempty"`
		Phone       string `json:"phone,omitempty"`
	}

	// AgreementDetails struct
	AgreementDetails struct {
		OutstandingBalance AmountPayout `json:"outstanding_balance"`
		CyclesRemaining    int          `json:"cycles_remaining,string"`
		CyclesCompleted    int          `json:"cycles_completed,string"`
		NextBillingDate    time.Time    `json:"next_billing_date"`
		LastPaymentDate    time.Time    `json:"last_payment_date"`
		LastPaymentAmount  AmountPayout `json:"last_payment_amount"`
		FinalPaymentDate   time.Time    `json:"final_payment_date"`
		FailedPaymentCount int          `json:"failed_payment_count,string"`
	}

	// Amount struct
	Amount struct {
		Currency string  `json:"currency"`
		Total    string  `json:"total"`
		Details  Details `json:"details,omitempty"`
	}

	// AmountPayout struct
	AmountPayout struct {
		Currency string `json:"currency"`
		Value    string `json:"value"`
	}

	// Authorization struct
	Authorization struct {
		Amount                    *Amount    `json:"amount,omitempty"`
		CreateTime                *time.Time `json:"create_time,omitempty"`
		UpdateTime                *time.Time `json:"update_time,omitempty"`
		State                     string     `json:"state,omitempty"`
		ParentPayment             string     `json:"parent_payment,omitempty"`
		ID                        string     `json:"id,omitempty"`
		ValidUntil                *time.Time `json:"valid_until,omitempty"`
		Links                     []Link     `json:"links,omitempty"`
		ClearingTime              string     `json:"clearing_time,omitempty"`
		ProtectionEligibility     string     `json:"protection_eligibility,omitempty"`
		ProtectionEligibilityType string     `json:"protection_eligibility_type,omitempty"`
	}

	// BatchHeader struct
	BatchHeader struct {
		Amount            *AmountPayout      `json:"amount,omitempty"`
		Fees              *AmountPayout      `json:"fees,omitempty"`
		PayoutBatchID     string             `json:"payout_batch_id,omitempty"`
		BatchStatus       string             `json:"batch_status,omitempty"`
		TimeCreated       *time.Time         `json:"time_created,omitempty"`
		TimeCompleted     *time.Time         `json:"time_completed,omitempty"`
		SenderBatchHeader *SenderBatchHeader `json:"sender_batch_header,omitempty"`
	}

	// BillingAgreement struct
	BillingAgreement struct {
		Name            string           `json:"name,omitempty"`
		Description     string           `json:"description,omitempty"`
		StartDate       JSONTime         `json:"start_date,omitempty"`
		Plan            BillingPlan      `json:"plan,omitempty"`
		Payer           Payer            `json:"payer,omitempty"`
		ShippingAddress *ShippingAddress `json:"shipping_address,omitempty"`
	}

	// BillingPlan struct
	BillingPlan struct {
		ID                  string               `json:"id,omitempty"`
		Name                string               `json:"name,omitempty"`
		Description         string               `json:"description,omitempty"`
		Type                string               `json:"type,omitempty"`
		PaymentDefinitions  []PaymentDefinition  `json:"payment_definitions,omitempty"`
		MerchantPreferences *MerchantPreferences `json:"merchant_preferences,omitempty"`
	}

	// Capture struct
	Capture struct {
		Amount         *Amount    `json:"amount,omitempty"`
		IsFinalCapture bool       `json:"is_final_capture"`
		CreateTime     *time.Time `json:"create_time,omitempty"`
		UpdateTime     *time.Time `json:"update_time,omitempty"`
		State          string     `json:"state,omitempty"`
		ParentPayment  string     `json:"parent_payment,omitempty"`
		ID             string     `json:"id,omitempty"`
		Links          []Link     `json:"links,omitempty"`
	}

	// ChargeModel struct
	ChargeModel struct {
		Type   string       `json:"type,omitempty"`
		Amount AmountPayout `json:"amount,omitempty"`
	}

	// Client represents a Paypal REST API Client
	Client struct {
		Client         *http.Client
		ClientID       string
		Secret         string
		APIBase        string
		Log            io.Writer // If user set log file name all requests will be logged there
		Token          *TokenResponse
		tokenExpiresAt time.Time
	}

	// CreditCard struct
	CreditCard struct {
		ID                 string   `json:"id,omitempty"`
		PayerID            string   `json:"payer_id,omitempty"`
		ExternalCustomerID string   `json:"external_customer_id,omitempty"`
		Number             string   `json:"number"`
		Type               string   `json:"type"`
		ExpireMonth        string   `json:"expire_month"`
		ExpireYear         string   `json:"expire_year"`
		CVV2               string   `json:"cvv2,omitempty"`
		FirstName          string   `json:"first_name,omitempty"`
		LastName           string   `json:"last_name,omitempty"`
		BillingAddress     *Address `json:"billing_address,omitempty"`
		State              string   `json:"state,omitempty"`
		ValidUntil         string   `json:"valid_until,omitempty"`
	}

	// CreditCards GET /v1/vault/credit-cards
	CreditCards struct {
		Items      []CreditCard `json:"items"`
		Links      []Link       `json:"links"`
		TotalItems int          `json:"total_items"`
		TotalPages int          `json:"total_pages"`
	}

	// CreditCardToken struct
	CreditCardToken struct {
		CreditCardID string `json:"credit_card_id"`
		PayerID      string `json:"payer_id,omitempty"`
		Last4        string `json:"last4,omitempty"`
		ExpireYear   string `json:"expire_year,omitempty"`
		ExpireMonth  string `json:"expire_month,omitempty"`
	}

	// CreditCardsFilter struct
	CreditCardsFilter struct {
		PageSize int
		Page     int
	}

	// CreditCardField PATCH /v1/vault/credit-cards/credit_card_id
	CreditCardField struct {
		Operation string `json:"op"`
		Path      string `json:"path"`
		Value     string `json:"value"`
	}

	// Currency struct
	Currency struct {
		Currency string `json:"currency,omitempty"`
		Value    string `json:"value,omitempty"`
	}

	// Details structure used in Amount structures as optional value
	Details struct {
		Subtotal         string `json:"subtotal,omitempty"`
		Shipping         string `json:"shipping,omitempty"`
		Tax              string `json:"tax,omitempty"`
		HandlingFee      string `json:"handling_fee,omitempty"`
		ShippingDiscount string `json:"shipping_discount,omitempty"`
		Insurance        string `json:"insurance,omitempty"`
		GiftWrap         string `json:"gift_wrap,omitempty"`
	}

	ErrorResponseDetail struct {
		Field string `json:"field"`
		Issue string `json:"issue"`
		Links []Link `json:"link"`
	}

	// ErrorResponse https://developer.paypal.com/docs/api/errors/
	ErrorResponse struct {
		Response        *http.Response        `json:"-"`
		Name            string                `json:"name"`
		DebugID         string                `json:"debug_id"`
		Message         string                `json:"message"`
		InformationLink string                `json:"information_link"`
		Details         []ErrorResponseDetail `json:"details"`
	}

	// ExecuteAgreementResponse struct
	ExecuteAgreementResponse struct {
		ID               string           `json:"id"`
		State            string           `json:"state"`
		Description      string           `json:"description,omitempty"`
		Payer            Payer            `json:"payer"`
		Plan             BillingPlan      `json:"plan"`
		StartDate        time.Time        `json:"start_date"`
		ShippingAddress  ShippingAddress  `json:"shipping_address"`
		AgreementDetails AgreementDetails `json:"agreement_details"`
		Links            []Link           `json:"links"`
	}

	// ExecuteResponse struct
	ExecuteResponse struct {
		ID           string        `json:"id"`
		Links        []Link        `json:"links"`
		State        string        `json:"state"`
		Payer        PaymentPayer  `json:"payer"`
		Transactions []Transaction `json:"transactions,omitempty"`
	}

	// FundingInstrument struct
	FundingInstrument struct {
		CreditCard      *CreditCard      `json:"credit_card,omitempty"`
		CreditCardToken *CreditCardToken `json:"credit_card_token,omitempty"`
	}

	// Item struct
	Item struct {
		Quantity    int    `json:"quantity"`
		Name        string `json:"name"`
		Price       string `json:"price"`
		Currency    string `json:"currency"`
		SKU         string `json:"sku,omitempty"`
		Description string `json:"description,omitempty"`
		Tax         string `json:"tax,omitempty"`
	}

	// ItemList struct
	ItemList struct {
		Items           []Item           `json:"items,omitempty"`
		ShippingAddress *ShippingAddress `json:"shipping_address,omitempty"`
	}

	// Link struct
	Link struct {
		Href    string `json:"href"`
		Rel     string `json:"rel,omitempty"`
		Method  string `json:"method,omitempty"`
		Enctype string `json:"enctype,omitempty"`
	}

	// MerchantPreferences struct
	MerchantPreferences struct {
		SetupFee                *AmountPayout `json:"setup_fee,omitempty"`
		ReturnURL               string        `json:"return_url,omitempty"`
		CancelURL               string        `json:"cancel_url,omitempty"`
		AutoBillAmount          string        `json:"auto_bill_amount,omitempty"`
		InitialFailAmountAction string        `json:"initial_fail_amount_action,omitempty"`
		MaxFailAttempts         string        `json:"max_fail_attempts,omitempty"`
	}

	// Order struct
	Order struct {
		ID            string     `json:"id,omitempty"`
		CreateTime    *time.Time `json:"create_time,omitempty"`
		UpdateTime    *time.Time `json:"update_time,omitempty"`
		State         string     `json:"state,omitempty"`
		Amount        *Amount    `json:"amount,omitempty"`
		PendingReason string     `json:"pending_reason,omitempty"`
		ParentPayment string     `json:"parent_payment,omitempty"`
		Links         []Link     `json:"links,omitempty"`
	}

	// Payer struct
	Payer struct {
		PaymentMethod      string              `json:"payment_method"`
		FundingInstruments []FundingInstrument `json:"funding_instruments,omitempty"`
		PayerInfo          *PayerInfo          `json:"payer_info,omitempty"`
		Status             string              `json:"payer_status,omitempty"`
	}

	// PayerInfo struct
	PayerInfo struct {
		Email           string           `json:"email,omitempty"`
		FirstName       string           `json:"first_name,omitempty"`
		LastName        string           `json:"last_name,omitempty"`
		PayerID         string           `json:"payer_id,omitempty"`
		Phone           string           `json:"phone,omitempty"`
		ShippingAddress *ShippingAddress `json:"shipping_address,omitempty"`
		TaxIDType       string           `json:"tax_id_type,omitempty"`
		TaxID           string           `json:"tax_id,omitempty"`
		CountryCode     string           `json:"country_code"`
	}

	// Payment struct
	Payment struct {
		Intent              string        `json:"intent"`
		Payer               *Payer        `json:"payer"`
		Transactions        []Transaction `json:"transactions"`
		RedirectURLs        *RedirectURLs `json:"redirect_urls,omitempty"`
		ID                  string        `json:"id,omitempty"`
		CreateTime          *time.Time    `json:"create_time,omitempty"`
		State               string        `json:"state,omitempty"`
		UpdateTime          *time.Time    `json:"update_time,omitempty"`
		ExperienceProfileID string        `json:"experience_profile_id,omitempty"`
	}

	// PaymentDefinition struct
	PaymentDefinition struct {
		ID                string        `json:"id,omitempty"`
		Name              string        `json:"name,omitempty"`
		Type              string        `json:"type,omitempty"`
		Frequency         string        `json:"frequency,omitempty"`
		FrequencyInterval string        `json:"frequency_interval,omitempty"`
		Amount            AmountPayout  `json:"amount,omitempty"`
		Cycles            string        `json:"cycles,omitempty"`
		ChargeModels      []ChargeModel `json:"charge_models,omitempty"`
	}

	PaymentOptions struct {
		AllowedPaymentMethod string `json:"allowed_payment_method,omitempty"`
	}

	// PaymentPatch PATCH /v1/payments/payment/{payment_id)
	PaymentPatch struct {
		Operation string      `json:"op"`
		Path      string      `json:"path"`
		Value     interface{} `json:"value"`
	}

	// PaymentPayer struct
	PaymentPayer struct {
		PaymentMethod string     `json:"payment_method"`
		Status        string     `json:"status,omitempty"`
		PayerInfo     *PayerInfo `json:"payer_info,omitempty"`
	}

	// PaymentResponse structure
	PaymentResponse struct {
		ID    string `json:"id"`
		Links []Link `json:"links"`
	}

	// Payout struct
	Payout struct {
		SenderBatchHeader *SenderBatchHeader `json:"sender_batch_header"`
		Items             []PayoutItem       `json:"items"`
	}

	// PayoutItem struct
	PayoutItem struct {
		RecipientType string        `json:"recipient_type"`
		Receiver      string        `json:"receiver"`
		Amount        *AmountPayout `json:"amount"`
		Note          string        `json:"note,omitempty"`
		SenderItemID  string        `json:"sender_item_id,omitempty"`
	}

	// PayoutItemResponse struct
	PayoutItemResponse struct {
		PayoutItemID      string        `json:"payout_item_id"`
		TransactionID     string        `json:"transaction_id"`
		TransactionStatus string        `json:"transaction_status"`
		PayoutBatchID     string        `json:"payout_batch_id,omitempty"`
		PayoutItemFee     *AmountPayout `json:"payout_item_fee,omitempty"`
		PayoutItem        *PayoutItem   `json:"payout_item"`
		TimeProcessed     *time.Time    `json:"time_processed,omitempty"`
		Links             []Link        `json:"links"`
		Error             ErrorResponse `json:"errors,omitempty"`
	}

	// PayoutResponse struct
	PayoutResponse struct {
		BatchHeader *BatchHeader         `json:"batch_header"`
		Items       []PayoutItemResponse `json:"items"`
		Links       []Link               `json:"links"`
	}

	// RedirectURLs struct
	RedirectURLs struct {
		ReturnURL string `json:"return_url,omitempty"`
		CancelURL string `json:"cancel_url,omitempty"`
	}

	// Refund struct
	Refund struct {
		ID            string     `json:"id,omitempty"`
		Amount        *Amount    `json:"amount,omitempty"`
		CreateTime    *time.Time `json:"create_time,omitempty"`
		State         string     `json:"state,omitempty"`
		CaptureID     string     `json:"capture_id,omitempty"`
		ParentPayment string     `json:"parent_payment,omitempty"`
		UpdateTime    *time.Time `json:"update_time,omitempty"`
	}

	// Related struct
	Related struct {
		Sale          *Sale          `json:"sale,omitempty"`
		Authorization *Authorization `json:"authorization,omitempty"`
		Order         *Order         `json:"order,omitempty"`
		Capture       *Capture       `json:"capture,omitempty"`
		Refund        *Refund        `json:"refund,omitempty"`
	}

	// Sale struct
	Sale struct {
		ID                        string     `json:"id,omitempty"`
		Amount                    *Amount    `json:"amount,omitempty"`
		TransactionFee            *Currency  `json:"transaction_fee,omitempty"`
		Description               string     `json:"description,omitempty"`
		CreateTime                *time.Time `json:"create_time,omitempty"`
		State                     string     `json:"state,omitempty"`
		ParentPayment             string     `json:"parent_payment,omitempty"`
		UpdateTime                *time.Time `json:"update_time,omitempty"`
		PaymentMode               string     `json:"payment_mode,omitempty"`
		PendingReason             string     `json:"pending_reason,omitempty"`
		ReasonCode                string     `json:"reason_code,omitempty"`
		ClearingTime              string     `json:"clearing_time,omitempty"`
		ProtectionEligibility     string     `json:"protection_eligibility,omitempty"`
		ProtectionEligibilityType string     `json:"protection_eligibility_type,omitempty"`
		Links                     []Link     `json:"links,omitempty"`
	}

	// SenderBatchHeader struct
	SenderBatchHeader struct {
		EmailSubject  string `json:"email_subject"`
		SenderBatchID string `json:"sender_batch_id,omitempty"`
	}

	// ShippingAddress struct
	ShippingAddress struct {
		RecipientName string `json:"recipient_name,omitempty"`
		Type          string `json:"type,omitempty"`
		Line1         string `json:"line1"`
		Line2         string `json:"line2,omitempty"`
		City          string `json:"city"`
		CountryCode   string `json:"country_code"`
		PostalCode    string `json:"postal_code,omitempty"`
		State         string `json:"state,omitempty"`
		Phone         string `json:"phone,omitempty"`
	}

	expirationTime int64

	// TokenResponse is for API response for the /oauth2/token endpoint
	TokenResponse struct {
		RefreshToken string         `json:"refresh_token"`
		Token        string         `json:"access_token"`
		Type         string         `json:"token_type"`
		ExpiresIn    expirationTime `json:"expires_in"`
	}

	// Transaction struct
	Transaction struct {
		Amount           *Amount         `json:"amount"`
		Description      string          `json:"description,omitempty"`
		ItemList         *ItemList       `json:"item_list,omitempty"`
		InvoiceNumber    string          `json:"invoice_number,omitempty"`
		Custom           string          `json:"custom,omitempty"`
		SoftDescriptor   string          `json:"soft_descriptor,omitempty"`
		RelatedResources []Related       `json:"related_resources,omitempty"`
		PaymentOptions   *PaymentOptions `json:"payment_options,omitempty"`
		NotifyURL        string          `json:"notify_url,omitempty"`
		OrderURL         string          `json:"order_url,omitempty"`
		Payee            *Payee          `json:"payee,omitempty"`
	}

	//Payee struct
	Payee struct {
		Email string `json:"email"`
	}

	// UserInfo struct
	UserInfo struct {
		ID              string   `json:"user_id"`
		Name            string   `json:"name"`
		GivenName       string   `json:"given_name"`
		FamilyName      string   `json:"family_name"`
		Email           string   `json:"email"`
		Verified        bool     `json:"verified,omitempty,string"`
		Gender          string   `json:"gender,omitempty"`
		BirthDate       string   `json:"birthdate,omitempty"`
		ZoneInfo        string   `json:"zoneinfo,omitempty"`
		Locale          string   `json:"locale,omitempty"`
		Phone           string   `json:"phone_number,omitempty"`
		Address         *Address `json:"address,omitempty"`
		VerifiedAccount bool     `json:"verified_account,omitempty,string"`
		AccountType     string   `json:"account_type,omitempty"`
		AgeRange        string   `json:"age_range,omitempty"`
		PayerID         string   `json:"payer_id,omitempty"`
	}

	// WebProfile represents the configuration of the payment web payment experience
	//
	// https://developer.paypal.com/docs/api/payment-experience/
	WebProfile struct {
		ID           string       `json:"id,omitempty"`
		Name         string       `json:"name"`
		Presentation Presentation `json:"presentation,omitempty"`
		InputFields  InputFields  `json:"input_fields,omitempty"`
		FlowConfig   FlowConfig   `json:"flow_config,omitempty"`
	}

	// Presentation represents the branding and locale that a customer sees on
	// redirect payments
	//
	// https://developer.paypal.com/docs/api/payment-experience/#definition-presentation
	Presentation struct {
		BrandName  string `json:"brand_name,omitempty"`
		LogoImage  string `json:"logo_image,omitempty"`
		LocaleCode string `json:"locale_code,omitempty"`
	}

	// InputFields represents the fields that are displayed to a customer on
	// redirect payments
	//
	// https://developer.paypal.com/docs/api/payment-experience/#definition-input_fields
	InputFields struct {
		AllowNote       bool `json:"allow_note,omitempty"`
		NoShipping      uint `json:"no_shipping,omitempty"`
		AddressOverride uint `json:"address_override,omitempty"`
	}

	// FlowConfig represents the general behaviour of redirect payment pages
	//
	// https://developer.paypal.com/docs/api/payment-experience/#definition-flow_config
	FlowConfig struct {
		LandingPageType   string `json:"landing_page_type,omitempty"`
		BankTXNPendingURL string `json:"bank_txn_pending_url,omitempty"`
		UserAction        string `json:"user_action,omitempty"`
	}
)

// Error method implementation for ErrorResponse struct
func (r *ErrorResponse) Error() string {
	return fmt.Sprintf("%v %v: %d %s", r.Response.Request.Method, r.Response.Request.URL, r.Response.StatusCode, r.Message)
}

// MarshalJSON for JSONTime
func (t JSONTime) MarshalJSON() ([]byte, error) {
	stamp := fmt.Sprintf(`"%s"`, time.Time(t).UTC().Format(time.RFC3339))
	return []byte(stamp), nil
}

func (e *expirationTime) UnmarshalJSON(b []byte) error {
	var n json.Number
	err := json.Unmarshal(b, &n)
	if err != nil {
		return err
	}
	i, err := n.Int64()
	if err != nil {
		return err
	}
	*e = expirationTime(i)
	return nil
}