package lulu

import (
	"encoding/json"
	"fmt"
)

//go:generate go run github.com/yawnak/string-enumer -t ShippingLevel -t Title --text -o ./ship_gen.go .

// ShippingLevel is the quality/speed with which a package is shipped.
type ShippingLevel string

const (
	Mail         ShippingLevel = "MAIL"          // Slowest ship method. Depending on the destination, tracking might not be available.
	PriorityMail ShippingLevel = "PRIORITY_MAIL" // Priority mail shipping
	Ground       ShippingLevel = "GROUND"        // Courier based shipping using ground transportation in the US.
	Expedited    ShippingLevel = "EXPEDITED"     // Expedited (2nd day) delivery via air mail or equivalent.
	Express      ShippingLevel = "EXPRESS"       // Overnight delivery. Fastest shipping available.
)

type Title string

const (
	Mr   Title = "MR"
	Miss Title = "MISS"
	Mrs  Title = "MRS"
	Ms   Title = "MS"
	Dr   Title = "DR"
)

type ShippingAddress struct {
	// ISO 3166-2 country code
	Country string `json:"country_code"`

	// 2 or 3 letter state code (officially called ISO-3166-2
	// subdivision codes). They are required for some countries (e.g.
	// US, MX, CA, AU).
	State string `json:"state_code"`

	City     string `json:"city"`
	Street1  string `json:"street1"`  // First address line
	Street2  string `json:"street2"`  // Second address line
	PostCode string `json:"postcode"` // Required for most countries

	// Only relevant for US addresses. Some US carriers don't deliver
	// to business-addresses on Saturday.
	IsBusiness bool `json:"is_business"`

	// Full name of the person, including first and last name.
	Name  string `json:"name"`
	Title Title  `json:"title"`

	// Name of an organization. Required if no person name is given.
	Organization string `json:"organization"`

	// Shipping carriers require an email address for notifications
	// or handling delivery issues. If no email is given, the default
	// email in the user profile will be used.
	Email EmailAddress `json:"email"`

	// Shipping carriers require a phone number for handling delivery
	// issues. If no phone number is given, the default in the API
	// user profile will be used.
	Phone PhoneNumber `json:"phone_number"`

	// The recipient's tax identification number. Required for
	// shipping addresses to Brazil, Chile, and Mexico.
	TaxId string `json:"recipient_tax_id"`
}

func (a *ShippingAddress) UnmarshalJSON(data []byte) error {
	var alias extShippingAddress
	if err := json.Unmarshal(data, &alias); err != nil {
		return err
	}
	addr, err := alias.addr()
	if err != nil {
		return err
	}
	*a = addr
	return nil
}

type ShippingAddressValidation struct {
	Address   ShippingAddress // The original address that was given to the server.
	Suggested ShippingAddress // The address that the server recommends.
	Warnings  []ShippingAddressWarning
}

func (av *ShippingAddressValidation) UnmarshalJSON(data []byte) error {
	var alias extShippingAddress
	if err := json.Unmarshal(data, &alias); err != nil {
		return err
	}
	addr, err := alias.addr()
	if err != nil {
		return err
	}
	av.Address = addr
	av.Suggested = alias.Suggested
	av.Warnings = alias.Warnings
	return nil
}

type ShippingAddressWarning struct {
	Type string `json:"type"`    // eg "validation_warning"
	Path string `json:"path"`    // eg "external"
	Code string `json:"code"`    // eg "REPLACED"
	Msg  string `json:"message"` // eg "street1: Holstenstr. 40 -> Holstenstraße 40"
}

// extShippingAddress is the extended shipping address that is seen in
// some responses. It includes "warnings" and "suggested_address". It
// also unmarshals either "country" or "country_code" etc. to account for
// the irregularities in the API.
type extShippingAddress struct {
	Country     string `json:"country"`
	CountryCode string `json:"country_code"`

	State     string `json:"state"`
	StateCode string `json:"state_code"`

	City       string `json:"city"`
	Street1    string `json:"street1"`
	Street2    string `json:"street2"`
	PostCode   string `json:"postcode"`
	IsBusiness bool   `json:"is_business"`

	Name      string `json:"name"`
	FirstName string `json:"first_name"`
	LastName  string `json:"last_name"`

	Title        Title        `json:"title"`
	Organization string       `json:"organization"`
	Email        EmailAddress `json:"email"`
	Phone        PhoneNumber  `json:"phone_number"`
	TaxId        string       `json:"recipient_tax_id"`

	Warnings  []ShippingAddressWarning `json:"warnings"`
	Suggested ShippingAddress          `json:"suggested_address"`
}

// addr takes the disjunctive union of the API's irregular fields
// ("country"/"country_code", etc.) and returns only those fields of the
// actual shipping address: excluding the suggested address and warnings.
// It returns error if two or more of the "same field" are present, eg.
// both "country" and "country_code".
func (ext extShippingAddress) addr() (ShippingAddress, error) {
	country, both := either(ext.Country, ext.CountryCode)
	if both {
		return ShippingAddress{}, fmt.Errorf(`address contains both "country" and "country_code"`)
	}

	state, both := either(ext.State, ext.StateCode)
	if both {
		return ShippingAddress{}, fmt.Errorf(`address contains both "state" and "state_code"`)
	}

	var name string
	hasName := ext.Name != ""
	hasFirst := ext.FirstName != ""
	hasLast := ext.LastName != ""
	if hasName && (hasFirst || hasLast) {
		return ShippingAddress{}, fmt.Errorf(`address contains both "name" and {"first_name", "last_name"}`)
	} else if hasName {
		name = ext.Name
	} else if hasFirst && hasLast {
		name = fmt.Sprintf("%s %s", ext.FirstName, ext.LastName)
	} else if hasLast {
		name = ext.LastName
	} else if hasFirst {
		name = ext.FirstName
	}

	return ShippingAddress{
		Country:      country,
		State:        state,
		City:         ext.City,
		Street1:      ext.Street1,
		Street2:      ext.Street2,
		PostCode:     ext.PostCode,
		IsBusiness:   ext.IsBusiness,
		Name:         name,
		Title:        ext.Title,
		Organization: ext.Organization,
		Email:        ext.Email,
		Phone:        ext.Phone,
		TaxId:        ext.TaxId,
	}, nil
}

func either(a, b string) (string, bool) {
	if a != "" && b != "" {
		return a, true
	} else if a != "" {
		return a, false
	}
	return b, false
}