implement POST /print-job-cost-calculations

13 files changed, 539 insertions, 342 deletions

diff --git a/.gitignore b/.gitignore
index 647f879..07aa8ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 *_gen.go
-testdata
+spec.yml
+testdata/clientkey
+testdata/clientsecret
 todo
diff --git a/Makefile b/Makefile
index ce6ef7e..3f144ca 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,9 @@ build: ${SRC} ${GEN}
 ${GEN}: ${SRC}
 	go generate
 
+spec.yml:
+	curl -L -o $@ 'https://api.lulu.com/api-docs/openapi-specs/openapi_public.yml'
+
 clean:
 	rm -f ${GEN}
 
diff --git a/cost.go b/cost.go
index 202fcde..ab605ce 100644
--- a/cost.go
+++ b/cost.go
@@ -1,38 +1,42 @@
 package lulu
 
-// TODO: should we remove the redundant tax/subtotal fields or remain
-// true to their retarded api?
-
 import (
 	"encoding/json"
-	"fmt"
 
 	"github.com/shopspring/decimal"
 )
 
-// printJobCostReq is the json body of a /print-job-cost-calculations/ request.
 type printJobCostReq struct {
-	LineItems []printJobCostLineItem `json:"line_items"`
-	ShipAddr  ShippingAddress        `json:"shipping_address"`
-	ShipOpt   ShippingLevel          `json:"shipping_option"`
+	LineItems []PrintJobCostLineItem  `json:"line_items"`
+	ShipAddr  printJobCostReqShipAddr `json:"shipping_address"`
+	ShipOpt   ShippingLevel           `json:"shipping_option"`
 }
 
-type printJobCostLineItem struct {
+type PrintJobCostLineItem struct {
 	NPages   uint  `json:"page_count"`
 	Mfg      PkgId `json:"pod_package_id"`
 	Quantity uint  `json:"quantity"`
 }
 
+type printJobCostReqShipAddr struct {
+	City     string `json:"city"`
+	Country  string `json:"country_code"`
+	PostCode string `json:"postcode"`
+	State    string `json:"state_code"`
+	Street1  string `json:"street1"`
+	Phone    string `json:"phone_number"`
+}
+
 // PrintJobCost is the response from /print-job-cost-calculations/.
 type PrintJobCost struct {
 	Addr, SuggestedAddr                                         ShippingAddress
-	AddrWarning                                                 ShippingAddressWarning
-	Currency                                                    string
+	AddrWarnings                                                []ShippingAddressWarning
 	Fees                                                        []Fee
-	FulfillmentCost                                             FulfillmentCost
 	LineItemCosts                                               []LineItemCost
 	ShipCost                                                    FulfillmentCost
-	TotalCostExclTax, TotalCostInclTax, TotalDiscount, TotalTax decimal.Decimal
+	FulfillmentCost                                             FulfillmentCost
+	TotalTax, TotalCostExclTax, TotalCostInclTax, TotalDiscount decimal.Decimal
+	Currency                                                    string
 }
 
 type ShippingAddressWarning struct {
@@ -53,113 +57,67 @@ type Fee struct {
 }
 
 type FulfillmentCost struct {
-	TaxRate          decimal.Decimal `json:"tax_rate"`
 	TotalCostExclTax decimal.Decimal `json:"total_cost_excl_tax"`
 	TotalCostInclTax decimal.Decimal `json:"total_cost_incl_tax"`
 	TotalTax         decimal.Decimal `json:"total_tax"`
+	TaxRate          decimal.Decimal `json:"tax_rate"`
 }
 
 type LineItemCost struct {
-	CostExclDiscounts      decimal.Decimal  `json:"cost_excl_discounts"`
-	Discounts              []Discount       `json:"discounts"`
-	Quantity               uint             `json:"quantity"`
-	TaxRate                decimal.Decimal  `json:"tax_rate"`
-	TotalCostExclDiscounts decimal.Decimal  `json:"total_cost_excl_discounts"`
-	TotalCostExclTax       decimal.Decimal  `json:"total_cost_excl_tax"`
-	TotalCostInclTax       decimal.Decimal  `json:"total_cost_incl_tax"`
-	TotalTax               decimal.Decimal  `json:"total_tax"`
-	UnitTierCost           *decimal.Decimal `json:"unit_tier_cost"`
+	CostExclDiscounts      decimal.Decimal `json:"cost_excl_discounts"`
+	TotalTax               decimal.Decimal `json:"total_tax"`
+	TaxRate                decimal.Decimal `json:"tax_rate"`
+	Quantity               uint            `json:"quantity"`
+	TotalCostExclTax       decimal.Decimal `json:"total_cost_excl_tax"`
+	TotalCostExclDiscounts decimal.Decimal `json:"total_cost_excl_discounts"`
+	TotalCostInclTax       decimal.Decimal `json:"total_cost_incl_tax"`
+	Discounts              []Discount      `json:"discounts"`
+	UnitTierCost           decimal.Decimal `json:"unit_tier_cost"`
 }
 
 type Discount struct {
-	Amount decimal.Decimal `json:"amount"`
-	Descr  string          `json:"description"`
+	Amount      decimal.Decimal `json:"amount"`
+	Description string          `json:"description"`
 }
 
-// printJobCostResp is the json body of a /print-job-cost-calculations/ response.
 type printJobCostResp struct {
-	Addr struct {
-		City        string                   `json:"city"`
-		CountryCode string                   `json:"country_code"`
-		IsBusiness  bool                     `json:"is_business"`
-		Name        string                   `json:"name"`
-		Phone       string                   `json:"phone_number"`
-		PostCode    string                   `json:"postcode"`
-		StateCode   string                   `json:"state_code"`
-		Street1     string                   `json:"street1"`
-		Street2     string                   `json:"street2"`
-		Warning     ShippingAddressWarning   `json:"warnings"`
-		Suggested   suggestedShippingAddress `json:"suggested_address"`
-	} `json:"shipping_address"`
-	Currency         string          `json:"currency"`
+	Addr             json.RawMessage `json:"shipping_address"`
 	Fees             []Fee           `json:"fees"`
-	FulfillmentCost  FulfillmentCost `json:"fulfillment_cost"`
 	LineItemCosts    []LineItemCost  `json:"line_item_costs"`
 	ShipCost         FulfillmentCost `json:"shipping_cost"`
+	FulfillmentCost  FulfillmentCost `json:"fulfillment_cost"`
+	TotalTax         decimal.Decimal `json:"total_tax"`
 	TotalCostExclTax decimal.Decimal `json:"total_cost_excl_tax"`
 	TotalCostInclTax decimal.Decimal `json:"total_cost_incl_tax"`
 	TotalDiscount    decimal.Decimal `json:"total_discount_amount"`
-	TotalTax         decimal.Decimal `json:"total_tax"`
-}
-
-// Some blockhead that Lulu hired thought it would be a good idea to use
-// a string in one place and a number in another for the postal code.
-// That's why this special struct is needed.
-type suggestedShippingAddress struct {
-	CountryCode string `json:"country_code"`
-	StateCode   string `json:"state_code"`
-	PostCode    uint   `json:"postcode"`
-	City        string `json:"city"`
-	Street1     string `json:"street1"`
-	Street2     string `json:"street2"`
+	Currency         string          `json:"currency"`
 }
 
 func (c *PrintJobCost) UnmarshalJSON(data []byte) error {
-	// Lulu decided to put warnings and suggested_address INSIDE
-	// shipping_address in the response. So we unmarshal into an
-	// alias struct and then map onto our own structs. The
-	// alternative is to add everything to our ShippingAddress
-	// struct, but that would be confusing to users of this library:
-	// ShippingAddress would have semantics because some fields would
-	// be "optional".
-
 	var resp printJobCostResp
 	if err := json.Unmarshal(data, &resp); err != nil {
 		return err
 	}
-
-	addr := resp.Addr
-	c.Addr = ShippingAddress{
-		City:        addr.City,
-		CountryCode: addr.CountryCode,
-		IsBusiness:  addr.IsBusiness,
-		Name:        addr.Name,
-		Phone:       addr.Phone,
-		PostCode:    addr.PostCode,
-		StateCode:   addr.StateCode,
-		Street1:     addr.Street1,
-		Street2:     addr.Street2,
+	if err := json.Unmarshal(resp.Addr, &c.Addr); err != nil {
+		return err
 	}
-	sugad := addr.Suggested
-	c.SuggestedAddr = ShippingAddress{
-		CountryCode: sugad.CountryCode,
-		StateCode:   sugad.StateCode,
-		PostCode:    fmt.Sprint(sugad.PostCode), // idiot
-		City:        sugad.City,
-		Street1:     sugad.Street1,
-		Street2:     sugad.Street2,
+	var warnsAndSugg struct {
+		Warnings  []ShippingAddressWarning `json:"warnings"`
+		Suggested ShippingAddress          `json:"suggested_address"`
 	}
-	c.AddrWarning = addr.Warning
-
-	c.Currency = resp.Currency
+	if err := json.Unmarshal(resp.Addr, &warnsAndSugg); err != nil {
+		return err
+	}
+	c.SuggestedAddr = warnsAndSugg.Suggested
+	c.AddrWarnings = warnsAndSugg.Warnings
 	c.Fees = resp.Fees
-	c.FulfillmentCost = resp.FulfillmentCost
 	c.LineItemCosts = resp.LineItemCosts
 	c.ShipCost = resp.ShipCost
+	c.FulfillmentCost = resp.FulfillmentCost
+	c.TotalTax = resp.TotalTax
 	c.TotalCostExclTax = resp.TotalCostExclTax
 	c.TotalCostInclTax = resp.TotalCostInclTax
 	c.TotalDiscount = resp.TotalDiscount
-	c.TotalTax = resp.TotalTax
-
+	c.Currency = resp.Currency
 	return nil
 }
diff --git a/cost_test.go b/cost_test.go
index a8aeb3d..1abe63c 100644
--- a/cost_test.go
+++ b/cost_test.go
@@ -1,247 +1,208 @@
 package lulu
 
 import (
+	_ "embed"
 	"testing"
 
 	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/text/currency"
 )
 
-func TestMarshalUnmarshalPrintJobCostReq(t *testing.T) {
-	j := `{
-		"line_items": [
-			{
-				"page_count": 32,
-				"pod_package_id": "0600X0900.BW.STD.PB.060UW444.MXX",
-				"quantity": 20
-			}, {
-				"page_count": 324,
-				"pod_package_id": "0425X0687.BW.STD.PB.060UW444.GXX",
-				"quantity": 200
-			}
-		],
-		"shipping_address": {
-			"city": "Lübeck",
-			"country_code": "DE",
-			"postcode": "23552",
-			"state_code": "",
-			"street1": "Holstenstr. 40",
-			"phone_number": "844-212-0689",
-			"name": "",
-			"street2": "",
-			"is_business": false
-			
-		},
-		"shipping_option": "EXPRESS"
-	}`
-	addr := printJobCostReq{
-		[]printJobCostLineItem{
-			{
-				32,
-				PkgId{UsTrade, Mono, Standard, Perfect, P60UncoatedWhite, Matte, NoLinen, NoFoil},
-				20,
-			}, {
-				324,
-				PkgId{Pocketbook, Mono, Standard, Perfect, P60UncoatedWhite, Gloss, NoLinen, NoFoil},
-				200,
-			},
-		},
-		ShippingAddress{
-			City:        "Lübeck",
-			CountryCode: "DE",
-			PostCode:    "23552",
-			Street1:     "Holstenstr. 40",
-			Phone:       "844-212-0689",
-			// TODO: does the API mind the extra fields?
-		},
-		Express,
-	}
-	requireMarshalJsonEq(t, j, addr)
-	requireUnmarshalJsonEq(t, addr, j)
-}
+var (
+	//go:embed testdata/printjobcostreq.json
+	printJobCostReqJson string
 
-func TestUnmarshalPrintJobCost(t *testing.T) {
-	j := `{
-		"shipping_address": {
-			"city": "Lübeck",
-			"country_code": "DE",
-			"is_business": false,
-			"name": "Hans Dampf",
-			"phone_number": "844-212-0689",
-			"postcode": "23552",
-			"state_code": "",
-			"street1": "Holstenstr. 40",
-			"street2": "",
-			"warnings": {
-				"type": "validation_warning",
-				"path": "external",
-				"code": "REPLACED",
-				"message": "street1: Holstenstr. 40 -> Holstenstraße 40"
-			},
-			"suggested_address": {
-				"country_code": "DE",
-				"state_code": null,
-				"postcode": 23552,
-				"city": "Lübeck",
-				"street1": "Holstenstraße 40\"",
-				"street2": null
-			}
-		},
-		"currency": "USD",
-		"fees": [
-			{
-				"currency": "USD",
-				"fee_type": "HANDLING_FEE",
-				"sku": "HANDLING_FEE",
-				"tax_rate": "0.060000",
-				"total_cost_excl_tax": "14.00",
-				"total_cost_incl_tax": "14.84",
-				"total_tax": "0.84"
-			},
-			{
-				"currency": "USD",
-				"fee_type": "FULFILLMENT_FEE",
-				"sku": "FULFILLMENT_FEE",
-				"tax_rate": "0.060000",
-				"total_cost_excl_tax": "0.75",
-				"total_cost_incl_tax": "0.80",
-				"total_tax": "0.05"
-			}
-		],
-		"fulfillment_cost": {
-			"tax_rate": "0.06",
-			"total_cost_excl_tax": "0.75",
-			"total_cost_incl_tax": "0.80",
-			"total_tax": "0.05"
-		},
-		"line_item_costs": [
-			{
-				"cost_excl_discounts": "2.55",
-				"discounts": [],
-				"quantity": 20,
-				"tax_rate": "0.060000",
-				"total_cost_excl_discounts": "51.00",
-				"total_cost_excl_tax": "51.00",
-				"total_cost_incl_tax": "54.06",
-				"total_tax": "3.06",
-				"unit_tier_cost": null
-			},
-			{
-				"cost_excl_discounts": "9.26",
-				"discounts": [
-					{
-						"amount": "92.60",
-						"description": "Volume Discount 5%"
-					}
-				],
-				"quantity": 200,
-				"tax_rate": "0.060000",
-				"total_cost_excl_discounts": "1852.00",
-				"total_cost_excl_tax": "1759.40",
-				"total_cost_incl_tax": "1864.96",
-				"total_tax": "105.56",
-				"unit_tier_cost": null
-			}
-		],
-		"shipping_cost": {
-			"tax_rate": "0.06",
-			"total_cost_excl_tax": "318.44",
-			"total_cost_incl_tax": "337.55",
-			"total_tax": "19.11"
-		},
-		"total_cost_excl_tax": "2129.59",
-		"total_cost_incl_tax": "2257.37",
-		"total_discount_amount": "92.60",
-		"total_tax": "127.78"
-	}`
+	//go:embed testdata/printjobcostresp.json
+	printJobCostRespJson string
+)
 
-	cost := PrintJobCost{
-		Addr: ShippingAddress{
-			City:        "Lübeck",
-			CountryCode: "DE",
-			IsBusiness:  false,
-			Name:        "Hans Dampf",
-			Phone:       "844-212-0689",
-			PostCode:    "23552",
-			StateCode:   "",
-			Street1:     "Holstenstr. 40",
-			Street2:     "",
-		},
-		SuggestedAddr: ShippingAddress{
-			CountryCode: "DE",
-			StateCode:   "",
-			PostCode:    "23552",
-			City:        "Lübeck",
-			Street1:     "Holstenstraße 40\"",
-			Street2:     "",
+var printJobCostReqSample = printJobCostReq{
+	[]PrintJobCostLineItem{
+		{
+			32,
+			PkgId{UsTrade, Mono, Standard, Perfect, P60UncoatedWhite, Matte, NoLinen, NoFoil},
+			20,
+		}, {
+			324,
+			PkgId{Pocketbook, Mono, Standard, Perfect, P60UncoatedWhite, Gloss, NoLinen, NoFoil},
+			200,
 		},
-		AddrWarning: ShippingAddressWarning{
-			"validation_warning",
-			"external",
-			"REPLACED",
-			"street1: Holstenstr. 40 -> Holstenstraße 40",
-		},
-		Currency: "USD",
-		Fees: []Fee{
-			{
-				Currency:         "USD",
-				Type:             "HANDLING_FEE",
-				Sku:              "HANDLING_FEE",
-				TaxRate:          decimal.RequireFromString("0.060000"),
-				TotalCostExclTax: decimal.RequireFromString("14.00"),
-				TotalCostInclTax: decimal.RequireFromString("14.84"),
-				TotalTax:         decimal.RequireFromString("0.84"),
-			}, {
-				Currency:         "USD",
-				Type:             "FULFILLMENT_FEE",
-				Sku:              "FULFILLMENT_FEE",
-				TaxRate:          decimal.RequireFromString("0.060000"),
-				TotalCostExclTax: decimal.RequireFromString("0.75"),
-				TotalCostInclTax: decimal.RequireFromString("0.80"),
-				TotalTax:         decimal.RequireFromString("0.05"),
-			},
-		},
-		FulfillmentCost: FulfillmentCost{
-			TaxRate:          decimal.RequireFromString("0.06"),
+	},
+	printJobCostReqShipAddr{
+		City:     "Lübeck",
+		Country:  "DE",
+		PostCode: "23552",
+		State:    "",
+		Street1:  "Holstenstr. 40",
+		Phone:    "844-212-0689",
+	},
+	Express,
+}
+
+var printJobCostSample = PrintJobCost{
+	Addr: ShippingAddress{
+		City:       "Lübeck",
+		PostCode:   "23552",
+		Street1:    "Holstenstr. 40",
+		Phone:      "844-212-0689",
+		State:      "",
+		Country:    "DE",
+		IsBusiness: false,
+		Name:       ". .",
+	},
+	SuggestedAddr: ShippingAddress{
+		Country:  "DE",
+		State:    "",
+		PostCode: "23552",
+		City:     "Lübeck",
+		Street1:  "Holstenstraße 40",
+		Street2:  "",
+	},
+	AddrWarnings: []ShippingAddressWarning{{
+		"validation_warning",
+		"external",
+		"REPLACED",
+		"street1: Holstenstr. 40 -> Holstenstraße 40",
+	}},
+	Fees: []Fee{
+		{
+			Currency:         "USD",
+			Type:             "HANDLING_FEE",
+			Sku:              "HANDLING_FEE",
+			TaxRate:          decimal.RequireFromString("0.060000"),
+			TotalCostExclTax: decimal.RequireFromString("14.00"),
+			TotalCostInclTax: decimal.RequireFromString("14.84"),
+			TotalTax:         decimal.RequireFromString("0.84"),
+		}, {
+			Currency:         "USD",
+			Type:             "FULFILLMENT_FEE",
+			Sku:              "FULFILLMENT_FEE",
+			TaxRate:          decimal.RequireFromString("0.060000"),
 			TotalCostExclTax: decimal.RequireFromString("0.75"),
 			TotalCostInclTax: decimal.RequireFromString("0.80"),
 			TotalTax:         decimal.RequireFromString("0.05"),
 		},
-		LineItemCosts: []LineItemCost{
-			{
-				CostExclDiscounts:      decimal.RequireFromString("2.55"),
-				Discounts:              []Discount{},
-				Quantity:               20,
-				TaxRate:                decimal.RequireFromString("0.060000"),
-				TotalCostExclDiscounts: decimal.RequireFromString("51.00"),
-				TotalCostExclTax:       decimal.RequireFromString("51.00"),
-				TotalCostInclTax:       decimal.RequireFromString("54.06"),
-				TotalTax:               decimal.RequireFromString("3.06"),
-				UnitTierCost:           nil,
-			}, {
-				CostExclDiscounts: decimal.RequireFromString("9.26"),
-				Discounts: []Discount{
-					{decimal.RequireFromString("92.60"), "Volume Discount 5%"},
-				},
-				Quantity:               200,
-				TaxRate:                decimal.RequireFromString("0.060000"),
-				TotalCostExclDiscounts: decimal.RequireFromString("1852.00"),
-				TotalCostExclTax:       decimal.RequireFromString("1759.40"),
-				TotalCostInclTax:       decimal.RequireFromString("1864.96"),
-				TotalTax:               decimal.RequireFromString("105.56"),
-				UnitTierCost:           nil,
-			},
-		},
-		ShipCost: FulfillmentCost{
-			TaxRate:          decimal.RequireFromString("0.06"),
-			TotalCostExclTax: decimal.RequireFromString("318.44"),
-			TotalCostInclTax: decimal.RequireFromString("337.55"),
-			TotalTax:         decimal.RequireFromString("19.11"),
+	},
+	LineItemCosts: []LineItemCost{
+		{
+			CostExclDiscounts:      decimal.RequireFromString("4.95"),
+			TotalTax:               decimal.RequireFromString("6.93"),
+			TaxRate:                decimal.RequireFromString("0.070000"),
+			Quantity:               20,
+			TotalCostExclTax:       decimal.RequireFromString("99.00"),
+			TotalCostExclDiscounts: decimal.RequireFromString("99.00"),
+			TotalCostInclTax:       decimal.RequireFromString("105.93"),
+			Discounts:              []Discount{},
+			UnitTierCost:           decimal.RequireFromString("4.95"),
+		}, {
+			CostExclDiscounts:      decimal.RequireFromString("16.19"),
+			TotalTax:               decimal.RequireFromString("215.33"),
+			TaxRate:                decimal.RequireFromString("0.070000"),
+			Quantity:               200,
+			TotalCostExclTax:       decimal.RequireFromString("3076.10"),
+			TotalCostExclDiscounts: decimal.RequireFromString("3238.00"),
+			TotalCostInclTax:       decimal.RequireFromString("3291.43"),
+			Discounts:              []Discount{{decimal.RequireFromString("161.90"), "Volume Discount 5%"}},
+			UnitTierCost:           decimal.RequireFromString("16.19"),
 		},
-		TotalCostExclTax: decimal.RequireFromString("2129.59"),
-		TotalCostInclTax: decimal.RequireFromString("2257.37"),
-		TotalDiscount:    decimal.RequireFromString("92.60"),
-		TotalTax:         decimal.RequireFromString("127.78"),
+	},
+	ShipCost: FulfillmentCost{
+		TotalCostExclTax: decimal.RequireFromString("1085.50"),
+		TotalCostInclTax: decimal.RequireFromString("1161.49"),
+		TotalTax:         decimal.RequireFromString("75.99"),
+		TaxRate:          decimal.RequireFromString("0.19"),
+	},
+	FulfillmentCost: FulfillmentCost{
+		TotalCostExclTax: decimal.RequireFromString("1.05"),
+		TotalCostInclTax: decimal.RequireFromString("1.12"),
+		TotalTax:         decimal.RequireFromString("0.07"),
+		TaxRate:          decimal.RequireFromString("0.19"),
+	},
+	TotalTax:         decimal.RequireFromString("298.32"),
+	TotalCostExclTax: decimal.RequireFromString("4261.65"),
+	TotalCostInclTax: decimal.RequireFromString("4559.97"),
+	TotalDiscount:    decimal.RequireFromString("161.90"),
+	Currency:         "CAD",
+}
+
+func TestMarshalPrintJobCostReq(t *testing.T) {
+	requireMarshalJsonEq(t, printJobCostReqJson, printJobCostReqSample)
+}
+
+func TestUnmarshalPrintJobCost(t *testing.T) {
+	requireUnmarshalJsonEq(t, printJobCostSample, printJobCostRespJson)
+}
+
+func TestPrintJobCost(t *testing.T) {
+	c := newClient(t)
+	items := printJobCostReqSample.LineItems
+	addr := ShippingAddress{
+		City:     "Lübeck",
+		Country:  "DE",
+		PostCode: "23552",
+		State:    "",
+		Street1:  "Holstenstr. 40",
+		Phone:    "844-212-0689",
+	}
+	shiplvl := printJobCostReqSample.ShipOpt
+	cost, err := c.PrintJobCost(items, addr, shiplvl)
+	require.NoError(t, err)
+	require.Equal(t, "Lübeck", cost.Addr.City)
+	require.Equal(t, "23552", cost.Addr.PostCode)
+	require.Equal(t, "Holstenstr. 40", cost.Addr.Street1)
+	require.Equal(t, "844-212-0689", cost.Addr.Phone)
+	require.Empty(t, cost.Addr.State)
+	require.Equal(t, "DE", cost.Addr.Country)
+	require.False(t, cost.Addr.IsBusiness)
+	require.Equal(t, printJobCostSample.SuggestedAddr, cost.SuggestedAddr)
+	require.Equal(t, printJobCostSample.AddrWarnings, cost.AddrWarnings)
+	requireCurrency(t, cost.Currency)
+	for _, fee := range cost.Fees {
+		requireCurrency(t, fee.Currency)
+		require.NotEmpty(t, fee.Type)
+		require.NotEmpty(t, fee.Sku)
+		requireNotZeroDec(t, fee.TaxRate)
+		requireNotZeroDec(t, fee.TotalCostExclTax)
+		requireNotZeroDec(t, fee.TotalCostInclTax)
+		requireNotZeroDec(t, fee.TotalTax)
+	}
+	requireNotZeroDec(t, cost.FulfillmentCost.TaxRate)
+	requireNotZeroDec(t, cost.FulfillmentCost.TotalCostExclTax)
+	requireNotZeroDec(t, cost.FulfillmentCost.TotalCostInclTax)
+	requireNotZeroDec(t, cost.FulfillmentCost.TotalTax)
+	require.NotEmpty(t, cost.LineItemCosts)
+	for _, lic := range cost.LineItemCosts {
+		requireNotZeroDec(t, lic.CostExclDiscounts)
+		for _, discount := range lic.Discounts {
+			require.Equal(t, "Volume Discount 5%", discount.Description)
+			requireNotZeroDec(t, discount.Amount)
+		}
+		require.NotZero(t, lic.Quantity)
+		requireNotZeroDec(t, lic.TaxRate)
+		requireNotZeroDec(t, lic.TotalCostExclDiscounts)
+		requireNotZeroDec(t, lic.TotalCostExclTax)
+		requireNotZeroDec(t, lic.TotalCostInclTax)
+		requireNotZeroDec(t, lic.TotalTax)
+		requireNotZeroDec(t, lic.UnitTierCost)
 	}
+	requireNotZeroDec(t, cost.ShipCost.TaxRate)
+	requireNotZeroDec(t, cost.ShipCost.TotalCostExclTax)
+	requireNotZeroDec(t, cost.ShipCost.TotalCostInclTax)
+	requireNotZeroDec(t, cost.ShipCost.TotalTax)
+	requireNotZeroDec(t, cost.TotalCostExclTax)
+	requireNotZeroDec(t, cost.TotalCostInclTax)
+	requireNotZeroDec(t, cost.TotalDiscount)
+	requireNotZeroDec(t, cost.TotalTax)
+}
+
+func requireCurrency(t *testing.T, s string) {
+	t.Helper()
+	_, err := currency.ParseISO(s)
+	require.NoError(t, err)
+}
 
-	requireUnmarshalJsonEq(t, cost, j)
+func requireNotZeroDec(t *testing.T, d decimal.Decimal) {
+	t.Helper()
+	require.False(t, d.IsZero())
 }
diff --git a/err.go b/err.go
index cb79500..58984dc 100644
--- a/err.go
+++ b/err.go
@@ -58,6 +58,6 @@ type errDecResp struct {
 
 func (e errDecResp) Error() string {
 	req := e.Response.Request
-	return fmt.Sprintf("%s %s: error decoding response body %q: %v",
+	return fmt.Sprintf("%s %s: error decoding response body `%s`: %v",
 		req.Method, req.URL, string(e.body), e.error)
 }
diff --git a/go.mod b/go.mod
index eda2d03..5f4d74d 100644
--- a/go.mod
+++ b/go.mod
@@ -6,6 +6,7 @@ require (
 	github.com/shopspring/decimal v1.4.0
 	github.com/stretchr/testify v1.11.1
 	golang.org/x/oauth2 v0.36.0
+	golang.org/x/text v0.37.0
 )
 
 require (
@@ -13,8 +14,8 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spf13/pflag v1.0.6 // indirect
 	github.com/yawnak/string-enumer v0.0.0-20250330104602-f50db3525c45 // indirect
-	golang.org/x/mod v0.24.0 // indirect
-	golang.org/x/sync v0.12.0 // indirect
-	golang.org/x/tools v0.31.0 // indirect
+	golang.org/x/mod v0.35.0 // indirect
+	golang.org/x/sync v0.20.0 // indirect
+	golang.org/x/tools v0.44.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index e9731b8..e8912ba 100644
--- a/go.sum
+++ b/go.sum
@@ -10,14 +10,16 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/yawnak/string-enumer v0.0.0-20250330104602-f50db3525c45 h1:0iUqJCEe0kuryd8KPqhnnczbXrD6r66Qrlus4Q7xrb4=
 github.com/yawnak/string-enumer v0.0.0-20250330104602-f50db3525c45/go.mod h1:14IQUPrpaeA3sucvDb4CoBSnKSaIrXhKZOfdy4ZIx1E=
-golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
-golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww=
+golang.org/x/mod v0.35.0 h1:Ww1D637e6Pg+Zb2KrWfHQUnH2dQRLBQyAtpr/haaJeM=
+golang.org/x/mod v0.35.0/go.mod h1:+GwiRhIInF8wPm+4AoT6L0FA1QWAad3OMdTRx4tFYlU=
 golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
 golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
-golang.org/x/sync v0.12.0 h1:MHc5BpPuC30uJk597Ri8TV3CNZcTLu6B6z4lJy+g6Jw=
-golang.org/x/sync v0.12.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
-golang.org/x/tools v0.31.0 h1:0EedkvKDbh+qistFTd0Bcwe/YLh4vHwWEkiI0toFIBU=
-golang.org/x/tools v0.31.0/go.mod h1:naFTU+Cev749tSJRXJlna0T3WxKvb1kWEx15xA4SdmQ=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/text v0.37.0 h1:Cqjiwd9eSg8e0QAkyCaQTNHFIIzWtidPahFWR83rTrc=
+golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
+golang.org/x/tools v0.44.0 h1:UP4ajHPIcuMjT1GqzDWRlalUEoY+uzoZKnhOjbIPD2c=
+golang.org/x/tools v0.44.0/go.mod h1:KA0AfVErSdxRZIsOVipbv3rQhVXTnlU6UhKxHd1seDI=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
diff --git a/lulu.go b/lulu.go
index 9e567a7..302bfc5 100644
--- a/lulu.go
+++ b/lulu.go
@@ -7,8 +7,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"net/url"
+	"os"
 
 	"golang.org/x/oauth2/clientcredentials"
 )
@@ -21,6 +23,7 @@ const (
 	validateInteriorPath = "/validate-interior"
 	coverDimensionsPath  = "/cover-dimensions"
 	validateCoverPath    = "/validate-cover"
+	printJobCostPath     = "/print-job-cost-calculations"
 )
 
 // ApiUrl is the location of the API server. It is set to the sandbox
@@ -28,6 +31,11 @@ const (
 // you are ready to deploy.
 var ApiUrl = SandboxUrl
 
+var (
+	Debug    = false // print debug info to stdout
+	debugLog = log.New(os.Stderr, "DEBUG ", log.LstdFlags|log.Llongfile)
+)
+
 type Client struct {
 	c *http.Client
 }
@@ -143,6 +151,29 @@ func (c *Client) GetCoverValidation(id uint) (CoverValidationRecord, error) {
 	return rec, nil
 }
 
+// PrintJobCost calculates the cost of a hypothetical print order without
+// actually creating a print job.
+//
+// https://api.lulu.com/docs/#tag/Print-Job-Cost-Calculations/operation/Print-Job-cost-calculations_create
+func (c *Client) PrintJobCost(items []PrintJobCostLineItem, addr ShippingAddress, shipOpt ShippingLevel) (PrintJobCost, error) {
+	reqAddr := printJobCostReqShipAddr{
+		City:     addr.City,
+		Country:  addr.Country,
+		PostCode: addr.PostCode,
+		State:    addr.State,
+		Street1:  addr.Street1,
+		Phone:    addr.Phone,
+	}
+	payload := printJobCostReq{items, reqAddr, shipOpt}
+	var cost PrintJobCost
+	err := c.postDecode(printJobCostPath, payload, http.StatusCreated, &cost)
+	if err != nil {
+		return cost, pkgErr(err)
+	}
+	return cost, nil
+}
+
+// getDecode sends a GET request and unmarshals the response.
 func (c *Client) getDecode(path string, v any) error {
 	url, err := url.JoinPath(ApiUrl, path)
 	if err != nil {
@@ -159,6 +190,7 @@ func (c *Client) getDecode(path string, v any) error {
 	return decodeResponse(resp, v)
 }
 
+// postDecode sends a POST request and unmarshals the response.
 func (c *Client) postDecode(path string, payload any, wantStatus int, v any) error {
 	resp, err := c.post(path, payload)
 	if err != nil {
@@ -184,13 +216,21 @@ func (c *Client) post(path string, payload any) (*http.Response, error) {
 }
 
 func decodeResponse(resp *http.Response, v any) error {
-	buf := new(bytes.Buffer)
-	if _, err := io.Copy(buf, resp.Body); err != nil {
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
 		return errReadResp{resp, err}
 	}
-	dec := json.NewDecoder(buf)
-	if err := dec.Decode(v); err != nil {
-		return errDecResp{resp, buf.Bytes(), err}
+
+	debugf("%s %s response: `%s`\n", resp.Request.Method, resp.Request.URL, body)
+
+	if err := json.Unmarshal(body, v); err != nil {
+		return errDecResp{resp, body, err}
 	}
 	return nil
 }
+
+func debugf(format string, a ...any) {
+	if Debug {
+		debugLog.Printf(format, a...)
+	}
+}
diff --git a/lulu_test.go b/lulu_test.go
index f657681..648ede7 100644
--- a/lulu_test.go
+++ b/lulu_test.go
@@ -31,6 +31,8 @@ var (
 )
 
 func TestMain(m *testing.M) {
+	Debug = true
+
 	if b, err := os.ReadFile(clientKeyPath); err == nil {
 		clientKey = strings.TrimSpace(string(b))
 	} else {
diff --git a/notes b/notes
new file mode 100644
index 0000000..331cabe
--- /dev/null
+++ b/notes
@@ -0,0 +1,11 @@
+-- Print Job Cost --
+
+The API doc is either out of date or was never correct to begin with.
+The response fields in the doc are different from what the server
+actually responds with. Therefore testdata/printjobcostresp.json is
+the union of the doc example and a real response from the sandbox
+server. For instance, the doc example has a "fees" field while the
+real response did not; thus "fees" is included in the testdata. The
+real response had "first_name" and "last_name" rather than just
+"name", so ShippingAddress has a custom UnmarshalJSON() function to
+account for both. And so on...
diff --git a/ship.go b/ship.go
index aef655e..b5aa822 100644
--- a/ship.go
+++ b/ship.go
@@ -1,6 +1,11 @@
 package lulu
 
-//go:generate go run github.com/yawnak/string-enumer -t ShippingLevel --text -o ./ship_gen.go .
+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
@@ -14,13 +19,107 @@ const (
 )
 
 type ShippingAddress struct {
-	Name        string `json:"name"`
-	Phone       string `json:"phone_number"`
-	CountryCode string `json:"country_code"`
-	PostCode    string `json:"postcode"`
-	StateCode   string `json:"state_code"`
-	City        string `json:"city"`
-	Street1     string `json:"street1"`
-	Street2     string `json:"street2"`
-	IsBusiness  bool   `json:"is_business"`
+	Country      string // ISO 3166-2 country code
+	State        string // 2 or 3 letter state codes (officially called ISO-3166-2 subdivision codes). They are required for some countries (e.g. US, MX, CA, AU)
+	City         string
+	Street1      string // First address line
+	Street2      string // Second address line
+	PostCode     string // Required for most countries
+	IsBusiness   bool   // Only relevant for US addresses. Some US carriers don't deliver to business-addresses on Saturday.
+	Name         string // Full name of the person, including first and last name.
+	Title        Title
+	Organization string // Name of an organization. Required if no person name is given.
+	Email        string // 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.
+	Phone        string // 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.
+	TaxId        string // The recipient’s tax identification number. Required for shipping addresses to Brazil, Chile, and Mexico.
+}
+
+// They use "country" in some places, "country_code" in others, etc.
+// This is the union of all of them.
+type shippingAddress 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        string `json:"email"`
+	Phone        string `json:"phone_number"`
+	TaxId        string `json:"recipient_tax_id"`
+}
+
+func (a *ShippingAddress) UnmarshalJSON(data []byte) error {
+	s := string(data)
+	var alias shippingAddress
+	if err := json.Unmarshal(data, &alias); err != nil {
+		return err
+	}
+
+	if country, both := either(alias.Country, alias.CountryCode); !both {
+		a.Country = country
+	} else {
+		return fmt.Errorf(`address contains both "country" and "country_code": %q`, s)
+	}
+
+	if state, both := either(alias.State, alias.StateCode); !both {
+		a.State = state
+	} else {
+		return fmt.Errorf(`address contains both "state" and "state_code": %q`, s)
+	}
+
+	a.City = alias.City
+	a.Street1 = alias.Street1
+	a.Street2 = alias.Street2
+	a.PostCode = alias.PostCode
+	a.IsBusiness = alias.IsBusiness
+
+	hasName := alias.Name != ""
+	hasFirst := alias.FirstName != ""
+	hasLast := alias.LastName != ""
+	if hasName && (hasFirst || hasLast) {
+		return fmt.Errorf(`address contains both "name" and {"first_name", "last_name"}: %q`, s)
+	} else if hasName {
+		a.Name = alias.Name
+	} else if hasFirst && hasLast {
+		a.Name = fmt.Sprintf("%s %s", alias.FirstName, alias.LastName)
+	} else if hasLast {
+		a.Name = alias.LastName
+	} else if hasFirst {
+		a.Name = alias.FirstName
+	}
+
+	a.Title = alias.Title
+	a.Organization = alias.Organization
+	a.Email = alias.Email
+	a.Phone = alias.Phone
+	a.TaxId = alias.TaxId
+
+	return nil
+}
+
+func either(a, b string) (string, bool) {
+	if a != "" && b != "" {
+		return a, true
+	} else if a != "" {
+		return a, false
+	}
+	return b, false
 }
+
+type Title string
+
+const (
+	Mr   Title = "MR"
+	Miss Title = "MISS"
+	Mrs  Title = "MRS"
+	Ms   Title = "MS"
+	Dr   Title = "DR"
+)
diff --git a/testdata/printjobcostreq.json b/testdata/printjobcostreq.json
new file mode 100644
index 0000000..d521f77
--- /dev/null
+++ b/testdata/printjobcostreq.json
@@ -0,0 +1,23 @@
+{
+  "line_items": [
+    {
+      "page_count": 32,
+      "pod_package_id": "0600X0900.BW.STD.PB.060UW444.MXX",
+      "quantity": 20
+    },
+    {
+      "page_count": 324,
+      "pod_package_id": "0425X0687.BW.STD.PB.060UW444.GXX",
+      "quantity": 200
+    }
+  ],
+  "shipping_address": {
+    "city": "Lübeck",
+    "country_code": "DE",
+    "postcode": "23552",
+    "state_code": "",
+    "street1": "Holstenstr. 40",
+    "phone_number": "844-212-0689"
+  },
+  "shipping_option": "EXPRESS"
+}
\ No newline at end of file
diff --git a/testdata/printjobcostresp.json b/testdata/printjobcostresp.json
new file mode 100644
index 0000000..f633183
--- /dev/null
+++ b/testdata/printjobcostresp.json
@@ -0,0 +1,95 @@
+{
+  "shipping_address": {
+    "city": "Lübeck",
+    "postcode": "23552",
+    "street1": "Holstenstr. 40",
+    "phone_number": "844-212-0689",
+    "state": "",
+    "country": "DE",
+    "is_business": false,
+    "first_name": ".",
+    "last_name": ".",
+    "warnings": [
+      {
+        "type": "validation_warning",
+        "code": "REPLACED",
+        "path": "external",
+        "message": "street1: Holstenstr. 40 -> Holstenstraße 40"
+      }
+    ],
+    "suggested_address": {
+      "country_code": "DE",
+      "state_code": null,
+      "postcode": "23552",
+      "city": "Lübeck",
+      "street1": "Holstenstraße 40",
+      "street2": null
+    }
+  },
+  "fees": [
+    {
+      "currency": "USD",
+      "fee_type": "HANDLING_FEE",
+      "sku": "HANDLING_FEE",
+      "tax_rate": "0.060000",
+      "total_cost_excl_tax": "14.00",
+      "total_cost_incl_tax": "14.84",
+      "total_tax": "0.84"
+    },
+    {
+      "currency": "USD",
+      "fee_type": "FULFILLMENT_FEE",
+      "sku": "FULFILLMENT_FEE",
+      "tax_rate": "0.060000",
+      "total_cost_excl_tax": "0.75",
+      "total_cost_incl_tax": "0.80",
+      "total_tax": "0.05"
+    }
+  ],
+  "line_item_costs": [
+    {
+      "cost_excl_discounts": "4.95",
+      "total_tax": "6.93",
+      "tax_rate": "0.070000",
+      "quantity": 20,
+      "total_cost_excl_tax": "99.00",
+      "total_cost_excl_discounts": "99.00",
+      "total_cost_incl_tax": "105.93",
+      "discounts": [],
+      "unit_tier_cost": "4.95"
+    },
+    {
+      "cost_excl_discounts": "16.19",
+      "total_tax": "215.33",
+      "tax_rate": "0.070000",
+      "quantity": 200,
+      "total_cost_excl_tax": "3076.10",
+      "total_cost_excl_discounts": "3238.00",
+      "total_cost_incl_tax": "3291.43",
+      "discounts": [
+        {
+          "amount": "161.90",
+          "description": "Volume Discount 5%"
+        }
+      ],
+      "unit_tier_cost": "16.19"
+    }
+  ],
+  "shipping_cost": {
+    "total_cost_excl_tax": "1085.50",
+    "total_cost_incl_tax": "1161.49",
+    "total_tax": "75.99",
+    "tax_rate": "0.19"
+  },
+  "fulfillment_cost": {
+    "total_cost_excl_tax": "1.05",
+    "total_cost_incl_tax": "1.12",
+    "total_tax": "0.07",
+    "tax_rate": "0.19"
+  },
+  "total_tax": "298.32",
+  "total_cost_excl_tax": "4261.65",
+  "total_cost_incl_tax": "4559.97",
+  "total_discount_amount": "161.90",
+  "currency": "CAD"
+}