goauto/server/app/goauto/shopeespec/client.go

// Package shopeespec fetches a Shopee product's complete colour and size list
// from the ERP-Go side service (#290).
//
// 存在的理由：虾皮档案里的颜色尺码是从 SYB 明细增量累积的（sybimport.mergeParsedSpec），
// SYB 送来什么才有什么，因此永远滞后于真实商品。新订单带来新组合时又变成“未匹配”，
// 采购员得反复去点 AI 匹配。拉取完整清单后可以一次性匹配完，之后新订单直接可采购。
package shopeespec

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"
)

const (
	// 返回体是颜色与尺码两个字符串数组，实测 462 字节；上限留足冗余即可。
	maxResponseBytes = 1 << 20
	requestTimeout   = 10 * time.Second
)

// ErrNotConfigured means the base URL or API key is absent, so the caller
// should skip the sync instead of failing the surrounding operation.
var ErrNotConfigured = errors.New("shopee spec service is not configured")

// Spec is the complete colour and size list of one Shopee product, exactly as
// the platform spells them — 【...】 annotations included.
type Spec struct {
	Colors []string
	Sizes  []string
}

// Client reads its endpoint and credential from the environment.
//
// `[必须]` 凭据只从环境变量读取，不接受参数传入、不落日志。本地由
// scripts/start-server.ps1 从 config.yaml 的 erpgo 段转换；线上在
// /etc/goauto/goauto.env 配置。
type Client struct {
	HTTP *http.Client
}

func NewClient() *Client { return &Client{HTTP: &http.Client{Timeout: requestTimeout}} }

// Fetch returns the full spec list for one Shopee item id.
func (c *Client) Fetch(ctx context.Context, shopeeItemID string) (Spec, error) {
	shopeeItemID = strings.TrimSpace(shopeeItemID)
	if shopeeItemID == "" {
		return Spec{}, errors.New("shopee item id is empty")
	}
	base := strings.TrimSpace(os.Getenv("GOAUTO_ERPGO_BASE_URL"))
	key := strings.TrimSpace(os.Getenv("GOAUTO_ERPGO_APIKEY"))
	if base == "" || key == "" {
		return Spec{}, ErrNotConfigured
	}
	endpoint, err := url.Parse(strings.TrimRight(base, "/") + "/api/v1/shopee/product/spec/" + url.PathEscape(shopeeItemID))
	if err != nil {
		return Spec{}, err
	}
	query := endpoint.Query()
	query.Set("apikey", key)
	endpoint.RawQuery = query.Encode()

	request, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint.String(), nil)
	if err != nil {
		return Spec{}, err
	}
	client := c.HTTP
	if client == nil {
		client = &http.Client{Timeout: requestTimeout}
	}
	response, err := client.Do(request)
	if err != nil {
		// `[必须]` 不要把 err 直接往外带：net/url 的错误会把完整 URL（含 apikey）
		// 写进错误文本，那会让凭据流进日志和工单。
		return Spec{}, fmt.Errorf("shopee spec request failed for item %s", shopeeItemID)
	}
	defer response.Body.Close()
	if response.StatusCode != http.StatusOK {
		return Spec{}, fmt.Errorf("shopee spec service returned %d for item %s", response.StatusCode, shopeeItemID)
	}
	body, err := io.ReadAll(io.LimitReader(response.Body, maxResponseBytes))
	if err != nil {
		return Spec{}, fmt.Errorf("shopee spec response unreadable for item %s", shopeeItemID)
	}
	var payload struct {
		Data struct {
			Color []string `json:"color"`
			Size  []string `json:"size"`
		} `json:"data"`
	}
	if err := json.Unmarshal(body, &payload); err != nil {
		return Spec{}, fmt.Errorf("shopee spec response is not decodable for item %s", shopeeItemID)
	}
	spec := Spec{Colors: clean(payload.Data.Color), Sizes: clean(payload.Data.Size)}
	if len(spec.Colors) == 0 && len(spec.Sizes) == 0 {
		return Spec{}, fmt.Errorf("shopee spec service returned no specs for item %s", shopeeItemID)
	}
	return spec, nil
}

func clean(values []string) []string {
	result := make([]string, 0, len(values))
	seen := map[string]bool{}
	for _, value := range values {
		value = strings.TrimSpace(value)
		if value == "" || seen[value] {
			continue
		}
		seen[value] = true
		result = append(result, value)
	}
	return result
}