feat(admin): authorize batch purchase starts

admin/internal/config/config.go

@@ -5,7 +5,9 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strconv"
 	"strings"
+	"time"
 
 	"golang.org/x/crypto/bcrypt"
 )
@@ -16,6 +18,9 @@ const (
 	sessionSecretEnv       = "CMBUYER_SESSION_SECRET"
 	cookieSecureEnv        = "CMBUYER_COOKIE_SECURE"
 	databaseSourceEnv      = "CMBUYER_DATABASE_SOURCE"
+	authorizationTTLEnv    = "CMBUYER_AUTHORIZATION_TTL"
+	maxTaskQuantityEnv     = "CMBUYER_MAX_TASK_QUANTITY"
+	maxTotalPriceEnv       = "CMBUYER_MAX_TOTAL_PRICE"
 	minimumSecretLength    = 32
 )
 
@@ -26,6 +31,9 @@ type Config struct {
 	SessionSecret       []byte
 	CookieSecure        bool
 	DatabaseSource      string
+	AuthorizationTTL    time.Duration
+	MaxTaskQuantity     int
+	MaxTotalPrice       string
 }
 
 // LoadFromEnv 从进程环境读取配置。错误只指出缺失或非法的变量名，绝不回显秘密。
@@ -71,6 +79,29 @@ func Load(lookup func(string) (string, bool)) (Config, error) {
 	if err != nil {
 		return Config{}, err
 	}
+	ttlText, err := required(lookup, authorizationTTLEnv)
+	if err != nil {
+		return Config{}, err
+	}
+	ttl, err := time.ParseDuration(ttlText)
+	if err != nil || ttl <= 0 {
+		return Config{}, fmt.Errorf("%s must be a positive duration", authorizationTTLEnv)
+	}
+	quantityText, err := required(lookup, maxTaskQuantityEnv)
+	if err != nil {
+		return Config{}, err
+	}
+	maxQuantity, err := strconv.Atoi(quantityText)
+	if err != nil || maxQuantity < 1 {
+		return Config{}, fmt.Errorf("%s must be a positive integer", maxTaskQuantityEnv)
+	}
+	maxPrice, err := required(lookup, maxTotalPriceEnv)
+	if err != nil {
+		return Config{}, err
+	}
+	if !canonicalMoney(maxPrice) {
+		return Config{}, fmt.Errorf("%s must be a canonical positive decimal", maxTotalPriceEnv)
+	}
 
 	return Config{
 		AdminUsername:       username,
@@ -78,9 +109,25 @@ func Load(lookup func(string) (string, bool)) (Config, error) {
 		SessionSecret:       []byte(secret),
 		CookieSecure:        cookieSecure,
 		DatabaseSource:      databaseSource,
+		AuthorizationTTL:    ttl, MaxTaskQuantity: maxQuantity, MaxTotalPrice: maxPrice,
 	}, nil
 }
 
+func canonicalMoney(value string) bool {
+	parts := strings.Split(value, ".")
+	if len(parts) != 2 || len(parts[0]) == 0 || len(parts[1]) != 2 || (len(parts[0]) > 1 && parts[0][0] == '0') {
+		return false
+	}
+	for _, part := range parts {
+		for _, ch := range part {
+			if ch < '0' || ch > '9' {
+				return false
+			}
+		}
+	}
+	return strings.Trim(parts[0]+parts[1], "0") != ""
+}
+
 func required(lookup func(string) (string, bool), name string) (string, error) {
 	value, present := lookup(name)
 	if !present || strings.TrimSpace(value) == "" {