feat(admin): authorize batch purchase starts

admin/internal/tasks/authorization.go

@@ -0,0 +1,128 @@
+package tasks
+
+import (
+	"errors"
+	"math"
+	"math/big"
+	"sort"
+	"strings"
+	"time"
+	_ "time/tzdata"
+)
+
+const maxStartItems = 100
+
+var (
+	ErrStartConflict = errors.New("purchase start conflicts with current task state")
+	ErrInvalidStart  = errors.New("invalid purchase start request")
+)
+
+type StartPolicy struct {
+	AuthorizationTTL time.Duration
+	MaxQuantity      int
+	MaxTotalPrice    string
+}
+type StartItem struct {
+	TaskID              string `json:"task_id"`
+	ExpectedTaskVersion int    `json:"expected_task_version"`
+}
+type StartCommand struct {
+	StartKey string      `json:"start_key"`
+	Tasks    []StartItem `json:"tasks"`
+}
+type AuthorizedTask struct {
+	TaskID          string    `json:"task_id"`
+	TaskVersion     int       `json:"task_version"`
+	AuthorizationID string    `json:"authorization_id"`
+	ExpiresAt       time.Time `json:"expires_at"`
+}
+type StartResult struct {
+	StartKey         string           `json:"start_key"`
+	AuthorizedCount  int              `json:"authorized_count"`
+	Tasks            []AuthorizedTask `json:"tasks"`
+	PaymentAutomated bool             `json:"payment_automated"`
+}
+type TaskFilter struct{ Keyword, Status, CreatedFrom, CreatedTo string }
+type TaskRow struct {
+	ID, Title, GoodsID, SKUColor, SKUSize, MaxTotalPrice, Status string
+	Quantity, Version                                            int
+	CreatedAt                                                    time.Time
+}
+
+func normalizeCents(value string) (string, *big.Int, bool) {
+	if value == "" || strings.TrimSpace(value) != value {
+		return "", nil, false
+	}
+	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 "", nil, false
+	}
+	for _, part := range parts {
+		for _, ch := range part {
+			if ch < '0' || ch > '9' {
+				return "", nil, false
+			}
+		}
+	}
+	cents := new(big.Int)
+	if _, ok := cents.SetString(parts[0]+parts[1], 10); !ok || cents.Sign() <= 0 {
+		return "", nil, false
+	}
+	return value, cents, true
+}
+
+func startItems(command StartCommand) ([]StartItem, error) {
+	if !validUUID(command.StartKey) || len(command.Tasks) == 0 || len(command.Tasks) > maxStartItems {
+		return nil, ErrInvalidStart
+	}
+	items := append([]StartItem(nil), command.Tasks...)
+	sort.Slice(items, func(i, j int) bool { return items[i].TaskID < items[j].TaskID })
+	for i, item := range items {
+		if !validUUID(item.TaskID) || item.ExpectedTaskVersion <= 0 || item.ExpectedTaskVersion == math.MaxInt || (i > 0 && item.TaskID == items[i-1].TaskID) {
+			return nil, ErrInvalidStart
+		}
+	}
+	return items, nil
+}
+
+func validTaskStatus(value string) bool {
+	if value == "" {
+		return true
+	}
+	for _, status := range []string{"DRAFT", "PENDING", "CLAIMED", "ORDERING", "NEEDS_MANUAL", "WAITING_PAYMENT", "RECONCILIATION_REQUIRED", "SUCCEEDED", "FAILED", "CANCELED"} {
+		if value == status {
+			return true
+		}
+	}
+	return false
+}
+
+func ShanghaiRange(from, to string) (time.Time, time.Time, error) {
+	if from == "" && to == "" {
+		return time.Time{}, time.Time{}, nil
+	}
+	location, err := time.LoadLocation("Asia/Shanghai")
+	if err != nil {
+		return time.Time{}, time.Time{}, err
+	}
+	parse := func(value string) (time.Time, error) { return time.ParseInLocation("2006-01-02", value, location) }
+	var start, end time.Time
+	if from != "" {
+		start, err = parse(from)
+		if err != nil {
+			return time.Time{}, time.Time{}, ErrInvalidStart
+		}
+		start = start.UTC()
+	}
+	if to != "" {
+		end, err = parse(to)
+		if err != nil {
+			return time.Time{}, time.Time{}, ErrInvalidStart
+		}
+		end = end.AddDate(0, 0, 1).UTC()
+	}
+	if !start.IsZero() && !end.IsZero() && !start.Before(end) {
+		return time.Time{}, time.Time{}, ErrInvalidStart
+	}
+	return start, end, nil
+}