package lewan

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"strings"
	"time"
)

type Config struct {
	BaseURL       string
	AccessKey     string
	SecretKey     string
	ApplicationID string
	WebhookSecret string
}

type Client struct {
	cfg        Config
	httpClient *http.Client
}

func NewClient(cfg Config, httpClient *http.Client) *Client {
	cfg.BaseURL = strings.TrimRight(strings.TrimSpace(cfg.BaseURL), "/")
	if cfg.BaseURL == "" {
		cfg.BaseURL = "https://shop.cloudtentacles.com"
	}
	if httpClient == nil {
		httpClient = &http.Client{Timeout: 15 * time.Second}
	}
	return &Client{
		cfg:        cfg,
		httpClient: httpClient,
	}
}

func (c *Client) SetHTTPClient(client *http.Client) {
	if client != nil {
		c.httpClient = client
	}
}

// 统一包装响应
type ResponseEnvelope struct {
	Data       json.RawMessage `json:"data"`
	RequestId  string          `json:"requestId"`
	StatusCode int             `json:"statusCode,omitempty"`
	Error      string          `json:"error,omitempty"`
	Message    interface{}     `json:"message,omitempty"` // string or []string
	Code       string          `json:"code,omitempty"`
}

// Product 代表乐玩平台商品
type Product struct {
	ID                 string `json:"id"`
	CategoryId         string `json:"categoryId"`
	CategoryName       string `json:"categoryName"`
	Name               string `json:"name"`
	Summary            string `json:"summary"`
	ThumbnailUrl       string `json:"thumbnailUrl"`
	Stock              int64  `json:"stock"`
	RoleDeliveryLimit  *int   `json:"roleDeliveryLimit"`
	DeliveryType       string `json:"deliveryType"` // LINK_BINDING, EMAIL_BINDING
	EffectiveUnitPrice string `json:"effectiveUnitPrice"`
	AccessMode         string `json:"accessMode"` // PURCHASE, VIEW
	UpdatedAt          string `json:"updatedAt"`
	ProductVersion     string `json:"productVersion"`
}

type ProductListResult struct {
	Items    []Product `json:"items"`
	Total    int64     `json:"total"`
	Page     int       `json:"page"`
	PageSize int       `json:"pageSize"`
}

// OrderItem 下单商品项
type OrderItem struct {
	ProductID string `json:"productId"`
	Quantity  int64  `json:"quantity"`
}

// CreateOrderReq 下单请求
type CreateOrderReq struct {
	CallerOrderID string      `json:"callerOrderId"`
	RoleID        string      `json:"roleId"`
	Items         []OrderItem `json:"items"`
}

// BindingAction 绑定动作快照
type BindingAction struct {
	BindingRequired         bool    `json:"bindingRequired"`
	BindingType             string  `json:"bindingType"`
	ExpiresAt               *string `json:"expiresAt"`
	BindingDeadline         *string `json:"bindingDeadline"`
	BindingUrl              string  `json:"bindingUrl"`
	BindingUrlIssuedAt      *string `json:"bindingUrlIssuedAt"`
	BindingUrlExpiresAt     *string `json:"bindingUrlExpiresAt"`
	BindingUrlExpired       bool    `json:"bindingUrlExpired"`
	BindingActionEndpoint   *string `json:"bindingActionEndpoint"`
	EmailCodeSent           bool    `json:"emailCodeSent"`
	AllocationInProgress    bool    `json:"allocationInProgress"`
	BindingActionInProgress bool    `json:"bindingActionInProgress"`
}

// LewanOrder 乐玩订单
type LewanOrder struct {
	ID                string         `json:"id"`
	OrderNo           string         `json:"orderNo"`
	CallerOrderID     string         `json:"callerOrderId"`
	OrderVersion      int            `json:"orderVersion"`
	RoleID            string         `json:"roleId"`
	CategoryId        string         `json:"categoryId"`
	DeliveryType      string         `json:"deliveryType"`
	OrderedAmount     string         `json:"orderedAmount"`
	SettledAmount     string         `json:"settledAmount"`
	ReleasedAmount    string         `json:"releasedAmount"`
	HeldAmount        string         `json:"heldAmount"`
	FeeAmount         string         `json:"feeAmount"`
	Quantity          int64          `json:"quantity"`
	SucceededQuantity int64          `json:"succeededQuantity"`
	FailedQuantity    int64          `json:"failedQuantity"`
	ReleasedQuantity  int64          `json:"releasedQuantity"`
	PendingQuantity   int64          `json:"pendingQuantity"`
	FailureCodes      []string       `json:"failureCodes"`
	Status            string         `json:"status"` // WAITING_BINDING, QUEUED, PROCESSING, RECONCILING, SUCCEEDED, PARTIAL_SUCCESS, FAILED, CANCELLED
	BindingDeadline   *string        `json:"bindingDeadline"`
	BindingAction     *BindingAction `json:"bindingAction,omitempty"`
	Binding           *BindingInfo   `json:"binding,omitempty"`
	CompletedAt       *string        `json:"completedAt,omitempty"`
}

// CreateOrderResult 下单响应
type CreateOrderResult struct {
	Order            *LewanOrder    `json:"order"`
	BindingAction    *BindingAction `json:"bindingAction"`
	IdempotentReplay bool           `json:"idempotentReplay"`
}

// BindingResult 绑定刷新响应
type BindingInfo struct {
	Status     string `json:"status"`
	Verified   bool   `json:"verified"`
	Matched    bool   `json:"matched"`
	RoleID     string `json:"roleId"`
	RoleName   string `json:"roleName"`
	RoleArea   string `json:"roleArea,omitempty"`
	ServerName string `json:"serverName"`
}

type RefreshBindingResult struct {
	Order   *LewanOrder  `json:"order"`
	Binding *BindingInfo `json:"binding"`
}

type WalletBalance struct {
	AvailableBalance string `json:"availableBalance"`
	FrozenBalance    string `json:"frozenBalance"`
	TotalBalance     string `json:"totalBalance"`
}

// ListProducts 查询当前可见商品列表
func (c *Client) ListProducts(ctx context.Context, page, pageSize int, keyword string) (*ProductListResult, error) {
	if page <= 0 {
		page = 1
	}
	if pageSize <= 0 {
		pageSize = 50
	}
	query := fmt.Sprintf("page=%d&pageSize=%d", page, pageSize)
	if keyword != "" {
		query += "&keyword=" + RFC3986Escape(keyword)
	}

	var out ProductListResult
	if err := c.do(ctx, http.MethodGet, "/openapi/v1/products", query, nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// GetProduct 查询单个商品详情
func (c *Client) GetProduct(ctx context.Context, id string) (*Product, error) {
	var out Product
	if err := c.do(ctx, http.MethodGet, "/openapi/v1/products/"+id, "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// CreateOrder 幂等创建聚合订单
func (c *Client) CreateOrder(ctx context.Context, req CreateOrderReq) (*CreateOrderResult, error) {
	body, err := json.Marshal(req)
	if err != nil {
		return nil, err
	}
	var out CreateOrderResult
	if err := c.do(ctx, http.MethodPost, "/openapi/v1/orders", "", body, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// GetOrder 按订单 ID 查单
func (c *Client) GetOrder(ctx context.Context, id string) (*LewanOrder, error) {
	var out LewanOrder
	if err := c.do(ctx, http.MethodGet, "/openapi/v1/orders/"+id, "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// GetOrderByCallerOrder 按调用方订单号精确查单（用于超时补偿）
func (c *Client) GetOrderByCallerOrder(ctx context.Context, callerOrderID string) (*LewanOrder, error) {
	query := "callerOrderId=" + RFC3986Escape(callerOrderID)
	var out LewanOrder
	if err := c.do(ctx, http.MethodGet, "/openapi/v1/orders/by-caller-order-id", query, nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// RestoreBindingAction 重新进入时显式获取或恢复原订单绑定动作
func (c *Client) RestoreBindingAction(ctx context.Context, orderID string) (*CreateOrderResult, error) {
	var out CreateOrderResult
	if err := c.do(ctx, http.MethodPost, fmt.Sprintf("/openapi/v1/orders/%s/binding/action", orderID), "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// RefreshBinding LINK 用户绑定后刷新角色信息；匹配成功即进入发货
func (c *Client) RefreshBinding(ctx context.Context, orderID string) (*RefreshBindingResult, error) {
	var out RefreshBindingResult
	if err := c.do(ctx, http.MethodPost, fmt.Sprintf("/openapi/v1/orders/%s/binding/refresh", orderID), "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// CancelOrder 取消整单（仅在未越过渠道提交边界时有效）
func (c *Client) CancelOrder(ctx context.Context, orderID string) (*LewanOrder, error) {
	var out LewanOrder
	if err := c.do(ctx, http.MethodPost, fmt.Sprintf("/openapi/v1/orders/%s/cancel", orderID), "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

// GetWallet 查询钱包余额
func (c *Client) GetWallet(ctx context.Context) (*WalletBalance, error) {
	var out WalletBalance
	if err := c.do(ctx, http.MethodGet, "/openapi/v1/wallets", "", nil, &out); err != nil {
		return nil, err
	}
	return &out, nil
}

func (c *Client) do(ctx context.Context, method, path, query string, body []byte, out interface{}) error {
	if c.cfg.AccessKey == "" || c.cfg.SecretKey == "" {
		return errors.New("乐玩开放平台 AccessKey 或 SecretKey 未配置")
	}
	ts := strconv.FormatInt(time.Now().Unix(), 10)
	nonce := GenerateNonce()
	bodySHA := SHA256Hex(body)

	signingStr := BuildSigningString(method, path, query, bodySHA, ts, nonce)
	signature := SignRequest(c.cfg.SecretKey, signingStr)

	reqURL := c.cfg.BaseURL + path
	if query != "" {
		reqURL += "?" + query
	}

	var bodyReader io.Reader
	if len(body) > 0 {
		bodyReader = bytes.NewReader(body)
	}

	req, err := http.NewRequestWithContext(ctx, method, reqURL, bodyReader)
	if err != nil {
		return fmt.Errorf("构建请求失败: %w", err)
	}

	req.Header.Set("Content-Type", "application/json; charset=utf-8")
	req.Header.Set(HeaderAccessKey, c.cfg.AccessKey)
	req.Header.Set(HeaderTimestamp, ts)
	req.Header.Set(HeaderNonce, nonce)
	req.Header.Set(HeaderSignature, signature)

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return fmt.Errorf("请求乐玩平台网络异常: %w", err)
	}
	defer resp.Body.Close()

	respBytes, err := io.ReadAll(io.LimitReader(resp.Body, 1<<21)) // limit 2MB
	if err != nil {
		return fmt.Errorf("读取乐玩响应失败: %w", err)
	}

	var envelope ResponseEnvelope
	if err := json.Unmarshal(respBytes, &envelope); err != nil {
		return fmt.Errorf("解析乐玩响应失败 (HTTP %d): %s", resp.StatusCode, string(respBytes))
	}

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		errMsg := ""
		switch v := envelope.Message.(type) {
		case string:
			errMsg = v
		case []interface{}:
			var parts []string
			for _, item := range v {
				parts = append(parts, fmt.Sprint(item))
			}
			errMsg = strings.Join(parts, "; ")
		}
		if errMsg == "" {
			errMsg = envelope.Error
		}
		if errMsg == "" {
			errMsg = fmt.Sprintf("HTTP %d", resp.StatusCode)
		}
		if envelope.Code != "" {
			return fmt.Errorf("[%s] %s", envelope.Code, errMsg)
		}
		return errors.New(errMsg)
	}

	if out != nil && len(envelope.Data) > 0 && string(envelope.Data) != "null" {
		if err := json.Unmarshal(envelope.Data, out); err != nil {
			return fmt.Errorf("解析乐玩业务数据失败: %w", err)
		}
	}
	return nil
}