package intelligence_finance_v1

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

// Client 业财连接SDK客户端
type Client struct {
	baseURL      string
	tenantID     string
	clientID     string
	clientSecret string
	httpClient   *http.Client
	debug        bool
}

// ClientOption 客户端配置选项
type ClientOption func(*Client)

// WithHTTPClient 设置自定义HTTP客户端
func WithHTTPClient(httpClient *http.Client) ClientOption {
	return func(c *Client) {
		c.httpClient = httpClient
	}
}

// WithDebug 开启调试模式
func WithDebug(debug bool) ClientOption {
	return func(c *Client) {
		c.debug = debug
	}
}

// WithTimeout 设置请求超时时间
func WithTimeout(timeout time.Duration) ClientOption {
	return func(c *Client) {
		c.httpClient.Timeout = timeout
	}
}

// NewClient 创建新的SDK客户端
//   - baseURL: API基础地址
//   - tenantID: 平台分配的租户唯一标识
//   - clientID: 平台分配的应用标识
//   - clientSecret: 平台分配的客户端密钥
//   - opts: 可选配置项
func NewClient(baseURL, tenantID, clientID, clientSecret string, opts ...ClientOption) *Client {
	c := &Client{
		baseURL:      baseURL,
		tenantID:     tenantID,
		clientID:     clientID,
		clientSecret: clientSecret,
		httpClient: &http.Client{
			Timeout: 30 * time.Second,
		},
	}
	for _, opt := range opts {
		opt(c)
	}
	return c
}

// doRequest 发送HTTP请求，自动添加签名和认证头
func (c *Client) doRequest(ctx context.Context, path string, request interface{}, response interface{}) error {
	bodyBytes, err := json.Marshal(request)
	if err != nil {
		return NewSDKError(ErrCodeInvalidParam, "请求序列化失败", err)
	}

	if c.debug {
		fmt.Printf("[DEBUG] Request URL: %s%s\n", c.baseURL, path)
		fmt.Printf("[DEBUG] Request Body: %s\n", string(bodyBytes))
	}

	// 生成时间戳和随机数
	timestamp := GenerateTimestamp()
	nonce, err := GenerateNonce(16)
	if err != nil {
		return NewSDKError(ErrCodeSignatureFailed, "生成随机数失败", err)
	}

	// 签名数据：timestamp + nonce
	signData := timestamp + nonce
	signature := HmacSHA256Base64(c.clientSecret, signData)

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+path, bytes.NewReader(bodyBytes))
	if err != nil {
		return NewSDKError(ErrCodeNetworkError, "创建请求失败", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("tenant-id", c.tenantID)
	req.Header.Set("client-id", c.clientID)
	req.Header.Set("x-bfl-signature-timestamp", timestamp)
	req.Header.Set("x-bfl-signature-nonce", nonce)
	req.Header.Set("x-bfl-signature", signature)

	if c.debug {
		fmt.Printf("[DEBUG] Headers: tenant-id=%s, client-id=%s, x-bfl-signature=%s\n", c.tenantID, c.clientID, signature)
	}

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return NewSDKError(ErrCodeNetworkError, "请求发送失败", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return NewSDKError(ErrCodeNetworkError, "读取响应失败", err)
	}

	if c.debug {
		fmt.Printf("[DEBUG] Response Status: %s\n", resp.Status)
		fmt.Printf("[DEBUG] Response Body: %s\n", string(respBody))
	}

	// 解析通用响应
	var commonResp CommonResponse
	if err := json.Unmarshal(respBody, &commonResp); err != nil {
		return NewSDKError(ErrCodeUnknown, "响应解析失败", err)
	}

	if commonResp.Code != 0 {
		return NewSDKError(commonResp.Code, commonResp.Msg, nil)
	}

	// 如果response不为nil，将commonResp.Data反序列化到response
	if response != nil {
		if err := json.Unmarshal(commonResp.Data, response); err != nil {
			return NewSDKError(ErrCodeUnknown, "响应数据解析失败", err)
		}
	}

	return nil
}

// ============================================================
// 接口1：订单开票
// ============================================================

// CreateInvoice 提交订单开票申请
// 文档：接口1 - 提交订单开票申请
func (c *Client) CreateInvoice(ctx context.Context, req *CreateInvoiceRequest) (*CreateInvoiceResponse, error) {
	path := "/api/v1/invoice/create"
	var resp CreateInvoiceResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口2：开票状态查询
// ============================================================

// QueryInvoiceStatus 查询订单开票状态
// 文档：接口2 - 查询订单开票状态
func (c *Client) QueryInvoiceStatus(ctx context.Context, req *QueryInvoiceStatusRequest) (*QueryInvoiceStatusResponse, error) {
	path := "/api/v1/invoice/query"
	var resp QueryInvoiceStatusResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口3：创建付款单据
// ============================================================

// CreatePayment 创建付款单据
// 文档：接口3 - 创建付款单据
func (c *Client) CreatePayment(ctx context.Context, req *CreatePaymentRequest) (*CreatePaymentResponse, error) {
	path := "/api/v1/payment/create"
	var resp CreatePaymentResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口4：支付完成通知（平台回调客户）
// 此接口由客户提供，平台调用。客户需实现HTTP Handler处理回调。
// ============================================================

// HandlePaymentNotification 处理支付完成通知
// 文档：接口4 - 支付完成通知回调处理
// 该函数用于解析平台发起的支付完成通知请求，返回SUCCESS或FAILED
// 注意：平台回调时，请求体为 NotificationRequest 结构，其中 Data 字段为 PaymentNotification 的JSON字符串
func HandlePaymentNotification(body []byte) (string, error) {
	// 先解析外层通知结构
	var notificationReq NotificationRequest
	if err := json.Unmarshal(body, &notificationReq); err != nil {
		return "FAILED", NewSDKError(ErrCodeInvalidParam, "解析通知请求失败", err)
	}

	// 根据bizType处理不同业务
	switch notificationReq.BizType {
	case "payment_notification":
		// 解析内部支付通知数据
		var paymentNotification PaymentNotification
		if err := json.Unmarshal([]byte(notificationReq.Data), &paymentNotification); err != nil {
			return "FAILED", NewSDKError(ErrCodeInvalidParam, "解析支付通知数据失败", err)
		}
		// 业务处理由调用方自行实现，此处仅返回成功
		// 调用方应在此函数基础上扩展业务逻辑
		_ = paymentNotification
	default:
		// 未知业务类型，记录日志后返回失败
		return "FAILED", NewSDKError(ErrCodeInvalidParam, "未知业务类型: "+notificationReq.BizType, nil)
	}

	return "SUCCESS", nil
}

// ============================================================
// 接口5：支付状态查询
// ============================================================

// QueryPaymentStatus 查询支付状态
// 文档：接口5 - 查询支付状态
func (c *Client) QueryPaymentStatus(ctx context.Context, req *QueryPaymentStatusRequest) (*QueryPaymentStatusResponse, error) {
	path := "/api/v1/payment/query"
	var resp QueryPaymentStatusResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口6：创建供应商
// ============================================================

// CreateSupplier 创建供应商
// 文档：接口6 - 创建供应商
func (c *Client) CreateSupplier(ctx context.Context, req *CreateSupplierRequest) (*CreateSupplierResponse, error) {
	path := "/api/v1/supplier/create"
	var resp CreateSupplierResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口7：根据名称查询供应商
// ============================================================

// QuerySupplierByName 根据供应商名称查询供应商
// 文档：接口7 - 根据名称查询供应商
func (c *Client) QuerySupplierByName(ctx context.Context, req *QuerySupplierByNameRequest) (*QuerySupplierByNameResponse, error) {
	path := "/api/v1/supplier/queryByName"
	var resp QuerySupplierByNameResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口8：更新供应商
// ============================================================

// UpdateSupplier 更新供应商信息
// 文档：接口8 - 更新供应商
func (c *Client) UpdateSupplier(ctx context.Context, req *UpdateSupplierRequest) (*UpdateSupplierResponse, error) {
	path := "/api/v1/supplier/update"
	var resp UpdateSupplierResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}

// ============================================================
// 接口9：根据用户自定义编码查询供应商
// ============================================================

// QuerySupplierByUserDefineCode 根据用户自定义编码查询供应商
// 文档：接口9 - 根据用户自定义编码查询供应商
func (c *Client) QuerySupplierByUserDefineCode(ctx context.Context, req *QuerySupplierByUserDefineCodeRequest) (*QuerySupplierByUserDefineCodeResponse, error) {
	path := "/api/v1/supplier/queryByCode"
	var resp QuerySupplierByUserDefineCodeResponse
	if err := c.doRequest(ctx, path, req, &resp); err != nil {
		return nil, err
	}
	return &resp, nil
}