package ymt_v3

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

// Env 环境
type Env string

const (
	EnvTest    Env = "test"
	EnvProduct Env = "product"
)

// 环境地址
const (
	testBaseURL    = "https://gateway.dev.cdlsxd.cn"
	productBaseURL = "https://market.api.86698.cn"
)

// ClientConfig 客户端配置
type ClientConfig struct {
	AppID       string        // 应用ID
	PrivateKey  string        // 应用私钥（PEM格式）
	PublicKey   string        // 平台公钥（PEM格式）
	Key         string        // 业务参数加密key
	EncryptType EncryptType   // 加密类型：aes 或 sm4
	Env         Env           // 环境：test 或 product
	HTTPClient  *http.Client  // HTTP客户端，可选
}

// Client SDK客户端
type Client struct {
	config     *ClientConfig
	httpClient *http.Client
	baseURL    string
}

// NewClient 创建新的SDK客户端
func NewClient(config *ClientConfig) (*Client, error) {
	if config.AppID == "" {
		return nil, fmt.Errorf("AppID不能为空")
	}
	if config.PrivateKey == "" {
		return nil, fmt.Errorf("PrivateKey不能为空")
	}
	if config.PublicKey == "" {
		return nil, fmt.Errorf("PublicKey不能为空")
	}
	if config.Key == "" {
		return nil, fmt.Errorf("Key不能为空")
	}
	if config.EncryptType == "" {
		config.EncryptType = EncryptTypeAES
	}
	if config.Env == "" {
		config.Env = EnvTest
	}

	var baseURL string
	switch config.Env {
	case EnvTest:
		baseURL = testBaseURL
	case EnvProduct:
		baseURL = productBaseURL
	default:
		return nil, fmt.Errorf("不支持的环境: %s", config.Env)
	}

	httpClient := config.HTTPClient
	if httpClient == nil {
		httpClient = &http.Client{}
	}

	return &Client{
		config:     config,
		httpClient: httpClient,
		baseURL:    baseURL,
	}, nil
}

// doRequest 发送请求并处理响应
func (c *Client) doRequest(path string, bizParams interface{}, result interface{}) error {
	// 1. 加密业务参数
	ciphertext, err := EncryptBizParams(bizParams, []byte(c.config.Key), c.config.EncryptType)
	if err != nil {
		return NewSDKError("加密业务参数失败", err)
	}

	// 2. 生成时间戳
	timestamp := GenerateTimestamp()

	// 3. 构建签名字符串并签名
	signStr := BuildSignStr(c.config.AppID, timestamp, ciphertext)
	sign, err := SignWithRSA(signStr, c.config.PrivateKey)
	if err != nil {
		return NewSDKError("签名失败", err)
	}

	// 4. 构建请求体
	reqBody := map[string]string{
		"ciphertext": ciphertext,
	}
	reqBodyBytes, err := json.Marshal(reqBody)
	if err != nil {
		return NewSDKError("序列化请求体失败", err)
	}

	// 5. 创建HTTP请求
	url := c.baseURL + path
	req, err := http.NewRequest("POST", url, bytes.NewReader(reqBodyBytes))
	if err != nil {
		return NewSDKError("创建HTTP请求失败", err)
	}

	// 6. 设置Header
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Appid", c.config.AppID)
	req.Header.Set("Timestamp", timestamp)
	req.Header.Set("Sign", sign)

	// 7. 发送请求
	resp, err := c.httpClient.Do(req)
	if err != nil {
		return NewSDKError("发送HTTP请求失败", err)
	}
	defer resp.Body.Close()

	// 8. 读取响应
	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return NewSDKError("读取响应失败", err)
	}

	// 9. 解析公共响应
	var commonResp CommonResponse
	if err := json.Unmarshal(respBody, &commonResp); err != nil {
		return NewSDKError("解析响应JSON失败", err)
	}

	// 10. 检查业务错误
	if commonResp.Code != 200 {
		return NewAPIError(commonResp.Code, commonResp.Message, commonResp.Reason)
	}

	// 11. 检查是否有加密数据
	if commonResp.Data == nil || commonResp.Data.Ciphertext == "" {
		return NewSDKError("响应中没有加密数据", nil)
	}

	// 12. 解密响应数据
	decrypted, err := DecryptBizParams(commonResp.Data.Ciphertext, []byte(c.config.Key), c.config.EncryptType)
	if err != nil {
		return NewSDKError("解密响应数据失败", err)
	}

	// 13. 解析解密后的数据到结果
	if err := json.Unmarshal(decrypted, result); err != nil {
		return NewSDKError("解析解密后的响应数据失败", err)
	}

	return nil
}

// ==================== API方法 ====================

// KeyOrder 获取券码
// POST /openapi/v1/key/order
func (c *Client) KeyOrder(req *KeyOrderRequest) (*KeyOrderResponse, error) {
	result := &KeyOrderResponse{}
	if err := c.doRequest("/openapi/v1/key/order", req, result); err != nil {
		return nil, err
	}
	return result, nil
}

// KeyQuery 券码查询
// POST /openapi/v1/key/query
func (c *Client) KeyQuery(req *KeyQueryRequest) (*KeyOrderResponse, error) {
	result := &KeyOrderResponse{}
	if err := c.doRequest("/openapi/v1/key/query", req, result); err != nil {
		return nil, err
	}
	return result, nil
}

// KeyDiscard 券码作废
// POST /openapi/v1/key/discard
func (c *Client) KeyDiscard(req *KeyDiscardRequest) (*KeyDiscardResponse, error) {
	result := &KeyDiscardResponse{}
	if err := c.doRequest("/openapi/v1/key/discard", req, result); err != nil {
		return nil, err
	}
	return result, nil
}

// BatchOrder 批量发卡
// POST /openapi/v1/key/batch_order
func (c *Client) BatchOrder(req *BatchOrderRequest) (*BatchOrderResponse, error) {
	result := &BatchOrderResponse{}
	if err := c.doRequest("/openapi/v1/key/batch_order", req, result); err != nil {
		return nil, err
	}
	return result, nil
}

// BatchQuery 批量查询
// POST /openapi/v1/key/batch_query
func (c *Client) BatchQuery(req *BatchQueryRequest) (*BatchQueryResponse, error) {
	result := &BatchQueryResponse{}
	if err := c.doRequest("/openapi/v1/key/batch_query", req, result); err != nil {
		return nil, err
	}
	return result, nil
}

// VerifyNotify 验证回调通知
func (c *Client) VerifyNotify(header *NotifyHeader, data interface{}) error {
	return VerifyNotifySign(header, data, []byte(c.config.Key), c.config.PublicKey, c.config.EncryptType)
}

// GetBaseURL 获取当前环境的基础URL
func (c *Client) GetBaseURL() string {
	return c.baseURL
}

// GetAppID 获取应用ID
func (c *Client) GetAppID() string {
	return c.config.AppID
}

// String 返回客户端配置的字符串表示（隐藏敏感信息）
func (c *Client) String() string {
	return fmt.Sprintf("Client{AppID: %s, Env: %s, BaseURL: %s, EncryptType: %s}",
		c.config.AppID, c.config.Env, c.baseURL, c.config.EncryptType)
}