package userManagement

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

// Client API 客户端
type Client struct {
	baseURL    string
	httpClient *http.Client
	accessToken string
	apiKey      string
}

// ClientOption 配置选项
type ClientOption func(*Client)

// WithAPIToken 设置 API Token（用于简单认证）
func WithAPIToken(token string) ClientOption {
	return func(c *Client) {
		c.apiKey = token
	}
}

// WithAccessToken 设置 Access Token（用于已认证请求）
func WithAccessToken(token string) ClientOption {
	return func(c *Client) {
		c.accessToken = token
	}
}

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

// NewClient 创建新的 API 客户端
func NewClient(baseURL string, opts ...ClientOption) *Client {
	c := &Client{
		baseURL: baseURL,
		httpClient: &http.Client{
			Timeout: 30 * time.Second,
		},
	}

	for _, opt := range opts {
		opt(c)
	}

	return c
}

// APIResponse 标准 API 响应
type APIResponse struct {
	Code    int             `json:"code"`
	Message string          `json:"message"`
	Data    json.RawMessage `json:"data,omitempty"`
}

// ErrorResponse 错误响应
type ErrorResponse struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

func (c *Client) doRequest(ctx context.Context, method, path string, body interface{}) (*http.Response, error) {
	u, err := url.JoinPath(c.baseURL, path)
	if err != nil {
		return nil, fmt.Errorf("failed to join URL: %w", err)
	}

	var reqBody io.Reader
	if body != nil {
		jsonData, err := json.Marshal(body)
		if err != nil {
			return nil, fmt.Errorf("failed to marshal request body: %w", err)
		}
		reqBody = bytes.NewReader(jsonData)
	}

	req, err := http.NewRequestWithContext(ctx, method, u, reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json")

	if c.accessToken != "" {
		req.Header.Set("Authorization", "Bearer "+c.accessToken)
	} else if c.apiKey != "" {
		req.Header.Set("X-API-Key", c.apiKey)
	}

	return c.httpClient.Do(req)
}

func (c *Client) parseResponse(resp *http.Response, result interface{}) error {
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("failed to read response body: %w", err)
	}

	if resp.StatusCode >= 400 {
		var errResp ErrorResponse
		if err := json.Unmarshal(body, &errResp); err == nil {
			return fmt.Errorf("API error %d: %s", resp.StatusCode, errResp.Message)
		}
		return fmt.Errorf("API error %d: %s", resp.StatusCode, string(body))
	}

	if result == nil {
		return nil
	}

	var apiResp APIResponse
	if err := json.Unmarshal(body, &apiResp); err != nil {
		return fmt.Errorf("failed to unmarshal response: %w", err)
	}

	if apiResp.Data != nil {
		if err := json.Unmarshal(apiResp.Data, result); err != nil {
			return fmt.Errorf("failed to unmarshal data: %w", err)
		}
	}

	return nil
}

// SetAccessToken 设置访问令牌
func (c *Client) SetAccessToken(token string) {
	c.accessToken = token
}
