package httpx

import (
	"context"
	"encoding/json"
	"fmt"
	"net/url"
	"sync"
	"time"

	"github.com/cloudwego/hertz/pkg/app/client"
	"github.com/cloudwego/hertz/pkg/protocol"
	"github.com/cloudwego/hertz/pkg/protocol/consts"
)

var (
	once           sync.Once
	clientInstance *HertzClient
)

// HertzClient 定义
type HertzClient struct {
	Client  *client.Client
	Timeout time.Duration
	Header  map[string]string
}

// Init 初始化单例
func Init() {
	once.Do(func() {
		c, _ := client.NewClient()
		clientInstance = &HertzClient{
			Client:  c,
			Timeout: 5 * time.Second,
			Header:  make(map[string]string),
		}
	})
}

// SetHeader 设置默认 header
func SetHeader(key, value string) {
	if clientInstance == nil {
		Init()
	}
	clientInstance.Header[key] = value
}

// 支持 value 为任意类型
func buildQueryString(query map[string][]any) string {
	if len(query) == 0 {
		return ""
	}

	values := url.Values{}
	for k, arr := range query {
		for _, v := range arr {
			values.Add(k, fmt.Sprintf("%v", v)) // 自动转 string
		}
	}
	return values.Encode()
}

func Get(ctx context.Context, urlStr string, query map[string][]any) (int, string, error) {
	if clientInstance == nil {
		Init()
	}
	h := clientInstance
	req := &protocol.Request{}
	res := &protocol.Response{}

	req.Header.SetMethod(consts.MethodGet)
	req.SetRequestURI(urlStr)
	if qs := buildQueryString(query); qs != "" {
		req.SetQueryString(qs)
	}

	for k, v := range h.Header {
		req.Header.Set(k, v)
	}

	ctx, cancel := context.WithTimeout(ctx, h.Timeout)
	defer cancel()

	err := h.Client.Do(ctx, req, res)
	if err != nil {
		return 0, "", err
	}

	return res.StatusCode(), string(res.Body()), nil
}

func PostJSON(ctx context.Context, urlStr string, query map[string][]any, payload any) (int, string, error) {
	if clientInstance == nil {
		Init()
	}
	h := clientInstance
	req := &protocol.Request{}
	res := &protocol.Response{}

	req.Header.SetMethod(consts.MethodPost)
	req.Header.SetContentTypeBytes([]byte("application/json"))
	req.SetRequestURI(urlStr)
	if qs := buildQueryString(query); qs != "" {
		req.SetQueryString(qs)
	}

	data, err := json.Marshal(payload)
	if err != nil {
		return 0, "", fmt.Errorf("marshal json error: %w", err)
	}
	req.SetBody(data)

	for k, v := range h.Header {
		req.Header.Set(k, v)
	}

	ctx, cancel := context.WithTimeout(ctx, h.Timeout)
	defer cancel()

	err = h.Client.Do(ctx, req, res)
	if err != nil {
		return 0, "", err
	}

	return res.StatusCode(), string(res.Body()), nil
}

func PostForm(ctx context.Context, urlStr string, query map[string][]any, form map[string]string) (int, string, error) {
	if clientInstance == nil {
		Init()
	}
	h := clientInstance
	req := &protocol.Request{}
	res := &protocol.Response{}

	req.Header.SetMethod(consts.MethodPost)
	req.SetRequestURI(urlStr)
	if qs := buildQueryString(query); qs != "" {
		req.SetQueryString(qs)
	}

	req.SetFormData(form)

	for k, v := range h.Header {
		req.Header.Set(k, v)
	}

	ctx, cancel := context.WithTimeout(ctx, h.Timeout)
	defer cancel()

	err := h.Client.Do(ctx, req, res)
	if err != nil {
		return 0, "", err
	}

	return res.StatusCode(), string(res.Body()), nil
}

func JSONStringToMap(jsonStr string) (map[string]interface{}, error) {
	var result map[string]interface{}
	if err := json.Unmarshal([]byte(jsonStr), &result); err != nil {
		return nil, err
	}
	return result, nil
}