package pairing

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

func httpJSON(method, url, token string, body interface{}) (int, []byte, error) {
	var buf bytes.Buffer
	if body != nil {
		raw, _ := json.Marshal(body)
		buf.Write(raw)
	}
	req, err := http.NewRequest(method, url, &buf)
	if err != nil {
		return 0, nil, err
	}
	req.Header.Set("Content-Type", "application/json")
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return 0, nil, err
	}
	defer resp.Body.Close()
	raw, _ := io.ReadAll(resp.Body)
	return resp.StatusCode, raw, nil
}

func field(raw []byte, key string) string {
	var m map[string]interface{}
	_ = json.Unmarshal(raw, &m)
	if d, ok := m["data"].(map[string]interface{}); ok {
		if v, ok := d[key]; ok {
			switch t := v.(type) {
			case string:
				return t
			case float64:
				return strconv.FormatInt(int64(t), 10)
			}
		}
	}
	return ""
}

type ginH map[string]interface{}

// AutoPair 开发便利：登录 → 取配对码 → 配对（无 UI 场景闭环用）
func AutoPair(server, email, password, deviceName, pubKeyB64 string) (uint64, error) {
	code, raw, err := httpJSON("POST", server+"/api/v1/auth/login", "", ginH{"email": email, "password": password})
	if err != nil || code != 200 {
		return 0, fmt.Errorf("login failed: %s", string(raw))
	}
	token := field(raw, "accessToken")
	code, raw, err = httpJSON("POST", server+"/api/v1/agent/pair-code", token, nil)
	if err != nil || code != 200 {
		return 0, fmt.Errorf("pair-code failed: %s", string(raw))
	}
	pairCode := field(raw, "code")
	return PairWithCode(server, pairCode, deviceName, "core", "0.2.0", pubKeyB64)
}

// PairWithCode 凭配对码注册设备，返回服务器分配的设备 ID
func PairWithCode(server, pairCode, deviceName, osName, version, pubKeyB64 string) (uint64, error) {
	code, raw, err := httpJSON("POST", server+"/api/v1/agent/pair", "", ginH{
		"code": pairCode, "deviceName": deviceName, "os": osName, "version": version, "publicKey": pubKeyB64,
	})
	if err != nil || code != 200 {
		return 0, fmt.Errorf("pair failed: %s", string(raw))
	}
	id, _ := strconv.ParseUint(field(raw, "deviceId"), 10, 64)
	if id == 0 {
		return 0, fmt.Errorf("pair response missing deviceId")
	}
	return id, nil
}