// 示例 15：OAuth 授权流程（无需 import miot）
//
// go run .  首次运行自动创建 user.json，打开授权链接完成授权后粘贴 code。

package main

import (
	"bufio"
	"crypto/rand"
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"

	"git.zeroonesoft.cn/golib/xiaomihome/xiaomi"
)

type userFile struct {
	UID     string `json:"uid"`
	UUID    string `json:"uuid"`
	Auth    struct {
		AccessToken  string `json:"access_token"`
		RefreshToken string `json:"refresh_token"`
		ExpiresTS    int64  `json:"expires_ts"`
	} `json:"auth"`
	DataDir string `json:"data_dir"`
}

const filePath = "user.json"

func load() *userFile {
	data, _ := os.ReadFile(filePath)
	var u userFile
	json.Unmarshal(data, &u)
	if u.UUID == "" {
		u.UUID = newUUID()
		save(&u)
	}
	return &u
}

func save(u *userFile) {
	data, _ := json.MarshalIndent(u, "", "  ")
	os.WriteFile(filePath, data, 0600)
}

func newUUID() string {
	b := make([]byte, 16)
	rand.Read(b)
	return fmt.Sprintf("%x", b)
}

func main() {
	ctx := context.Background()
	u := load()

	if u.Auth.AccessToken != "" {
		fmt.Println("已完成授权")
		fmt.Printf("UID: %s\n", u.UID)
		fmt.Printf("AccessToken:  %s...\n", u.Auth.AccessToken[:min(20, len(u.Auth.AccessToken))])
		fmt.Printf("RefreshToken: %s...\n", u.Auth.RefreshToken[:min(20, len(u.Auth.RefreshToken))])
		return
	}

	authURL := xiaomi.AuthURL(xiaomi.Config{UUID: u.UUID})
	fmt.Println("========== OAuth 授权 ==========")
	fmt.Println("请打开以下链接完成授权，然后把地址栏中的 code 粘贴回来：")
	fmt.Println()
	fmt.Println(" ", authURL)
	fmt.Println()
	fmt.Print("输入 code: ")

	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	code := scanner.Text()
	if code == "" {
		log.Fatal("未输入 code")
	}

	result, err := xiaomi.ExchangeCode(ctx, xiaomi.Config{UUID: u.UUID}, code)
	if err != nil {
		log.Fatal("ExchangeCode 失败:", err)
	}

	u.UID = result.UID
	u.Auth.AccessToken = result.AccessToken
	u.Auth.RefreshToken = result.RefreshToken
	u.Auth.ExpiresTS = result.ExpiresTS
	u.DataDir = "./data/" + u.UID
	save(u)

	fmt.Println("\n=== Token 已保存 ===")
	fmt.Printf("UID:          %s\n", u.UID)
	fmt.Printf("AccessToken:  %s...\n", u.Auth.AccessToken[:min(20, len(u.Auth.AccessToken))])
	fmt.Printf("RefreshToken: %s...\n", u.Auth.RefreshToken[:min(20, len(u.Auth.RefreshToken))])
}