package main

import (
	"bufio"
	"bytes"
	"context"
	"crypto/tls"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"os"
	"os/signal"
	"path/filepath"
	"regexp"
	"sort"
	"strings"
	"sync"
	"sync/atomic"
	"syscall"
	"time"

	"github.com/google/uuid"
	"github.com/skip2/go-qrcode"
)

const (
	version       = "1.4.1"
	upstreamBase  = "https://copilot.tencent.com"
	clientUA      = "CLI/2.143.1 CodeBuddy/2.143.1"
	originReferer = "https://www.codebuddy.cn"

	endpointAuthState    = upstreamBase + "/v2/plugin/auth/state?platform=VSCode"
	endpointLoginAcct    = upstreamBase + "/v2/plugin/login/account?state="
	endpointAuthToken    = upstreamBase + "/v2/plugin/auth/token?state="
	endpointTokenRefresh = upstreamBase + "/v2/plugin/auth/token/refresh"
	endpointChat         = upstreamBase + "/v2/chat/completions"

	loginTTL = 5 * time.Minute
)

// -----------------------------------------------------------------------------
// 数据结构定义
// -----------------------------------------------------------------------------

type StoredAuth struct {
	Auth    StoredTokens  `json:"auth"`
	Account StoredAccount `json:"account"`
}

type StoredTokens struct {
	AccessToken  string `json:"accessToken"`
	RefreshToken string `json:"refreshToken"`
	ExpiresAt    int64  `json:"expiresAt"`
	Domain       string `json:"domain"`
}

type StoredAccount struct {
	UID          string `json:"uid"`
	EnterpriseID string `json:"enterpriseId"`
	Nickname     string `json:"nickname"`
}

type apiEnvelope struct {
	Code int             `json:"code"`
	Msg  string          `json:"msg"`
	Data json.RawMessage `json:"data"`
}

type tokenData struct {
	AccessToken      string `json:"accessToken"`
	RefreshToken     string `json:"refreshToken"`
	ExpiresIn        int64  `json:"expiresIn"`
	RefreshExpiresIn int64  `json:"refreshExpiresIn"`
	Domain           string `json:"domain"`
}

type accountData struct {
	UID          string `json:"uid"`
	EnterpriseID string `json:"enterpriseId"`
	Nickname     string `json:"nickname"`
}

type authStateData struct {
	State   string `json:"state"`
	AuthURL string `json:"authUrl"`
}

// -----------------------------------------------------------------------------
// 全局状态与配置
// -----------------------------------------------------------------------------

type Config struct {
	Addr         string
	Port         int
	AuthFile     string
	AuthDir      string
	AuthExplicit bool // 用户是否显式指定了 -auth（未指定时自动扫描目录下所有 workbuddy*.json）
	APIKey       string
	ProxyURL     string
	Verbose      bool
	HttpClient   *http.Client
}

// Account 表示一个 CodeBuddy 账号凭据及其运行时状态。
type Account struct {
	Path           string      // 凭据文件路径
	Auth           *StoredAuth // 凭据内容（失效标记恢复时可能为 nil）
	CooldownUntil  time.Time   // 冷却截止时间（429 频率限制后自动屏蔽到该时间）
	CooldownMsg    string      // 触发冷却的原因/上游提示
	Disabled       bool        // 授权失效（token 过期且无法刷新/已撤销）：禁止调度
	DisabledReason string      // 失效原因，用于控制台展示
	Nickname       string      // 失效标记持久化字段：昵称（Auth 为 nil 时使用）
	UID            string      // 失效标记持久化字段：UID
	lock           sync.Mutex  // 单账号串行锁（防止同账号并发触发 11128）
}

// disabledMarker 是授权失效账号的持久化标记（凭据文件删除后用于控制台提示重新登录）。
type disabledMarker struct {
	Path       string `json:"path"`
	Reason     string `json:"reason"`
	DisabledAt int64  `json:"disabledAt"`
	Nickname   string `json:"nickname,omitempty"`
	UID        string `json:"uid,omitempty"`
}

// markerPath 返回与凭据文件同目录的失效标记文件路径。
func markerPath(authPath string) string {
	return authPath + ".disabled"
}

var (
	cfg        Config
	authLock   sync.RWMutex
	currAuth   *StoredAuth
	reqCounter uint64

	accountMu sync.Mutex // 账号池保护锁
	accounts  []*Account // 多账号池（单账号时长度为 1，行为与旧版完全一致）
	rrIndex   int        // 轮询游标
)

// -----------------------------------------------------------------------------
// 主入口与命令行控制
// -----------------------------------------------------------------------------

func main() {
	if len(os.Args) > 1 {
		first := os.Args[1]
		if first == "help" || first == "-h" || first == "--help" {
			printHelp()
			return
		}
		if first == "version" || first == "-v" || first == "--version" {
			fmt.Printf("WorkBuddy Local Gateway v%s\n", version)
			return
		}
	}

	command := "serve"
	args := os.Args[1:]
	if len(os.Args) > 1 && !strings.HasPrefix(os.Args[1], "-") {
		command = os.Args[1]
		args = os.Args[2:]
	}

	fs := flag.NewFlagSet(command, flag.ExitOnError)
	fs.StringVar(&cfg.Addr, "addr", "127.0.0.1", "网关监听地址")
	fs.IntVar(&cfg.Port, "port", 8317, "网关监听端口")
	fs.StringVar(&cfg.AuthFile, "auth", "workbuddy.json", "凭据存储文件路径（支持逗号分隔多个文件实现多账号）")
	fs.StringVar(&cfg.AuthDir, "auth-dir", "", "凭据目录：自动加载目录下所有 workbuddy*.json 作为多账号池")
	fs.StringVar(&cfg.APIKey, "api-key", "", "可选：访问网关所需的 API Key (客户端 Bearer 校验)")
	fs.StringVar(&cfg.ProxyURL, "proxy", "", "可选：上游请求代理 (如 http://127.0.0.1:7890)")
	fs.BoolVar(&cfg.Verbose, "verbose", false, "输出详细调试日志")
	_ = fs.Parse(args)

	// 检测 -auth 是否被显式指定：
	// 若未指定 -auth 且未指定 -auth-dir，则自动扫描当前目录下所有 workbuddy*.json 组成账号池，
	// 这样把多个凭据文件放进工作目录即可自动多账号，无需手写参数。
	fs.Visit(func(f *flag.Flag) {
		if f.Name == "auth" {
			cfg.AuthExplicit = true
		}
	})

	// 初始化 HTTP 客户端
	initHTTPClient()

	switch command {
	case "serve", "run", "start":
		runServe()
	case "login":
		runLogin()
	case "status":
		runStatus()
	case "refresh":
		runRefresh()
	case "version", "-v", "--version":
		fmt.Printf("WorkBuddy Local Gateway v%s\n", version)
	default:
		fmt.Printf("未知命令: %s\n\n", command)
		printHelp()
		os.Exit(1)
	}
}

func printHelp() {
	fmt.Println(`WorkBuddy Local Gateway - 轻量化跨平台本地 AI 网关
将腾讯 CodeBuddy / 混元反代为标准 OpenAI 协议，支持直接透传任意模型到上游。
支持多账号池：轮询使用多个账号均衡额度；账号触发 429 频率限制后自动冷却屏蔽，
由其余账号代偿，冷却到期自动恢复。

用法:
  workbuddy-gateway [command] [options]

命令:
  serve       启动本地网关 (默认操作)
  login       微信/企业微信扫码登录，获取/更新凭据
  status      查看账号池状态（含冷却状态与过期时间）
  refresh     手动立即刷新所有账号访问令牌 (Access Token)
  version     查看版本信息
  help        查看帮助说明

参数选项:
  -addr <ip>        网关监听地址 (默认: 127.0.0.1)
  -port <port>      网关监听端口 (默认: 8317)
  -auth <path>      凭据文件路径；支持逗号分隔多个文件实现多账号
                    (默认: 自动发现当前目录下所有 workbuddy*.json)
  -auth-dir <dir>   凭据目录：自动加载目录下所有 workbuddy*.json 作为账号池
  -api-key <key>    设置后，调用网关必须携带 Bearer <key> 鉴权
  -proxy <url>      设置上游转发代理 (例如 http://127.0.0.1:7890 或 socks5://...)
  -verbose          输出详细调试日志 (请求/响应体)

多账号说明:
  # 登录第二个账号（保存到不同文件）
  workbuddy-gateway login -auth workbuddy2.json

  # 自动发现：把多个凭据文件放进工作目录即可自动多账号（无需任何参数）
  workbuddy-gateway serve        # 自动加载 ./workbuddy*.json

  # 启动时指定多个凭据文件（轮询 + 429 自动冷却代偿）
  workbuddy-gateway serve -auth workbuddy.json,workbuddy2.json

  # 或使用目录模式：目录内所有 workbuddy*.json 自动组成账号池
  workbuddy-gateway serve -auth-dir ./auths

示例:
  # 首次使用扫码登录
  workbuddy-gateway login

  # 启动本地网关 (监听 127.0.0.1:8317)
  workbuddy-gateway serve

  # 启动网关并指定端口和代理
  workbuddy-gateway serve -port 9000 -proxy http://127.0.0.1:7890`)
}

func initHTTPClient() {
	jar, _ := cookiejar.New(nil)
	transport := &http.Transport{
		MaxIdleConns:        50,
		IdleConnTimeout:     90 * time.Second,
		MaxIdleConnsPerHost: 10,
		TLSClientConfig:     &tls.Config{InsecureSkipVerify: false},
	}
	if cfg.ProxyURL != "" {
		pURL, err := url.Parse(cfg.ProxyURL)
		if err != nil {
			log.Fatalf("错误: 无效的代理地址 %s: %v", cfg.ProxyURL, err)
		}
		transport.Proxy = http.ProxyURL(pURL)
	}
	cfg.HttpClient = &http.Client{
		Timeout:   180 * time.Second,
		Transport: transport,
		Jar:       jar,
	}
}

// -----------------------------------------------------------------------------
// 凭据加载、保存与自动续期
// -----------------------------------------------------------------------------

func loadAuth() (*StoredAuth, error) {
	authLock.RLock()
	if currAuth != nil {
		defer authLock.RUnlock()
		return currAuth, nil
	}
	authLock.RUnlock()

	data, err := os.ReadFile(cfg.AuthFile)
	if err != nil {
		return nil, fmt.Errorf("读取凭据文件失败 (%s): %w", cfg.AuthFile, err)
	}
	var sa StoredAuth
	if err := json.Unmarshal(data, &sa); err != nil {
		return nil, fmt.Errorf("解析凭据文件失败: %w", err)
	}
	if sa.Auth.AccessToken == "" {
		return nil, fmt.Errorf("凭据文件中缺少 AccessToken")
	}

	authLock.Lock()
	currAuth = &sa
	authLock.Unlock()
	return &sa, nil
}

func saveAuth(sa *StoredAuth) error {
	authLock.Lock()
	currAuth = sa
	authLock.Unlock()

	dir := filepath.Dir(cfg.AuthFile)
	if dir != "" && dir != "." {
		_ = os.MkdirAll(dir, 0755)
	}
	data, err := json.MarshalIndent(sa, "", "  ")
	if err != nil {
		return err
	}
	if err := os.WriteFile(cfg.AuthFile, data, 0600); err != nil {
		return err
	}
	clearDisabledMarker(cfg.AuthFile)
	return nil
}

// saveAuthTo 将凭据写入指定路径（多账号模式使用）。
// 写入成功后清除该路径的失效标记（表示账号已重新登录）。
func saveAuthTo(path string, sa *StoredAuth) error {
	dir := filepath.Dir(path)
	if dir != "" && dir != "." {
		_ = os.MkdirAll(dir, 0755)
	}
	data, err := json.MarshalIndent(sa, "", "  ")
	if err != nil {
		return err
	}
	if err := os.WriteFile(path, data, 0600); err != nil {
		return err
	}
	clearDisabledMarker(path)
	return nil
}

// loadAccountFile 从指定路径读取并解析凭据（不修改全局缓存）。
func loadAccountFile(path string) (*StoredAuth, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("读取凭据文件失败 (%s): %w", path, err)
	}
	var sa StoredAuth
	if err := json.Unmarshal(data, &sa); err != nil {
		return nil, fmt.Errorf("解析凭据文件失败 (%s): %w", path, err)
	}
	if sa.Auth.AccessToken == "" {
		return nil, fmt.Errorf("凭据文件缺少 AccessToken (%s)", path)
	}
	return &sa, nil
}

// collectConfiguredAuthPaths 解析应加载的凭据路径列表：
//  1) -auth-dir 指定目录 → 目录下所有 workbuddy*.json
//  2) 显式 -auth → 逗号分隔的凭据文件列表（保持用户顺序）
//  3) 均未指定（自动发现模式）→ 扫描当前目录下所有 workbuddy*.json，
//     这样把多个凭据文件放进工作目录即可自动组成多账号池；若一个都没有则回退默认 cfg.AuthFile
func collectConfiguredAuthPaths() []string {
	var paths []string

	if cfg.AuthDir != "" {
		entries, err := os.ReadDir(cfg.AuthDir)
		if err == nil {
			for _, e := range entries {
				if e.IsDir() {
					continue
				}
				name := e.Name()
				if strings.HasPrefix(name, "workbuddy") && strings.HasSuffix(name, ".json") {
					paths = append(paths, filepath.Join(cfg.AuthDir, name))
				}
			}
			sort.Strings(paths)
		}
		return paths
	}

	if cfg.AuthExplicit {
		for _, p := range strings.Split(cfg.AuthFile, ",") {
			p = strings.TrimSpace(p)
			if p != "" {
				paths = append(paths, p)
			}
		}
		return paths
	}

	// 自动发现模式：扫描当前工作目录（systemd WorkingDirectory 即凭据目录）
	entries, err := os.ReadDir(".")
	if err == nil {
		for _, e := range entries {
			if e.IsDir() {
				continue
			}
			name := e.Name()
			if strings.HasPrefix(name, "workbuddy") && strings.HasSuffix(name, ".json") {
				paths = append(paths, name)
			}
		}
		sort.Strings(paths)
	}
	if len(paths) == 0 {
		// 无任何凭据文件时回退默认路径，便于给出"请先 login"的友好提示
		paths = append(paths, cfg.AuthFile)
	}
	return paths
}

// loadAccounts 构建账号池。
// -auth 支持逗号分隔多个凭据文件；-auth-dir 自动加载目录下所有 workbuddy*.json；
// 两者都未指定时自动发现当前目录下所有 workbuddy*.json（多账号免参数）。
func loadAccounts() error {
	accountMu.Lock()
	defer accountMu.Unlock()

	accounts = nil
	rrIndex = 0

	for _, p := range collectConfiguredAuthPaths() {
		sa, err := loadAccountFile(p)
		if err != nil {
			log.Printf("[Auth] 跳过无效凭据文件 %s: %v", p, err)
			continue
		}
		accounts = append(accounts, &Account{Path: p, Auth: sa})
	}

	// 恢复持久化的失效账号标记（凭据文件已删除，仅供控制台提示重新登录）
	loadDisabledMarkers()

	if len(accounts) == 0 {
		return fmt.Errorf("未找到有效凭据，请先执行 login 命令扫码登录")
	}
	return nil
}

// nextAccount 轮询选择下一个未处于冷却状态且未被禁用的账号。
// 若全部账号不可用，返回错误并附带说明。
func nextAccount() (*Account, error) {
	accountMu.Lock()
	defer accountMu.Unlock()

	if len(accounts) == 0 {
		return nil, fmt.Errorf("账号池为空")
	}
	now := time.Now()
	disabledCount := 0
	cooldownCount := 0
	for i := 0; i < len(accounts); i++ {
		idx := (rrIndex + i) % len(accounts)
		acc := accounts[idx]
		if acc.Disabled {
			disabledCount++
			continue
		}
		if acc.CooldownUntil.After(now) {
			cooldownCount++
			continue
		}
		rrIndex = (idx + 1) % len(accounts)
		return acc, nil
	}
	// 全部不可用：优先报告失效账号
	for _, a := range accounts {
		if a.Disabled {
			return nil, fmt.Errorf("账号 %s 已失效（授权过期或已撤销，凭据文件已删除），请重新执行 login 登录", a.Path)
		}
	}
	// 全部冷却：返回最早解封时间
	earliest := accounts[0].CooldownUntil
	for _, a := range accounts {
		if a.CooldownUntil.Before(earliest) {
			earliest = a.CooldownUntil
		}
	}
	return nil, fmt.Errorf("所有账号均处于冷却状态，最早解封时间: %s", earliest.Format("2006-01-02 15:04:05"))
}

// markCooldown 将账号屏蔽至指定时间。
func markCooldown(acc *Account, until time.Time, msg string) {
	accountMu.Lock()
	acc.CooldownUntil = until
	acc.CooldownMsg = msg
	accountMu.Unlock()
	log.Printf("[Cooldown] 账号 %s 触发频率限制，自动屏蔽至 %s (提示: %s)",
		acc.Path, until.Format("2006-01-02 15:04:05"), msg)
}

// disableAccount 将账号标记为失效（授权过期/撤销），禁止调度并删除凭据文件，
// 同时写入持久化失效标记，便于控制台提示用户重新登录。
func disableAccount(acc *Account, reason string) {
	accountMu.Lock()
	acc.Disabled = true
	acc.DisabledReason = reason
	acc.CooldownUntil = time.Time{}
	path := acc.Path
	nickname := ""
	uid := ""
	if acc.Auth != nil {
		nickname = acc.Auth.Account.Nickname
		uid = acc.Auth.Account.UID
		acc.Nickname = nickname
		acc.UID = uid
	}
	accountMu.Unlock()

	// 写持久化失效标记（凭据删除后仍能在 status 中提示重新登录）
	marker := disabledMarker{
		Path:       path,
		Reason:     reason,
		DisabledAt: time.Now().Unix(),
		Nickname:   nickname,
		UID:        uid,
	}
	if data, err := json.MarshalIndent(marker, "", "  "); err == nil {
		if werr := os.WriteFile(markerPath(path), data, 0600); werr != nil {
			log.Printf("[Auth] 账号 %s 失效标记写入失败: %v", path, werr)
		}
	}

	// 删除失效的凭据文件，方便用户下次重新登录
	if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
		log.Printf("[Auth] 账号 %s 凭据文件删除失败: %v", path, err)
	}
	log.Printf("[Auth] ⚠️ 账号 %s 授权失效，已禁止调度并删除凭据文件: %s", path, reason)
}

// loadDisabledMarkers 扫描失效标记文件，将其恢复为账号池中的失效账号（Auth 为 nil）。
func loadDisabledMarkers() {
	// 收集标记文件路径：
	// - AuthDir 模式：目录下 *.json.disabled 即为标记文件
	// - 显式 -auth 模式：<凭据路径>.disabled 为标记文件
	// - 自动发现模式：扫描当前目录下所有 *.json.disabled 标记文件
	var markerPaths []string
	if cfg.AuthDir != "" {
		entries, err := os.ReadDir(cfg.AuthDir)
		if err != nil {
			return
		}
		for _, e := range entries {
			if e.IsDir() {
				continue
			}
			name := e.Name()
			if strings.HasSuffix(name, ".json.disabled") {
				markerPaths = append(markerPaths, filepath.Join(cfg.AuthDir, name))
			}
		}
	} else if cfg.AuthExplicit {
		for _, p := range strings.Split(cfg.AuthFile, ",") {
			p = strings.TrimSpace(p)
			if p != "" {
				markerPaths = append(markerPaths, markerPath(p))
			}
		}
	} else {
		// 自动发现模式：扫描当前工作目录
		entries, err := os.ReadDir(".")
		if err == nil {
			for _, e := range entries {
				if e.IsDir() {
					continue
				}
				name := e.Name()
				if strings.HasPrefix(name, "workbuddy") && strings.HasSuffix(name, ".json.disabled") {
					markerPaths = append(markerPaths, name)
				}
			}
			sort.Strings(markerPaths)
		}
	}

	for _, mp := range markerPaths {
		data, err := os.ReadFile(mp)
		if err != nil {
			continue
		}
		var m disabledMarker
		if err := json.Unmarshal(data, &m); err != nil {
			continue
		}
		// 避免与已加载的有效账号重复
		dup := false
		for _, a := range accounts {
			if a.Path == m.Path {
				dup = true
				break
			}
		}
		if dup {
			continue
		}
		accounts = append(accounts, &Account{
			Path:           m.Path,
			Disabled:       true,
			DisabledReason: m.Reason,
			Nickname:       m.Nickname,
			UID:            m.UID,
		})
	}
}

// clearDisabledMarker 在重新登录成功后清除失效标记。
func clearDisabledMarker(path string) {
	mp := markerPath(path)
	if err := os.Remove(mp); err != nil && !os.IsNotExist(err) {
		log.Printf("[Auth] 失效标记清除失败 (%s): %v", mp, err)
	}
}

// isAuthFailure 判断上游响应是否为授权失效（401/403 / invalid token / 登录过期等）。
func isAuthFailure(statusCode int, body string) bool {
	if statusCode == http.StatusUnauthorized || statusCode == http.StatusForbidden {
		return true
	}
	low := strings.ToLower(body)
	if strings.Contains(low, "invalid token") ||
		strings.Contains(low, "unauthorized") ||
		strings.Contains(low, "登录已过期") ||
		strings.Contains(low, "登录失效") ||
		strings.Contains(low, "token 已失效") ||
		strings.Contains(low, "authentication required") {
		return true
	}
	return false
}

var resetTimeRe = regexp.MustCompile(`将在\s*(\d{4}-\d{2}-\d{2})\s+(\d{2}:\d{2}:\d{2})\s*(UTC[+-]\d+(?::\d{2})?)?`)

// parseResetTime 从上游 429 错误消息中解析频率限制重置时间。
// 示例: "您的使用量已超出频率限制，将在 2026-09-04 07:48:15 UTC+8 重置"
func parseResetTime(s string) (time.Time, bool) {
	m := resetTimeRe.FindStringSubmatch(s)
	if m == nil {
		return time.Time{}, false
	}
	offset := 8 * 3600 // 默认按 UTC+8 解析
	if m[3] != "" {
		zone := m[3]
		zone = strings.TrimPrefix(zone, "UTC")
		zone = strings.TrimPrefix(zone, "utc")
		var h, mi int
		if _, err := fmt.Sscanf(zone, "%d:%d", &h, &mi); err == nil {
			offset = h*3600 + mi*60
		} else if _, err := fmt.Sscanf(zone, "%d", &h); err == nil {
			offset = h * 3600
		}
	}
	loc := time.FixedZone("UTC", offset)
	t, err := time.ParseInLocation("2006-01-02 15:04:05", m[1]+" "+m[2], loc)
	if err != nil {
		return time.Time{}, false
	}
	return t, true
}

// isRateLimited 判断上游响应是否属于频率限制（429 或 code 6004 / 频率限制提示）。
func isRateLimited(statusCode int, body string) bool {
	if statusCode == http.StatusTooManyRequests {
		return true
	}
	if strings.Contains(body, `"code":6004`) || strings.Contains(body, "频率限制") || strings.Contains(body, "frequency limit") {
		return true
	}
	return false
}

// ensureValidTokenFor 对指定账号检查并刷新令牌（多账号版）。
// 失效账号（Disabled 或 Auth 为 nil）直接跳过，不参与调度。
func ensureValidTokenFor(acc *Account) error {
	if acc == nil || acc.Disabled || acc.Auth == nil {
		return nil
	}
	if time.Now().Unix() > acc.Auth.Auth.ExpiresAt-900 {
		log.Printf("[Auth] 账号 %s 访问令牌即将/已经过期，正在自动刷新...", acc.Path)
		return doRefreshTokenFor(acc)
	}
	return nil
}

func ensureValidToken() error {
	sa, err := loadAuth()
	if err != nil {
		return err
	}
	// 如果距过期不足 15 分钟，则自动刷新
	if time.Now().Unix() > sa.Auth.ExpiresAt-900 {
		log.Printf("[Auth] 访问令牌即将或已经过期 (ExpiresAt=%s)，正在自动刷新...", time.Unix(sa.Auth.ExpiresAt, 0).Format("2006-01-02 15:04:05"))
		return doRefreshToken(sa)
	}
	return nil
}

func doRefreshToken(sa *StoredAuth) error {
	if sa == nil || sa.Auth.RefreshToken == "" {
		return fmt.Errorf("无法刷新：缺少 RefreshToken")
	}
	if _, err := refreshTokenPayload(sa); err != nil {
		return err
	}
	if err := saveAuth(sa); err != nil {
		return fmt.Errorf("写回凭据失败: %w", err)
	}
	log.Printf("[Auth] Token 刷新成功！新过期时间: %s", time.Unix(sa.Auth.ExpiresAt, 0).Format("2006-01-02 15:04:05"))
	return nil
}

// doRefreshTokenFor 刷新指定账号的令牌并保存回其凭据文件（多账号版）。
// 若刷新因授权失效失败（401/403/refresh token 无效），自动禁用该账号并删除凭据文件。
func doRefreshTokenFor(acc *Account) error {
	if acc == nil || acc.Disabled || acc.Auth == nil || acc.Auth.Auth.RefreshToken == "" {
		return fmt.Errorf("无法刷新：账号缺少 RefreshToken 或已失效")
	}
	status, err := refreshTokenPayload(acc.Auth)
	if err != nil {
		if isAuthFailure(status, err.Error()) {
			disableAccount(acc, fmt.Sprintf("令牌刷新失败 (HTTP %d): %v", status, err))
		}
		return err
	}
	if err := saveAuthTo(acc.Path, acc.Auth); err != nil {
		return fmt.Errorf("写回凭据失败: %w", err)
	}
	log.Printf("[Auth] 账号 %s Token 刷新成功！新过期时间: %s", acc.Path, time.Unix(acc.Auth.Auth.ExpiresAt, 0).Format("2006-01-02 15:04:05"))
	return nil
}

// refreshTokenPayload 调用上游刷新接口并更新内存中的令牌字段（不落盘）。
// 返回上游 HTTP 状态码（成功或失败时均为实际状态；网络错误为 0）。
func refreshTokenPayload(sa *StoredAuth) (int, error) {
	headers := func(r *http.Request) {
		commonHeaders(r)
		r.Header.Set("X-Refresh-Token", sa.Auth.RefreshToken)
		if sa.Account.EnterpriseID != "" {
			r.Header.Set("X-Enterprise-Id", sa.Account.EnterpriseID)
		}
		r.Header.Set("X-Auth-Refresh-Source", "workbuddy")
	}

	data, status, err := doJSON(cfg.HttpClient, http.MethodPost, endpointTokenRefresh, headers, nil)
	if err != nil {
		return status, fmt.Errorf("上游刷新拒绝 (HTTP %d): %w", status, err)
	}
	var tok tokenData
	if err := json.Unmarshal(data, &tok); err != nil || tok.AccessToken == "" {
		return status, fmt.Errorf("解析新 Token 失败: %w", err)
	}

	sa.Auth.AccessToken = tok.AccessToken
	if tok.RefreshToken != "" {
		sa.Auth.RefreshToken = tok.RefreshToken
	}
	if tok.Domain != "" {
		sa.Auth.Domain = tok.Domain
	}
	if tok.ExpiresIn > 0 {
		sa.Auth.ExpiresAt = time.Now().Add(time.Duration(tok.ExpiresIn) * time.Second).Unix()
	}
	return status, nil
}

// -----------------------------------------------------------------------------
// CLI 子命令实现: login, status, refresh
// -----------------------------------------------------------------------------

// formatAccountStatus 生成单个账号的完整状态文本（status 命令与 serve 启动横幅共用）。
// idx 从 1 开始的账号序号；now 为当前时间（用于冷却/过期判定）。
func formatAccountStatus(acc *Account, idx int, now time.Time) string {
	var sb strings.Builder
	sb.WriteString(fmt.Sprintf("\n--- 账号 #%d ---\n", idx))
	sb.WriteString(fmt.Sprintf("凭据文件:     %s\n", acc.Path))

	if acc.Disabled {
		// 失效账号（Auth 可能为 nil：凭据文件已删除，信息来自失效标记）
		nickname := acc.Nickname
		uid := acc.UID
		if acc.Auth != nil {
			nickname = acc.Auth.Account.Nickname
			uid = acc.Auth.Account.UID
		}
		sb.WriteString(fmt.Sprintf("用户昵称:     %s\n", ifEmpty(nickname, "(未知)")))
		sb.WriteString(fmt.Sprintf("用户 UID:     %s\n", ifEmpty(uid, "(未知)")))
		sb.WriteString("账号状态:     ❌ 授权失效（禁止调度）\n")
		sb.WriteString(fmt.Sprintf("失效原因:     %s\n", truncate(acc.DisabledReason, 200)))
		sb.WriteString(fmt.Sprintf("处理建议:     ⚠️ 凭据文件已删除，请重新执行: workbuddy-gateway login -auth %s\n", acc.Path))
		return sb.String()
	}

	if acc.Auth == nil {
		return sb.String()
	}

	expTime := time.Unix(acc.Auth.Auth.ExpiresAt, 0)
	remaining := time.Until(expTime)
	statusStr := "有效"
	if remaining <= 0 {
		statusStr = "已过期"
	}

	sb.WriteString(fmt.Sprintf("用户昵称:     %s\n", acc.Auth.Account.Nickname))
	sb.WriteString(fmt.Sprintf("用户 UID:     %s\n", acc.Auth.Account.UID))
	sb.WriteString(fmt.Sprintf("企业 ID:      %s\n", ifEmpty(acc.Auth.Account.EnterpriseID, "(个人账号)")))
	sb.WriteString(fmt.Sprintf("认证域名:     %s\n", ifEmpty(acc.Auth.Auth.Domain, "www.codebuddy.cn")))
	if acc.CooldownUntil.After(now) {
		sb.WriteString(fmt.Sprintf("冷却状态:     🔒 冷却中 (解封: %s, 剩余 %v)\n",
			acc.CooldownUntil.Format("2006-01-02 15:04:05"),
			time.Until(acc.CooldownUntil).Round(time.Minute)))
		sb.WriteString(fmt.Sprintf("冷却原因:     %s\n", truncate(acc.CooldownMsg, 120)))
	} else {
		sb.WriteString("冷却状态:     ✅ 可用\n")
	}
	sb.WriteString(fmt.Sprintf("Token 状态:   %s\n", statusStr))
	sb.WriteString(fmt.Sprintf("过期时间:     %s (剩余 %v)\n", expTime.Format("2006-01-02 15:04:05"), remaining.Round(time.Minute)))
	return sb.String()
}

func runStatus() {
	if err := loadAccounts(); err != nil {
		fmt.Printf("未找到有效凭据: %v\n请先执行: workbuddy-gateway login 扫码登录。\n", err)
		return
	}

	accountMu.Lock()
	defer accountMu.Unlock()

	fmt.Println("================== WorkBuddy 账号池状态 ==================")
	fmt.Printf("账号总数: %d\n", len(accounts))
	now := time.Now()
	for i, acc := range accounts {
		fmt.Print(formatAccountStatus(acc, i+1, now))
	}
	fmt.Println("\n=======================================================")
}

func runRefresh() {
	if err := loadAccounts(); err != nil {
		fmt.Printf("读取凭据失败: %v\n", err)
		return
	}
	accountMu.Lock()
	defer accountMu.Unlock()
	if len(accounts) == 0 {
		fmt.Println("账号池为空")
		return
	}
	ok := 0
	fail := 0
	skipped := 0
	for i, acc := range accounts {
		fmt.Printf("正在刷新账号 #%d (%s)... ", i+1, acc.Path)
		if acc.Disabled || acc.Auth == nil {
			fmt.Printf("⏭️ 跳过（授权失效，请重新登录）\n")
			skipped++
			continue
		}
		if err := doRefreshTokenFor(acc); err != nil {
			fmt.Printf("❌ %v\n", err)
			fail++
		} else {
			fmt.Println("✅")
			ok++
		}
	}
	fmt.Printf("\n刷新完成: 成功 %d 个，失败 %d 个，跳过 %d 个（授权失效）\n", ok, fail, skipped)
}

func runLogin() {
	fmt.Println("================ WorkBuddy 扫码登录 ================")
	fmt.Println("正在生成登录凭据与二维码...")

	loginClient := &http.Client{
		Timeout: 30 * time.Second,
		Jar:     cfg.HttpClient.Jar,
	}

	data, _, err := doJSON(loginClient, http.MethodPost, endpointAuthState, nil, bytes.NewReader([]byte("{}")))
	if err != nil {
		fmt.Printf("获取登录状态失败: %v\n", err)
		return
	}
	var st authStateData
	_ = json.Unmarshal(data, &st)
	if st.State == "" || st.AuthURL == "" {
		fmt.Println("上游返回的登录状态信息异常，请重试。")
		return
	}

	// 终端字符二维码
	qr, err := qrcode.New(st.AuthURL, qrcode.Medium)
	if err == nil {
		fmt.Println("\n请使用 微信 或 企业微信 扫描下方二维码登录：")
		fmt.Println(qr.ToSmallString(false))
	}

	fmt.Println("如无法扫码，也可在浏览器中直接打开以下链接：")
	fmt.Printf("👉 %s\n\n", st.AuthURL)
	fmt.Println("等待扫码授权中 (按 Ctrl+C 可取消)...")

	deadline := time.Now().Add(loginTTL)
	ticker := time.NewTicker(2 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			if time.Now().After(deadline) {
				fmt.Println("\n登录已超时，请重新执行 login 命令。")
				return
			}
			tokRaw, _, errTok := doJSON(loginClient, http.MethodGet, endpointAuthToken+st.State, nil, nil)
			if errTok != nil {
				continue
			}
			var tok tokenData
			if err := json.Unmarshal(tokRaw, &tok); err != nil || tok.AccessToken == "" {
				continue
			}

			// 登录成功，拉取账号信息
			var acct accountData
			acctHeaders := func(r *http.Request) {
				commonHeaders(r)
				r.Header.Set("Authorization", "Bearer "+tok.AccessToken)
			}
			if acctRaw, _, errAcct := doJSON(loginClient, http.MethodGet, endpointLoginAcct+st.State, acctHeaders, nil); errAcct == nil {
				_ = json.Unmarshal(acctRaw, &acct)
			}

			sa := &StoredAuth{
				Auth: StoredTokens{
					AccessToken:  tok.AccessToken,
					RefreshToken: tok.RefreshToken,
					ExpiresAt:    time.Now().Add(time.Duration(tok.ExpiresIn) * time.Second).Unix(),
					Domain:       tok.Domain,
				},
				Account: StoredAccount{
					UID:          acct.UID,
					EnterpriseID: acct.EnterpriseID,
					Nickname:     acct.Nickname,
				},
			}

			if err := saveAuth(sa); err != nil {
				fmt.Printf("\n登录成功但保存凭据失败: %v\n", err)
				return
			}

			fmt.Println("\n🎉 登录成功！")
			fmt.Printf("欢迎，%s (UID: %s)\n", sa.Account.Nickname, sa.Account.UID)
			fmt.Printf("凭据已成功保存至: %s\n", cfg.AuthFile)
			fmt.Printf("令牌有效期至: %s\n", time.Unix(sa.Auth.ExpiresAt, 0).Format("2006-01-02 15:04:05"))
			fmt.Println("\n现在您可以运行以下命令启动网关服务：")
			fmt.Println("  workbuddy-gateway serve")
			return
		}
	}
}

// -----------------------------------------------------------------------------
// 本地 HTTP API 网关服务 (OpenAI 协议兼容)
// -----------------------------------------------------------------------------

func runServe() {
	if err := loadAccounts(); err != nil {
		fmt.Printf("警告: 未检测到有效凭据 (%v)。\n请先执行: workbuddy-gateway login 扫码登录，或确保凭据文件存在。\n\n", err)
	} else {
		accountMu.Lock()
		for _, acc := range accounts {
			if acc.Disabled || acc.Auth == nil {
				continue
			}
			_ = ensureValidTokenFor(acc)
		}
		accountMu.Unlock()
	}

	// 启动后台自动刷新协程
	go backgroundTokenRefresher()

	mux := http.NewServeMux()
	mux.HandleFunc("/v1/chat/completions", handleChatCompletions)
	mux.HandleFunc("/chat/completions", handleChatCompletions)
	mux.HandleFunc("/v1/models", handleModels)
	mux.HandleFunc("/models", handleModels)
	mux.HandleFunc("/health", handleHealth)
	mux.HandleFunc("/ping", handleHealth)
	mux.HandleFunc("/", handleIndex)

	listenAddr := fmt.Sprintf("%s:%d", cfg.Addr, cfg.Port)
	server := &http.Server{
		Addr:         listenAddr,
		Handler:      corsMiddleware(authMiddleware(mux)),
		ReadTimeout:  120 * time.Second,
		WriteTimeout: 300 * time.Second,
	}

	fmt.Println("================================================================")
	fmt.Printf("🚀 WorkBuddy 本地网关已启动！\n")
	fmt.Printf("   服务监听地址:  http://%s\n", listenAddr)
	fmt.Printf("   Chat 接口地址: http://%s/v1/chat/completions\n", listenAddr)
	fmt.Printf("   Models 接口:   http://%s/v1/models\n", listenAddr)
	fmt.Printf("   模型转发策略:  【完全透传】客户端请求的任意 model 原样中继至上游\n")
	if cfg.APIKey != "" {
		fmt.Printf("   API 鉴权:      已启用 (Bearer %s)\n", cfg.APIKey)
	} else {
		fmt.Printf("   API 鉴权:      未启用 (任何客户端均可直连)\n")
	}
	if cfg.ProxyURL != "" {
		fmt.Printf("   上游出口代理:  %s\n", cfg.ProxyURL)
	}

	// 启动时展示所有账号状态（与 status 命令一致）
	accountMu.Lock()
	accCount := len(accounts)
	activeCount := 0
	disabledCount := 0
	now := time.Now()
	for _, acc := range accounts {
		if acc.Disabled || acc.Auth == nil {
			disabledCount++
		} else {
			activeCount++
		}
	}
	fmt.Printf("   账号池:        %d 个账号 (有效 %d, 失效 %d)\n", accCount, activeCount, disabledCount)
	if accCount > 0 {
		fmt.Println("   ----------------------------------------------------------")
		for i, acc := range accounts {
			fmt.Print(formatAccountStatus(acc, i+1, now))
		}
		fmt.Println("   ----------------------------------------------------------")
	}
	accountMu.Unlock()

	fmt.Println("================================================================")
	fmt.Println("等待客户端请求中 (按 Ctrl+C 安全停止)...")

	stopChan := make(chan os.Signal, 1)
	signal.Notify(stopChan, os.Interrupt, syscall.SIGTERM)

	go func() {
		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("HTTP 服务异常退出: %v", err)
		}
	}()

	<-stopChan
	fmt.Println("\n正在关闭网关服务...")
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	_ = server.Shutdown(ctx)
	fmt.Println("网关已安全停止。")
}

func backgroundTokenRefresher() {
	ticker := time.NewTicker(5 * time.Minute)
	defer ticker.Stop()
	for range ticker.C {
		accountMu.Lock()
		accs := make([]*Account, len(accounts))
		copy(accs, accounts)
		accountMu.Unlock()
		for _, acc := range accs {
			if err := ensureValidTokenFor(acc); err != nil {
				log.Printf("[BackgroundAuth] 账号 %s 自动检查/续期令牌异常: %v", acc.Path, err)
			}
		}
	}
}

// -----------------------------------------------------------------------------
// 中间件: CORS 与可选 APIKey 校验
// -----------------------------------------------------------------------------

func corsMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "*")
		if r.Method == http.MethodOptions {
			w.WriteHeader(http.StatusOK)
			return
		}
		next.ServeHTTP(w, r)
	})
}

func authMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if cfg.APIKey != "" && r.URL.Path != "/health" && r.URL.Path != "/ping" && r.URL.Path != "/" {
			authHeader := r.Header.Get("Authorization")
			token := strings.TrimPrefix(authHeader, "Bearer ")
			if token != cfg.APIKey {
				writeOpenAIError(w, http.StatusUnauthorized, "invalid_api_key", "未提供有效 API 密钥")
				return
			}
		}
		next.ServeHTTP(w, r)
	})
}

// -----------------------------------------------------------------------------
// 路由处理: /v1/chat/completions (支持任意 model 透传)
// -----------------------------------------------------------------------------

func handleChatCompletions(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeOpenAIError(w, http.StatusMethodNotAllowed, "method_not_allowed", "仅支持 POST 请求")
		return
	}

	reqID := atomic.AddUint64(&reqCounter, 1)
	startTime := time.Now()

	bodyBytes, err := io.ReadAll(r.Body)
	if err != nil {
		writeOpenAIError(w, http.StatusBadRequest, "read_error", "读取请求体失败")
		return
	}
	defer r.Body.Close()

	var reqObj map[string]any
	if err := json.Unmarshal(bodyBytes, &reqObj); err != nil {
		writeOpenAIError(w, http.StatusBadRequest, "invalid_json", "无效的 JSON 请求体")
		return
	}

	// 核心特性：完全透传 model 字段
	// 客户端传什么 model，我们就透传什么 model 给上游，不做任何硬编码限制！
	modelName, _ := reqObj["model"].(string)
	if modelName == "" {
		modelName = "hy4-preview" // 默认保底
		reqObj["model"] = modelName
	}

	isStream, _ := reqObj["stream"].(bool)

	// 腾讯上游强制要求 stream 必须为 true，非流式会被拦截 (code 11101)
	reqObj["stream"] = true

	// 深度思考 (Thinking) 自动适配：混元系列如果未关闭思考，自动赋予 high 档位保证深度思考输出
	applyThinkingRules(reqObj, modelName)

	// 模板净化：改写 Claude Code 等框架被腾讯官方逐字拉黑的固定 prompt 语句
	sanitizeMessages(reqObj)

	upstreamBytes, err := json.Marshal(reqObj)
	if err != nil {
		writeOpenAIError(w, http.StatusInternalServerError, "encode_error", "序列化请求失败")
		return
	}

	if cfg.Verbose {
		log.Printf("[#%d][Req] Model: %s | Stream: %v | BodyLen: %d", reqID, modelName, isStream, len(upstreamBytes))
	} else {
		log.Printf("[#%d] POST /v1/chat/completions -> Upstream [Model: %s, Stream: %v]", reqID, modelName, isStream)
	}

	// 多账号轮询 + 429 自动冷却代偿：
	// 按轮询顺序尝试账号；命中 429 频率限制时立即将当前账号屏蔽到重置时间，
	// 并自动改用下一个可用账号重试（代偿），直至成功或所有账号均不可用。
	accountMu.Lock()
	poolSize := len(accounts)
	accountMu.Unlock()
	if poolSize == 0 {
		writeOpenAIError(w, http.StatusUnauthorized, "no_auth", "未找到有效登录凭据，请先执行 login 命令扫码登录")
		return
	}

	var lastRateErr string
	var lastAuthErr string
	for attempt := 0; attempt < poolSize; attempt++ {
		acc, err := nextAccount()
		if err != nil {
			// 所有账号均不可用（冷却或失效）
			msg := fmt.Sprintf("无可用账号: %v", err)
			if lastAuthErr != "" {
				msg += " | 最近一次授权失效: " + truncate(lastAuthErr, 200)
			}
			if lastRateErr != "" {
				msg += " | 最近一次频率限制: " + truncate(lastRateErr, 200)
			}
			log.Printf("[#%d] %s", reqID, msg)
			writeOpenAIError(w, http.StatusServiceUnavailable, "no_available_account", msg)
			return
		}
		_ = ensureValidTokenFor(acc)
		// 令牌刷新时若发现授权失效会禁用账号；若被禁用则跳过换下一个
		accountMu.Lock()
		disabled := acc.Disabled
		accountMu.Unlock()
		if disabled {
			lastAuthErr = acc.DisabledReason
			continue
		}

		upstreamReq, err := http.NewRequestWithContext(r.Context(), http.MethodPost, endpointChat, bytes.NewReader(upstreamBytes))
		if err != nil {
			writeOpenAIError(w, http.StatusInternalServerError, "req_create_error", err.Error())
			return
		}
		// 注入 CodeBuddy 凭据与指纹 Header
		backendHeaders(upstreamReq, acc.Auth)

		// 限制同一账号向腾讯上游的请求严格单并发串行排队，防止 DSH 同时发起标题生成+主对话触发腾讯 11128 风控
		acc.lock.Lock()
		resp, err := cfg.HttpClient.Do(upstreamReq)
		acc.lock.Unlock()
		if err != nil {
			log.Printf("[#%d] 账号 %s 上游请求失败: %v", reqID, acc.Path, err)
			writeOpenAIError(w, http.StatusBadGateway, "upstream_network_error", fmt.Sprintf("网络转发失败: %v", err))
			return
		}

		// 上游非 200 响应处理
		if resp.StatusCode >= 400 {
			errBody, _ := io.ReadAll(resp.Body)
			resp.Body.Close()
			errStr := string(errBody)
			log.Printf("[#%d] 账号 %s 上游返回 HTTP %d: %s (耗时 %v)", reqID, acc.Path, resp.StatusCode, errStr, time.Since(startTime))

			if isRateLimited(resp.StatusCode, errStr) {
				// 429 频率限制：解析重置时间并屏蔽该账号，交由其他账号代偿
				until, ok := parseResetTime(errStr)
				if !ok {
					until = time.Now().Add(60 * time.Second) // 无法解析时默认冷却 60 秒
				}
				markCooldown(acc, until, errStr)
				lastRateErr = errStr
				continue // 尝试下一个账号
			}

			if isAuthFailure(resp.StatusCode, errStr) {
				// 授权失效（401/403 / token 无效 / 登录过期）：禁用该账号并删除凭据文件，
				// 自动改用下一个可用账号，控制台提示用户重新登录
				disableAccount(acc, fmt.Sprintf("上游鉴权失败 (HTTP %d): %s", resp.StatusCode, truncate(errStr, 200)))
				lastAuthErr = errStr
				continue // 尝试下一个账号
			}

			writeOpenAIError(w, resp.StatusCode, "upstream_error", fmt.Sprintf("upstream %d: %s", resp.StatusCode, errStr))
			return
		}

		if isStream {
			// 客户端需要流式响应
			w.Header().Set("Content-Type", "text/event-stream")
			w.Header().Set("Cache-Control", "no-cache")
			w.Header().Set("Connection", "keep-alive")
			w.Header().Set("X-Accel-Buffering", "no")

			flusher, ok := w.(http.Flusher)
			if !ok {
				resp.Body.Close()
				writeOpenAIError(w, http.StatusInternalServerError, "streaming_unsupported", "服务器不支持流式响应 Flush")
				return
			}

			scanner := bufio.NewScanner(resp.Body)
			scanner.Buffer(make([]byte, 64*1024), 4*1024*1024)

			for scanner.Scan() {
				line := scanner.Text()
				cleanData := stripDataPrefix(line)
				if cleanData == "" {
					continue
				}
				if cleanData == "[DONE]" {
					_, _ = fmt.Fprintf(w, "data: [DONE]\n\n")
					flusher.Flush()
					break
				}
				cleanedChunk := cleanChunkJSON(cleanData)
				if cleanedChunk != "" {
					_, _ = fmt.Fprintf(w, "data: %s\n\n", cleanedChunk)
					flusher.Flush()
				}
			}
			resp.Body.Close()
			log.Printf("[#%d] 流式输出完成 (账号 %s, 耗时 %v)", reqID, acc.Path, time.Since(startTime))
		} else {
			// 客户端需要完整 JSON 响应，聚合 SSE 数据流
			completionJSON, err := aggregateCompletion(resp.Body, modelName)
			resp.Body.Close()
			if err != nil {
				log.Printf("[#%d] 聚合响应失败: %v", reqID, err)
				writeOpenAIError(w, http.StatusInternalServerError, "aggregate_error", "聚合上游流式响应失败: "+err.Error())
				return
			}
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			_, _ = w.Write(completionJSON)
			log.Printf("[#%d] 非流式响应完成 (账号 %s, 耗时 %v)", reqID, acc.Path, time.Since(startTime))
		}
		return
	}

	// 理论上不可达（poolSize 次尝试后未成功即已在循环内返回）
	writeOpenAIError(w, http.StatusTooManyRequests, "all_accounts_cooldown", "所有账号均处于冷却状态")
}

// -----------------------------------------------------------------------------
// 路由处理: /v1/models (列出常见模型供客户端自动补全)
// -----------------------------------------------------------------------------

func handleModels(w http.ResponseWriter, r *http.Request) {
	// 动态内置常见模型，用户直接传入任何未列出的 model 也会直接透传到上游
	modelsList := []map[string]any{
		{"id": "hy4-preview", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "hy3-preview-agent", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "hy3-preview", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "hy3", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "glm-5.2", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "glm-5.1", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "kimi-k2.7", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "deepseek-v4-pro", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "deepseek-v4-flash", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
		{"id": "minimax-m3-pay", "object": "model", "owned_by": "workbuddy", "permission": []any{}},
	}
	resp := map[string]any{
		"object": "list",
		"data":   modelsList,
	}
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(resp)
}

func handleHealth(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(map[string]any{
		"status":    "healthy",
		"timestamp": time.Now().Unix(),
		"version":   version,
	})
}

func handleIndex(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.NotFound(w, r)
		return
	}
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	_, _ = fmt.Fprintf(w, "WorkBuddy Local Gateway v%s is running.\n\nEndpoints:\n- POST /v1/chat/completions\n- GET  /v1/models\n- GET  /health\n", version)
}

// -----------------------------------------------------------------------------
// 请求转译与净化工具函数
// -----------------------------------------------------------------------------

func applyThinkingRules(obj map[string]any, modelName string) {
	// 遵循 CodeBuddy 规范：仅当客户端显式设置了 reasoning_effort 时才传递与规范化
	// 绝不可强行对普通请求注入 reasoning_effort，否则极易触发腾讯内容与安全策略拦截 (code 11128)
	currEff, exists := obj["reasoning_effort"].(string)
	if !exists || currEff == "" || currEff == "off" || currEff == "none" {
		delete(obj, "reasoning_effort")
		delete(obj, "reasoning_summary")
		return
	}
	// 客户端显式请求思考时，设置 auto
	obj["reasoning_summary"] = "auto"
}

func sanitizeMessages(obj map[string]any) {
	messages, ok := obj["messages"].([]any)
	if !ok {
		return
	}
	for _, m := range messages {
		msg, ok := m.(map[string]any)
		if !ok {
			continue
		}
		switch c := msg["content"].(type) {
		case string:
			msg["content"] = sanitizeBlockedTemplates(c)
		case []any:
			for _, partAny := range c {
				part, ok := partAny.(map[string]any)
				if !ok {
					continue
				}
				if t, ok := part["text"].(string); ok {
					part["text"] = sanitizeBlockedTemplates(t)
				}
			}
		}
	}
}

func sanitizeBlockedTemplates(s string) string {
	s = strings.ReplaceAll(s,
		"You are Claude Code, Anthropic's official CLI for Claude.",
		"You are Claude Code, Anthropic's official CLI tool for Claude.")
	s = strings.ReplaceAll(s,
		"Main branch (you will usually use this for PRs)",
		"Default branch (you will usually use this for PRs)")
	return s
}

// backendHeaders 设置 CodeBuddy 上游专用指纹与鉴权 Header
func backendHeaders(req *http.Request, sa *StoredAuth) {
	commonHeaders(req)
	reqID := uuid.New().String()
	req.Header.Set("X-Request-ID", reqID)
	req.Header.Set("X-Trace-ID", reqID)
	req.Header.Set("X-Client-ID", "codebuddy-cli")
	req.Header.Set("X-Client-Version", "2.143.1")

	if sa != nil && sa.Auth.AccessToken != "" {
		req.Header.Set("Authorization", "Bearer "+sa.Auth.AccessToken)
	} else {
		req.Header.Set("X-No-Authorization", "1")
	}
	if sa != nil && sa.Account.UID != "" {
		req.Header.Set("X-User-Id", sa.Account.UID)
	} else {
		req.Header.Set("X-No-User-Id", "1")
	}
	if sa != nil && sa.Account.EnterpriseID != "" {
		req.Header.Set("X-Enterprise-Id", sa.Account.EnterpriseID)
	} else {
		req.Header.Set("X-No-Enterprise-Id", "1")
	}
	if sa != nil && sa.Auth.RefreshToken != "" {
		req.Header.Set("X-Refresh-Token", sa.Auth.RefreshToken)
	}
	if sa != nil && sa.Auth.Domain != "" {
		req.Header.Set("X-Domain", sa.Auth.Domain)
	} else {
		req.Header.Set("X-No-Department-Info", "1")
	}
	req.Header.Set("X-Product", "SaaS")
}

func commonHeaders(req *http.Request) {
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json, text/plain, */*")
	req.Header.Set("X-Requested-With", "XMLHttpRequest")
	req.Header.Set("Origin", originReferer)
	req.Header.Set("Referer", originReferer+"/")
	req.Header.Set("User-Agent", clientUA)
}

func doJSON(client *http.Client, method, fullURL string, headers func(*http.Request), body io.Reader) (json.RawMessage, int, error) {
	req, err := http.NewRequest(method, fullURL, body)
	if err != nil {
		return nil, 0, err
	}
	if headers != nil {
		headers(req)
	} else {
		commonHeaders(req)
	}
	resp, err := client.Do(req)
	if err != nil {
		return nil, 0, err
	}
	defer resp.Body.Close()
	raw, _ := io.ReadAll(resp.Body)
	if resp.StatusCode >= 400 {
		return nil, resp.StatusCode, fmt.Errorf("http_error: upstream %d: %s", resp.StatusCode, string(raw))
	}
	var env apiEnvelope
	if err := json.Unmarshal(raw, &env); err != nil {
		return nil, resp.StatusCode, fmt.Errorf("解析上游 JSON 失败: %w", err)
	}
	if env.Code != 0 {
		return nil, resp.StatusCode, fmt.Errorf("code=%d msg=%s", env.Code, env.Msg)
	}
	return env.Data, resp.StatusCode, nil
}

// -----------------------------------------------------------------------------
// 流式聚合与格式清理
// -----------------------------------------------------------------------------

func aggregateCompletion(r io.Reader, model string) ([]byte, error) {
	var content, reasoning, role, respModel, respID, finish string
	var created int64
	var usage map[string]any
	var toolCalls []map[string]any

	scanner := bufio.NewScanner(r)
	scanner.Buffer(make([]byte, 64*1024), 4*1024*1024)
	for scanner.Scan() {
		data := stripDataPrefix(scanner.Text())
		if data == "" || data == "[DONE]" {
			continue
		}
		var chunk map[string]any
		if json.Unmarshal([]byte(data), &chunk) != nil {
			continue
		}
		if v, ok := chunk["id"].(string); ok && v != "" {
			respID = v
		}
		if v, ok := chunk["model"].(string); ok && v != "" {
			respModel = v
		}
		if v, ok := chunk["created"].(float64); ok {
			created = int64(v)
		}
		if v, ok := chunk["usage"].(map[string]any); ok {
			usage = v
		}
		choices, _ := chunk["choices"].([]any)
		for _, c := range choices {
			choice, _ := c.(map[string]any)
			if delta, ok := choice["delta"].(map[string]any); ok {
				if v, ok := delta["role"].(string); ok && v != "" {
					role = v
				}
				if v, ok := delta["content"].(string); ok {
					content += v
				}
				if v, ok := delta["reasoning_content"].(string); ok {
					reasoning += v
				}
				if tcs, ok := delta["tool_calls"].([]any); ok {
					for _, tc := range tcs {
						if call, ok := tc.(map[string]any); ok {
							toolCalls = append(toolCalls, call)
						}
					}
				}
			}
			if v, ok := choice["finish_reason"].(string); ok && v != "" {
				finish = v
			}
		}
	}

	message := map[string]any{"role": ifEmpty(role, "assistant"), "content": content}
	if reasoning != "" {
		message["reasoning_content"] = reasoning
	}
	if len(toolCalls) > 0 {
		message["tool_calls"] = toolCalls
	}
	if created == 0 {
		created = time.Now().Unix()
	}
	result := map[string]any{
		"id":      ifEmpty(respID, fmt.Sprintf("chatcmpl-%d", time.Now().UnixNano())),
		"object":  "chat.completion",
		"created": created,
		"model":   ifEmpty(respModel, model),
		"choices": []map[string]any{{
			"index":         0,
			"message":       message,
			"finish_reason": ifEmpty(finish, "stop"),
		}},
	}
	if usage != nil {
		result["usage"] = usage
	}
	return json.Marshal(result)
}

func cleanChunkJSON(s string) string {
	var obj map[string]any
	if json.Unmarshal([]byte(s), &obj) != nil {
		return s
	}
	if choices, ok := obj["choices"].([]any); ok {
		for _, c := range choices {
			choice, ok := c.(map[string]any)
			if !ok {
				continue
			}
			if delta, ok := choice["delta"].(map[string]any); ok {
				for k, v := range delta {
					if isEmptyValue(v) {
						delete(delta, k)
					}
				}
			}
		}
	}
	out, err := json.Marshal(obj)
	if err != nil {
		return s
	}
	return string(out)
}

func isEmptyValue(v any) bool {
	switch x := v.(type) {
	case nil:
		return true
	case string:
		return x == ""
	case []any:
		return len(x) == 0
	case map[string]any:
		return len(x) == 0
	}
	return false
}

func stripDataPrefix(s string) string {
	s = strings.TrimSpace(s)
	for strings.HasPrefix(s, "data:") {
		s = strings.TrimSpace(strings.TrimPrefix(s, "data:"))
	}
	return s
}

func writeOpenAIError(w http.ResponseWriter, statusCode int, errType, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(statusCode)
	_ = json.NewEncoder(w).Encode(map[string]any{
		"error": map[string]any{
			"message": message,
			"type":    errType,
			"code":    statusCode,
		},
	})
}

func ifEmpty(val, fallback string) string {
	if strings.TrimSpace(val) == "" {
		return fallback
	}
	return val
}

func truncate(s string, n int) string {
	if len(s) <= n {
		return s
	}
	return s[:n] + "..."
}