// cdp 共享浏览器基础设施：独立档案启动（每账号一档案）、代理、指纹、扫码登录。
// 一期驱动 rod-launcher 管理的 Chromium；ChromePath 给定则驱动系统 Chrome/Edge。
package cdp

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	"github.com/go-rod/rod"
	"github.com/go-rod/rod/lib/launcher"
	"github.com/go-rod/rod/lib/proto"
	rodstealth "github.com/go-rod/stealth"
)

// Options 浏览器启动选项
type Options struct {
	UserDataDir string // 每账号独立档案目录
	Proxy       string // 账号固定 IP 代理（http://ip:port）
	Headless    bool
	ChromePath  string // 系统 Chrome/Edge 可执行文件（空=自动探测/下载）
}

// Browser 浏览器封装
type Browser struct {
	rod  *rod.Browser
	Page *rod.Page
}

// defaultChromePath 常见系统浏览器路径（Windows 优先，macOS 兜底）
func defaultChromePath() string {
	candidates := []string{
		"C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe",
		"C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe",
		"C:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe",
		"C:\\Program Files\\Microsoft\\Edge\\Application\\msedge.exe",
	}
	if runtime.GOOS == "darwin" {
		candidates = append(candidates, "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome")
	}
	for _, p := range candidates {
		if _, err := os.Stat(p); err == nil {
			return p
		}
	}
	return ""
}

// Launch 启动浏览器（独立档案 + 指纹 + 反自动化）
func Launch(ctx context.Context, opts Options) (*Browser, error) {
	l := launcher.New()
	if opts.UserDataDir != "" {
		if err := os.MkdirAll(opts.UserDataDir, 0o700); err != nil {
			return nil, err
		}
		l = l.UserDataDir(opts.UserDataDir)
	}
	if opts.Proxy != "" {
		l = l.Set("proxy-server", opts.Proxy)
	}
	bin := opts.ChromePath
	if bin == "" {
		bin = defaultChromePath()
	}
	if bin != "" {
		l = l.Bin(bin)
	}
	l = l.Headless(opts.Headless).
		Set("no-first-run").
		Set("no-default-browser-check").
		Set("disable-blink-features", "AutomationControlled").
		Set("window-size", "1440,900")
	url, err := l.Launch()
	if err != nil {
		return nil, err
	}
	browser := rod.New().ControlURL(url)
	if err = browser.Connect(); err != nil {
		return nil, err
	}
	// 指纹/反自动化（stealth 注入）
	page, err := rodstealth.Page(browser)
	if err != nil {
		browser.Close()
		return nil, err
	}
	return &Browser{rod: browser, Page: page}, nil
}

// Close 关闭浏览器
func (b *Browser) Close() {
	_ = b.rod.Close()
}

// Screenshot 截图回执（PNG 本地保存，返回路径；二期上传服务器）
func (b *Browser) Screenshot(receiptDir, name string) string {
	if err := os.MkdirAll(receiptDir, 0o755); err != nil {
		return ""
	}
	path := filepath.Join(receiptDir, name)
	_ = b.Page.MustWaitLoad().MustScreenshot(path)
	return path
}

// InjectCookies 注入登录 cookie（免重复扫码）
func (b *Browser) InjectCookies(cookieStr, domain string) error {
	for _, part := range strings.Split(cookieStr, ";") {
		part = strings.TrimSpace(part)
		if part == "" {
			continue
		}
		i := strings.Index(part, "=")
		if i <= 0 {
			continue
		}
		name, value := part[:i], part[i+1:]
		cookie := &proto.NetworkCookieParam{
			Name:   name,
			Value:  value,
			Domain: domain,
			Path:   "/",
		}
		_ = b.rod.SetCookies([]*proto.NetworkCookieParam{cookie})
	}
	return nil
}

// Cookies 导出当前浏览器 cookie（域名过滤）
func (b *Browser) Cookies(domain string) string {
	cookies, err := b.rod.GetCookies()
	if err != nil {
		return ""
	}
	parts := make([]string, 0, len(cookies))
	for _, c := range cookies {
		if domain != "" && !strings.Contains(c.Domain, domain) {
			continue
		}
		parts = append(parts, c.Name+"="+c.Value)
	}
	return strings.Join(parts, "; ")
}

// QRLoginConfig 扫码登录配置
type QRLoginConfig struct {
	LoginURL    string
	LoginPathMarker string // 登录页 URL 特征（登录成功=URL 离开该特征）
	QRSelector  string // 二维码元素选择器
	SuccessWait time.Duration
}

// QRLogin 通用扫码登录：打开登录页 → 截图二维码经 onQR 展示 → 轮询 URL 直到登录成功
func (b *Browser) QRLogin(ctx context.Context, cfg QRLoginConfig, onQR func(qrToken, qrURL string)) (string, error) {
	if err := b.Page.Navigate(cfg.LoginURL); err != nil {
		return "", err
	}
	_ = b.Page.WaitLoad()
	// 截图二维码 → 临时 PNG → file:// URI → onQR（壳端 BitmapImage 展示）
	qrEl, err := b.Page.Element(cfg.QRSelector)
	if err == nil {
		raw, serr := qrEl.Screenshot(proto.PageCaptureScreenshotFormatPng, 100)
		if serr == nil && len(raw) > 0 {
			qrPath := filepath.Join(os.TempDir(), "ep-qr-"+time.Now().Format("150405")+".png")
			if werr := os.WriteFile(qrPath, raw, 0o600); werr == nil && onQR != nil {
				onQR("", "file://"+qrPath)
			}
		}
	}
	// 轮询登录状态
	deadline := time.Now().Add(cfg.SuccessWait)
	for time.Now().Before(deadline) {
		select {
		case <-ctx.Done():
			return "", fmt.Errorf("cancelled")
		default:
		}
		info, ierr := b.Page.Info()
		if ierr == nil && !strings.Contains(info.URL, cfg.LoginPathMarker) {
			return b.Cookies(""), nil
		}
		time.Sleep(2 * time.Second)
	}
	return "", fmt.Errorf("扫码登录超时")
}

// DownloadFile 下载素材到临时文件（返回路径与清理函数）
func DownloadFile(ctx context.Context, rawURL string) (string, func(), error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
	if err != nil {
		return "", nil, err
	}
	client := &http.Client{Timeout: 10 * time.Minute}
	resp, err := client.Do(req)
	if err != nil {
		return "", nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", nil, fmt.Errorf("下载 http %d", resp.StatusCode)
	}
	tmp, err := os.CreateTemp("", "ep-material-*")
	if err != nil {
		return "", nil, err
	}
	_, err = io.Copy(tmp, resp.Body)
	tmp.Close()
	if err != nil {
		os.Remove(tmp.Name())
		return "", nil, err
	}
	return tmp.Name(), func() { _ = os.Remove(tmp.Name()) }, nil
}

// EscapeJSON 转义字符串供嵌入 JSON
func EscapeJSON(s string) string {
	raw, _ := json.Marshal(s)
	return string(raw[1 : len(raw)-1])
}

// Log 调试输出
func Log(format string, args ...interface{}) {
	log.Printf("[cdp] "+format, args...)
}