package gui

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
	"path/filepath"
	"runtime"
	"strings"

	"github.com/azoic/wormhole-client/internal/config"
	"github.com/azoic/wormhole-client/internal/proxy"
	"github.com/azoic/wormhole-client/internal/routing"
	"github.com/azoic/wormhole-client/internal/system"
	"github.com/azoic/wormhole-client/pkg/logger"
)

// GUIServer Web GUI 服务器
type GUIServer struct {
	config         *config.Config
	socks5Proxy    *proxy.SOCKS5Proxy
	systemProxyMgr *system.SystemProxyManager
	routeMatcher   *routing.RouteMatcher
	mode           string
	templates      *template.Template
}

// NewGUIServer 创建 GUI 服务器
func NewGUIServer(cfg *config.Config, socks5Proxy *proxy.SOCKS5Proxy,
	systemProxyMgr *system.SystemProxyManager, routeMatcher *routing.RouteMatcher, mode string) *GUIServer {

	gui := &GUIServer{
		config:         cfg,
		socks5Proxy:    socks5Proxy,
		systemProxyMgr: systemProxyMgr,
		routeMatcher:   routeMatcher,
		mode:           mode,
	}

	// 加载模板
	gui.loadTemplates()

	return gui
}

// RegisterRoutes 注册 GUI 路由
func (g *GUIServer) RegisterRoutes(mux *http.ServeMux) {
	// 静态文件路由
	mux.HandleFunc("/static/", g.handleStatic)

	// Web 界面路由
	mux.HandleFunc("/gui", g.handleGUI)
	mux.HandleFunc("/gui/", g.handleGUI)

	// API 路由
	mux.HandleFunc("/api/status", g.handleStatus)
	mux.HandleFunc("/api/config", g.handleConfig)
	mux.HandleFunc("/api/proxy/toggle", g.handleProxyToggle)
	mux.HandleFunc("/api/routing/stats", g.handleRoutingStats)
	mux.HandleFunc("/api/system/proxy", g.handleSystemProxy)
}

// handleGUI 处理 GUI 主页面
func (g *GUIServer) handleGUI(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")

	data := g.getTemplateData()

	if err := g.templates.Execute(w, data); err != nil {
		logger.Error("Failed to execute template: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}
}

// handleStatic 处理静态文件
func (g *GUIServer) handleStatic(w http.ResponseWriter, r *http.Request) {
	path := strings.TrimPrefix(r.URL.Path, "/static/")

	var content string
	var contentType string

	switch filepath.Ext(path) {
	case ".css":
		content = g.getCSS()
		contentType = "text/css"
	case ".js":
		content = g.getJS()
		contentType = "application/javascript"
	default:
		http.NotFound(w, r)
		return
	}

	w.Header().Set("Content-Type", contentType)
	w.Write([]byte(content))
}

// handleStatus 处理状态 API
func (g *GUIServer) handleStatus(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var proxyStats interface{}
	if g.socks5Proxy != nil {
		proxyStats = g.socks5Proxy.GetStats()
	}

	var routingStats interface{}
	if g.routeMatcher != nil {
		routingStats = g.routeMatcher.GetStats()
	}

	status := map[string]interface{}{
		"mode":          g.mode,
		"system_proxy":  g.systemProxyMgr.IsEnabled(),
		"proxy_stats":   proxyStats,
		"routing_stats": routingStats,
		"server_addr":   g.config.GetServerAddr(),
		"local_port":    g.config.Proxy.LocalPort,
		"os":            runtime.GOOS,
	}

	g.writeJSON(w, status)
}

// handleConfig 处理配置 API
func (g *GUIServer) handleConfig(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodGet:
		g.writeJSON(w, g.config)
	case http.MethodPost:
		// TODO: 实现配置更新
		http.Error(w, "Configuration update not implemented", http.StatusNotImplemented)
	default:
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
	}
}

// handleProxyToggle 处理代理开关
func (g *GUIServer) handleProxyToggle(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var req struct {
		Enable bool `json:"enable"`
	}

	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid JSON", http.StatusBadRequest)
		return
	}

	if req.Enable && !g.systemProxyMgr.IsEnabled() {
		// 启用系统代理
		httpProxy := fmt.Sprintf("127.0.0.1:%d", g.config.Proxy.LocalPort)
		if err := g.systemProxyMgr.SetGlobalProxy(httpProxy, httpProxy, ""); err != nil {
			g.writeJSON(w, map[string]interface{}{
				"success": false,
				"error":   err.Error(),
			})
			return
		}
	} else if !req.Enable && g.systemProxyMgr.IsEnabled() {
		// 禁用系统代理
		if err := g.systemProxyMgr.RestoreProxy(); err != nil {
			g.writeJSON(w, map[string]interface{}{
				"success": false,
				"error":   err.Error(),
			})
			return
		}
	}

	g.writeJSON(w, map[string]interface{}{
		"success": true,
		"enabled": g.systemProxyMgr.IsEnabled(),
	})
}

// handleRoutingStats 处理路由统计
func (g *GUIServer) handleRoutingStats(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var stats interface{}
	if g.routeMatcher != nil {
		stats = g.routeMatcher.GetStats()
	}

	g.writeJSON(w, stats)
}

// handleSystemProxy 处理系统代理信息
func (g *GUIServer) handleSystemProxy(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	currentProxy, err := g.systemProxyMgr.GetCurrentProxy()
	if err != nil {
		g.writeJSON(w, map[string]interface{}{
			"error": err.Error(),
		})
		return
	}

	g.writeJSON(w, map[string]interface{}{
		"enabled":       g.systemProxyMgr.IsEnabled(),
		"current_proxy": currentProxy,
	})
}

// writeJSON 写入 JSON 响应
func (g *GUIServer) writeJSON(w http.ResponseWriter, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")

	if err := json.NewEncoder(w).Encode(data); err != nil {
		logger.Error("Failed to encode JSON: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// getTemplateData 获取模板数据
func (g *GUIServer) getTemplateData() map[string]interface{} {
	var proxyStats interface{}
	if g.socks5Proxy != nil {
		proxyStats = g.socks5Proxy.GetStats()
	}

	var routingStats interface{}
	if g.routeMatcher != nil {
		routingStats = g.routeMatcher.GetStats()
	}

	return map[string]interface{}{
		"Title":        "Wormhole SOCKS5 Client",
		"Mode":         g.mode,
		"ServerAddr":   g.config.GetServerAddr(),
		"LocalPort":    g.config.Proxy.LocalPort,
		"SystemProxy":  g.systemProxyMgr.IsEnabled(),
		"ProxyStats":   proxyStats,
		"RoutingStats": routingStats,
		"OS":           runtime.GOOS,
	}
}

// loadTemplates 加载模板
func (g *GUIServer) loadTemplates() {
	g.templates = template.Must(template.New("index.html").Parse(g.getHTMLTemplate()))
}