package webserver

import (
	"fmt"
	"log"
	"net/http"

	serveractions "manage-servers/server-actions"

	"github.com/gorilla/websocket"
	"golang.org/x/crypto/ssh"
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
	CheckOrigin: func(r *http.Request) bool {
		return true // Allowing all origins for local tool
	},
}

func (ws *WebServer) handleSSH(w http.ResponseWriter, r *http.Request) {
	serverName := r.URL.Query().Get("name")
	if serverName == "" {
		http.Error(w, "Missing server name", http.StatusBadRequest)
		return
	}

	var targetServer *serveractions.Server
	for _, s := range ws.servers {
		if s.Name == serverName {
			targetServer = &s
			break
		}
	}

	if targetServer == nil {
		http.Error(w, "Server not found", http.StatusNotFound)
		return
	}

	if targetServer.SSHUser == "" || targetServer.SSHPass == "" {
		conn, err := upgrader.Upgrade(w, r, nil)
		if err == nil {
			conn.WriteMessage(websocket.TextMessage, []byte("\r\n[Error] SSH Credentials missing for this node.\r\nPlease edit the server entry and save with a Username and Password.\r\n"))
			conn.Close()
		}
		return
	}

	conn, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		log.Printf("Websocket upgrade failed: %v", err)
		return
	}
	defer conn.Close()

	client, err := serveractions.GetSSHClient(*targetServer)
	if err != nil {
		conn.WriteMessage(websocket.TextMessage, []byte(fmt.Sprintf("\r\n[Error] SSH Connection failed: %v\r\n", err)))
		return
	}
	defer client.Close()

	session, err := client.NewSession()
	if err != nil {
		conn.WriteMessage(websocket.TextMessage, []byte(fmt.Sprintf("\r\n[Error] SSH Session failed: %v\r\n", err)))
		return
	}
	defer session.Close()

	// Request pseudo-terminal
	modes := ssh.TerminalModes{
		ssh.ECHO:          1,
		ssh.TTY_OP_ISPEED: 14400,
		ssh.TTY_OP_OSPEED: 14400,
	}

	// Default to 24x80 if not provided
	rows := 24
	cols := 80
	if r.URL.Query().Get("rows") != "" {
		fmt.Sscanf(r.URL.Query().Get("rows"), "%d", &rows)
	}
	if r.URL.Query().Get("cols") != "" {
		fmt.Sscanf(r.URL.Query().Get("cols"), "%d", &cols)
	}

	// Sanity check for dimensions
	if rows <= 0 {
		rows = 24
	}
	if cols <= 0 {
		cols = 80
	}

	if err := session.RequestPty("xterm-256color", rows, cols, modes); err != nil {
		conn.WriteMessage(websocket.TextMessage, []byte(fmt.Sprintf("\r\n[Error] Request for PTY failed: %v\r\n", err)))
		return
	}

	stdin, err := session.StdinPipe()
	if err != nil {
		return
	}
	stdout, err := session.StdoutPipe()
	if err != nil {
		return
	}
	stderr, err := session.StderrPipe()
	if err != nil {
		return
	}

	if err := session.Shell(); err != nil {
		conn.WriteMessage(websocket.TextMessage, []byte(fmt.Sprintf("\r\n[Error] Shell start failed: %v\r\n", err)))
		return
	}

	// Proxy stdout/stderr to WebSocket
	go func() {
		buf := make([]byte, 1024)
		for {
			n, err := stdout.Read(buf)
			if n > 0 {
				if err := conn.WriteMessage(websocket.TextMessage, buf[:n]); err != nil {
					return
				}
			}
			if err != nil {
				return
			}
		}
	}()

	go func() {
		buf := make([]byte, 1024)
		for {
			n, err := stderr.Read(buf)
			if n > 0 {
				if err := conn.WriteMessage(websocket.TextMessage, buf[:n]); err != nil {
					return
				}
			}
			if err != nil {
				return
			}
		}
	}()

	// Proxy WebSocket to stdin
	for {
		_, message, err := conn.ReadMessage()
		if err != nil {
			break
		}
		if _, err := stdin.Write(message); err != nil {
			break
		}
	}
}