package app

import (
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"strings"
)

func handleVPNLoginState(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	state := VPNLoginState{
		State: "no_login",
		Msg:   "login state file not found",
		Text:  "AdGuard VPN: (no login data)",
		Color: "gray30",
	}

	data, err := os.ReadFile(loginStatePath)
	if err == nil {
		var fileState VPNLoginState
		if err := json.Unmarshal(data, &fileState); err == nil {
			if fileState.State != "" {
				state.State = fileState.State
			}
			if fileState.Email != "" {
				state.Email = fileState.Email
			}
			if fileState.Msg != "" {
				state.Msg = fileState.Msg
			}
		} else {
			state.State = "error"
			state.Msg = "invalid adguard-login.json: " + err.Error()
		}
	} else if !os.IsNotExist(err) {
		state.State = "error"
		state.Msg = err.Error()
	}

	// text/color для GUI
	switch state.State {
	case "ok":
		if state.Email != "" {
			state.Text = fmt.Sprintf("AdGuard VPN: logged in as %s", state.Email)
		} else {
			state.Text = "AdGuard VPN: logged in"
		}
		state.Color = "green4"
	case "no_login":
		state.Text = "AdGuard VPN: (no login data)"
		state.Color = "gray30"
	default:
		state.Text = "AdGuard VPN: " + state.State
		state.Color = "orange3"
	}

	writeJSON(w, http.StatusOK, state)
}

func handleVPNLogout(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	appendTraceLine("login", "logout")
	stdout, stderr, exitCode, err := runCommand(adgvpnCLI, "logout")
	res := cmdResult{
		OK:       err == nil && exitCode == 0,
		ExitCode: exitCode,
		Stdout:   stdout,
		Stderr:   stderr,
	}
	if err != nil {
		res.Message = err.Error()
	} else {
		res.Message = "logout done"
	}

	// refresh login state
	_, _, _, _ = runCommand("systemctl", "restart", adgvpnUnit)

	writeJSON(w, http.StatusOK, res)
}

func handleSystemdState(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	unit := strings.TrimSpace(r.URL.Query().Get("unit"))
	if unit == "" {
		http.Error(w, "unit required", http.StatusBadRequest)
		return
	}
	stdout, _, _, err := runCommand("systemctl", "is-active", unit)
	st := strings.TrimSpace(stdout)
	if err != nil || st == "" {
		st = "unknown"
	}
	writeJSON(w, http.StatusOK, SystemdState{State: st})
}