package main

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"

	"github.com/orohi/vpn-panel/internal/xraycfg"
)

const xrayContainer = "vpn-panel-xray"

// Official Xray-core image: https://github.com/XTLS/Xray-core
const xrayImage = "ghcr.io/xtls/xray-core:latest"

func (a *Agent) applyXray(cfg map[string]any) {
	xrayDir := filepath.Join(a.dataDir, "xray")
	certDir := filepath.Join(xrayDir, "certs")
	_ = os.MkdirAll(certDir, 0o755)
	configPath := filepath.Join(xrayDir, "config.json")

	var list []xraycfg.Inbound
	inboundsRaw, _ := cfg["inbounds"].([]any)
	for _, raw := range inboundsRaw {
		m, ok := raw.(map[string]any)
		if !ok {
			continue
		}
		in := xraycfg.FromMap(m)
		if in.TLSCertPEM != "" && in.TLSKeyPEM != "" {
			id := in.ID
			if id == "" {
				id = sanitizeFile(in.Tag)
			}
			_ = os.WriteFile(filepath.Join(certDir, id+".crt"), []byte(in.TLSCertPEM), 0o600)
			_ = os.WriteFile(filepath.Join(certDir, id+".key"), []byte(in.TLSKeyPEM), 0o600)
		}
		list = append(list, in)
	}

	// Paths inside the Xray container
	containerCertDir := "/usr/local/etc/xray/certs"
	xrayCfg, n, err := xraycfg.Build(list, containerCertDir)
	if err != nil {
		log.Printf("xray build: %v", err)
		return
	}
	b, err := json.MarshalIndent(xrayCfg, "", "  ")
	if err != nil {
		log.Printf("xray marshal: %v", err)
		return
	}
	if err := os.WriteFile(configPath, b, 0o600); err != nil {
		log.Printf("xray write config: %v", err)
		return
	}
	log.Printf("xray-core config written: %d inbound(s)", n)

	if n == 0 {
		_ = dockerRun("rm", "-f", xrayContainer)
		log.Printf("xray stopped (no inbounds)")
		return
	}

	hostData := os.Getenv("HOST_DATA_DIR")
	if hostData == "" {
		hostData = a.dataDir
	}
	hostXray := filepath.Join(hostData, "xray")
	if err := ensureXrayContainer(hostXray); err != nil {
		log.Printf("xray container: %v", err)
		return
	}
	log.Printf("xray-core container ready (%s)", xrayImage)
}

func ensureXrayContainer(hostXrayDir string) error {
	if _, err := exec.LookPath("docker"); err != nil {
		return fmt.Errorf("docker not found (mount docker.sock): %w", err)
	}
	abs := hostXrayDir
	if a, err := filepath.Abs(hostXrayDir); err == nil {
		abs = a
	}
	// Prefer recreate for clean config pickup (official image has no inotify reload by default).
	_ = dockerRun("rm", "-f", xrayContainer)
	return dockerRun("run", "-d",
		"--name", xrayContainer,
		"--network", "host",
		"--restart", "unless-stopped",
		"-v", abs+":/usr/local/etc/xray",
		xrayImage,
		"run", "-c", "/usr/local/etc/xray/config.json",
	)
}

func dockerRun(args ...string) error {
	cmd := exec.Command("docker", args...)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("docker %v: %v (%s)", args, err, strings.TrimSpace(string(out)))
	}
	return nil
}

func sanitizeFile(tag string) string {
	tag = strings.Map(func(r rune) rune {
		if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '-' || r == '_' {
			return r
		}
		return '_'
	}, tag)
	if tag == "" {
		return "inbound"
	}
	return tag
}