package nginx

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"

	"github.com/panelhosting/panel/internal/ssl"
)

type Manager struct {
	sitesDir   string
	reloadCmd  string
	sslStorage string
}

func NewManager(sitesDir, reloadCmd, sslStorage string) *Manager {
	return &Manager{sitesDir: sitesDir, reloadCmd: reloadCmd, sslStorage: sslStorage}
}

func (m *Manager) Enabled() bool {
	return m.sitesDir != ""
}

func (m *Manager) PrepareHTTPChallenge(domain, documentRoot string) error {
	if !m.Enabled() {
		return nil
	}
	if err := os.MkdirAll(m.sitesDir, 0o755); err != nil {
		return err
	}
	if err := os.MkdirAll(filepath.Join(documentRoot, ".well-known", "acme-challenge"), 0o755); err != nil {
		return err
	}

	cfg := fmt.Sprintf(`# PanelHosting — HTTP challenge for %s
server {
    listen 80;
    listen [::]:80;
    server_name %s;

    location ^~ /.well-known/acme-challenge/ {
        root %s;
        default_type "text/plain";
        try_files $uri =404;
    }

    location / {
        return 404;
    }
}
`, domain, domain, documentRoot)

	path := filepath.Join(m.sitesDir, sanitize(domain)+".conf")
	if err := os.WriteFile(path, []byte(cfg), 0o644); err != nil {
		return err
	}
	return m.reload()
}

func (m *Manager) ApplyHTTPS(domain, documentRoot string) error {
	if !m.Enabled() {
		return nil
	}
	certPath, keyPath := ssl.CertPaths(m.sslStorage, domain)
	cfg := fmt.Sprintf(`# PanelHosting — %s
server {
    listen 80;
    listen [::]:80;
    server_name %s;

    location ^~ /.well-known/acme-challenge/ {
        root %s;
        default_type "text/plain";
        try_files $uri =404;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

server {
    listen 443 ssl;
    listen [::]:443 ssl;
    http2 on;
    server_name %s;

    ssl_certificate %s;
    ssl_certificate_key %s;

    root %s;
    index index.php index.html;

    location / {
        try_files $uri $uri/ =404;
    }
}
`, domain, domain, documentRoot, domain, domain, certPath, keyPath, documentRoot)

	path := filepath.Join(m.sitesDir, sanitize(domain)+".conf")
	if err := os.WriteFile(path, []byte(cfg), 0o644); err != nil {
		return err
	}
	return m.reload()
}

func (m *Manager) reload() error {
	cmd := strings.TrimSpace(m.reloadCmd)
	if cmd == "" {
		return nil
	}
	parts := strings.Fields(cmd)
	if len(parts) == 0 {
		return nil
	}
	c := exec.Command(parts[0], parts[1:]...)
	if out, err := c.CombinedOutput(); err != nil {
		return fmt.Errorf("nginx reload: %w: %s", err, strings.TrimSpace(string(out)))
	}
	return nil
}

func sanitize(domain string) string {
	return strings.NewReplacer(".", "_", ":", "_").Replace(domain)
}