package traefik

import (
	"fmt"
	"os/exec"
	"strings"
)

const DefaultVersion = "v3.3.0"

func downloadURL(version string) string {
	return fmt.Sprintf("https://github.com/traefik/traefik/releases/download/%s/traefik_%s_linux_amd64.tar.gz", version, version)
}

func InstallLocal(version string) error {
	if version == "" {
		version = DefaultVersion
	}
	if _, err := exec.LookPath("traefik"); err == nil {
		ensureDirs()
		return nil
	}
	url := downloadURL(version)
	cmd := exec.Command("bash", "-c",
		fmt.Sprintf(`curl -fsSL %s | tar -xzf - -C /usr/local/bin/ traefik && chmod +x /usr/local/bin/traefik`, url))
	if out, err := cmd.CombinedOutput(); err != nil {
		return fmt.Errorf("download traefik %s: %w (output: %s)", version, err, string(out))
	}
	ensureDirs()
	writeSystemdUnit()
	_ = exec.Command("systemctl", "daemon-reload").Run()
	_ = exec.Command("systemctl", "enable", "--now", "orca-traefik").Run()
	return nil
}

type RemoteExecFunc func(cmd string) ([]byte, error)

func InstallRemote(version string, execFn RemoteExecFunc) error {
	if version == "" {
		version = DefaultVersion
	}
	if out, err := execFn("command -v traefik"); err == nil && len(strings.TrimSpace(string(out))) > 0 {
		_, _ = execFn("mkdir -p /etc/traefik/dynamic")
		return nil
	}
	url := downloadURL(version)
	installCmd := fmt.Sprintf(`curl -fsSL %s | tar -xzf - -C /usr/local/bin/ traefik && chmod +x /usr/local/bin/traefik && mkdir -p /etc/traefik/dynamic`, url)
	if out, err := execFn(installCmd); err != nil {
		return fmt.Errorf("download traefik on remote: %w (output: %s)", err, string(out))
	}
	unit := systemdUnitContent()
	_, _ = execFn(fmt.Sprintf(`echo '%s' > /etc/systemd/system/orca-traefik.service`, unit))
	_, _ = execFn("systemctl daemon-reload && systemctl enable --now orca-traefik")
	return nil
}

func ensureDirs() {
	_ = exec.Command("mkdir", "-p", "/etc/traefik/dynamic").Run()
}

func writeSystemdUnit() {
	_ = exec.Command("bash", "-c", fmt.Sprintf(`echo '%s' > /etc/systemd/system/orca-traefik.service`, systemdUnitContent())).Run()
}

func systemdUnitContent() string {
	return `[Unit]
Description=Orca Traefik Data Plane
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/traefik --configFile=/etc/traefik/traefik.yml
Restart=on-failure
RestartSec=5s

[Install]
WantedBy=multi-user.target`
}