package handlers

import (
	"encoding/json"
	"net/http"
	"net/url"

	"github.com/forgeo/forgebucket/internal/config"
)

type InstanceHandler struct {
	cfg *config.Config
}

func NewInstanceHandler(cfg *config.Config) *InstanceHandler {
	return &InstanceHandler{cfg: cfg}
}

// Get returns the public instance configuration needed by the frontend to
// construct clone URLs (SSH host, SSH port, instance name).
func (h *InstanceHandler) Get(w http.ResponseWriter, r *http.Request) {
	sshHost := h.sshHost(r)
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{ //nolint:errcheck
		"sshHost":      sshHost,
		"sshPort":      h.cfg.SSHPort,
		"instanceName": h.cfg.InstanceName,
	})
}

// sshHost extracts the hostname from InstanceURL. Falls back to the request
// host when InstanceURL is unset (common in local development).
func (h *InstanceHandler) sshHost(r *http.Request) string {
	if h.cfg.InstanceURL != "" {
		if u, err := url.Parse(h.cfg.InstanceURL); err == nil && u.Hostname() != "" {
			return u.Hostname()
		}
	}
	// Strip port from Host header if present.
	host := r.Host
	if u, err := url.Parse("http://" + host); err == nil {
		return u.Hostname()
	}
	return host
}