package graph

import (
	"io"
	"net/http"
	"os"
	"strings"

	"github.com/brasse-b/archivum/internal/config"
)

func NewServer(cfg *config.Config) http.Handler {
	mux := http.NewServeMux()

	mux.HandleFunc("/graphql", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
		if r.Method == http.MethodOptions {
			w.WriteHeader(http.StatusNoContent)
			return
		}
		if cfg == nil {
			_, _ = w.Write([]byte(`{"data":{"systemStatus":"REQUIRE_SETUP"}}`))
			return
		}
		// Stub: inspect operation name to return sensible responses.
		body, _ := io.ReadAll(r.Body)
		bs := string(body)
		switch {
		case strings.Contains(bs, "testLdapConnection"):
			_, _ = w.Write([]byte(`{"data":{"testLdapConnection":{"success":false,"message":"LDAP resolver not yet implemented"}}}`))
		case strings.Contains(bs, "setup"):
			_, _ = w.Write([]byte(`{"data":{"setup":true}}`))
		case strings.Contains(bs, "login"):
			_, _ = w.Write([]byte(`{"data":{"login":"stub-token"}}`))
		default:
			_, _ = w.Write([]byte(`{"data":{"systemStatus":"OK","documents":[]}}`))
		}
	})

	mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	})

	uiDir := os.Getenv("UI_DIR")
	if uiDir == "" {
		uiDir = "/srv/archivum/ui"
	}
	mux.Handle("/", spaHandler(uiDir))

	return mux
}

// spaHandler serves static files and falls back to index.html for all paths
// that don't resolve to a real file — required for client-side routing.
func spaHandler(dir string) http.Handler {
	fs := http.Dir(dir)
	fileServer := http.FileServer(fs)

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Assets (JS, CSS, images) must be served as-is.
		if isAssetPath(r.URL.Path) {
			fileServer.ServeHTTP(w, r)
			return
		}
		// Try to open the path; if it exists serve it, otherwise serve SPA root.
		f, err := fs.Open(r.URL.Path)
		if err == nil {
			f.Close()
			fileServer.ServeHTTP(w, r)
			return
		}
		http.ServeFile(w, r, dir+"/index.html")
	})
}

func isAssetPath(path string) bool {
	return strings.HasPrefix(path, "/assets/") ||
		strings.HasPrefix(path, "/icons/") ||
		path == "/favicon.ico" ||
		path == "/favicon.svg" ||
		path == "/manifest.webmanifest" ||
		path == "/registerSW.js" ||
		path == "/sw.js"
}