package web

import (
	"fmt"
	"html/template"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"sync"

	"gitea.dooplex.hu/admin/felhom-controller/internal/backup"
	"gitea.dooplex.hu/admin/felhom-controller/internal/config"
	"gitea.dooplex.hu/admin/felhom-controller/internal/notify"
	"gitea.dooplex.hu/admin/felhom-controller/internal/scheduler"
	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
	"gitea.dooplex.hu/admin/felhom-controller/internal/stacks"
	"gitea.dooplex.hu/admin/felhom-controller/internal/system"
)

type Server struct {
	cfg              *config.Config
	stackMgr         *stacks.Manager
	cpuCollector     *system.CPUCollector
	backupMgr        *backup.Manager
	crossDriveRunner *backup.CrossDriveRunner
	scheduler        *scheduler.Scheduler
	settings         *settings.Settings
	alertManager     *AlertManager
	notifier         *notify.Notifier
	logger           *log.Logger
	version          string
	tmpl             *template.Template

	sessions   map[string]*session
	sessionsMu sync.RWMutex
	done       chan struct{}

	// Disk operation state (format/migrate jobs)
	diskJobMu sync.Mutex
	diskJob   *activeDiskJob

	// Active raw mount for the attach wizard (empty when not in use)
	activeRawMount string

	// DR restore mode state
	restoreMu   sync.RWMutex
	restorePlan *backup.RestorePlan
}

func NewServer(cfg *config.Config, stackMgr *stacks.Manager, cpuCollector *system.CPUCollector, backupMgr *backup.Manager, crossDrive *backup.CrossDriveRunner, sched *scheduler.Scheduler, sett *settings.Settings, alertMgr *AlertManager, notif *notify.Notifier, logger *log.Logger, version string) *Server {
	s := &Server{
		cfg:              cfg,
		stackMgr:         stackMgr,
		cpuCollector:     cpuCollector,
		backupMgr:        backupMgr,
		crossDriveRunner: crossDrive,
		scheduler:        sched,
		settings:         sett,
		alertManager:     alertMgr,
		notifier:         notif,
		logger:           logger,
		version:          version,
		sessions:         make(map[string]*session),
		done:             make(chan struct{}),
	}
	s.loadTemplates()
	go s.cleanupSessions()

	// Log auth source on startup
	if sett != nil && sett.GetPasswordHash() != "" {
		logger.Printf("[INFO] Auth: using password from settings.json")
	} else if cfg.Web.PasswordHash != "" {
		logger.Printf("[INFO] Auth: using password from controller.yaml")
	} else {
		logger.Printf("[INFO] Auth: no password configured — dashboard is open")
	}

	// Sync FileBrowser config on startup to ensure mounts and sources are current
	go s.syncFileBrowserMounts()

	return s
}

func (s *Server) loadTemplates() {
	s.tmpl = template.Must(
		template.New("").Funcs(s.templateFuncMap()).ParseFS(templateFS, "templates/*.html"),
	)
}

// SetRestoreState puts the server into DR restore mode with the given plan.
func (s *Server) SetRestoreState(plan *backup.RestorePlan) {
	s.restoreMu.Lock()
	defer s.restoreMu.Unlock()
	s.restorePlan = plan
}

// InRestoreMode returns true if the server is in DR restore mode.
func (s *Server) InRestoreMode() bool {
	s.restoreMu.RLock()
	defer s.restoreMu.RUnlock()
	return s.restorePlan != nil
}

// ServeHTTP handles all non-API web requests.
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	path := r.URL.Path

	// DR restore mode: intercept all routes except restore page, static, and restore API
	if s.InRestoreMode() {
		switch {
		case path == "/restore":
			s.restorePageHandler(w, r)
			return
		case path == "/api/restore/status":
			s.apiRestoreStatus(w, r)
			return
		case path == "/api/restore/all" && r.Method == http.MethodPost:
			s.apiRestoreAll(w, r)
			return
		case path == "/api/restore/skip" && r.Method == http.MethodPost:
			s.apiRestoreSkip(w, r)
			return
		case strings.HasPrefix(path, "/static/"):
			// Allow static assets through
		default:
			// Redirect everything else to the restore page
			http.Redirect(w, r, "/restore", http.StatusFound)
			return
		}
	}

	switch {
	case path == "/" || path == "/dashboard":
		s.dashboardHandler(w, r)
	case path == "/stacks":
		s.stacksHandler(w, r)
	case path == "/backups":
		s.backupsHandler(w, r)
	case path == "/monitoring":
		s.monitoringHandler(w, r)
	case path == "/settings":
		s.settingsHandler(w, r)
	case path == "/settings/password" && r.Method == http.MethodPost:
		s.settingsPasswordHandler(w, r)
	case path == "/settings/notifications" && r.Method == http.MethodPost:
		s.settingsNotificationsHandler(w, r)
	case path == "/settings/notifications/test" && r.Method == http.MethodPost:
		s.settingsNotificationsTestHandler(w, r)
	case path == "/settings/storage/add" && r.Method == http.MethodPost:
		s.settingsStorageAddHandler(w, r)
	case path == "/settings/storage/remove" && r.Method == http.MethodPost:
		s.settingsStorageRemoveHandler(w, r)
	case path == "/settings/storage/default" && r.Method == http.MethodPost:
		s.settingsStorageDefaultHandler(w, r)
	case path == "/settings/storage/schedulable" && r.Method == http.MethodPost:
		s.settingsStorageSchedulableHandler(w, r)
	case path == "/settings/storage/label" && r.Method == http.MethodPost:
		s.settingsStorageLabelHandler(w, r)
	case strings.HasPrefix(path, "/settings/cross-backup/") && r.Method == http.MethodPost:
		name := strings.TrimPrefix(path, "/settings/cross-backup/")
		s.settingsCrossBackupHandler(w, r, name)
	case path == "/backup/restore" && r.Method == http.MethodPost:
		s.backupRestoreHandler(w, r)
	case path == "/settings/storage/init":
		s.storageInitHandler(w, r)
	case path == "/settings/storage/attach":
		s.storageAttachHandler(w, r)
	case strings.HasPrefix(path, "/stacks/") && strings.HasSuffix(path, "/migrate"):
		name := strings.TrimPrefix(path, "/stacks/")
		name = strings.TrimSuffix(name, "/migrate")
		s.migratePageHandler(w, r, name)
	case strings.HasPrefix(path, "/stacks/") && strings.HasSuffix(path, "/logs"):
		name := strings.TrimPrefix(path, "/stacks/")
		name = strings.TrimSuffix(name, "/logs")
		s.logsHandler(w, r, name)
	case strings.HasPrefix(path, "/stacks/") && strings.HasSuffix(path, "/deploy"):
		name := strings.TrimPrefix(path, "/stacks/")
		name = strings.TrimSuffix(name, "/deploy")
		s.deployHandler(w, r, name)
	case path == "/static/style.css":
		s.serveCSSHandler(w, r)
	case path == "/static/chart.min.js":
		s.serveChartJSHandler(w, r)
	case path == "/static/felhom-logo.svg":
		s.serveLogoHandler(w, r)
	case strings.HasPrefix(path, "/static/assets/"):
		s.serveAsset(w, r, strings.TrimPrefix(path, "/static/assets/"))
	case strings.HasPrefix(path, "/apps/"):
		slug := strings.TrimPrefix(path, "/apps/")
		s.appDetailHandler(w, r, slug)
	default:
		http.NotFound(w, r)
	}
}

// ServeStorageAPI handles /api/storage/* routes (JSON API for disk operations).
func (s *Server) ServeStorageAPI(w http.ResponseWriter, r *http.Request) {
	s.storageAPIHandler(w, r)
}

// primaryHDDPath returns the default storage path, or the legacy config value.
func (s *Server) primaryHDDPath() string {
	if p := s.settings.GetDefaultStoragePath(); p != "" {
		return p
	}
	return s.cfg.Paths.HDDPath
}

func (s *Server) render(w http.ResponseWriter, name string, data interface{}) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := s.tmpl.ExecuteTemplate(w, name, data); err != nil {
		s.logger.Printf("[ERROR] Template error (%s): %v", name, err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
	}
}

// --- Static file / asset serving ---

func (s *Server) serveCSSHandler(w http.ResponseWriter, r *http.Request) {
	data, err := templateFS.ReadFile("templates/style.css")
	if err != nil {
		http.Error(w, "CSS not found", 500)
		return
	}
	w.Header().Set("Content-Type", "text/css; charset=utf-8")
	w.Header().Set("Cache-Control", "public, max-age=3600")
	w.Write(data)
}

func (s *Server) serveChartJSHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/javascript; charset=utf-8")
	w.Header().Set("Cache-Control", "public, max-age=86400")
	w.Write(chartJS)
}

func (s *Server) serveLogoHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "image/svg+xml")
	w.Header().Set("Cache-Control", "public, max-age=86400")
	fmt.Fprint(w, felhomLogoSVG)
}

// serveAsset serves baked-in app assets (logos, screenshots) from /usr/share/felhom/assets/
const assetsDir = "/usr/share/felhom/assets"

func (s *Server) serveAsset(w http.ResponseWriter, r *http.Request, filename string) {
	filename = filepath.Base(filename)
	path := filepath.Join(assetsDir, filename)

	if _, err := os.Stat(path); os.IsNotExist(err) {
		http.NotFound(w, r)
		return
	}

	w.Header().Set("Cache-Control", "public, max-age=86400")
	http.ServeFile(w, r, path)
}