package handler

import (
	"context"
	"database/sql"
	"net/http"

	"dealroom/internal/rbac"
	"dealroom/internal/store"

	"github.com/gorilla/sessions"
)

// Handler contains dependencies for HTTP handlers
type Handler struct {
	db       *sql.DB
	store    *store.Store
	rbac     *rbac.Engine
	sessions *sessions.CookieStore
	config   *Config
}

// Config holds configuration for handlers
type Config struct {
	BaseURL    string
	SessionKey string
	K25APIURL  string
	K25APIKey  string
	SMTPHost   string
	SMTPUser   string
	SMTPPass   string
}

// New creates a new handler instance
func New(db *sql.DB, fileStore *store.Store, config *Config) *Handler {
	return &Handler{
		db:       db,
		store:    fileStore,
		rbac:     rbac.New(db),
		sessions: sessions.NewCookieStore([]byte(config.SessionKey)),
		config:   config,
	}
}

// RegisterRoutes sets up all HTTP routes
func (h *Handler) RegisterRoutes(mux *http.ServeMux) {
	// Static files
	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))

	// Authentication routes
	mux.HandleFunc("/auth/login", h.handleLogin)
	mux.HandleFunc("/auth/verify/", h.handleVerifyLogin)
	mux.HandleFunc("/auth/logout", h.handleLogout)
	mux.HandleFunc("/auth/me", h.handleMe)

	// Page routes
	mux.HandleFunc("/", h.handleDashboard)
	mux.HandleFunc("/login", h.handleLoginPage)
	mux.HandleFunc("/deal-rooms/", h.handleDealRoom)
	mux.HandleFunc("/documents/", h.handleDocument)
	mux.HandleFunc("/admin", h.requireAuth(h.requireAdmin(h.handleAdmin)))
	mux.HandleFunc("/profile", h.requireAuth(h.handleProfile))
	mux.HandleFunc("/activity", h.requireAuth(h.handleActivity))

	// API routes
	mux.HandleFunc("/api/deal-rooms", h.requireAuth(h.handleAPIEndpoint("deal-rooms")))
	mux.HandleFunc("/api/deal-rooms/", h.requireAuth(h.handleAPIEndpoint("deal-rooms")))
	mux.HandleFunc("/api/entries", h.requireAuth(h.handleAPIEndpoint("entries")))
	mux.HandleFunc("/api/entries/", h.requireAuth(h.handleAPIEndpoint("entries")))
	mux.HandleFunc("/api/search", h.requireAuth(h.handleSearch))
	mux.HandleFunc("/api/activity/", h.requireAuth(h.handleAPIActivity))
}

// Middleware

func (h *Handler) requireAuth(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		session, _ := h.sessions.Get(r, "dealroom")
		userID, ok := session.Values["user_id"].(string)
		
		if !ok || userID == "" {
			if isAPIRequest(r) {
				http.Error(w, "Authentication required", http.StatusUnauthorized)
				return
			}
			http.Redirect(w, r, "/login", http.StatusSeeOther)
			return
		}

		// Add user ID to request context
		ctx := r.Context()
		ctx = setUserID(ctx, userID)
		next.ServeHTTP(w, r.WithContext(ctx))
	}
}

func (h *Handler) requireAdmin(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID := getUserID(r.Context())
		
		// Check if user is admin
		var role string
		err := h.db.QueryRow("SELECT role FROM users WHERE id = ?", userID).Scan(&role)
		if err != nil || role != "admin" {
			http.Error(w, "Admin access required", http.StatusForbidden)
			return
		}

		next.ServeHTTP(w, r)
	}
}

// Placeholder handlers - to be implemented

func (h *Handler) handleLogin(w http.ResponseWriter, r *http.Request) {
	// TODO: Implement magic link login
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleVerifyLogin(w http.ResponseWriter, r *http.Request) {
	// TODO: Implement login verification
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleLogout(w http.ResponseWriter, r *http.Request) {
	session, _ := h.sessions.Get(r, "dealroom")
	session.Values["user_id"] = ""
	session.Save(r, w)
	http.Redirect(w, r, "/login", http.StatusSeeOther)
}

func (h *Handler) handleMe(w http.ResponseWriter, r *http.Request) {
	// TODO: Return current user info
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleDashboard(w http.ResponseWriter, r *http.Request) {
	// TODO: Render dashboard template
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleLoginPage(w http.ResponseWriter, r *http.Request) {
	// TODO: Render login template
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleDealRoom(w http.ResponseWriter, r *http.Request) {
	// TODO: Handle deal room pages
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleDocument(w http.ResponseWriter, r *http.Request) {
	// TODO: Handle document viewing
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleAdmin(w http.ResponseWriter, r *http.Request) {
	// TODO: Render admin panel
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleProfile(w http.ResponseWriter, r *http.Request) {
	// TODO: Render user profile
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleActivity(w http.ResponseWriter, r *http.Request) {
	// TODO: Render activity feed
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleAPIEndpoint(endpoint string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// TODO: Implement REST API endpoints
		http.Error(w, "Not implemented", http.StatusNotImplemented)
	}
}

func (h *Handler) handleSearch(w http.ResponseWriter, r *http.Request) {
	// TODO: Implement search API
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

func (h *Handler) handleAPIActivity(w http.ResponseWriter, r *http.Request) {
	// TODO: Implement activity API
	http.Error(w, "Not implemented", http.StatusNotImplemented)
}

// Helper functions

func isAPIRequest(r *http.Request) bool {
	return r.Header.Get("Accept") == "application/json" || 
		   r.Header.Get("Content-Type") == "application/json" ||
		   r.URL.Path[:5] == "/api/"
}

// Context helpers would go in a separate context.go file
func setUserID(ctx context.Context, userID string) context.Context {
	// TODO: Implement context helpers
	return ctx
}

func getUserID(ctx context.Context) string {
	// TODO: Implement context helpers
	return ""
}