package server

import (
	"crypto/rand"
	"encoding/base64"
	"encoding/json"
	"net/http"
	"path/filepath"
	"time"
	"golang.org/x/crypto/bcrypt"
	"yoresee_dropbox/internal/store"
)

type createShareRequest struct {
	Password       string `json:"password"`
	ExpiresInHours int    `json:"expires_in_hours"`
}

func (s *Server) handleCreateShare(w http.ResponseWriter, r *http.Request) {
	fileID := r.PathValue("id")
	var req createShareRequest
	json.NewDecoder(r.Body).Decode(&req)

	token := generateShareToken()
	share := &store.Share{
		ID:        generateUUID(),
		FileID:    fileID,
		Token:     token,
		CreatedAt: time.Now().Unix(),
	}

	if req.Password != "" {
		hash, err := bcrypt.GenerateFromPassword([]byte(req.Password), 10)
		if err != nil {
			http.Error(w, "Failed to hash password", http.StatusInternalServerError)
			return
		}
		share.PasswordHash = string(hash)
	}

	if req.ExpiresInHours > 0 {
		share.ExpiresAt = time.Now().Add(time.Duration(req.ExpiresInHours) * time.Hour).Unix()
	}

	if err := s.store.ShareCreate(share); err != nil {
		http.Error(w, "Failed to create share", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(map[string]any{
		"url":   "/s/" + token,
		"token": token,
	})
}

func (s *Server) handleListShares(w http.ResponseWriter, r *http.Request) {
	shares, err := s.store.ShareList()
	if err != nil {
		http.Error(w, "Failed to list", http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(map[string]any{"shares": shares})
}

func (s *Server) handleDeleteShare(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	if err := s.store.ShareDelete(id); err != nil {
		http.Error(w, "Failed to delete", http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (s *Server) handleShareAccess(w http.ResponseWriter, r *http.Request) {
	token := r.PathValue("token")
	share, err := s.store.ShareGetByToken(token)
	if err != nil {
		http.Error(w, "Not found", http.StatusNotFound)
		return
	}

	if share.ExpiresAt > 0 && time.Now().Unix() > share.ExpiresAt {
		s.store.ShareDelete(share.ID)
		http.Error(w, "Share expired", http.StatusGone)
		return
	}

	if share.PasswordHash != "" {
		cookie, err := r.Cookie("ydropbox_share_" + share.ID)
		if err != nil || !s.verifyShareCookie(share.ID, cookie.Value) {
			w.Header().Set("Content-Type", "text/html")
			w.Write([]byte(`<!DOCTYPE html><html><body>
				<form method="POST"><input type="password" name="password"><button>Submit</button></form>
			</body></html>`))
			return
		}
	}

	s.serveSharedFile(w, r, share)
}

func (s *Server) handleSharePassword(w http.ResponseWriter, r *http.Request) {
	token := r.PathValue("token")
	share, err := s.store.ShareGetByToken(token)
	if err != nil {
		http.Error(w, "Not found", http.StatusNotFound)
		return
	}

	password := r.FormValue("password")
	if err := bcrypt.CompareHashAndPassword([]byte(share.PasswordHash), []byte(password)); err != nil {
		http.Error(w, "Wrong password", http.StatusForbidden)
		return
	}

	cookieVal := generateSessionID()
	s.mu.Lock()
	if s.shareSessions == nil {
		s.shareSessions = make(map[string]string)
	}
	s.shareSessions[cookieVal] = share.ID
	s.mu.Unlock()

	http.SetCookie(w, &http.Cookie{
		Name:     "ydropbox_share_" + share.ID,
		Value:    cookieVal,
		Path:     "/",
		HttpOnly: true,
		SameSite: http.SameSiteLaxMode,
		MaxAge:   3600,
	})

	http.Redirect(w, r, "/s/"+token, http.StatusFound)
}

func (s *Server) serveSharedFile(w http.ResponseWriter, r *http.Request, share *store.Share) {
	f, err := s.store.FileGet(share.FileID)
	if err != nil {
		http.Error(w, "File not found", http.StatusNotFound)
		return
	}

	path := filepath.Join(s.workspace, f.Dir, f.StorageName)
	w.Header().Set("Content-Disposition", "attachment; filename="+f.OriginalName)
	w.Header().Set("X-Content-Type-Options", "nosniff")
	http.ServeFile(w, r, path)
}

func (s *Server) verifyShareCookie(shareID, cookieVal string) bool {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.shareSessions[cookieVal] == shareID
}

func generateShareToken() string {
	b := make([]byte, 24)
	rand.Read(b)
	return base64.URLEncoding.EncodeToString(b)
}