package handlers

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

	"github.com/gorilla/mux"
	"go.mongodb.org/mongo-driver/v2/bson"

	"github.com/noteapp/backend/internal/application/dto"
	"github.com/noteapp/backend/internal/application/services"
	"github.com/noteapp/backend/internal/interfaces/middleware"
)

// NoteHandler handles note endpoints
type NoteHandler struct {
	noteService *services.NoteService
}

// NewNoteHandler creates a new note handler
func NewNoteHandler(noteService *services.NoteService) *NoteHandler {
	return &NoteHandler{
		noteService: noteService,
	}
}

// CreateNote creates a new note
func (h *NoteHandler) CreateNote(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	spaceID := mux.Vars(r)["spaceId"]
	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	var req dto.CreateNoteRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	note, err := h.noteService.CreateNote(r.Context(), spaceObjID, userObjID, &req)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(note)
}

// GetNote retrieves a note
func (h *NoteHandler) GetNote(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	vars := mux.Vars(r)
	spaceID := vars["spaceId"]
	noteID := vars["noteId"]

	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	noteObjID, _ := bson.ObjectIDFromHex(noteID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	note, err := h.noteService.GetNote(r.Context(), noteObjID, spaceObjID, userObjID)
	if err != nil {
		http.Error(w, err.Error(), http.StatusNotFound)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(note)
}

// GetNotesBySpace retrieves notes in a space
func (h *NoteHandler) GetNotesBySpace(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	spaceID := mux.Vars(r)["spaceId"]
	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	// Pagination
	skip, _ := strconv.Atoi(r.URL.Query().Get("skip"))
	limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
	if limit == 0 || limit > 100 {
		limit = 20
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	notes, err := h.noteService.GetNotesBySpace(r.Context(), spaceObjID, userObjID, skip, limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(notes)
}

// SearchNotes performs full-text search
func (h *NoteHandler) SearchNotes(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	spaceID := mux.Vars(r)["spaceId"]
	query := r.URL.Query().Get("q")

	if query == "" {
		http.Error(w, "Missing search query", http.StatusBadRequest)
		return
	}

	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	notes, err := h.noteService.SearchNotes(r.Context(), spaceObjID, userObjID, query)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(notes)
}

// UpdateNote updates a note
func (h *NoteHandler) UpdateNote(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPut {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	vars := mux.Vars(r)
	spaceID := vars["spaceId"]
	noteID := vars["noteId"]

	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	var req dto.UpdateNoteRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	noteObjID, _ := bson.ObjectIDFromHex(noteID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	note, err := h.noteService.UpdateNote(r.Context(), noteObjID, spaceObjID, userObjID, &req)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(note)
}

// DeleteNote deletes a note
func (h *NoteHandler) DeleteNote(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodDelete {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	vars := mux.Vars(r)
	spaceID := vars["spaceId"]
	noteID := vars["noteId"]

	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	noteObjID, _ := bson.ObjectIDFromHex(noteID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	if err := h.noteService.DeleteNote(r.Context(), noteObjID, spaceObjID, userObjID); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}

// UnlockNote verifies a note password and returns full note content
func (h *NoteHandler) UnlockNote(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	vars := mux.Vars(r)
	spaceID := vars["spaceId"]
	noteID := vars["noteId"]

	userID, err := middleware.GetUserIDFromContext(r.Context())
	if err != nil {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	var req dto.UnlockNoteRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	spaceObjID, _ := bson.ObjectIDFromHex(spaceID)
	noteObjID, _ := bson.ObjectIDFromHex(noteID)
	userObjID, _ := bson.ObjectIDFromHex(userID)

	note, err := h.noteService.UnlockNote(r.Context(), noteObjID, spaceObjID, userObjID, req.Password)
	if err != nil {
		if err.Error() == "invalid note password" {
			http.Error(w, err.Error(), http.StatusUnauthorized)
			return
		}
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(note)
}