package activity

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

	"rideaware/internal/config"
	"rideaware/internal/equipment"
	"rideaware/internal/middleware"
)

type Handler struct {
	service      *Service
	equipmentSvc *equipment.Service
}

func NewHandler() *Handler {
	return &Handler{
		service:      NewService(),
		equipmentSvc: equipment.NewService(),
	}
}

// ImportActivity POST /api/protected/workouts/import
// Accepts multipart form with:
//   - file: activity file (FIT/TCX/GPX) - required
//   - workout_id: existing workout ID to update (optional)
//   - title: custom title (optional)
//   - equipment_id: equipment to associate (optional)
//   - notes: optional notes
func (h *Handler) ImportActivity(w http.ResponseWriter, r *http.Request) {
	claims := r.Context().Value(middleware.UserContextKey).(*config.CustomClaims)
	if claims == nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusUnauthorized)
		json.NewEncoder(w).Encode(map[string]string{"error": "unauthorized"})
		return
	}

	if err := r.ParseMultipartForm(20 << 20); err != nil { // 20MB max
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": "file too large or invalid form data"})
		return
	}

	file, handler, err := r.FormFile("file")
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": "no file provided"})
		return
	}
	defer file.Close()

	fileData := make([]byte, handler.Size)
	if _, err := file.Read(fileData); err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": "failed to read file"})
		return
	}

	opts := ImportOptions{
		Title: r.FormValue("title"),
		Notes: r.FormValue("notes"),
	}

	if idStr := r.FormValue("workout_id"); idStr != "" {
		if id, err := strconv.ParseUint(idStr, 10, 32); err == nil {
			opts.WorkoutID = uint(id)
		}
	}

	if eqIDStr := r.FormValue("equipment_id"); eqIDStr != "" {
		if eqID, err := strconv.ParseUint(eqIDStr, 10, 32); err == nil {
			id := uint(eqID)
			opts.EquipmentID = &id
		}
	}

	workout, err := h.service.ImportActivity(claims.UserID, fileData, handler.Filename, opts)
	if err != nil {
		log.Printf("Activity import error: %v", err)
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
		return
	}

	// Auto-update equipment mileage if equipment is assigned
	if workout.EquipmentID != nil && workout.Status == "completed" {
		if err := h.equipmentSvc.IncrementMileage(*workout.EquipmentID, claims.UserID, workout.Distance, workout.Duration); err != nil {
			log.Printf("Equipment mileage update error: %v", err)
		}
	}

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