package routes

import (
	"database/sql"
	"encoding/json"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
)

func (rt *Router) UploadSimulationResource(w http.ResponseWriter, r *http.Request, idStr string) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	var simName string
	err := rt.DB.QueryRow("SELECT name FROM simulations WHERE id = ?", idStr).Scan(&simName)
	if err != nil {
		if err == sql.ErrNoRows {
			http.Error(w, "Simulation not found", http.StatusNotFound)
		} else {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		return
	}

	err = r.ParseMultipartForm(500 << 20) // 500 MB max memory/file bounds
	if err != nil {
		http.Error(w, "Error parsing form: "+err.Error(), http.StatusBadRequest)
		return
	}

	file, handler, err := r.FormFile("file")
	if err != nil {
		http.Error(w, "Error retrieving the file", http.StatusBadRequest)
		return
	}
	defer file.Close()

	destPath := filepath.Join("../results", simName, handler.Filename)
	dst, err := os.Create(destPath)
	if err != nil {
		http.Error(w, "Error creating destination file: "+err.Error(), http.StatusInternalServerError)
		return
	}
	defer dst.Close()

	_, err = io.Copy(dst, file)
	if err != nil {
		http.Error(w, "Error saving file: "+err.Error(), http.StatusInternalServerError)
		return
	}

	finalFilename := TranscodeIfNeeded(filepath.Join("../results", simName), handler.Filename)

	var resID int
	err = rt.DB.QueryRow("SELECT id FROM resources WHERE simulation_id = ? AND filename = ?", idStr, finalFilename).Scan(&resID)
	if err == sql.ErrNoRows {
		_, err = rt.DB.Exec("INSERT INTO resources(simulation_id, filename) VALUES(?, ?)", idStr, finalFilename)
		if err != nil {
			log.Println("Error inserting uploaded resource into db:", err)
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{
		"status":   "success",
		"filename": finalFilename,
	})
}

func (rt *Router) DeleteSimulationResource(w http.ResponseWriter, r *http.Request, idStr string, fileName string) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	var simName string
	err := rt.DB.QueryRow("SELECT name FROM simulations WHERE id = ?", idStr).Scan(&simName)
	if err != nil {
		if err == sql.ErrNoRows {
			http.Error(w, "Simulation not found", http.StatusNotFound)
		} else {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		return
	}

	_, err = rt.DB.Exec("DELETE FROM resources WHERE simulation_id = ? AND filename = ?", idStr, fileName)
	if err != nil {
		log.Println("Error deleting resource from DB:", err)
		http.Error(w, "Failed to delete from database", http.StatusInternalServerError)
		return
	}

	filePath := filepath.Join("../results", simName, fileName)
	if _, statErr := os.Stat(filePath); statErr == nil {
		err = os.Remove(filePath)
		if err != nil {
			log.Println("Warning: Failed deleting physical file:", err)
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{"status": "success"})
}