package com.microchip.mplab.progcli;

import java.io.File;

/**
 * Resolves CMSIS pack repository locations so the Java engine reads packs from
 * wherever {@code mplabx packs install} writes them.
 *
 * Resolution order deliberately mirrors src/packs.zig:
 *   user repo   : -Dpackslib.userpacksfolder -> $MPLABX_PACKS_DIR -> ~/.mchp_packs
 *   system repo : -Dpackslib.packsfolder     -> $MPLABX_SYSTEM_PACKS_DIR -> (unset)
 *
 * Stock ipecmd derived these from the ipecmd.jar install path, which tied the
 * engine to a full MPLAB X installation. Nothing here touches the network or
 * installs packs; acquisition is the Zig pack manager's job.
 */
public final class PackPaths {
   public static final String USER_PACKS_PROPERTY = "packslib.userpacksfolder";
   public static final String SYSTEM_PACKS_PROPERTY = "packslib.packsfolder";
   public static final String THIRDPARTY_PROPERTY = "mplabx.thirdparty.lib.path";

   private PackPaths() {
   }

   /** Populates the system properties the crownking/packslib code reads. */
   public static void install() {
      String userRepo = userRepo();
      if (userRepo != null) {
         System.setProperty(USER_PACKS_PROPERTY, userRepo);
      }

      String systemRepo = systemRepo();
      if (systemRepo != null) {
         System.setProperty(SYSTEM_PACKS_PROPERTY, systemRepo);
      }

      String thirdparty = firstNonEmpty(System.getProperty(THIRDPARTY_PROPERTY), System.getenv("MPLABX_THIRDPARTY_DIR"));
      if (thirdparty != null) {
         System.setProperty(THIRDPARTY_PROPERTY, thirdparty);
      }
   }

   /** User pack repository, i.e. the directory {@code mplabx packs install} populates. */
   public static String userRepo() {
      String explicit = firstNonEmpty(System.getProperty(USER_PACKS_PROPERTY), System.getenv("MPLABX_PACKS_DIR"));
      if (explicit != null) {
         return explicit;
      }

      String home = System.getProperty("user.home");
      if (home == null || home.isEmpty()) {
         return null;
      }

      return home + File.separator + ".mchp_packs";
   }

   /** Optional read-only system pack repository (an MPLAB X install's packs/ dir). */
   public static String systemRepo() {
      return firstNonEmpty(System.getProperty(SYSTEM_PACKS_PROPERTY), System.getenv("MPLABX_SYSTEM_PACKS_DIR"));
   }

   private static String firstNonEmpty(String... values) {
      for (String value : values) {
         if (value != null && !value.trim().isEmpty()) {
            return value;
         }
      }

      return null;
   }
}