using System.Collections.Generic;
using System.Reflection;
using System.Reflection.Emit;
using HarmonyLib;

namespace PriorityUX {
  [HarmonyPatch(typeof(PriorityScreen))]
  static class PriorityScreenPatches {
    static readonly MethodInfo SetScreenPriorityMethodName = typeof(PriorityScreen).GetMethod(nameof(PriorityScreen.SetScreenPriority));

    [HarmonyPatch(nameof(PriorityScreen.ResetPriority))]
    [HarmonyPrefix]
    static bool ResetPriority_Prefix(PriorityScreen __instance) {
      var options = Options.Instance;
      Debug.Log("[PriorityUX] >> ResetPriority patch options.resetPriority:" + options.resetPriority);
      if (options.resetPriority) {
        __instance.SetScreenPriority(new PrioritySetting(PriorityScreen.PriorityClass.basic, options.resetPriorityLevel));
      }
      return false; // Ignore base implementation
    }

    [HarmonyPatch(nameof(PriorityScreen.SetScreenPriority))]
    [HarmonyPostfix]
    static void SetScreenPriorityPostfix(PrioritySetting priority, PriorityScreen __instance) {
      if (__instance == ToolMenu.Instance.PriorityScreen ||
      __instance == Utils.getPlanPriorityScreen()) {
        // Debug.Log("[PriorityUX] >> SetScreenPriorityPostfix: " + priority.priority_class.ToString() + "-" + priority.priority_value);
        Utils.setLastPriority(priority);
      }

      // If this was set from some other instance than the tool menu, propagate the setting here
      // var toolPriorityScreen = ToolMenu.Instance.PriorityScreen;
      // if (toolPriorityScreen != null && toolPriorityScreen != __instance) {
      //   Debug.Log("[PriorityUX] >> Syncing priority to tool priority");
      //   if (toolPriorityScreen.gameObject.activeSelf) {
      //     Debug.Log("[PriorityUX] >> & active");
      //     toolPriorityScreen.SetScreenPriority(priority);
      //   }
      // }
    }

    static void SetInitialPriority(PriorityScreen priorityScreen) {
      Debug.Log("[PriorityUX] >> SetInitialPriority", priorityScreen);
      priorityScreen.SetScreenPriority(Utils.getLastPriority());
    }

    [HarmonyPatch(nameof(PriorityScreen.InstantiateButtons))]
    [HarmonyTranspiler]
    static IEnumerable<CodeInstruction> InstantiateButtonsTranspiler(IEnumerable<CodeInstruction> instructions) {
      foreach (var instruction in instructions) {
        // SetScreenPriority(new PrioritySetting(PriorityClass.basic, 5));
        // IL_0166: ldarg.0
        // IL_0167: ldc.i4.0
        // IL_0168: ldc.i4.5
        // IL_0169: newobj instance void PrioritySetting::.ctor(valuetype PriorityScreen/PriorityClass, int32)
        // IL_016e: ldc.i4.0
        // IL_016f: call instance void PriorityScreen::SetScreenPriority(valuetype PrioritySetting, bool)
        if (instruction.Calls(SetScreenPriorityMethodName)) {
          Debug.Log("[PriorityUX] >> Transpile default priority in InstantiateButtons");
          yield return new CodeInstruction(OpCodes.Pop); // Priority
          yield return new CodeInstruction(OpCodes.Pop); // Bool
          yield return CodeInstruction.Call(typeof(PriorityScreenPatches), nameof(PriorityScreenPatches.SetInitialPriority));
          continue;
        }
        yield return instruction;
      }
    }
  }
}