using System.Collections.Generic;
using TMPro;
using UnityEngine;

namespace DepthsOfGreed.HandbookUI
{
    public sealed partial class SupplyBasementController
    {
        [Header("Versorgungssystem – optional")]
        [Tooltip("MonoBehaviour mit ISupplyGameplay. Leer = bisherige Bedien- und Fahrvorschau.")]
        [SerializeField] private MonoBehaviour supplyBackend;
        public TMP_Text[] storageAmounts, bufferAmounts, magazineAmounts;
        public bool HasSupplyBackend => supplyBackend && supplyBackend is ISupplyGameplay;
        public ISupplyGameplay SupplyBackend => HasSupplyBackend ? (ISupplyGameplay)supplyBackend : null;
        private SupplyState supplyState;
        private float commandMessageUntil;
        private readonly List<BuiltObjectSnapshot> supplyObjects = new List<BuiltObjectSnapshot>();

        public void BindSupplyBackend(MonoBehaviour backend)
        {
            if (backend && !(backend is ISupplyGameplay))
            { Debug.LogError("Versorgung: Komponente muss ISupplyGameplay implementieren.", backend); return; }
            supplyBackend = backend;
            // Filled on the next UI refresh; safe even before Awake.
            nextRefresh = 0;
        }
        private IReadOnlyList<BuiltObjectSnapshot> GetSupplyObjects()
        {
            if (!HasSupplyBackend)
                return placement && placement.Backend != null ? placement.Backend.BuiltObjects : null;
            supplyState = SupplyBackend.ReadState();
            supplyObjects.Clear();
            if (supplyState?.towers != null)
                foreach (var t in supplyState.towers)
                    if (t != null && t.type) supplyObjects.Add(new BuiltObjectSnapshot { instanceId = t.instanceId, type = t.type });
            Priority = supplyState == null ? -1 : (int)supplyState.priority;
            RenderPriority(); RenderAmounts();
            return supplyObjects;
        }
        private TowerSupplyState FindTower(long id)
        {
            if (supplyState?.towers != null) foreach (var t in supplyState.towers) if (t != null && t.instanceId == id) return t;
            return null;
        }
        private bool TrySetBackendConnection(long id, bool connected)
        {
            if (!HasSupplyBackend) return false;
            var result = SupplyBackend.SetConnected(id, connected);
            if (result.accepted) ConnectionChanged?.Invoke(id, connected);
            else ShowCommandMessage(result.message);
            RefreshConnections(); return true;
        }
        private bool TrySetBackendPriority(int kind)
        {
            if (!HasSupplyBackend) return false;
            int desired = Priority == kind ? -1 : kind;
            var result = SupplyBackend.SetPriority((SupplyKind)desired);
            if (result.accepted) PriorityChanged?.Invoke(desired);
            else ShowCommandMessage(result.message);
            RefreshConnections(); return true;
        }
        private void ShowCommandMessage(string message)
        { truckStatus.text = string.IsNullOrWhiteSpace(message) ? "Aktion derzeit nicht möglich" : message; commandMessageUntil = Time.unscaledTime + 2; }
        private void RenderPriority()
        {
            for (int i = 0; i < priorityButtons.Length; i++)
            {
                priorityButtons[i].GetComponent<UnityEngine.UI.Image>().color = Priority == i ? ColorFor(i) : new Color(.72f,.72f,.72f);
                priorityLabels[i].text = Priority == i ? "Vorrang aktiv" : "Vorrang geben";
            }
        }
        private static string Amount(float value, float capacity)
            => Mathf.Max(0,value).ToString("0.#") + " / " + Mathf.Max(0,capacity).ToString("0.#");
        private void RenderAmounts()
        {
            for (int i = 0; i < 3; i++)
            {
                SupplyChannelState channel = null;
                if (supplyState?.channels != null) foreach (var item in supplyState.channels) if (item != null && (int)item.kind == i) { channel = item; break; }
                if (storageAmounts != null && i < storageAmounts.Length && storageAmounts[i]) storageAmounts[i].text = channel == null ? "— / —" : Amount(channel.storage, channel.storageCapacity);
                if (bufferAmounts != null && i < bufferAmounts.Length && bufferAmounts[i]) bufferAmounts[i].text = channel == null ? "Vorrat: —" : Amount(channel.buffer, channel.bufferCapacity);
            }
        }
        private void RenderMagazine(int slot, long id)
        {
            if (magazineAmounts == null || slot >= magazineAmounts.Length || !magazineAmounts[slot]) return;
            var state = HasSupplyBackend ? FindTower(id) : null;
            magazineAmounts[slot].gameObject.SetActive(state != null);
            if (state != null) magazineAmounts[slot].text = "Magazin: " + Amount(state.magazine, state.magazineCapacity);
        }
        private float StopX(SupplyStop stop) => stop == SupplyStop.Distributor ? unloadingPosition : loadingPositions[Mathf.Clamp((int)stop,0,2)];
        private void RenderBackendTruck()
        {
            var state = supplyState?.truck;
            if (state == null) { if(Time.unscaledTime >= commandMessageUntil)truckStatus.text = "LKW bereit"; return; }
            var p = truck.anchoredPosition;
            p.x = state.phase == SupplyTruckPhase.Driving
                ? Mathf.Lerp(StopX(state.from), StopX(state.to), Mathf.Clamp01(state.progress)) : StopX(state.to);
            truck.anchoredPosition = p;
            float direction = StopX(state.to) - StopX(state.from);
            if (state.phase == SupplyTruckPhase.Driving && Mathf.Abs(direction) > .1f)
                truck.localScale = new Vector3(Mathf.Abs(truckScale.x)*Mathf.Sign(direction),truckScale.y,truckScale.z);
            if(Time.unscaledTime < commandMessageUntil)return;
            string phase = state.phase == SupplyTruckPhase.Loading ? "Beladen" : state.phase == SupplyTruckPhase.Unloading ? "Abladen" : state.phase == SupplyTruckPhase.Driving ? "Unterwegs" : "Bereit";
            int kind = (int)state.cargoKind;
            truckStatus.text = phase + (kind >= 0 && kind < kinds.Length ? " · " + kinds[kind] + " " + Amount(state.cargo,state.cargoCapacity) : "");
        }
    }
}