using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using GameCult.Aetheria.EveRuntime;
using GameCult.Aetheria.State.Verse;
using GameCult.Eve.Surface;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.Utilities;
using UnityEngine.UIElements;

public class InputDisplayLayout : MonoBehaviour
{
    private UIDocument _surfaceDocument;
    private AetheriaInput _ownedInput;
    private AetheriaClient _client;
    private string _clientStatePath = "";
    private AetheriaRuntimePlayerSettingsSnapshot _playerSettings;
    private InputAction _captureAction;
    private InputActionAsset _input;
    private string _captureActionName = "";
    private int _captureBindingIndex = -1;
    private string _captureBindingLabel = "";
    private readonly AetheriaEveUnitySurfaceChrome _surfaceChrome = new AetheriaEveUnitySurfaceChrome
    {
        RootAlignItems = Align.Center,
        RootJustifyContent = Justify.Center,
        RootPaddingLeft = 24f,
        RootPaddingRight = 24f,
        RootPaddingTop = 24f,
        RootPaddingBottom = 24f,
        RootBackgroundColor = new Color(0f, 0f, 0f, 0.72f),
        Width = 1080f,
        MinWidth = 0f,
        MaxWidth = 1080f,
        MaxHeight = 900f,
        FlexGrow = 1f,
        PaddingLeft = 20f,
        PaddingRight = 20f,
        PaddingTop = 20f,
        PaddingBottom = 20f,
        BorderRadius = 0f,
        BorderWidth = 0f,
        BackgroundColor = new Color(0.08f, 0.1f, 0.14f, 0.96f)
    };

    public InputActionAsset Input
    {
        get => _input;
        set
        {
            _input = value;
            if (isActiveAndEnabled)
            {
                RenderSurface();
            }
        }
    }

    private void Start()
    {
        EnsureInputAsset();
        EnsureCaptureAction();
        HideLegacyChildren();
        RenderSurface();
    }

    private void OnEnable()
    {
        EnsureInputAsset();
        EnsureCaptureAction();
        HideLegacyChildren();
        RenderSurface();
    }

    private void OnDisable()
    {
        ClearCapture();
        if (_captureAction != null)
        {
            _captureAction.Disable();
        }

        if (_surfaceDocument != null)
        {
            AetheriaEveUnitySurfaceHost.Hide(_surfaceDocument);
        }
    }

    private void OnDestroy()
    {
        _captureAction?.Dispose();
        _captureAction = null;

        _ownedInput?.Dispose();
        _ownedInput = null;

        DisposeClient();

        if (_surfaceDocument != null)
        {
            AetheriaEveUnitySurfaceHost.DestroyDocument(_surfaceDocument);
            _surfaceDocument = null;
        }
    }

    private void EnsureInputAsset()
    {
        if (Input != null)
        {
            return;
        }

        _ownedInput ??= new AetheriaInput();
        Input = _ownedInput.asset;
    }

    private void HideLegacyChildren()
    {
        for (var index = 0; index < transform.childCount; index++)
        {
            var child = transform.GetChild(index);
            if (_surfaceDocument != null && child.gameObject == _surfaceDocument.gameObject)
            {
                continue;
            }

            child.gameObject.SetActive(false);
        }
    }

    private void EnsureCaptureAction()
    {
        if (_captureAction != null)
        {
            return;
        }

        _captureAction = new InputAction("Aetheria Input Capture");
        _captureAction.AddBinding("<Keyboard>/anyKey");
        _captureAction.AddBinding("<Mouse>/leftButton");
        _captureAction.AddBinding("<Mouse>/rightButton");
        _captureAction.AddBinding("<Mouse>/middleButton");
        _captureAction.AddBinding("<Mouse>/forwardButton");
        _captureAction.AddBinding("<Mouse>/backButton");
        _captureAction.performed += OnCapturePerformed;
    }

    private void RenderSurface()
    {
        if (!isActiveAndEnabled)
        {
            return;
        }

        EnsureInputAsset();
        EnsureCaptureAction();

        var document = AetheriaRuntimeInputSettingsSurfaceBuilder.Build(ProjectSurfaceState());

        _surfaceDocument = AetheriaEveUnitySurfaceHost.RenderRuntime(
            transform,
            _surfaceDocument,
            "Aetheria Input Surface",
            document,
            HandleSurfaceCommand,
            _surfaceChrome);
    }

    private AetheriaRuntimeInputSettingsSurfaceState ProjectSurfaceState()
    {
        var runtimeSettings = ResolvePlayerSettings();
        return AetheriaRuntimeInputSettingsSurfaceBuilder.Project(
            ProjectObservedBindings(),
            runtimeSettings?.ActionBarInputs ?? Array.Empty<string>(),
            capturePending: _captureBindingIndex >= 0 && !string.IsNullOrWhiteSpace(_captureActionName),
            capturePrompt: BuildCapturePrompt(),
            updatedAtUtc: DateTime.UtcNow.ToString("O"));
    }

    private IReadOnlyList<AetheriaRuntimeObservedInputBinding> ProjectObservedBindings()
    {
        if (Input == null)
        {
            return Array.Empty<AetheriaRuntimeObservedInputBinding>();
        }

        return Input
            .Where(action => action.actionMap.name != "UI")
            .SelectMany(action =>
                action.bindings
                    .Select((binding, bindingIndex) => new { action, binding, bindingIndex }))
            .Where(entry =>
                !entry.binding.isComposite &&
                !string.IsNullOrWhiteSpace(entry.binding.effectivePath) &&
                AetheriaRuntimeInputSettingsSurfaceBuilder.IsSupportedCapturePath(entry.binding.effectivePath))
            .Select(entry => new AetheriaRuntimeObservedInputBinding(
                entry.action.name,
                entry.bindingIndex,
                DescribeBinding(entry.action.name, entry.binding),
                entry.binding.effectivePath,
                DescribeInputPath(entry.binding.effectivePath),
                include: true))
            .ToArray();
    }

    private static string DescribeBinding(string actionName, InputBinding binding)
    {
        if (binding.isPartOfComposite && !string.IsNullOrWhiteSpace(binding.name))
        {
            return $"{actionName} {binding.name}";
        }

        return actionName;
    }

    private static string DescribeInputPath(string inputPath)
    {
        if (string.IsNullOrWhiteSpace(inputPath))
        {
            return "Unbound";
        }

        var label = InputControlPath.ToHumanReadableString(
            inputPath,
            InputControlPath.HumanReadableStringOptions.OmitDevice);
        return string.IsNullOrWhiteSpace(label) ? inputPath : label;
    }

    private string BuildCapturePrompt()
    {
        if (_captureBindingIndex < 0 || string.IsNullOrWhiteSpace(_captureActionName))
        {
            return "";
        }

        return $"Capture pending for {_captureBindingLabel}. Press a keyboard or mouse input now.";
    }

    private void HandleSurfaceCommand(EveSurfaceCommandRequest request)
    {
        if (!AetheriaRuntimeInputSettingsSurfaceCommands.TryRead(request, out var command))
        {
            Debug.LogWarning($"Unknown input-settings command: {request?.Command}");
            return;
        }

        switch (command.Kind)
        {
            case AetheriaRuntimeInputSettingsCommandKind.Refresh:
                RenderSurface();
                return;
            case AetheriaRuntimeInputSettingsCommandKind.CancelCapture:
                ClearCapture();
                RenderSurface();
                return;
            case AetheriaRuntimeInputSettingsCommandKind.BeginCapture:
                BeginCapture(command);
                return;
            case AetheriaRuntimeInputSettingsCommandKind.ToggleActionBar:
                ToggleActionBarInput(command);
                return;
            default:
                Debug.LogWarning($"Unknown input-settings command: {request?.Command}");
                return;
        }
    }

    private void BeginCapture(AetheriaRuntimeInputSettingsSurfaceCommand command)
    {
        if (string.IsNullOrWhiteSpace(command.ActionName) || command.BindingIndex < 0)
        {
            Debug.LogWarning("Input capture requested without a valid action name and binding index.");
            return;
        }

        _captureActionName = command.ActionName;
        _captureBindingIndex = command.BindingIndex;
        _captureBindingLabel = string.IsNullOrWhiteSpace(command.BindingLabel)
            ? command.ActionName
            : command.BindingLabel;
        _captureAction?.Enable();
        RenderSurface();
    }

    private void ToggleActionBarInput(AetheriaRuntimeInputSettingsSurfaceCommand command)
    {
        if (string.IsNullOrWhiteSpace(command.InputPath))
        {
            Debug.LogWarning("Action-bar toggle requested without a valid input path and enabled state.");
            return;
        }

        SendInputSettingsCommand(
            AetheriaRuntimeEveCommandKind.SetActionBarEnabled,
            new AetheriaRuntimeInputSettingsCommandBody
            {
                InputSystemPath = command.InputPath,
                Enabled = command.Enabled
            },
            "action-bar input");
        RenderSurface();
    }

    private void OnCapturePerformed(InputAction.CallbackContext context)
    {
        if (_captureBindingIndex < 0 || string.IsNullOrWhiteSpace(_captureActionName))
        {
            return;
        }

        var inputPath = context.control?.path ?? "";
        if (string.IsNullOrWhiteSpace(inputPath) ||
            inputPath.EndsWith("anyKey", StringComparison.Ordinal) ||
            !AetheriaRuntimeInputSettingsSurfaceBuilder.IsSupportedCapturePath(inputPath) ||
            Input == null)
        {
            return;
        }

        var action = Input.FindAction(_captureActionName, throwIfNotFound: false);
        if (action == null || _captureBindingIndex >= action.bindings.Count)
        {
            Debug.LogWarning($"Input capture target no longer exists for {_captureActionName}:{_captureBindingIndex}.");
            ClearCapture();
            RenderSurface();
            return;
        }

        action.ApplyBindingOverride(_captureBindingIndex, inputPath);
        SendInputSettingsCommand(
            AetheriaRuntimeEveCommandKind.SetBindingOverride,
            new AetheriaRuntimeInputSettingsCommandBody
            {
                ActionName = action.name,
                BindingIndex = _captureBindingIndex,
                InputSystemPath = inputPath
            },
            "input binding override");
        ClearCapture();
        RenderSurface();
    }

    private void SendInputSettingsCommand(
        AetheriaRuntimeEveCommandKind command,
        AetheriaRuntimeInputSettingsCommandBody body,
        string label)
    {
        try
        {
            var submitted = ResolveClient()
                .Ui.InputSettingsAsync(command, body, "unity-input-screen")
                .GetAwaiter()
                .GetResult();

            Debug.Log($"Submitted Aetheria {label} Eve operation: {submitted.OperationId}");
        }
        catch (Exception ex)
        {
            Debug.LogError($"Failed to send Aetheria {label} Eve command: {ex}");
        }
    }

    private AetheriaClient ResolveClient()
    {
        var gameDataDirectory = new DirectoryInfo(Path.Combine(Application.dataPath, "..", "GameData"));
        var stateBoot = AetheriaRuntimeStateBoot.Inspect(gameDataDirectory);
        if (!stateBoot.SupportsLocalStateFileRead || !stateBoot.StateFileExists)
        {
            throw new InvalidOperationException(
                $"Input settings require a readable local Aetheria Verse state file: {stateBoot.FailureMessage}");
        }

        if (_client != null && string.Equals(_clientStatePath, stateBoot.StateFilePath, StringComparison.Ordinal))
        {
            return _client;
        }

        DisposeClient();
        _client = AetheriaClient
            .OpenAsync(
                stateBoot.StateFilePath,
                "unity-input-screen",
                "local",
                startServer: false,
                pullOnOpen: true)
            .GetAwaiter()
            .GetResult();
        _clientStatePath = stateBoot.StateFilePath;
        return _client;
    }

    private void DisposeClient()
    {
        _client?.Dispose();
        _client = null;
        _clientStatePath = "";
        _playerSettings = null;
    }

    private AetheriaRuntimePlayerSettingsSnapshot ResolvePlayerSettings()
    {
        if (_playerSettings != null)
            return _playerSettings;

        try
        {
            _playerSettings = ResolveClient()
                .PlayerSettingsAsync()
                .GetAwaiter()
                .GetResult();
        }
        catch (Exception ex)
        {
            Debug.LogWarning($"Failed to read Aetheria player settings for input screen: {ex.Message}");
        }

        return _playerSettings;
    }

    private void ClearCapture()
    {
        _captureActionName = "";
        _captureBindingIndex = -1;
        _captureBindingLabel = "";
    }

}