using System;
using System.Collections.Generic;
using System.Linq;
using Luneraria.Core;
using Luneraria.View;
using UnityEngine;
using UnityEngine.UIElements;

namespace Luneraria.UI
{
    /// <summary>
    /// One Champions of Luneraria match on screen with the HUD (port of the HUD side of
    /// scripts/luneraria/lune_game.gd): the human player's commands go through the same command
    /// interface as the bots (LuneMatch.Submit); Ready, tempo and pause go to the host loop; HUD
    /// clicks and hotkeys move the camera; a left click in the field selects an own unit. During
    /// planning the own draft army stands in its formation and the own deployment areas light up.
    /// Offline, planning waits for the human; pause and tempo are local. Nothing here decides a rule.
    /// Runs after the match view (execution order 200 after 100), so name tags follow the figures
    /// of the same frame.
    /// </summary>
    [DefaultExecutionOrder(200)]
    public sealed class LuneGame : MonoBehaviour
    {
        public LuneMatchDriver Driver;
        public LuneMatchView View;
        public LuneCameraRig Rig;
        public LuneUiAssets UiAssets;
        /// <summary>The human seat (Godot default 1: Blau Mid). -1 makes the match a bot match watched from seat 0.</summary>
        public int HumanSlot = 1;
        /// <summary>Optional render target for tests and captures (null: the screen).</summary>
        public RenderTexture Target;

        public LuneHud Hud { get; private set; }
        public LuneMatch Match { get { return Driver.Runner.Match; } }
        /// <summary>The human seat of the running match (-1: a bot match, e.g. tests and the benchmark).</summary>
        int Seat { get { return _runner != null ? _runner.HumanSlot : -1; } }
        bool Human { get { return Seat >= 0; } }
        /// <summary>Whose view the HUD shows: the human seat, or in a bot match seat max(0, HumanSlot) as in Godot.</summary>
        int Viewer { get { return Human ? Seat : Math.Max(0, HumanSlot); } }

        Camera _camera;
        LuneMatchRunner _runner;
        readonly System.Diagnostics.Stopwatch _clock = new System.Diagnostics.Stopwatch();
        double _updateMs;
        double _lateMs;
        LuneMatchRunner.Stage _lastStage = (LuneMatchRunner.Stage)(-1);
        int _laneCycle;
        bool _pausedBySettings;
        VisualElement _leave;
        readonly List<(Renderer renderer, int team, string lane)> _pads = new List<(Renderer, int, string)>();
        readonly List<(GameObject ring, int team)> _grottoRings = new List<(GameObject, int)>();
        string _deployment = "";
        MaterialPropertyBlock _block;

        void Start()
        {
            _camera = View != null && View.ViewCamera != null ? View.ViewCamera : Camera.main;
            // The benchmark keeps its bot match; otherwise the configured seat plays.
            if (!LuneBenchmark.Running && (Driver.HumanSlot != HumanSlot || Driver.Runner == null || Driver.Runner.HumanSlot != Driver.HumanSlot))
            {
                Driver.HumanSlot = HumanSlot;
                Driver.Restart();
            }
            FindPads();
            Hud = gameObject.GetComponent<LuneHud>() ?? gameObject.AddComponent<LuneHud>();
            Bind();
            LuneSettingsPanel.Apply();
            if (Rig != null)
            {
                Rig.PointerBlocked = () => Hud != null && Hud.IsPointerOverHud(Input.mousePosition);
                Rig.KeysBlocked = () => Hud != null && Hud.Settings.Open;
                Rig.ResetRequested = () => ResetCamera();
            }
            StartCamera(true);
            // The benchmark counts the HUD scripts: its Tick plus this controller's frame work.
            LuneBenchmark.UiMs = () => (Hud != null ? Hud.LastTickMs : 0.0) + _updateMs + _lateMs;
        }

        void OnDestroy()
        {
            LuneBenchmark.UiMs = null;
        }

        /// <summary>(Re)builds the HUD for the driver's current match and wires its events.</summary>
        void Bind()
        {
            _runner = Driver.Runner;
            _lastStage = (LuneMatchRunner.Stage)(-1);
            Hud.Init(_runner.Match, Viewer, View.Library, UiAssets, Target);
            Hud.CommandRequested += command => Feedback(Send(command));
            Hud.UndoRequested += () => Feedback(Human ? Match.Undo(Seat) : new CommandResult(false, "Kein eigener Platz."));
            Hud.ReadyRequested += OnReady;
            Hud.StarterRequested += Starter;
            Hud.SpeedRequested += CycleSpeed;
            Hud.PauseRequested += TogglePause;
            Hud.LaneFocusRequested += lane => FocusLane(lane);
            Hud.MapFocusRequested += point => Rig?.LookAt(point);
            Hud.CameraRequested += FocusTarget;
            Hud.MenuRequested += AskLeave;
            Hud.RematchRequested += Rematch;
            Hud.SettingsRequested += () => Hud.Settings.Show();
            Hud.Settings.Opened += () =>
            {
                // A running combat pauses offline while the options are open (lune_settings.gd).
                _pausedBySettings = _runner.Current == LuneMatchRunner.Stage.Combat && !Driver.Paused;
                if (_pausedBySettings)
                    Driver.Paused = true;
            };
            Hud.Settings.Closed += () =>
            {
                if (_pausedBySettings)
                    Driver.Paused = false;
                _pausedBySettings = false;
                Hud.SetSpeedLabel(Driver.Tempo, Driver.Paused);
            };
            Hud.SetSpeedLabel(Driver.Tempo, Driver.Paused);
            BuildLeaveDialog();
        }

        CommandResult Send(Command command)
        {
            if (!Human)
                return new CommandResult(false, "Zuschauer können nicht planen.");
            return Match.Submit(Seat, command);
        }

        void Feedback(CommandResult result)
        {
            Hud.Notify(result.Message, !result.Ok);
            RebuildPreview();
            Hud.MarkDirty();
        }

        void Starter()
        {
            List<string> ids = Match.BaseIds(Match.Players[Viewer].Bund);
            foreach (int index in new[] { 1, 0, 2 })
            {
                CommandResult result = Send(Command.Buy(ids[index]));
                if (!result.Ok)
                {
                    Feedback(result);
                    return;
                }
            }
            Feedback(new CommandResult(true, "Startaufstellung: Front, Nahkampf und Fernkampf gekauft."));
        }

        void OnReady()
        {
            if (Match.Phase != Phase.Planning || !Human)
                return;
            _runner.Ready();
            Hud.MarkDirty();
        }

        void CycleSpeed()
        {
            Driver.CycleSpeed();
            Hud.SetSpeedLabel(Driver.Tempo, Driver.Paused);
        }

        void TogglePause()
        {
            if (Driver.TogglePause())
                Hud.SetSpeedLabel(Driver.Tempo, Driver.Paused);
        }

        void Rematch()
        {
            Driver.Seed += 1;
            Driver.Restart();
            View.Preview = null;
            Bind();
            StartCamera(true);
        }

        // ---------------------------------------------------------------- camera targets
        int OwnTeam { get { return Match.Players[Viewer].Team; } }

        public void FocusLane(string lane, bool instant = false)
        {
            if (Rig == null)
                return;
            LanePath path = Match.Map.LanePaths[lane];
            // Planning looks at the own deployment and inner tower, combat at the contested middle.
            double fraction = Match.Phase == Phase.Planning ? .2 : .42;
            Rig.LookAt(Match.Map.LanePoint(OwnTeam, lane, path.Length * fraction), 24f, instant);
        }

        public void FocusTarget(string target)
        {
            if (Rig == null)
                return;
            switch (target)
            {
                case "grotto":
                    Rig.LookAt(Match.Map.GrottoCenter(), 22f);
                    break;
                case "base":
                    Rig.LookAt(Match.Map.CorePosition(OwnTeam), 26f);
                    break;
                case "enemy_base":
                    Rig.LookAt(Match.Map.CorePosition(1 - OwnTeam), 26f);
                    break;
                case "hero":
                    FocusHero();
                    break;
                default:
                    if (Array.IndexOf(LuneMap.Lanes, target) >= 0)
                        FocusLane(target);
                    break;
            }
        }

        /// <summary>The own hero: its planning preview or, in combat, the live unit.</summary>
        LuneUnit OwnHeroUnit()
        {
            if (!Human)
                return null;
            LuneCombat source = Match.Phase == Phase.Combat ? Match.Combat : View.Preview;
            return source?.Units.FirstOrDefault(u => u.Kind == "hero" && u.OwnerSlot == Seat && u.Alive);
        }

        public bool FocusHero()
        {
            LuneUnit unit = OwnHeroUnit();
            if (unit == null)
            {
                Hud.Notify("Kein Held im Feld – im Reiter „Held“ anwerben.", true);
                return false;
            }
            Rig?.LookAt(unit.Position, 16f);
            return true;
        }

        /// <summary>The first view of a match (Godot _ready): the own lane at planning distance, a bot match from above.</summary>
        public void StartCamera(bool instant = true)
        {
            if (Rig == null)
                return;
            if (Human)
                FocusLane(Match.Players[Seat].Lane, instant);
            else
                Rig.Overview(instant);
        }

        public void ResetCamera(bool instant = false)
        {
            if (Rig == null)
                return;
            string lane = Match.Players[Viewer].Lane;
            Rig.ResetView(Match.Map.LanePoint(OwnTeam, lane, Match.Map.LanePaths[lane].Length * .2), instant);
        }

        // ---------------------------------------------------------------- planning preview and deployment areas
        /// <summary>
        /// The formation areas (Deployment_team_lane) and grotto entrance rings (GrottoEntry_team) of
        /// the scene. They are built inactive, like Godot's hidden pads, so the search includes
        /// inactive objects.
        /// </summary>
        void FindPads()
        {
            _pads.Clear();
            _grottoRings.Clear();
            foreach (Renderer renderer in FindObjectsByType<Renderer>(FindObjectsInactive.Include, FindObjectsSortMode.None))
            {
                string[] parts = renderer.gameObject.name.Split('_');
                if (parts.Length >= 3 && parts[0] == "Deployment" && int.TryParse(parts[1], out int team))
                    _pads.Add((renderer, team, parts[2]));
                else if (parts.Length == 2 && parts[0] == "GrottoEntry" && int.TryParse(parts[1], out int side))
                    _grottoRings.Add((renderer.gameObject, side));
            }
            _deployment = "";
        }

        /// <summary>
        /// Planning shows the own formation areas, lanes that hold own units light up, and the own
        /// grotto entrance while the grotto is open (Godot show_deployment). Checked every frame,
        /// applied only when something changed.
        /// </summary>
        void UpdateDeployment()
        {
            bool planning = Match.Phase == Phase.Planning && Human;
            var used = new Dictionary<string, int>();
            if (planning)
            {
                Draft draft = Match.Players[Seat].Draft;
                foreach (RosterEntry entry in draft.Roster)
                    used[entry.Lane] = used.GetValueOrDefault(entry.Lane, 0) + 1;
                if (draft.Hero != null)
                    used[draft.Hero.Lane] = used.GetValueOrDefault(draft.Hero.Lane, 0) + 1;
            }
            bool grotto = planning && Match.GrottoAvailable();
            string signature = planning + "|" + OwnTeam + "|" + grotto + "|" + string.Join(",", LuneMap.Lanes.Select(lane => used.GetValueOrDefault(lane, 0) > 0 ? lane : ""));
            if (signature == _deployment)
                return;
            _deployment = signature;
            _block ??= new MaterialPropertyBlock();
            foreach (var pad in _pads)
            {
                bool visible = planning && pad.team == OwnTeam;
                if (pad.renderer.gameObject.activeSelf != visible)
                    pad.renderer.gameObject.SetActive(visible);
                if (!visible)
                    continue;
                pad.renderer.GetPropertyBlock(_block);
                _block.SetFloat("_Highlight", used.GetValueOrDefault(pad.lane, 0) > 0 ? 1f : 0f);
                pad.renderer.SetPropertyBlock(_block);
            }
            foreach (var entry in _grottoRings)
            {
                bool visible = grotto && entry.team == OwnTeam;
                if (entry.ring.activeSelf != visible)
                    entry.ring.SetActive(visible);
            }
        }

        /// <summary>
        /// The human player's current draft army in its formation (Godot _rebuild_preview); after
        /// every own command, and by fixtures that change the draft directly (g3_views).
        /// </summary>
        public void RebuildPreview()
        {
            UpdateDeployment();
            if (Match.Phase != Phase.Planning || !Human)
                return;
            var preview = new LuneCombat(Match.Map, Match.Balance, Match.RoundNumber);
            Player player = Match.Players[Seat];
            var perLane = new Dictionary<string, int>();
            var entries = new List<(UnitDef def, string lane, string uid, string kind)>();
            foreach (RosterEntry entry in player.Draft.Roster)
                entries.Add((DataCatalog.GetUnit(entry.TypeId), entry.Lane, entry.Uid, "troop"));
            HeroState hero = player.Draft.Hero;
            if (hero != null)
                entries.Add((LuneContent.HeroDefinition(hero), hero.Lane, hero.Uid, "hero"));
            foreach (var entry in entries)
            {
                int index = perLane.GetValueOrDefault(entry.lane, 0);
                perLane[entry.lane] = index + 1;
                LuneUnit unit;
                if (entry.lane == LuneMatch.Grotto)
                {
                    // Grotto orders preview at the team's grotto entrance.
                    Vec2 at = Match.Map.GrottoEntry(player.Team) + new Vec2(index % 3 - 1.0, index / 3) * 1.1;
                    unit = preview.SpawnAt(entry.kind, player.Team, "grotto", entry.def, at, Seat, entry.uid);
                }
                else
                {
                    unit = preview.Spawn(entry.kind, player.Team, entry.lane, entry.def, Math.Max(.4, 7.2 - (index / 4) * 1.5), (index % 4 - 1.5) * 1.2, Seat, entry.uid);
                }
                unit.PreviousPosition = unit.Position;
            }
            View.Preview = preview;
        }

        // ---------------------------------------------------------------- frame
        void Update()
        {
            _clock.Restart();
            FrameUpdate();
            _updateMs = _clock.Elapsed.TotalMilliseconds;
        }

        void FrameUpdate()
        {
            if (Driver.Runner != _runner)
            {
                // Somebody restarted the driver (tests, rematch from elsewhere): follow it.
                View.Preview = null;
                Bind();
            }
            TrackStage();
            UpdateDeployment();
            HandleKeys();
            HandleClicks();
        }

        /// <summary>After the match view moved the figures: name tags and the minimap's camera frame.</summary>
        void LateUpdate()
        {
            if (Hud == null || _camera == null)
                return;
            _clock.Restart();
            Hud.FieldTags.Sync(View.Units, _camera, Hud);
            if (Rig != null)
                Hud.Minimap.SetCamera(Rig.Focus, Rig.Zoom, Rig.Footprint(_camera));
            _lateMs = _clock.Elapsed.TotalMilliseconds;
        }

        void TrackStage()
        {
            LuneMatchRunner.Stage stage = _runner.Current;
            if (stage == _lastStage)
                return;
            LuneMatchRunner.Stage previous = _lastStage;
            _lastStage = stage;
            if (stage == LuneMatchRunner.Stage.Planning)
            {
                RebuildPreview();
            }
            else if (stage == LuneMatchRunner.Stage.Combat)
            {
                View.Preview = null;
                UpdateDeployment();
            }
            else if (stage == LuneMatchRunner.Stage.Over && Rig != null && Match.Combat != null)
            {
                Driver.Paused = false;
                int fallen = Match.Combat.DestroyedCores.Contains(0) ? 0 : 1;
                Rig.LookAt(Match.Map.CorePosition(fallen), 26f);
            }
            Hud.SetSpeedLabel(Driver.Tempo, Driver.Paused);
        }

        static readonly KeyCode[] GameKeys =
        {
            KeyCode.Escape, KeyCode.F1, KeyCode.M, KeyCode.F11, KeyCode.Space, KeyCode.P, KeyCode.Tab, KeyCode.F2, KeyCode.F3, KeyCode.F4,
            KeyCode.B, KeyCode.G, KeyCode.H, KeyCode.Alpha1, KeyCode.Alpha2, KeyCode.Alpha3, KeyCode.Alpha4, KeyCode.Alpha5,
            KeyCode.Keypad1, KeyCode.Keypad2, KeyCode.Keypad3, KeyCode.Keypad4, KeyCode.Keypad5,
        };

        /// <summary>Game keys (Godot _input); they act even while a HUD button has focus.</summary>
        void HandleKeys()
        {
            foreach (KeyCode code in GameKeys)
            {
                if (Input.GetKeyDown(code))
                    Key(code);
            }
        }

        bool Blocked { get { return Hud.Settings.Open || (_leave != null && LuneUi.Visible(_leave)); } }

        /// <summary>One game key, as pressed by the player (also the entry point of the playtest).</summary>
        public void Key(KeyCode code)
        {
            switch (code)
            {
                case KeyCode.Escape:
                    if (_leave != null && LuneUi.Visible(_leave))
                        LuneUi.Show(_leave, false);
                    else
                        Hud.HandleEscape();
                    return;
                case KeyCode.F1:
                    if (Hud.Settings.Open)
                        Hud.Settings.Close();
                    else
                        Hud.Settings.Show();
                    return;
                case KeyCode.M:
                    LunePreferences.Muted = !LunePreferences.Muted;
                    LunePreferences.Commit();
                    LuneSettingsPanel.Apply();
                    return;
                case KeyCode.F11:
                    LunePreferences.Fullscreen = !LunePreferences.Fullscreen;
                    LunePreferences.Commit();
                    LuneSettingsPanel.Apply();
                    return;
            }
            if (Blocked)
                return;
            switch (code)
            {
                case KeyCode.Space:
                    if (Match.Phase == Phase.Planning)
                    {
                        // A Space meant as pause at the very end of a combat must not skip the planning.
                        if (!Hud.ReadyBlocked())
                            OnReady();
                    }
                    else
                    {
                        TogglePause();
                    }
                    return;
                case KeyCode.P:
                    TogglePause();
                    return;
                case KeyCode.Tab:
                    _laneCycle = (_laneCycle + 1) % 3;
                    FocusLane(LuneMap.Lanes[_laneCycle]);
                    return;
                case KeyCode.F2:
                case KeyCode.F3:
                case KeyCode.F4:
                    // F1 stays the options key; F2–F4 jump to Top, Mid and Bottom.
                    _laneCycle = code - KeyCode.F2;
                    FocusLane(LuneMap.Lanes[_laneCycle]);
                    return;
                case KeyCode.B:
                    FocusTarget("base");
                    return;
                case KeyCode.G:
                    FocusTarget("grotto");
                    return;
                case KeyCode.H:
                    FocusHero();
                    return;
            }
            int index = code >= KeyCode.Alpha1 && code <= KeyCode.Alpha5 ? code - KeyCode.Alpha1 : code >= KeyCode.Keypad1 && code <= KeyCode.Keypad5 ? code - KeyCode.Keypad1 : -1;
            if (index < 0 || Match.Phase != Phase.Planning || !Human)
                return;
            if (Match.Players[Seat].Ready)
            {
                // After Ready the plan is binding (the host refuses); the keys do nothing.
                Hud.Notify("Bereit gemeldet – die Planung ist verbindlich.", true);
                return;
            }
            List<string> ids = Match.BaseIds(Match.Players[Seat].Bund);
            Feedback(Send(Command.Buy(ids[index])));
        }

        /// <summary>Left click in the field selects an own unit (details in the HUD); it never orders anything.</summary>
        void HandleClicks()
        {
            if (Input.GetMouseButtonDown(0))
                ClickField(Input.mousePosition);
        }

        /// <summary>A left click at a screen point (pixels, origin bottom left); HUD areas take it themselves.</summary>
        public void ClickField(Vector2 screen)
        {
            if (_camera == null || Blocked || Hud.IsPointerOverHud(screen))
                return;
            LuneUnit picked = PickOwnUnit(screen);
            if (picked != null && picked.Kind == "hero")
                Hud.OpenHero();
            else if (picked != null)
                Hud.SelectUnit(picked.PersistentUid);
            else if (Hud.SelectedUid.Length > 0)
                Hud.ClearSelection();
        }

        /// <summary>The own troop or hero whose figure is nearest to a screen point (within 34 px), or null.</summary>
        public LuneUnit PickOwnUnit(Vector2 screen)
        {
            if (!Human)
                return null;
            LuneUnit best = null;
            float bestDistance = 34f;
            foreach (LuneUnitView view in View.Units)
            {
                LuneUnit unit = view.Unit;
                if (unit == null || !unit.Alive || unit.OwnerSlot != Seat || (unit.Kind != "troop" && unit.Kind != "hero") || !view.gameObject.activeInHierarchy)
                    continue;
                Vector3 at = _camera.WorldToScreenPoint(view.AimPoint);
                if (at.z <= 0f)
                    continue;
                float distance = Vector2.Distance(new Vector2(at.x, at.y), screen);
                if (distance < bestDistance)
                {
                    bestDistance = distance;
                    best = unit;
                }
            }
            return best;
        }

        // ---------------------------------------------------------------- leaving the match
        void BuildLeaveDialog()
        {
            _leave = new VisualElement();
            _leave.style.position = Position.Absolute;
            _leave.style.left = 0f;
            _leave.style.top = 0f;
            _leave.style.right = 0f;
            _leave.style.bottom = 0f;
            _leave.style.backgroundColor = new Color(.02f, .03f, .04f, .72f);
            _leave.style.justifyContent = Justify.Center;
            _leave.style.alignItems = Align.Center;
            var panel = new LunePanel(LunePanels.Menu);
            panel.style.minWidth = 520f;
            _leave.Add(panel);
            VisualElement column = LuneUi.Box(true, 14f, panel);
            column.style.alignItems = Align.Center;
            LuneUi.Label("Partie verlassen?", "HeadingLabel", column);
            LuneUi.Wrap(LuneUi.Label("Ein Hauptmenü gibt es im Unity-Port noch nicht; Verlassen beendet das Spiel.", "MutedLabel", column)).style.unityTextAlign = TextAnchor.MiddleCenter;
            VisualElement row = LuneUi.Box(false, 12f, column);
            new LuneButton("SPIEL BEENDEN", LuneButtons.Primary, row).Clicked += Quit;
            new LuneButton("Zurück", LuneButtons.Secondary, row).Clicked += () => LuneUi.Show(_leave, false);
            LuneUi.Show(_leave, false);
            Hud.Root.Add(_leave);
        }

        void AskLeave()
        {
            LuneUi.Show(_leave, true);
            _leave.BringToFront();
        }

        static void Quit()
        {
#if UNITY_EDITOR
            UnityEditor.EditorApplication.isPlaying = false;
#else
            Application.Quit();
#endif
        }
    }
}