using System;
using System.Collections.Generic;
using System.IO;
using UnityEngine;
using UnityEngine.InputSystem;

namespace Ironspore
{
    public sealed class GameSession : MonoBehaviour
    {
        public static GameSession Active
        {
            get; private set;
        }
        public ChassisDefinition[] chassis;
        public EquipmentDefinition[] equipment;
        public GameObject mechModel;
        public InputActionAsset inputTemplate;
        public UnityEngine.UIElements.StyleSheet uiStyle;
        public UnityEngine.UIElements.PanelSettings uiPanel;
        public LocalizationCatalog localization;
        public bool startInRange;
        public ProfileStore Store
        {
            get; private set;
        }
        ProfileStore mainStore;
        public RunRecord Run => Store.Data.run;
        public MechPilot Pilot
        {
            get; private set;
        }
        public WarzoneDirector World
        {
            get; private set;
        }
        public GameHud Hud
        {
            get; private set;
        }
        public InputActionAsset Input
        {
            get; private set;
        }
        public SettingsService Settings { get; private set; }
        public readonly List<string> SelectedCargo = new List<string>();
        public bool MenuOpen { get; private set; } = true;
        public bool Paused
        {
            get; private set;
        }
        public bool Trial
        {
            get; private set;
        }
        public int SelectedChassis = 1;
        public int[] InitialEquipment = { 0, 0, 0, 0 };
        LocalizedMessage noticeMessage;
        public string Notice => noticeMessage?.ToString() ?? "";
        public float CargoProgress
        {
            get; private set;
        }
        public bool InField
        {
            get; private set;
        }
        LocalizedMessage reportMessage = GameLocalization.Message("report.ready");
        public string Report => reportMessage.ToString();
        float noticeUntil;
        float autosaveTimer;
        int cargoDamageFrame = -1;
        bool ending;

        void Awake()
        {
            Active = this;
            GameLocalization.Initialize(localization);
            Application.targetFrameRate = 120;
            mainStore = new ProfileStore(Path.Combine(GameDataPaths.DirectoryPath, "profile.json"));
            Store = mainStore;
            Input = Instantiate(inputTemplate);
            var defaults = SettingsService.RuntimeDefaults();
            Settings = new SettingsService(new SettingsStore(Path.Combine(GameDataPaths.DirectoryPath, "settings.json"), defaults), Input, defaults);
            Input.Enable();
            World = gameObject.AddComponent<WarzoneDirector>();
            Hud = gameObject.AddComponent<GameHud>();
            Hud.Initialize(this);
        }

        void Start()
        {
            World.BuildHangar();
            Hud.ShowHangar();
            SetMenu(true);
            if (startInRange)
                StartTrial();
        }

        public EquipmentDefinition Part(int slot, int index)
        {
            var list = Array.FindAll(equipment, x => x.slot == slot);
            return list[Mathf.Clamp(index, 0, list.Length - 1)];
        }
        public int PartCount(int slot) => Array.FindAll(equipment, x => x.slot == slot).Length;
        public bool Fits(int frame, int[] parts)
        {
            float mass = 0, power = 0;
            for (int i = 0; i < 4; i++)
            {
                var p = Part(i, parts[i]);
                mass += p.mass;
                power += p.power;
            }
            return mass <= chassis[frame].massCapacity && power <= chassis[frame].powerCapacity;
        }
        public bool StartingPartsUnlocked()
        {
            var unlocked = mainStore.Data.unlocked;
            return (InitialEquipment[0] != 1 || unlocked.Contains("blueprint_coil_capacitor"))
                && (InitialEquipment[2] != 1 || unlocked.Contains("blueprint_boost_efficient"))
                && (InitialEquipment[3] != 1 || unlocked.Contains("blueprint_reactive_guard"));
        }

        public void BeginSortie()
        {
            if (Store.Data.run.active)
            {
                Notify("notice.unfinished");
                return;
            }
            if (!Fits(SelectedChassis, InitialEquipment))
            {
                Notify("notice.budget");
                return;
            }
            if (!StartingPartsUnlocked())
            {
                Notify("notice.researchFirst");
                return;
            }
            Trial = false;
            Store = mainStore;
            if (!Store.Begin(SelectedChassis, InitialEquipment, chassis[SelectedChassis].armor, Environment.TickCount))
            {
                NotifySaveFailure();
                return;
            }
            EnterField();
        }
        public void StartTrial()
        {
            Trial = true;
            Store = new ProfileStore(Path.Combine(GameDataPaths.DirectoryPath, "range.json"));
            Store.Begin(SelectedChassis, InitialEquipment, chassis[SelectedChassis].armor, 1739);
            EnterField();
        }
        public void Resume()
        {
            Trial = false;
            Store = mainStore;
            if (Run.active)
                EnterField();
        }
        void EnterField()
        {
            ending = false;
            InField = true;
            SelectedCargo.Clear();
            CargoProgress = 0;
            World.BuildWarzone();
            Pilot = World.Player;
            SetMenu(false);
            Hud.ShowField();
            if (Trial)
                Notify("notice.range", Settings.Bindings.Display("View"), Settings.Bindings.Display("Interact"));
            else
                Notify("notice.enter");
        }
        public void SetMenu(bool open)
        {
            MenuOpen = open;
            Cursor.lockState = open ? CursorLockMode.None : CursorLockMode.Locked;
            Cursor.visible = open;
            if (Pilot)
                Pilot.RequireFreshTrigger();
            if (open)
                CargoProgress = 0;
        }
        public void CloseMenu()
        {
            Paused = false;
            Time.timeScale = 1;
            if (InField)
            {
                SetMenu(false);
                Hud.ShowField();
            }
        }
        public void Notify(string key, params object[] args)
        {
            noticeMessage = GameLocalization.Message(key, args);
            noticeUntil = Time.unscaledTime + 5;
            Hud.RefreshHangarNotice();
        }
        void NotifySaveFailure(string fallbackKey = "notice.saveFailed")
        {
            if (!string.IsNullOrEmpty(Store.Error))
                Debug.LogError("Save failed: " + Store.Error);
            Notify(string.IsNullOrEmpty(Store.Error) ? fallbackKey : "notice.saveFailed");
        }
        public InputAction Action(string name) => Input.FindAction("Pilot/" + name, true);

        void Update()
        {
            if (Time.unscaledTime > noticeUntil)
                noticeMessage = null;
            if (Hud && (Hud.SettingsOpen || Hud.MenuInputConsumedThisFrame))
                return;
            if (!InField || !Pilot || ending)
                return;
            if (Action("Pause").WasPressedThisFrame())
            {
                if (MenuOpen)
                    CloseMenu();
                else
                {
                    Paused = true;
                    Time.timeScale = 0;
                    SetMenu(true);
                    Hud.ShowPause();
                }
            }
            if (Paused)
                return;
            Run.elapsed += Time.deltaTime;
            if (Action("Inventory").WasPressedThisFrame())
            {
                if (MenuOpen)
                    CloseMenu();
                else
                {
                    SetMenu(true);
                    Hud.ShowCargo();
                }
            }
            if (!MenuOpen && Action("Interact").WasPressedThisFrame() && World.Focused)
                World.Focused.Activate();
            TickCargo();
            if (Pilot.Health <= 0)
            {
                EndSortie(true);
                return;
            }
            autosaveTimer += Time.deltaTime;
            if (autosaveTimer >= 10)
            {
                SnapshotVitals();
                Store.Commit(s => true);
                autosaveTimer = 0;
            }
        }
        void TickCargo()
        {
            bool uninterrupted = Pilot.LastDamageFrame == cargoDamageFrame;
            cargoDamageFrame = Pilot.LastDamageFrame;
            bool preparing = !MenuOpen && !Run.podUsed && SelectedCargo.Count > 0 && Action("Cargo").IsPressed() && Pilot.Grounded && Action("Move").ReadValue<Vector2>().sqrMagnitude < .01f && Pilot.HorizontalSpeed < .2f && uninterrupted;
            if (!preparing)
            {
                CargoProgress = 0;
                return;
            }
            CargoProgress += Time.deltaTime;
            if (CargoProgress < 3)
                return;
            SnapshotVitals();
            if (Store.SendCargo(SelectedCargo))
            {
                World.LaunchPod(Pilot.transform.position);
                Notify("notice.podSecured");
                GameAudio.Cue(720, .3f);
                SelectedCargo.Clear();
            }
            else
                NotifySaveFailure("notice.cargoUnavailable");
            CargoProgress = 0;
        }
        public void ToggleCargo(string uid)
        {
            if (SelectedCargo.Contains(uid))
                SelectedCargo.Remove(uid);
            else if (SelectedCargo.Count < 2)
                SelectedCargo.Add(uid);
            else
                Notify("notice.twoSlots");
            Hud.ShowCargo();
        }
        public void SnapshotVitals()
        {
            if (!Pilot)
                return;
            Run.armor = Mathf.Max(0, Pilot.Health);
            Run.energy = Pilot.Energy;
        }
        public void Search(WorldInteractable target)
        {
            if (!Store.AddCargo(target.itemId, target.amount, target.key))
            {
                NotifySaveFailure("notice.holdFull");
                return;
            }
            target.collected = true;
            target.RefreshLabel();
            Notify("notice.recovered", GameLocalization.Message("item." + target.itemId), target.amount);
            GameAudio.Cue(520, .12f);
            if (target.offersPart)
            {
                SetMenu(true);
                Hud.ShowPart(target.partSlot, target.partIndex);
            }
        }
        public void Install(int slot, int index)
        {
            var next = (int[])Run.equipment.Clone();
            next[slot] = index;
            if (!Fits(Run.chassis, next))
            {
                Notify("notice.partBudget");
                return;
            }
            Store.Commit(s => { s.run.equipment = next; return true; });
            Pilot.ApplyLoadout();
            CloseMenu();
            Notify("notice.refit", GameLocalization.Message("equipment." + Part(slot, index).id + ".name"));
        }
        public void CompleteObjective()
        {
            if (Run.objectiveDone)
                return;
            Store.Commit(s => { s.run.objectiveDone = true; return true; });
            Notify("notice.routeOpen");
            GameAudio.Cue(850, .2f);
        }
        public void CompleteTerminal()
        {
            if (!Store.CompleteRoute())
                return;
            Notify("notice.complete");
            GameAudio.Cue(1100, .4f);
        }
        public void OpenRoutes()
        {
            if (!Run.objectiveDone)
            {
                Notify("notice.objectiveFirst");
                return;
            }
            if (Trial)
            {
                Notify("notice.rangeComplete");
                return;
            }
            if (Run.stage >= 4)
            {
                Notify("notice.extract");
                return;
            }
            SetMenu(true);
            Hud.ShowRoutes();
        }
        public void NextZone(int option)
        {
            SnapshotVitals();
            bool ok = Store.Commit(s =>
            {
                if (s.run.stage == 1)
                    s.run.branch = option;
                s.run.stage++;
                s.run.biome = option;
                s.run.objectiveDone = false;
                s.run.upgrades++;
                return true;
            });
            if (ok)
                EnterField();
            else
                NotifySaveFailure();
        }
        public void Unlock(string id)
        {
            bool ok = Store.Commit(s =>
            {
                if (!s.blueprints.Contains(id) || s.unlocked.Contains(id) || s.alloy < 2 || s.cells < 1)
                    return false;
                s.alloy -= 2;
                s.cells--;
                s.unlocked.Add(id);
                return true;
            });
            Notify(ok ? "notice.researched" : "notice.researchCost");
            Hud.ShowHangar();
        }
        public void EndSortie(bool destroyed)
        {
            if (ending)
                return;
            SnapshotVitals();
            bool complete = Run.routeCompleted;
            int lost = Run.cargo.Count;
            if (!Store.Finish(destroyed))
            {
                NotifySaveFailure();
                return;
            }
            ending = true;
            reportMessage = GameLocalization.Message(Trial ? "report.range" : destroyed ? "report.destroyed" : complete ? "report.complete" : "report.extracted", lost);
            InField = false;
            Trial = false;
            Store = mainStore;
            Pilot = null;
            World.BuildHangar();
            SetMenu(true);
            Hud.ShowHangar();
        }
        void OnApplicationFocus(bool focus)
        {
            if (!focus && Hud && Hud.SettingsOpen)
            {
                Hud.CancelSettingsInput();
                return;
            }
            if (!focus && InField && Hud)
            {
                Paused = true;
                Time.timeScale = 0;
                SetMenu(true);
                Hud.ShowPause();
            }
        }
        void OnApplicationQuit()
        {
            if (InField && Pilot)
            {
                SnapshotVitals();
                Store.Commit(s => true);
            }
        }
        void OnDestroy()
        {
            Settings?.Dispose();
            if (Input)
                Destroy(Input);
            Time.timeScale = 1;
            if (Active == this)
                Active = null;
        }
    }
}