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

namespace Parking
{
    public class ParkingManager : MonoBehaviour
    {
        public const float Width = 68;
        public const float Height = 29;

        public static ParkingManager Instance;

        private static readonly TimeSpan StartTime = TimeSpan.FromHours(5) + TimeSpan.FromMinutes(45);
        private static readonly TimeSpan EndTime = TimeSpan.FromHours(17) + TimeSpan.FromMinutes(15);
        private static TimeSpan _currentTime = StartTime;

        [SerializeField] private int stepTime = 15;
        [SerializeField] private TextMeshProUGUI timeText;
        [SerializeField] public TextMeshProUGUI countsText;
        [SerializeField] public TextMeshProUGUI rejectedText;
        [SerializeField] public GameObject spotPrefabA;
        [SerializeField] public GameObject spotPrefabB;
        [SerializeField] public GameObject spotPrefabC;
        [SerializeField] public GameObject spotPrefabD;
        [SerializeField] public GameObject carPrefab;

        private readonly float[] _spotHeights = {3.5f, 4f, 5f, 7.5f};

        private readonly List<List<Spot>> _spotMap = new()
            {new List<Spot>(), new List<Spot>(), new List<Spot>(), new List<Spot>()};

        private int _initialConfigurationSpotCount;
        private int[] _rejectedDrivers = {0, 0, 0, 0};


        private void Awake()
        {
            Instance = this;
        }

        private void Start()
        {
            timeText.text = _currentTime.ToString();
            rejectedText.text = $"Małe: {_rejectedDrivers[0]} Średnie: {_rejectedDrivers[1]} " +
                                $"Duże: {_rejectedDrivers[2]}";
            DataImporter.ReadFile("Assets/Data/Tablica1.csv");
            InitialConfigurationGenerator generator = new();
            ArrangeSpots(generator.FindSolution());
            ReserveInitialSpots();
        }

        private void ReserveInitialSpots()
        {
            for (var j = 3; j >= 0; j--)
                foreach (Spot spot in _spotMap[j]) {
                    spot.Reserved = false;
                    spot.ReservedPriority = 0;
                }

            for (var i = 0; i < Math.Min(DataImporter.Drivers.Count, _initialConfigurationSpotCount); i++) {
                bool found = false;
                // Find spot
                for (var j = 3; j >= 0 && !found; j--)
                    foreach (Spot spot in _spotMap[j])
                        if (spot.Size == DataImporter.Drivers[i].Size && !spot.Reserved) {
                            spot.Reserved = true;
                            spot.ReservedPriority = DataImporter.Drivers[i].Priority;
                            found = true;
                            break;
                        }
            }

            // Find spot
            for (var j = 3; j >= 0; j--)
                foreach (Spot spot in _spotMap[j])
                    if (!spot.Reserved && spot.Size != Size.D)
                        Debug.Log("Spot not reserved");
        }

        public void AdvanceTime()
        {
            // Update time
            _currentTime += TimeSpan.FromMinutes(stepTime);
            if (_currentTime > EndTime) {
                _currentTime = StartTime;
                ReserveInitialSpots();
                ResetDrivers();
                _rejectedDrivers = new[] {0, 0, 0, 0};
                rejectedText.text = $"Małe: {_rejectedDrivers[0]} Średnie: {_rejectedDrivers[1]} " +
                                    $"Duże: {_rejectedDrivers[2]}";
                timeText.text = _currentTime.ToString();
                return;
            }

            timeText.text = _currentTime.ToString();


            foreach (Driver driver in DataImporter.Drivers) {
                // TODO: Check if car can stay before other reservation - may not work for priority-based reservations
                var triesToPark = _currentTime <= driver.Times[3].TimeOfDay && _currentTime > driver.Times[2].TimeOfDay;
                var leftTheParking = _currentTime > driver.Times[3].TimeOfDay && driver.Parked;
                bool reservedButTimedout =
                    (_currentTime - driver.Times[0].TimeOfDay).TotalMinutes > driver.UpdateInterval && 
                    GetReservedSpotCount(driver.Priority, driver.Size) > 0
                    && !driver.Parked && !driver.Rejected && _currentTime <= driver.Times[3].TimeOfDay;
                if (triesToPark && !driver.Parked && !driver.Rejected) {
                    if (!PlaceCarOnParking(driver)) {
                        Debug.Log($"Placing failed for car {driver.Number}");
                        driver.Rejected = true;
                        _rejectedDrivers[(int) driver.Size]++;
                        rejectedText.text = $"Małe: {_rejectedDrivers[0]} Średnie: {_rejectedDrivers[1]} " +
                                            $"Duże: {_rejectedDrivers[2]}";
                    }
                }
                else if (leftTheParking) {
                    driver.Spot.Reserved = false;
                    driver.Reset();
                } else if (reservedButTimedout) {
                    Debug.Log($"Reserved but timed out driver {driver.Number}");
                    driver.Rejected = true;
                }
            }

            ReconfigureSpots();
        }

        private void ResetDrivers()
        {
            foreach (Driver driver in DataImporter.Drivers){
                if (driver.Spot != null) {
                    driver.Spot.Reserved = false;
                    driver.Spot.ReservedPriority = 0;
                }
                driver.Reset();
            }
        }

        private int GetReservedSpotCount(int priority, Size size)
        {
            int count = 0;
            foreach (List<Spot> list in _spotMap) {
                foreach (Spot spot in list) {
                    if (spot.Size == size && spot.Reserved && spot.ReservedPriority == priority)
                        count++;
                }
            }

            return count;
        }

        private bool FindReservedSpot(Driver driver, out Spot spot)
        {
            foreach (var list in _spotMap)
            foreach (Spot spot1 in list)
                if (spot1.Reserved && spot1.ReservedPriority == driver.Priority) {
                    spot = spot1;
                    return true;
                }

            spot = new Spot();

            return false;
        }

        private bool PlaceCarOnParking(Driver driver)
        {
            if (FindReservedSpot(driver, out Spot reservedSpot)) {
                if (reservedSpot.Free) {
                    PlaceDriverOnSpot(driver, reservedSpot);
                    return true;
                }
                else
                    Debug.Log("Spot should be reserved but is taken");
            }


            foreach (var t in _spotMap)
            foreach (Spot spot in t) {
                var spotAvailable = spot.Size == driver.Size && spot.Free &&
                                    (spot.ParkingDirection == driver.ParkingPreference ||
                                     spot.ParkingDirection == ParkingPreference.Any)
                                    && !spot.Reserved;
                
                if (spotAvailable) {
                    PlaceDriverOnSpot(driver, spot);
                    return true;
                }
            }

            foreach (var t in _spotMap)
            foreach (Spot spot in t)
                if (spot.Size == driver.Size && spot.Free && !spot.Reserved) {
                    PlaceDriverOnSpot(driver, spot);
                    return true;
                }

            return false;
        }

        private void PlaceDriverOnSpot(Driver driver, Spot spot)
        {
            spot.Free = false;
            spot.Reserved = false;
            driver.Spot = spot;
            driver.Parked = true;
            driver.GameObject = Instantiate(carPrefab, spot.GameObject.transform, true);
            driver.GameObject.GetComponentInChildren<TextMeshProUGUI>().text = driver.Number.ToString();
            driver.GameObject.GetComponentInChildren<TextMeshProUGUI>().transform.rotation =
                Quaternion.Euler(new Vector3(0, 0, spot.Flipped ? 180 : 0));
            driver.GameObject.transform.position = spot.GameObject.transform.position;
            driver.GameObject.transform.rotation =
                Quaternion.Euler(new Vector3(0, 0, spot.Flipped ? 180 : 0));
        }

        public void UpdateText(string text)
        {
            countsText.text = text;
        }

        private void ReconfigureSpots()
        {
            var freeSpots = GetFreeSpotCount();
            var nextCars = GetNextCars(10);
            int[] plannedSpots = {0, 0, 0, 0};
            foreach (Driver driver in nextCars)
                plannedSpots[(int) driver.Size]++;

            int[] neededSpots = {0, 0, 0, 0};

            for (var i = 0; i < neededSpots.Length; i++)
                neededSpots[i] = Math.Max(plannedSpots[i] - freeSpots[i], 0);
            if (neededSpots.Sum() > 5) {
                Debug.Log($"Needed spots = {neededSpots[0]} {neededSpots[1]} {neededSpots[2]} {neededSpots[3]}");
                Debug.Log("Attempting reconfiguration...");
            }

        }

        private int[] GetFreeSpotCount()
        {
            int[] freeSpots = {0, 0, 0, 0};
            foreach (var t in _spotMap)
            foreach (Spot spot in t)
                if (spot.Free)
                    freeSpots[(int) spot.Size]++;
            return freeSpots;
        }

        private List<Driver> GetNextCars(int n)
        {
            var nextCars = new List<Driver>();
            TimeSpan updatedTime = _currentTime + TimeSpan.FromMinutes(stepTime);
            while (nextCars.Count < n && updatedTime < EndTime) {
                foreach (Driver driver in DataImporter.Drivers)
                    if (updatedTime <= driver.Times[1].TimeOfDay &&
                        updatedTime > driver.Times[0].TimeOfDay &&
                        !driver.Parked && !driver.Rejected && !nextCars.Contains(driver))
                        nextCars.Add(driver);
                updatedTime += TimeSpan.FromMinutes(stepTime);
            }

            return nextCars;
        }

        private void ArrangeSpots(int[,] spotsCreated)
        {
            var spotMap = GenerateSpotMap(spotsCreated);

            var maxP3 = _spotHeights[(int) spotMap[2].Max().Size];
            var maxP2 = _spotHeights[(int) spotMap[1].Max().Size];

            for (var i = 0; i < 4; i++) {
                float currentY;
                switch (i) {
                    case 0:
                        currentY = -Height / 2.0f + 2f;
                        break;
                    case 1:
                        currentY = Height / 2 - 5.5f - 5f - maxP3 / 2.0f - maxP2;
                        break;
                    case 2:
                        currentY = Height / 2 - 5.5f - 5f - maxP3 / 2.0f;
                        break;
                    case 3:
                        currentY = Height / 2.0f - 2f;
                        break;
                    default:
                        currentY = -10;
                        break;
                }

                float currentX;
                if (i != 0) currentX = -Width / 2f - 2.25f / 2f + 2.25f;
                else currentX = -Width / 2f + 5.5f - 2.25f / 2f + 2.25f + 1.75f;

                var flipped = false;
                var parkingFromTop = i % 2 != 0;

                for (var j = 0; j < spotMap[i].Count; j++) {
                    spotMap[i][j].Flipped = flipped;
                    var alignTop = i % 2 != 0;
                    switch (spotMap[i][j].Size) {
                        case Size.A:
                            spotMap[i][j].GameObject = Instantiate(Instance.spotPrefabA);
                            spotMap[i][j].GameObject.transform.position = new Vector3(currentX, currentY, 0);
                            break;
                        case Size.B:
                            spotMap[i][j].GameObject = Instantiate(Instance.spotPrefabB);
                            spotMap[i][j].GameObject.transform.position =
                                new Vector3(currentX, currentY + (alignTop ? -1 : 1) * 0.25f, 0);
                            break;
                        case Size.C:
                            spotMap[i][j].GameObject = Instantiate(Instance.spotPrefabC);
                            spotMap[i][j].GameObject.transform.position =
                                new Vector3(currentX, currentY + (alignTop ? -1 : 1) * 0.5f, 0);
                            break;
                        case Size.D:
                            spotMap[i][j].GameObject = Instantiate(Instance.spotPrefabD);
                            spotMap[i][j].GameObject.transform.position =
                                new Vector3(currentX, currentY - 2.0f, 0);
                            break;
                    }

                    spotMap[i][j].GameObject.transform.rotation =
                        Quaternion.Euler(new Vector3(0, 0, spotMap[i][j].Flipped ? 180 : 0));

                    var frontalParking = !parkingFromTop ^ flipped;
                    spotMap[i][j].ParkingDirection = frontalParking ? ParkingPreference.Front : ParkingPreference.Back;

                    currentX += 2.25f;

                    flipped = !flipped;
                }
            }
        }

        private List<List<Spot>> GenerateSpotMap(int[,] spotsCreated)
        {
            for (var i = 0; i < 4; i++)
            for (var j = 0; j < spotsCreated.GetLength(1); j++)
            for (var k = 0; k < spotsCreated[i, j]; k++) {
                _spotMap[i].Add(new Spot((Size) j, false));
                _initialConfigurationSpotCount++;
            }

            _spotMap[0].Sort((a, b) => a.Size.CompareTo(b.Size)); // ascending sort
            _spotMap[1].Sort((a, b) => b.Size.CompareTo(a.Size)); // descending sort
            _spotMap[2].Sort((a, b) => b.Size.CompareTo(a.Size)); // descending sort
            _spotMap[3].Sort((a, b) => a.Size.CompareTo(b.Size)); // ascending sort
            _spotMap[2].Add(new Spot(Size.D, false));
            return _spotMap;
        }
    }
}