using System;
using System.Collections.Generic;
using System.Linq;

using UnityEngine;
using UnityEditor;
using UnityEngine.SceneManagement;

public enum SectorColour {
    Green,
    Purple,
    White,
    Yellow,
}

[Serializable]
public struct SectorTime {
    public int Sector;
    public double Seconds;
    public override string ToString() => $"{Seconds:0.000}";
}

[Serializable]
public struct Lap {
    public string Map;
    public int Number;
    public List<SectorTime> Sectors;

    // 0:1:39
    public override string ToString() {
        return $"{TimeSpan.FromSeconds(TotalTime()):m\\:ss\\.fff}";
    }

    public double TotalTime() {
        return Sectors.Sum(s => s.Seconds);
    }
}

static class LapStorageService {
    static Dictionary<string, LapJSON> lapsByMap;
    static string lapStoragePath = Path.Combine(Application.persistentDataPath, "lapStorage.json");

    static void GetPlayerLaps() {
        // read json
        // assign it to lapStorage
    }

    // laps.count
    static int NumberOfCompletions() {}

    // finds your PB in all completions
    static int Rank() {}

    // open json
    public static void PersistLap(Lap lap) {
        bool found = lapsByMap.TryGetValue(lap.Map, out var lapJson);
        if (!found)
            lapJson = new LapJSON { Map = lap.Map, Laps = new List<Lap>() };
        LapJson.Laps.Add(lap);
        lapsByMap[lap.Map] = lapJson;

        LapStorage lapStorage = new LapStorage { Laps = lapsByMap.Values.ToList() };
        File.WriteAllText(lapStoragePath, JsonUtility.ToJson(lapStorage));
    }

}

[Serializable]
public class LapJSON {
    public string Map;
    public List<Lap> Laps;
}

public class LapStorage {
    public List<LapJSON> Laps;
}

public class Timing: MonoBehaviour {
    [SerializeField]
    public List<Lap> lapTimes;
    [SerializeField]
    public List<SectorTime> sectorTimes;
    public bool timerEnabled;

    public double sectorTime;
    public double lapTime;
    double sectorStart;
    double lapStart;
    public Sector[] sectors;

    public LapStorage lapStorage;

    string mapName;

    void Awake() {
        lapTimes = new();
        sectorTimes = new List<SectorTime>();
        sectorStart = 0.0;
        sectorTime = 0.0;
        sectors = GetComponentsInChildren<Sector>().OrderBy(s => s.sector).ToArray();

        // set map name
        Scene scene = SceneManager.GetActiveScene();
        mapName = scene.name;

        Debug.Log("Track Sector Count - " + sectors.Length);
        Persist();
    }

    void Update() {
        if (timerEnabled) {
            sectorTime = Time.timeAsDouble - sectorStart;
            lapTime = Time.timeAsDouble - lapStart;
        }
    }

    public void StartTimer() {
        if (sectors.Length == 0) {
            Debug.LogWarning("No Sectors found in timing");
            return;
        }

        Debug.Log("Started Timer");

        timerEnabled = true;
        lapStart = Time.timeAsDouble;
        sectorStart = Time.timeAsDouble;
    }

    public void StopTimer() {
        sectorTimes = new List<SectorTime>();
        timerEnabled = false;
        sectorTime = 0;
        lapTime = 0;
        Debug.Log("Timer Stopped");
    }

    public void NextSector(int sector) {
        if (!timerEnabled)
            return;

        // they turned around or somethin?
        if (sectorTimes.Any(s => s.Sector == sector))
            return;

        // this basically makes sure the timer doesn't do anything weird
        // due to respawns, driving in the wrong direction etc
        // you have to hit the sectors in numbered order
        // ---------------
        // make sure sectors are only accessible by being hit by following
        // the track correctly!
        if (sector != sectorTimes.Count + 1)
            return;

        double sTime = Time.timeAsDouble - sectorStart;

        SectorTime s = new SectorTime { Sector = sector, Seconds = sTime };
        sectorTimes.Add(s);
        sectorStart = Time.timeAsDouble;

        Debug.Log($"{sectorTimes.Count} / {sectors.Length}");

        if (sectorTimes.Count == sectors.Length) {
            EndLap();
            NextLap();
        }
    }

    void NextLap() {
        Debug.Log("NextLap" + lapTimes.Count);
        sectorTimes = new List<SectorTime>();
        StartTimer();
    }

    public void EndLap() {
        // when live reloading this happens
        if (sectorTimes == null)
            Awake();

        Debug.Log($"Ending lap Sectors={sectorTimes.Count} Name={mapName} Lap={lapTimes.Count}");

        Lap l = new Lap { Map = mapName, Number = lapTimes.Count, Sectors = sectorTimes };
        Debug.Log($"EndLap {l}");
        lapTimes.Add(l);
        Persist();
    }

    public SectorColour GetSectorColour(SectorTime s) {
        if (lapTimes.Count == 0)
            return SectorColour.Green;

        var fastestLap = lapTimes.MinBy(l => l.TotalTime());
        var fastestSector = fastestLap.Sectors.Single(fls => fls.Sector == s.Sector);

        return (s.Seconds < fastestSector.Seconds) switch {
            true => SectorColour.Green,
            false => SectorColour.Yellow,
        };
    }

    void Load() {
        try {
            string json = File.ReadAllText(lapStoragePath);
            JsonUtility.FromJsonOverwrite(json, lapStorage);
        } catch {
            // file doesn't exist yet
            return Persist();
        }
    }

    void Persist() {
        LapJSON lapJson = new LapJSON { Map = mapName, Laps = lapTimes };
        string lapJsonStr = JsonUtility.ToJson(lapJson);
        Debug.Log($"Lap JSON {lapJsonStr}");
    }
}