using System.Text.RegularExpressions;
using Content.Server.GameTicking;
using Content.Server.Fax;
using Content.Server.Station.Systems;
using Content.Shared.CCVar;
using Content.Shared.Random;
using Content.Shared.Random.Helpers;
using Robust.Shared.Configuration;
using Robust.Shared.Prototypes;
using Robust.Shared.Random;
using Content.Shared.Dataset;
using Content.Shared.Fax.Components;

namespace Content.Server.StationGoal;

/// <summary>
///     System for station goals
/// </summary>
public sealed class StationGoalPaperSystem : EntitySystem
{
    [Dependency] private readonly IPrototypeManager _prototype = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly FaxSystem _fax = default!;
    [Dependency] private readonly IConfigurationManager _config = default!;
    [Dependency] private readonly StationSystem _station = default!;

    private static readonly Regex StationIdRegex = new(@".*-(\d+)$");

    [ValidatePrototypeId<WeightedRandomPrototype>]
    private const string RandomPrototype = "StationGoals";
    [ValidatePrototypeId<DatasetPrototype>]
    private const string RandomSignature = "names_last";

    public override void Initialize()
    {
        base.Initialize();

        SubscribeLocalEvent<RoundStartedEvent>(OnRoundStarted);
    }


    private void OnRoundStarted(RoundStartedEvent ev)
    {
        if (_config.GetCVar(CCVars.StationGoalsEnabled)
        	&& _random.Prob(_config.GetCVar(CCVars.StationGoalsChance)))
            SendRandomGoal();
    }

    /// <summary>
    ///     Send a random station goal to all faxes which are authorized to receive it
    /// </summary>
    /// <returns>If the fax was successful</returns>
    /// <exception cref="Exception">Raised when station goal types in the prototype is invalid</exception>
    public bool SendRandomGoal()
    {
        // Get the random station goal list
        if (!_prototype.TryIndex<WeightedRandomPrototype>(RandomPrototype, out var goals))
        {
            Log.Error($"StationGoalPaperSystem: Random station goal prototype '{RandomPrototype}' not found");
            return false;
        }

        // Get a random goal
        var goal = RecursiveRandom(goals);

        // Send the goal
        return SendStationGoal(goal);
    }

    private StationGoalPrototype RecursiveRandom(WeightedRandomPrototype random)
    {
        var goal = random.Pick(_random);

        if (_prototype.TryIndex<StationGoalPrototype>(goal, out var goalPrototype))
            return goalPrototype;

        if (_prototype.TryIndex<WeightedRandomPrototype>(goal, out var goalRandom))
            return RecursiveRandom(goalRandom);

        throw new Exception($"StationGoalPaperSystem: Random station goal could not be found from prototypes {RandomPrototype} and {random.ID}");
    }

    /// <summary>
    ///     Send a station goal to all faxes which are authorized to receive it
    /// </summary>
    /// <returns>True if at least one fax received paper</returns>
    public bool SendStationGoal(StationGoalPrototype goal)
    {
        var enumerator = EntityManager.EntityQueryEnumerator<FaxMachineComponent>();
        var wasSent = false;
        var signerName = _prototype.Index<DatasetPrototype>(RandomSignature);

        while (enumerator.MoveNext(out var uid, out var fax))
        {
            if (!fax.ReceiveStationGoal
                || !TryComp<MetaDataComponent>(_station.GetOwningStation(uid), out var meta))
                continue;

            var stationId = StationIdRegex.Match(meta.EntityName).Groups[1].Value;

            var printout = new FaxPrintout(
                Loc.GetString("station-goal-fax-paper-header",
                    ("date", DateTime.Now.AddYears(1000).ToString("yyyy MMMM dd")),
                    ("station", string.IsNullOrEmpty(stationId) ? "???" : stationId),
                    ("content", goal.Text),
                    ("name", _random.Pick(signerName.Values))
                ),
                Loc.GetString("station-goal-fax-paper-name"),
                "StationGoalPaper"
            );

            _fax.Receive(uid, printout, null, fax);

            wasSent = true;
        }

        return wasSent;
    }
}