using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace back.DataModels;

public class RankingGroup 
{
    public const float ExtremlyBad = 1/5f;
    public const float Bad = 2 / 5f;
    public const float Normal = 3 / 5f;
    public const float Good = 4 / 5f;
    public const float ExtremlyGood = 5 / 5f;

    public static string GetGroup(float score) => (float)Math.Ceiling(score) switch
    {
        <= ExtremlyBad => nameof(ExtremlyBad),
        <= Bad => nameof(Bad),
        <= Normal => nameof(Normal),
        <= Good => nameof(Good),
        _ => nameof(ExtremlyGood)
    };
}

[Table("Rankings")]
public partial class Ranking : IEquatable<Ranking>
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public string Id { get; set; } = null!;
    public int TotalVotes { get; set; }
    public int UpVotes { get; set; }
    public int DownVotes { get; set; }

    public Ranking(int totalVotes, int upVotes = 0, int downVotes = 0)
    {
        TotalVotes = totalVotes;
        UpVotes = upVotes;
        DownVotes = downVotes;
    }

    public Ranking()
    {
        TotalVotes = 0;
        UpVotes = 0;
        DownVotes = 0;
    }

    public void DownVote()
    {
        DownVotes++;
        TotalVotes++;
    }

    public void UpVote()
    {
        UpVotes++;
        TotalVotes++;
    }

    public float Score
    {
        get
        {
            if (TotalVotes == 0) return 0;
            return (float)(UpVotes - DownVotes) / TotalVotes;
        }
    }

    public string Group => RankingGroup.GetGroup(Score);

    public override int GetHashCode() => HashCode.Combine(Id, TotalVotes, UpVotes, DownVotes);

    public override bool Equals(object? obj) => obj is Ranking otherEvent && Equals(otherEvent);

    public bool Equals(Ranking? other)
    {
        if (other is null) return false;
        if (ReferenceEquals(this, other)) return true;
        return
            Id == other.Id 
            || GetHashCode() == other.GetHashCode()
            || (TotalVotes == other.TotalVotes && UpVotes == other.UpVotes && DownVotes == other.DownVotes);
    }

    public static bool operator ==(Ranking ranking1, Ranking ranking2) 
    {
        if (ranking1 is null && ranking2 is null) return true;
        if (ranking1 is null || ranking2 is null) return false;
        return ranking1.Equals(ranking2);
    }

    public static bool operator !=(Ranking ranking1, Ranking ranking2)
    {
        if (ranking1 is null && ranking2 is null) return false;
        if (ranking1 is null || ranking2 is null) return true;
        return !ranking1.Equals(ranking2);
    }

    public static bool operator < (Ranking ranking1, Ranking ranking2)
    {
        ArgumentNullException.ThrowIfNull(ranking1, nameof(ranking1));
        ArgumentNullException.ThrowIfNull(ranking2, nameof(ranking2));
        return ranking1.Score < ranking2.Score;
    }

    public static bool operator > (Ranking ranking1, Ranking ranking2)
    {
        ArgumentNullException.ThrowIfNull(ranking1, nameof(ranking1));
        ArgumentNullException.ThrowIfNull(ranking2, nameof(ranking2));
        if (ranking1 is null && ranking2 is null) return true;
        if (ranking1 is null || ranking2 is null) return false;
        return ranking1.Score > ranking2.Score;
    }

    public static bool operator <= (Ranking ranking1, Ranking ranking2)
        => ranking1 == ranking2 || ranking1 < ranking2;

    public static bool operator >= (Ranking ranking1, Ranking ranking2)
        => ranking1 == ranking2 || ranking1 > ranking2;
}