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

namespace Lagerbestand.Models;

/// <summary>
/// Condition rating of a single tire as reported by the measurement device.
/// </summary>
public enum TireMeasureRating
{
    Unknown = 0,
    Ok = 1,
    Warning = 2,
    Critical = 3
}

/// <summary>
/// A tread depth / condition measurement for a tire stack, typically imported
/// from a Launch TTS01 report (QR code) during checkin.
/// </summary>
public class TireInspection
{
    [Key]
    public Guid Id { get; set; } = Guid.NewGuid();

    public Guid TireStackId { get; set; }

    [ForeignKey(nameof(TireStackId))]
    [System.Text.Json.Serialization.JsonIgnore]
    public TireStack? TireStack { get; set; }

    [MaxLength(50)]
    public string Source { get; set; } = "Launch TTS01";

    [MaxLength(100)]
    public string? RecordSn { get; set; }

    [MaxLength(500)]
    public string? ReportUrl { get; set; }

    public DateTime? MeasuredAt { get; set; }

    [MaxLength(20)]
    public string? LicensePlate { get; set; }

    public int? Mileage { get; set; }

    [Column(TypeName = "decimal(5,2)")]
    public decimal? TreadDepthFL { get; set; }

    [Column(TypeName = "decimal(5,2)")]
    public decimal? TreadDepthFR { get; set; }

    [Column(TypeName = "decimal(5,2)")]
    public decimal? TreadDepthRL { get; set; }

    [Column(TypeName = "decimal(5,2)")]
    public decimal? TreadDepthRR { get; set; }

    public TireMeasureRating RatingFL { get; set; }
    public TireMeasureRating RatingFR { get; set; }
    public TireMeasureRating RatingRL { get; set; }
    public TireMeasureRating RatingRR { get; set; }

    [MaxLength(1000)]
    public string? Recommendation { get; set; }

    public string? RawJson { get; set; }

    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;

    public Guid? CreatedByUserId { get; set; }

    [NotMapped]
    public decimal? MinTreadDepth
    {
        get
        {
            var values = new[] { TreadDepthFL, TreadDepthFR, TreadDepthRL, TreadDepthRR }.Where(v => v.HasValue).Select(v => v!.Value).ToList();
            return values.Count == 0 ? null : values.Min();
        }
    }

    [NotMapped]
    public TireMeasureRating WorstRating
    {
        get
        {
            var ratings = new[] { RatingFL, RatingFR, RatingRL, RatingRR };
            return ratings.Max();
        }
    }

    [NotMapped]
    public bool HasTreadData => TreadDepthFL.HasValue || TreadDepthFR.HasValue || TreadDepthRL.HasValue || TreadDepthRR.HasValue;

    /// <summary>Legal minimum tread depth in Germany (mm).</summary>
    public const decimal DefaultCriticalThreshold = 1.6m;

    /// <summary>Common workshop recommendation threshold for replacement (mm).</summary>
    public const decimal DefaultWarningThreshold = 3.0m;

    /// <summary>
    /// Derives a rating from a tread depth in mm. Values below <paramref name="critical"/>
    /// are critical, values up to <paramref name="warning"/> are a warning.
    /// </summary>
    public static TireMeasureRating RateDepth(decimal? mm, decimal? critical = null, decimal? warning = null)
    {
        if (!mm.HasValue) return TireMeasureRating.Unknown;
        var crit = critical ?? DefaultCriticalThreshold;
        var warn = Math.Max(warning ?? DefaultWarningThreshold, crit);
        if (mm.Value < crit) return TireMeasureRating.Critical;
        if (mm.Value <= warn) return TireMeasureRating.Warning;
        return TireMeasureRating.Ok;
    }
}