namespace Lagerbestand.Models;

/// <summary>
/// Represents the position within a shelf slot (side + level).
/// The value corresponds to position C in the location code (ABCD format).
/// </summary>
public enum ShelfPosition
{
    /// <summary>
    /// Links oben - Code: 1
    /// </summary>
    LinksOben = 1,

    /// <summary>
    /// Links unten - Code: 2
    /// </summary>
    LinksUnten = 2,

    /// <summary>
    /// Rechts oben - Code: 3
    /// </summary>
    RechtsOben = 3,

    /// <summary>
    /// Rechts unten - Code: 4
    /// </summary>
    RechtsUnten = 4
}

/// <summary>
/// Extension methods for ShelfPosition enum.
/// </summary>
public static class ShelfPositionExtensions
{
    /// <summary>
    /// Gets the German display name for the shelf position.
    /// </summary>
    public static string GetDisplayName(this ShelfPosition position) => position switch
    {
        ShelfPosition.LinksOben => "Links oben",
        ShelfPosition.LinksUnten => "Links unten",
        ShelfPosition.RechtsOben => "Rechts oben",
        ShelfPosition.RechtsUnten => "Rechts unten",
        _ => position.ToString()
    };

    /// <summary>
    /// Gets a short display name (e.g., "L↑") for compact grid views.
    /// </summary>
    public static string GetShortName(this ShelfPosition position) => position switch
    {
        ShelfPosition.LinksOben => "L↑",
        ShelfPosition.LinksUnten => "L↓",
        ShelfPosition.RechtsOben => "R↑",
        ShelfPosition.RechtsUnten => "R↓",
        _ => position.ToString()
    };

    /// <summary>
    /// Whether the position is on the left side of the shelf.
    /// </summary>
    public static bool IsLeft(this ShelfPosition position) =>
        position is ShelfPosition.LinksOben or ShelfPosition.LinksUnten;

    /// <summary>
    /// Whether the position is on the top level of the shelf.
    /// </summary>
    public static bool IsTop(this ShelfPosition position) =>
        position is ShelfPosition.LinksOben or ShelfPosition.RechtsOben;

    /// <summary>
    /// Gets the single-digit code for the position.
    /// </summary>
    public static string GetCode(this ShelfPosition position) => ((int)position).ToString();

    /// <summary>
    /// Parses a code digit to ShelfPosition.
    /// </summary>
    /// <param name="code">Single digit code (1-4)</param>
    /// <exception cref="ArgumentException">If code is not valid</exception>
    public static ShelfPosition FromCode(char code) => code switch
    {
        '1' => ShelfPosition.LinksOben,
        '2' => ShelfPosition.LinksUnten,
        '3' => ShelfPosition.RechtsOben,
        '4' => ShelfPosition.RechtsUnten,
        _ => throw new ArgumentException($"Ungültiger Positionscode: {code}. Erlaubt: 1-4", nameof(code))
    };

    /// <summary>
    /// Tries to parse a code digit to ShelfPosition.
    /// </summary>
    public static bool TryFromCode(char code, out ShelfPosition position)
    {
        position = default;
        if (code is < '1' or > '4')
            return false;

        position = (ShelfPosition)(code - '0');
        return true;
    }

    /// <summary>
    /// All shelf positions in display order.
    /// </summary>
    public static readonly ShelfPosition[] All =
    [
        ShelfPosition.LinksOben,
        ShelfPosition.LinksUnten,
        ShelfPosition.RechtsOben,
        ShelfPosition.RechtsUnten
    ];
}