// Emit a C# enum of every spell in portal.dat's SpellTable.
//
// Generated rather than hand-written or copied from another project: the ids
// and names come from the user's own game data, so the enum cannot drift from
// what the client actually loads, and regenerating is a one-liner.
using System.Text;
using AcDream.Core.Spells;

namespace SpellDump;

internal static class EmitEnum
{
    public static void Run(SpellTable table, string outPath, string ns, string typeName)
    {
        var byName = new Dictionary<string, uint>(StringComparer.Ordinal);
        var ordered = new List<(uint Id, string Ident, string Name)>();

        foreach (uint id in table.SpellIds.OrderBy(i => i))
        {
            if (!table.TryGet(id, out SpellMetadata meta))
                continue;
            string ident = Identifier(meta.Name);
            if (ident.Length == 0)
                ident = "Spell";
            // Retail reuses display names across ids; suffix collisions with the
            // id so every member stays addressable and stable.
            if (byName.ContainsKey(ident))
                ident = $"{ident}_{id:X4}";
            byName[ident] = id;
            ordered.Add((id, ident, meta.Name));
        }

        var sb = new StringBuilder();
        sb.AppendLine("// <auto-generated>");
        sb.AppendLine("//   Generated by tools/SpellDump from portal.dat's SpellTable (0x0E00000E).");
        sb.AppendLine("//   Do not edit by hand. Regenerate with:");
        sb.AppendLine("//     dotnet run --project tools/SpellDump -- --enum");
        sb.AppendLine("// </auto-generated>");
        sb.AppendLine();
        sb.AppendLine($"namespace {ns};");
        sb.AppendLine();
        sb.AppendLine("/// <summary>Every spell id in the retail spell table, by name.</summary>");
        sb.AppendLine($"public enum {typeName} : uint");
        sb.AppendLine("{");
        foreach (var (id, ident, name) in ordered)
        {
            sb.AppendLine($"    /// <summary>{System.Security.SecurityElement.Escape(name)}</summary>");
            sb.AppendLine($"    {ident} = 0x{id:X4},");
        }
        sb.AppendLine("}");

        File.WriteAllText(outPath, sb.ToString());
        Console.WriteLine($"wrote {outPath}: {ordered.Count} spells");
    }

    private static string Identifier(string name)
    {
        var sb = new StringBuilder(name.Length);
        bool upper = true;
        foreach (char c in name)
        {
            if (char.IsLetterOrDigit(c))
            {
                sb.Append(upper ? char.ToUpperInvariant(c) : c);
                upper = false;
            }
            else
            {
                upper = true;   // word break -> PascalCase
            }
        }
        string ident = sb.ToString();
        if (ident.Length > 0 && char.IsDigit(ident[0]))
            ident = "S" + ident;
        return ident;
    }
}