using System;
using System.Threading;
using System.Threading.Tasks;
using StellaOps.Scanner.Analyzers.Lang.Rust.Internal;

namespace StellaOps.Scanner.Analyzers.Lang.Rust;

public sealed class RustLanguageAnalyzer : ILanguageAnalyzer
{
    public string Id => "rust";

    public string DisplayName => "Rust Analyzer (preview)";

    public ValueTask AnalyzeAsync(LanguageAnalyzerContext context, LanguageComponentWriter writer, CancellationToken cancellationToken)
    {
        ArgumentNullException.ThrowIfNull(context);
        ArgumentNullException.ThrowIfNull(writer);

        cancellationToken.ThrowIfCancellationRequested();

        var collection = RustAnalyzerCollector.Collect(context, cancellationToken);

        EmitRecords(Id, writer, collection.Crates);
        EmitRecords(Id, writer, collection.Heuristics);
        EmitRecords(Id, writer, collection.Fallbacks);

        return ValueTask.CompletedTask;
    }

    private static void EmitRecords(string analyzerId, LanguageComponentWriter writer, IReadOnlyList<RustComponentRecord> records)
    {
        foreach (var record in records)
        {
            if (record is null)
            {
                continue;
            }

            if (!string.IsNullOrEmpty(record.Purl))
            {
                writer.AddFromPurl(
                    analyzerId: analyzerId,
                    purl: record.Purl!,
                    name: record.Name,
                    version: record.Version,
                    type: record.Type,
                    metadata: record.Metadata,
                    evidence: record.Evidence,
                    usedByEntrypoint: record.UsedByEntrypoint);
            }
            else
            {
                writer.AddFromExplicitKey(
                    analyzerId: analyzerId,
                    componentKey: record.ComponentKey,
                    purl: null,
                    name: record.Name,
                    version: record.Version,
                    type: record.Type,
                    metadata: record.Metadata,
                    evidence: record.Evidence,
                    usedByEntrypoint: record.UsedByEntrypoint);
            }
        }
    }
}