using System;

namespace StellaOps.Provenance;

public static partial class ProvenanceExtensions
{
    /// <summary>
    /// Attach DSSE provenance + trust info to an event document in-place.
    /// Designed for generic DocumentObject-based event envelopes.
    /// </summary>
    public static DocumentObject AttachDsseProvenance(
        this DocumentObject eventDoc,
        DsseProvenance dsse,
        TrustInfo trust)
    {
        if (eventDoc is null) throw new ArgumentNullException(nameof(eventDoc));
        if (dsse is null) throw new ArgumentNullException(nameof(dsse));
        if (trust is null) throw new ArgumentNullException(nameof(trust));

        var dsseDoc = new DocumentObject
        {
            { "envelopeDigest", dsse.EnvelopeDigest },
            { "payloadType", dsse.PayloadType },
            {
                "key", new DocumentObject
                {
                    { "keyId", dsse.Key.KeyId },
                    { "issuer", StringOrNull(dsse.Key.Issuer) },
                    { "algo", StringOrNull(dsse.Key.Algo) }
                }
            }
        };

        if (dsse.Rekor is not null)
        {
            var rekorDoc = new DocumentObject
            {
                { "logIndex", dsse.Rekor.LogIndex },
                { "uuid", dsse.Rekor.Uuid }
            };

            if (dsse.Rekor.IntegratedTime is not null)
                rekorDoc.Add("integratedTime", dsse.Rekor.IntegratedTime);

            if (dsse.Rekor.MirrorSeq is not null)
                rekorDoc.Add("mirrorSeq", dsse.Rekor.MirrorSeq);

            dsseDoc.Add("rekor", rekorDoc);
        }

        if (dsse.Chain is not null && dsse.Chain.Count > 0)
        {
            var chainArray = new DocumentArray();
            foreach (var link in dsse.Chain)
            {
                chainArray.Add(new DocumentObject
                {
                    { "type", link.Type },
                    { "id", link.Id },
                    { "digest", link.Digest }
                });
            }

            dsseDoc.Add(ChainFieldName, chainArray);
        }

        var trustDoc = new DocumentObject
        {
            { "verified", trust.Verified },
            { "verifier", StringOrNull(trust.Verifier) }
        };

        if (trust.Witnesses is not null)
            trustDoc.Add("witnesses", trust.Witnesses);

        if (trust.PolicyScore is not null)
            trustDoc.Add("policyScore", trust.PolicyScore);

        var provenanceDoc = new DocumentObject
        {
            { DsseFieldName, dsseDoc }
        };

        eventDoc[ProvenanceFieldName] = provenanceDoc;
        eventDoc[TrustFieldName] = trustDoc;

        return eventDoc;
    }
}