// Licensed under BUSL-1.1. Copyright (C) 2026 StellaOps Contributors.
// Postgres-backed repositories for VulnExplorer adapters (VXLM-005 gap fix).
// Replaces ConcurrentDictionary in-memory stores with durable persistence.

using Microsoft.Extensions.Logging;
using Npgsql;
using NpgsqlTypes;
using StellaOps.Findings.Ledger.Infrastructure.Postgres;
using StellaOps.Findings.Ledger.WebService.Contracts.VulnExplorer;
using System.Text.Json;

namespace StellaOps.Findings.Ledger.WebService.Services;

// ============================================================================
// Interfaces
// ============================================================================

public interface IVexDecisionRepository
{
    Task<VexDecisionDto> CreateAsync(string tenantId, VexDecisionDto decision, CancellationToken ct = default);
    Task<VexDecisionDto?> UpdateAsync(string tenantId, Guid id, UpdateVexDecisionRequest request, DateTimeOffset updatedAt, CancellationToken ct = default);
    Task<VexDecisionDto?> GetAsync(string tenantId, Guid id, CancellationToken ct = default);
    Task<IReadOnlyList<VexDecisionDto>> QueryAsync(string tenantId, string? vulnerabilityId, string? subjectName, VexStatus? status, int skip, int take, CancellationToken ct = default);
    Task<int> CountAsync(string tenantId, CancellationToken ct = default);
}

public interface IFixVerificationRepository
{
    Task<FixVerificationRecord> CreateAsync(string tenantId, FixVerificationRecord record, CancellationToken ct = default);
    Task<FixVerificationRecord?> UpdateAsync(string tenantId, string cveId, string verdict, FixVerificationTransition transition, CancellationToken ct = default);
}

public interface IAuditBundleRepository
{
    Task<AuditBundleResponse> CreateAsync(string tenantId, AuditBundleResponse bundle, IReadOnlyList<Guid> decisionIds, CancellationToken ct = default);
    Task<string> NextBundleIdAsync(string tenantId, CancellationToken ct = default);
}

// ============================================================================
// JSON serialization options (shared)
// ============================================================================

internal static class VulnExplorerJsonOptions
{
    internal static readonly JsonSerializerOptions Default = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        WriteIndented = false,
        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter(JsonNamingPolicy.CamelCase) }
    };
}

// ============================================================================
// PostgresVexDecisionRepository
// ============================================================================

public sealed class PostgresVexDecisionRepository : IVexDecisionRepository
{
    private readonly LedgerDataSource _dataSource;
    private readonly ILogger<PostgresVexDecisionRepository> _logger;

    public PostgresVexDecisionRepository(LedgerDataSource dataSource, ILogger<PostgresVexDecisionRepository> logger)
    {
        _dataSource = dataSource;
        _logger = logger;
    }

    public async Task<VexDecisionDto> CreateAsync(string tenantId, VexDecisionDto decision, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "vex-write", ct).ConfigureAwait(false);

        const string sql = """
            INSERT INTO findings.vex_decisions
                (id, tenant_id, vulnerability_id, subject, status, justification_type,
                 justification_text, evidence_refs, scope, valid_for, attestation_ref,
                 signed_override, supersedes_decision_id, created_by, created_at, updated_at)
            VALUES
                (@id, @tenant_id, @vulnerability_id, @subject::jsonb, @status, @justification_type,
                 @justification_text, @evidence_refs::jsonb, @scope::jsonb, @valid_for::jsonb,
                 @attestation_ref::jsonb, @signed_override::jsonb, @supersedes_decision_id,
                 @created_by::jsonb, @created_at, @updated_at)
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("id", decision.Id);
        cmd.Parameters.AddWithValue("tenant_id", tenantId);
        cmd.Parameters.AddWithValue("vulnerability_id", decision.VulnerabilityId);
        cmd.Parameters.Add(new NpgsqlParameter("subject", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(decision.Subject, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.AddWithValue("status", decision.Status.ToString());
        cmd.Parameters.AddWithValue("justification_type", decision.JustificationType.ToString());
        cmd.Parameters.AddWithValue("justification_text", (object?)decision.JustificationText ?? DBNull.Value);
        cmd.Parameters.Add(new NpgsqlParameter("evidence_refs", NpgsqlDbType.Jsonb) { Value = decision.EvidenceRefs is not null ? JsonSerializer.Serialize(decision.EvidenceRefs, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("scope", NpgsqlDbType.Jsonb) { Value = decision.Scope is not null ? JsonSerializer.Serialize(decision.Scope, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("valid_for", NpgsqlDbType.Jsonb) { Value = decision.ValidFor is not null ? JsonSerializer.Serialize(decision.ValidFor, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("attestation_ref", NpgsqlDbType.Jsonb) { Value = decision.AttestationRef is not null ? JsonSerializer.Serialize(decision.AttestationRef, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("signed_override", NpgsqlDbType.Jsonb) { Value = decision.SignedOverride is not null ? JsonSerializer.Serialize(decision.SignedOverride, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.AddWithValue("supersedes_decision_id", (object?)decision.SupersedesDecisionId ?? DBNull.Value);
        cmd.Parameters.Add(new NpgsqlParameter("created_by", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(decision.CreatedBy, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.AddWithValue("created_at", decision.CreatedAt);
        cmd.Parameters.AddWithValue("updated_at", (object?)decision.UpdatedAt ?? DBNull.Value);

        await cmd.ExecuteNonQueryAsync(ct).ConfigureAwait(false);
        _logger.LogDebug("Created VEX decision {DecisionId} for tenant {TenantId}", decision.Id, tenantId);
        return decision;
    }

    public async Task<VexDecisionDto?> UpdateAsync(string tenantId, Guid id, UpdateVexDecisionRequest request, DateTimeOffset updatedAt, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "vex-write", ct).ConfigureAwait(false);

        // First fetch the existing record
        var existing = await GetInternalAsync(connection, id, ct).ConfigureAwait(false);
        if (existing is null)
        {
            return null;
        }

        var updated = existing with
        {
            Status = request.Status ?? existing.Status,
            JustificationType = request.JustificationType ?? existing.JustificationType,
            JustificationText = request.JustificationText ?? existing.JustificationText,
            EvidenceRefs = request.EvidenceRefs ?? existing.EvidenceRefs,
            Scope = request.Scope ?? existing.Scope,
            ValidFor = request.ValidFor ?? existing.ValidFor,
            SupersedesDecisionId = request.SupersedesDecisionId ?? existing.SupersedesDecisionId,
            UpdatedAt = updatedAt
        };

        const string sql = """
            UPDATE findings.vex_decisions SET
                status = @status,
                justification_type = @justification_type,
                justification_text = @justification_text,
                evidence_refs = @evidence_refs::jsonb,
                scope = @scope::jsonb,
                valid_for = @valid_for::jsonb,
                supersedes_decision_id = @supersedes_decision_id,
                updated_at = @updated_at
            WHERE id = @id
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("id", id);
        cmd.Parameters.AddWithValue("status", updated.Status.ToString());
        cmd.Parameters.AddWithValue("justification_type", updated.JustificationType.ToString());
        cmd.Parameters.AddWithValue("justification_text", (object?)updated.JustificationText ?? DBNull.Value);
        cmd.Parameters.Add(new NpgsqlParameter("evidence_refs", NpgsqlDbType.Jsonb) { Value = updated.EvidenceRefs is not null ? JsonSerializer.Serialize(updated.EvidenceRefs, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("scope", NpgsqlDbType.Jsonb) { Value = updated.Scope is not null ? JsonSerializer.Serialize(updated.Scope, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.Add(new NpgsqlParameter("valid_for", NpgsqlDbType.Jsonb) { Value = updated.ValidFor is not null ? JsonSerializer.Serialize(updated.ValidFor, VulnExplorerJsonOptions.Default) : DBNull.Value });
        cmd.Parameters.AddWithValue("supersedes_decision_id", (object?)updated.SupersedesDecisionId ?? DBNull.Value);
        cmd.Parameters.AddWithValue("updated_at", updatedAt);

        await cmd.ExecuteNonQueryAsync(ct).ConfigureAwait(false);
        _logger.LogDebug("Updated VEX decision {DecisionId} for tenant {TenantId}", id, tenantId);
        return updated;
    }

    public async Task<VexDecisionDto?> GetAsync(string tenantId, Guid id, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "vex-read", ct).ConfigureAwait(false);
        return await GetInternalAsync(connection, id, ct).ConfigureAwait(false);
    }

    public async Task<IReadOnlyList<VexDecisionDto>> QueryAsync(
        string tenantId, string? vulnerabilityId, string? subjectName, VexStatus? status,
        int skip, int take, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "vex-read", ct).ConfigureAwait(false);

        var sql = "SELECT id, vulnerability_id, subject, status, justification_type, justification_text, evidence_refs, scope, valid_for, attestation_ref, signed_override, supersedes_decision_id, created_by, created_at, updated_at FROM findings.vex_decisions WHERE 1=1";
        var parameters = new List<NpgsqlParameter>();

        if (vulnerabilityId is not null)
        {
            sql += " AND vulnerability_id = @vulnerability_id";
            parameters.Add(new NpgsqlParameter("vulnerability_id", vulnerabilityId));
        }

        if (subjectName is not null)
        {
            sql += " AND subject->>'name' ILIKE @subject_name";
            parameters.Add(new NpgsqlParameter("subject_name", $"%{subjectName}%"));
        }

        if (status is not null)
        {
            sql += " AND status = @status";
            parameters.Add(new NpgsqlParameter("status", status.Value.ToString()));
        }

        sql += " ORDER BY created_at DESC, id ASC LIMIT @take OFFSET @skip";
        parameters.Add(new NpgsqlParameter("take", take));
        parameters.Add(new NpgsqlParameter("skip", skip));

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddRange(parameters.ToArray());

        var results = new List<VexDecisionDto>();
        await using var reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
        while (await reader.ReadAsync(ct).ConfigureAwait(false))
        {
            results.Add(MapDecision(reader));
        }

        return results;
    }

    public async Task<int> CountAsync(string tenantId, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "vex-read", ct).ConfigureAwait(false);

        const string sql = "SELECT COUNT(*) FROM findings.vex_decisions";
        await using var cmd = new NpgsqlCommand(sql, connection);
        var result = await cmd.ExecuteScalarAsync(ct).ConfigureAwait(false);
        return Convert.ToInt32(result);
    }

    private static async Task<VexDecisionDto?> GetInternalAsync(NpgsqlConnection connection, Guid id, CancellationToken ct)
    {
        const string sql = """
            SELECT id, vulnerability_id, subject, status, justification_type, justification_text,
                   evidence_refs, scope, valid_for, attestation_ref, signed_override,
                   supersedes_decision_id, created_by, created_at, updated_at
            FROM findings.vex_decisions
            WHERE id = @id
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("id", id);

        await using var reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
        return await reader.ReadAsync(ct).ConfigureAwait(false) ? MapDecision(reader) : null;
    }

    private static VexDecisionDto MapDecision(NpgsqlDataReader reader)
    {
        var statusStr = reader.GetString(reader.GetOrdinal("status"));
        var justTypeStr = reader.GetString(reader.GetOrdinal("justification_type"));

        return new VexDecisionDto(
            Id: reader.GetGuid(reader.GetOrdinal("id")),
            VulnerabilityId: reader.GetString(reader.GetOrdinal("vulnerability_id")),
            Subject: JsonSerializer.Deserialize<SubjectRefDto>(reader.GetString(reader.GetOrdinal("subject")), VulnExplorerJsonOptions.Default)!,
            Status: Enum.TryParse<VexStatus>(statusStr, ignoreCase: true, out var s) ? s : VexStatus.NotAffected,
            JustificationType: Enum.TryParse<VexJustificationType>(justTypeStr, ignoreCase: true, out var j) ? j : VexJustificationType.Other,
            JustificationText: reader.IsDBNull(reader.GetOrdinal("justification_text")) ? null : reader.GetString(reader.GetOrdinal("justification_text")),
            EvidenceRefs: reader.IsDBNull(reader.GetOrdinal("evidence_refs")) ? null : JsonSerializer.Deserialize<IReadOnlyList<EvidenceRefDto>>(reader.GetString(reader.GetOrdinal("evidence_refs")), VulnExplorerJsonOptions.Default),
            Scope: reader.IsDBNull(reader.GetOrdinal("scope")) ? null : JsonSerializer.Deserialize<VexScopeDto>(reader.GetString(reader.GetOrdinal("scope")), VulnExplorerJsonOptions.Default),
            ValidFor: reader.IsDBNull(reader.GetOrdinal("valid_for")) ? null : JsonSerializer.Deserialize<ValidForDto>(reader.GetString(reader.GetOrdinal("valid_for")), VulnExplorerJsonOptions.Default),
            AttestationRef: reader.IsDBNull(reader.GetOrdinal("attestation_ref")) ? null : JsonSerializer.Deserialize<AttestationRefDto>(reader.GetString(reader.GetOrdinal("attestation_ref")), VulnExplorerJsonOptions.Default),
            SignedOverride: reader.IsDBNull(reader.GetOrdinal("signed_override")) ? null : JsonSerializer.Deserialize<VexOverrideAttestationDto>(reader.GetString(reader.GetOrdinal("signed_override")), VulnExplorerJsonOptions.Default),
            SupersedesDecisionId: reader.IsDBNull(reader.GetOrdinal("supersedes_decision_id")) ? null : reader.GetGuid(reader.GetOrdinal("supersedes_decision_id")),
            CreatedBy: JsonSerializer.Deserialize<ActorRefDto>(reader.GetString(reader.GetOrdinal("created_by")), VulnExplorerJsonOptions.Default)!,
            CreatedAt: reader.GetFieldValue<DateTimeOffset>(reader.GetOrdinal("created_at")),
            UpdatedAt: reader.IsDBNull(reader.GetOrdinal("updated_at")) ? null : reader.GetFieldValue<DateTimeOffset>(reader.GetOrdinal("updated_at"))
        );
    }
}

// ============================================================================
// PostgresFixVerificationRepository
// ============================================================================

public sealed class PostgresFixVerificationRepository : IFixVerificationRepository
{
    private readonly LedgerDataSource _dataSource;
    private readonly ILogger<PostgresFixVerificationRepository> _logger;

    public PostgresFixVerificationRepository(LedgerDataSource dataSource, ILogger<PostgresFixVerificationRepository> logger)
    {
        _dataSource = dataSource;
        _logger = logger;
    }

    public async Task<FixVerificationRecord> CreateAsync(string tenantId, FixVerificationRecord record, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "fix-write", ct).ConfigureAwait(false);

        const string sql = """
            INSERT INTO findings.fix_verifications
                (cve_id, tenant_id, component_purl, artifact_digest, verdict, transitions, created_at, updated_at)
            VALUES
                (@cve_id, @tenant_id, @component_purl, @artifact_digest, @verdict, @transitions::jsonb, @created_at, @updated_at)
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("cve_id", record.CveId);
        cmd.Parameters.AddWithValue("tenant_id", tenantId);
        cmd.Parameters.AddWithValue("component_purl", record.ComponentPurl);
        cmd.Parameters.AddWithValue("artifact_digest", (object?)record.ArtifactDigest ?? DBNull.Value);
        cmd.Parameters.AddWithValue("verdict", record.Verdict);
        cmd.Parameters.Add(new NpgsqlParameter("transitions", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(record.Transitions, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.AddWithValue("created_at", record.CreatedAt);
        cmd.Parameters.AddWithValue("updated_at", record.UpdatedAt);

        await cmd.ExecuteNonQueryAsync(ct).ConfigureAwait(false);
        _logger.LogDebug("Created fix verification for CVE {CveId} in tenant {TenantId}", record.CveId, tenantId);
        return record;
    }

    public async Task<FixVerificationRecord?> UpdateAsync(string tenantId, string cveId, string verdict, FixVerificationTransition transition, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "fix-write", ct).ConfigureAwait(false);

        // First fetch existing
        var existing = await GetInternalAsync(connection, cveId, ct).ConfigureAwait(false);
        if (existing is null)
        {
            return null;
        }

        var transitions = existing.Transitions.ToList();
        transitions.Add(transition);

        var updated = existing with
        {
            Verdict = verdict,
            Transitions = transitions.ToArray(),
            UpdatedAt = transition.ChangedAt
        };

        const string sql = """
            UPDATE findings.fix_verifications SET
                verdict = @verdict,
                transitions = @transitions::jsonb,
                updated_at = @updated_at
            WHERE cve_id = @cve_id
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("cve_id", cveId);
        cmd.Parameters.AddWithValue("verdict", verdict);
        cmd.Parameters.Add(new NpgsqlParameter("transitions", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(transitions, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.AddWithValue("updated_at", transition.ChangedAt);

        await cmd.ExecuteNonQueryAsync(ct).ConfigureAwait(false);
        _logger.LogDebug("Updated fix verification {CveId} to verdict {Verdict} in tenant {TenantId}", cveId, verdict, tenantId);
        return updated;
    }

    private static async Task<FixVerificationRecord?> GetInternalAsync(NpgsqlConnection connection, string cveId, CancellationToken ct)
    {
        const string sql = """
            SELECT cve_id, component_purl, artifact_digest, verdict, transitions, created_at, updated_at
            FROM findings.fix_verifications
            WHERE cve_id = @cve_id
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("cve_id", cveId);

        await using var reader = await cmd.ExecuteReaderAsync(ct).ConfigureAwait(false);
        if (!await reader.ReadAsync(ct).ConfigureAwait(false))
        {
            return null;
        }

        return new FixVerificationRecord(
            CveId: reader.GetString(reader.GetOrdinal("cve_id")),
            ComponentPurl: reader.GetString(reader.GetOrdinal("component_purl")),
            ArtifactDigest: reader.IsDBNull(reader.GetOrdinal("artifact_digest")) ? null : reader.GetString(reader.GetOrdinal("artifact_digest")),
            Verdict: reader.GetString(reader.GetOrdinal("verdict")),
            Transitions: JsonSerializer.Deserialize<IReadOnlyList<FixVerificationTransition>>(reader.GetString(reader.GetOrdinal("transitions")), VulnExplorerJsonOptions.Default) ?? [],
            CreatedAt: reader.GetFieldValue<DateTimeOffset>(reader.GetOrdinal("created_at")),
            UpdatedAt: reader.GetFieldValue<DateTimeOffset>(reader.GetOrdinal("updated_at"))
        );
    }
}

// ============================================================================
// PostgresAuditBundleRepository
// ============================================================================

public sealed class PostgresAuditBundleRepository : IAuditBundleRepository
{
    private readonly LedgerDataSource _dataSource;
    private readonly ILogger<PostgresAuditBundleRepository> _logger;

    public PostgresAuditBundleRepository(LedgerDataSource dataSource, ILogger<PostgresAuditBundleRepository> logger)
    {
        _dataSource = dataSource;
        _logger = logger;
    }

    public async Task<AuditBundleResponse> CreateAsync(string tenantId, AuditBundleResponse bundle, IReadOnlyList<Guid> decisionIds, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "audit-write", ct).ConfigureAwait(false);

        const string sql = """
            INSERT INTO findings.audit_bundles
                (bundle_id, tenant_id, decision_ids, decisions, evidence_refs, created_at)
            VALUES
                (@bundle_id, @tenant_id, @decision_ids::jsonb, @decisions::jsonb, @evidence_refs::jsonb, @created_at)
            """;

        await using var cmd = new NpgsqlCommand(sql, connection);
        cmd.Parameters.AddWithValue("bundle_id", bundle.BundleId);
        cmd.Parameters.AddWithValue("tenant_id", tenantId);
        cmd.Parameters.Add(new NpgsqlParameter("decision_ids", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(decisionIds, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.Add(new NpgsqlParameter("decisions", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(bundle.Decisions, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.Add(new NpgsqlParameter("evidence_refs", NpgsqlDbType.Jsonb) { Value = JsonSerializer.Serialize(bundle.EvidenceRefs, VulnExplorerJsonOptions.Default) });
        cmd.Parameters.AddWithValue("created_at", bundle.CreatedAt);

        await cmd.ExecuteNonQueryAsync(ct).ConfigureAwait(false);
        _logger.LogDebug("Created audit bundle {BundleId} for tenant {TenantId}", bundle.BundleId, tenantId);
        return bundle;
    }

    public async Task<string> NextBundleIdAsync(string tenantId, CancellationToken ct = default)
    {
        await using var connection = await _dataSource.OpenConnectionAsync(tenantId, "audit-write", ct).ConfigureAwait(false);

        const string sql = "SELECT nextval('findings.audit_bundle_seq')";
        await using var cmd = new NpgsqlCommand(sql, connection);
        var result = await cmd.ExecuteScalarAsync(ct).ConfigureAwait(false);
        return $"bundle-{Convert.ToInt64(result):D6}";
    }
}