using ZB.MOM.WW.Auth.ApiKeys.Admin;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Security;

namespace ZB.MOM.WW.ScadaBridge.Security;

/// <summary>
/// Implements the Commons <see cref="IInboundApiKeyAdmin"/> management seam over the shared
/// <c>ZB.MOM.WW.Auth.ApiKeys</c> admin facade (<see cref="ApiKeyAdminCommands"/>). This is the
/// single shared path through which CLI and CentralUI create / list / enable / disable / delete
/// inbound keys and edit their method-scopes, so all front-ends drive identical library behaviour.
/// </summary>
/// <remarks>
/// Mapping from the library projection to the app DTO:
/// <list type="bullet">
///   <item>A key is "enabled" iff its <c>RevokedUtc</c> is null.</item>
///   <item>"Methods" are the library's <c>Scopes</c>, sorted ordinally for a stable display order.</item>
///   <item>Delete is best-effort revoke-then-delete: the library only deletes already-revoked keys,
///         so we revoke first (a harmless no-op when already revoked) and the delete is authoritative.</item>
/// </list>
/// </remarks>
public sealed class LibraryInboundApiKeyAdmin : IInboundApiKeyAdmin
{
    private readonly ApiKeyAdminCommands _admin;

    /// <summary>Creates the seam over the supplied library admin command set.</summary>
    /// <param name="admin">The shared library admin facade.</param>
    public LibraryInboundApiKeyAdmin(ApiKeyAdminCommands admin)
    {
        ArgumentNullException.ThrowIfNull(admin);
        _admin = admin;
    }

    /// <inheritdoc />
    public async Task<InboundApiKeyCreated> CreateAsync(
        string name, IReadOnlyCollection<string> methods, CancellationToken ct = default)
    {
        ArgumentException.ThrowIfNullOrWhiteSpace(name);
        ArgumentNullException.ThrowIfNull(methods);

        // "N" format = 32 hex chars, no hyphens/underscores — the library rejects underscores
        // in keyId because they delimit the sbk_<keyId>_<secret> token.
        var keyId = Guid.NewGuid().ToString("N");
        var result = await _admin.CreateKeyAsync(
            keyId, name, methods.ToHashSet(StringComparer.Ordinal),
            constraintsJson: null, remoteAddress: null, ct).ConfigureAwait(false);

        // Token is non-null on create success; CreateKeyAsync throws rather than returning a
        // null token on the failure path, so a successful return always carries the secret.
        return new InboundApiKeyCreated(result.KeyId, result.Token!);
    }

    /// <inheritdoc />
    public async Task<IReadOnlyList<InboundApiKeyInfo>> ListAsync(CancellationToken ct = default)
    {
        var items = await _admin.ListKeysAsync(ct).ConfigureAwait(false);
        var result = new List<InboundApiKeyInfo>(items.Count);
        foreach (var item in items)
        {
            result.Add(new InboundApiKeyInfo(
                KeyId: item.KeyId,
                Name: item.DisplayName,
                Enabled: item.RevokedUtc is null,
                Methods: item.Scopes.OrderBy(s => s, StringComparer.Ordinal).ToList(),
                CreatedUtc: item.CreatedUtc,
                LastUsedUtc: item.LastUsedUtc));
        }

        return result;
    }

    /// <inheritdoc />
    public async Task<bool> SetEnabledAsync(string keyId, bool enabled, CancellationToken ct = default) =>
        (await _admin.SetEnabledAsync(keyId, enabled, remoteAddress: null, ct).ConfigureAwait(false)).Succeeded;

    /// <inheritdoc />
    public async Task<bool> SetMethodsAsync(
        string keyId, IReadOnlyCollection<string> methods, CancellationToken ct = default)
    {
        ArgumentNullException.ThrowIfNull(methods);
        return (await _admin.SetScopesAsync(
            keyId, methods.ToHashSet(StringComparer.Ordinal), remoteAddress: null, ct)
            .ConfigureAwait(false)).Succeeded;
    }

    /// <inheritdoc />
    public async Task<bool> DeleteAsync(string keyId, CancellationToken ct = default)
    {
        // Best-effort revoke first so the library permits the delete (it only deletes
        // already-revoked keys). Revoking an already-disabled key is a harmless no-op;
        // the delete result is authoritative.
        await _admin.RevokeKeyAsync(keyId, remoteAddress: null, ct).ConfigureAwait(false);
        return (await _admin.DeleteKeyAsync(keyId, remoteAddress: null, ct).ConfigureAwait(false)).Succeeded;
    }

    /// <inheritdoc />
    public async Task<IReadOnlyList<string>> GetMethodsForKeyAsync(string keyId, CancellationToken ct = default)
    {
        var keys = await ListAsync(ct).ConfigureAwait(false);
        var match = keys.FirstOrDefault(k => string.Equals(k.KeyId, keyId, StringComparison.Ordinal));
        return match?.Methods ?? (IReadOnlyList<string>)Array.Empty<string>();
    }

    /// <inheritdoc />
    public async Task<IReadOnlyList<string>> GetKeysForMethodAsync(string methodName, CancellationToken ct = default)
    {
        var keys = await ListAsync(ct).ConfigureAwait(false);
        return keys
            .Where(k => k.Methods.Contains(methodName, StringComparer.Ordinal))
            .Select(k => k.KeyId)
            .ToList();
    }
}
