jobtrackingapp/JobTrackerApi/Services/EmailProviders/MicrosoftGraphProvider.cs

using JobTrackerApi.Services;

namespace JobTrackerApi.Services.EmailProviders
{
    /// <summary>
    /// Outlook / Microsoft 365 implementation of <see cref="IEmailProvider"/>. Adapts
    /// <see cref="IMicrosoftGraphOAuthService"/> (Microsoft Graph client) to the provider-neutral
    /// contract, mapping Graph DTOs to the neutral shapes.
    /// </summary>
    public sealed class MicrosoftGraphProvider : IEmailProvider
    {
        private readonly IMicrosoftGraphOAuthService _graph;

        public MicrosoftGraphProvider(IMicrosoftGraphOAuthService graph)
        {
            _graph = graph;
        }

        public string ProviderKey => "microsoft";

        public async Task<EmailConnectionInfo?> GetConnectionAsync(string ownerUserId, CancellationToken cancellationToken)
        {
            var connection = await _graph.GetConnectionAsync(ownerUserId, cancellationToken);
            return connection is null ? null : new EmailConnectionInfo("microsoft", connection.MailAddress ?? "");
        }

        public async Task<IReadOnlyList<EmailMessageSummary>> SearchAsync(string ownerUserId, string? query, int maxResults, CancellationToken cancellationToken)
        {
            var messages = await _graph.ListMessagesAsync(ownerUserId, query, maxResults, cancellationToken);
            return messages.Select(ToSummary).ToList();
        }

        public async Task<IReadOnlyList<EmailMessageSummary>> ListThreadMessagesAsync(string ownerUserId, string threadId, CancellationToken cancellationToken)
        {
            var messages = await _graph.ListThreadMessagesAsync(ownerUserId, threadId, cancellationToken);
            return messages.Select(ToSummary).ToList();
        }

        public async Task<EmailMessageDetail> GetMessageAsync(string ownerUserId, string messageId, CancellationToken cancellationToken)
        {
            var detail = await _graph.GetMessageAsync(ownerUserId, messageId, cancellationToken);
            var attachments = detail.Attachments
                .Select(a => new EmailAttachmentRef(a.FileName, a.MimeType, a.SizeBytes, a.GraphAttachmentId, a.Inline))
                .ToList();

            return new EmailMessageDetail(
                detail.Id,
                detail.ConversationId,
                detail.Subject,
                detail.From,
                detail.To,
                detail.Date,
                detail.Snippet,
                detail.BodyText,
                detail.BodyHtml,
                detail.Labels,
                attachments);
        }

        private static EmailMessageSummary ToSummary(MicrosoftGraphMessageSummary m)
            => new(m.Id, m.ConversationId, m.Subject, m.From, m.To, m.Date, m.Snippet);
    }
}