using Api.Services.Contracts;
using CvMatcher.Models.Responses;
using Email.Data.Services;
using Email.Models.Clients;
using Email.Models.Requests;
using Microsoft.Extensions.Options;
using Models.Requests;
using Models.Settings;
using System.Net;

namespace Api.Services;

/// <summary>
/// Implements <see cref="IEmailSender"/> by delegating all email dispatch to the internal email-api service via Refit.
/// </summary>
public sealed class EmailApiEmailSender : IEmailSender
{
    private readonly IEmailApiClient _emailApi;
    private readonly ContactSettings _contact;
    private readonly SubscribeSettings _subscribe;
    private readonly FileStorageSettings _fileStorage;
    private readonly IEmailTemplateService _emailTemplates;
    private readonly ILogger<EmailApiEmailSender> _log;

    public EmailApiEmailSender(
        IEmailApiClient emailApi,
        IOptions<ContactSettings> contact,
        IOptions<SubscribeSettings> subscribe,
        IOptions<FileStorageSettings> fileStorage,
        IEmailTemplateService emailTemplates,
        ILogger<EmailApiEmailSender> log)
    {
        _emailApi = emailApi;
        _contact = contact.Value;
        _subscribe = subscribe.Value;
        _fileStorage = fileStorage.Value;
        _emailTemplates = emailTemplates;
        _log = log;
    }

    /// <inheritdoc />
    public async Task SendContactAsync(ContactRequest req, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(_contact.ToEmail))
        {
            _log.LogDebug("Contact email skipped - ToEmail not configured");
            throw new InvalidOperationException("Contact email recipient is not configured.");
        }

        _log.LogInformation("Preparing contact email from {SenderEmail} to {RecipientEmail}",
            req.Email, _contact.ToEmail);

        var htmlBody = $"""
            <h2 style="color:#2c5282;margin:0 0 20px">New Contact Message</h2>
            <table cellpadding="10" cellspacing="0" style="width:100%;border-collapse:collapse;margin-bottom:24px">
              <tr style="background:#f8f9fa">
                <td style="font-weight:600;width:100px;border:1px solid #dee2e6;color:#495057">Name</td>
                <td style="border:1px solid #dee2e6">{req.Name}</td>
              </tr>
              <tr>
                <td style="font-weight:600;border:1px solid #dee2e6;color:#495057">Email</td>
                <td style="border:1px solid #dee2e6">{req.Email}</td>
              </tr>
              <tr style="background:#f8f9fa">
                <td style="font-weight:600;border:1px solid #dee2e6;color:#495057">Subject</td>
                <td style="border:1px solid #dee2e6">{req.Subject}</td>
              </tr>
            </table>
            <h3 style="color:#2c5282;border-bottom:2px solid #e9ecef;padding-bottom:6px">Message</h3>
            <p style="color:#495057;line-height:1.7;white-space:pre-wrap">{req.Message}</p>
            """;

        await _emailApi.SendAsync(new SendEmailRequest
        {
            To = [_contact.ToEmail],
            ReplyTo = req.Email,
            Subject = $"{_contact.SubjectPrefix} {req.Subject}".Trim(),
            HtmlBody = htmlBody
        }, ct);

        _log.LogInformation("Contact email sent successfully from {SenderEmail}", req.Email);
    }

    /// <inheritdoc />
    public async Task SendSubscribeAsync(SubscribeRequest req, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(_subscribe.ToEmail))
        {
            _log.LogDebug("Subscription email skipped - ToEmail not configured");
            throw new InvalidOperationException("Subscription email recipient is not configured.");
        }

        _log.LogInformation("Processing subscription request for {Email}", req.Email);

        var htmlBody = $"""
            <h2 style="color:#2c5282;margin:0 0 20px">New Subscription Request</h2>
            <p style="color:#495057">A new user has subscribed:</p>
            <table cellpadding="10" cellspacing="0" style="border-collapse:collapse;margin-top:12px">
              <tr style="background:#f8f9fa">
                <td style="font-weight:600;border:1px solid #dee2e6;color:#495057;padding:10px 16px">Email</td>
                <td style="border:1px solid #dee2e6;padding:10px 16px">{req.Email}</td>
              </tr>
            </table>
            """;

        await _emailApi.SendAsync(new SendEmailRequest
        {
            To = [_subscribe.ToEmail],
            ReplyTo = req.Email,
            Subject = _subscribe.SubjectPrefix.Trim(),
            HtmlBody = htmlBody
        }, ct);

        _log.LogInformation("Subscription email sent successfully for {Email}", req.Email);
    }

    /// <inheritdoc />
    public async Task SendFileDownloadNotificationAsync(string fileName, string? userIp, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(_fileStorage.ToEmail))
        {
            _log.LogDebug("File download notification skipped - ToEmail not configured");
            return;
        }

        _log.LogInformation("Preparing file download notification for {FileName}", fileName);

        var htmlBody = $"""
            <h2 style="color:#2c5282;margin:0 0 20px">File Download Notification</h2>
            <table cellpadding="10" cellspacing="0" style="width:100%;border-collapse:collapse">
              <tr style="background:#f8f9fa">
                <td style="font-weight:600;width:120px;border:1px solid #dee2e6;color:#495057">File</td>
                <td style="border:1px solid #dee2e6">{fileName}</td>
              </tr>
              <tr>
                <td style="font-weight:600;border:1px solid #dee2e6;color:#495057">Downloaded at</td>
                <td style="border:1px solid #dee2e6">{DateTime.UtcNow:yyyy-MM-dd HH:mm:ss} UTC</td>
              </tr>
              <tr style="background:#f8f9fa">
                <td style="font-weight:600;border:1px solid #dee2e6;color:#495057">IP Address</td>
                <td style="border:1px solid #dee2e6">{userIp ?? _emailTemplates.Get("email.notification.unknown-ip", "en")}</td>
              </tr>
            </table>
            """;

        await _emailApi.SendAsync(new SendEmailRequest
        {
            To = [_fileStorage.ToEmail],
            Subject = $"{_fileStorage.SubjectPrefix} {fileName}".Trim(),
            HtmlBody = htmlBody
        }, ct);

        _log.LogInformation("File download notification sent successfully for {FileName}", fileName);
    }

    /// <inheritdoc />
    public async Task SendMatchAsync(string? explicitTo, string subject, string body, string? attachmentPath, CancellationToken ct)
    {
        var operatorCopy = _emailTemplates.GetOperatorCopy("email.match.subject", "en");

        var recipients = new List<string>();
        if (!string.IsNullOrWhiteSpace(explicitTo))
            recipients.Add(explicitTo);

        if (!string.IsNullOrWhiteSpace(operatorCopy) &&
            !recipients.Any(x => string.Equals(x, operatorCopy, StringComparison.OrdinalIgnoreCase)))
            recipients.Add(operatorCopy);

        if (recipients.Count == 0)
        {
            _log.LogDebug("Match email skipped - no recipients configured");
            return;
        }

        string? relativeAttachment = null;
        if (!string.IsNullOrWhiteSpace(attachmentPath))
            relativeAttachment = Path.GetFileName(attachmentPath);

        foreach (var recipient in recipients)
        {
            _log.LogInformation("Preparing CV match email to {RecipientEmail}", recipient);

            await _emailApi.SendAsync(new SendEmailRequest
            {
                To = [recipient],
                Subject = subject,
                HtmlBody = body,
                AttachmentPath = relativeAttachment
            }, ct);

            _log.LogInformation("CV match email sent successfully to {RecipientEmail}", recipient);
        }
    }

    /// <inheritdoc />
    public string BuildMatchEmailBody(string cvDocumentId, JobMatchResponse result, string? jobLabel, string language, string? jobSearchLink = null, int expiryDays = 7)
    {
        // Build HTML lists for strengths, gaps, and recommendations
        var strengths = result.Strengths?.Count > 0
            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
              string.Join("", result.Strengths.Select(s => $"<li>{s}</li>")) + "</ul>"
            : "<p style=\"color:#6c757d;margin:0\">—</p>";

        var gaps = result.Gaps?.Count > 0
            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
              string.Join("", result.Gaps.Select(g => $"<li>{g}</li>")) + "</ul>"
            : "<p style=\"color:#6c757d;margin:0\">—</p>";

        var recommendations = result.Recommendations?.Count > 0
            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
              string.Join("", result.Recommendations.Select(r => $"<li>{r}</li>")) + "</ul>"
            : "<p style=\"color:#6c757d;margin:0\">—</p>";

        // Render the HTML template with substituted values
        // email.match.body is now stored as HTML in the database
        var body = _emailTemplates.Render("email.match.body", language,
            ("cvDocumentId", cvDocumentId),
            ("jobLabel", jobLabel ?? _emailTemplates.Get("email.match.fallback-na", language)),
            ("jobUrl", result.JobUrl ?? _emailTemplates.Get("email.match.fallback-na", language)),
            ("score", result.Score.ToString()),
            ("summary", WebUtility.HtmlEncode(result.Summary ?? string.Empty)),
            ("strengths", strengths),
            ("gaps", gaps),
            ("recommendations", recommendations));

        // Append the job search footer if link is provided
        if (!string.IsNullOrWhiteSpace(jobSearchLink))
        {
            body += _emailTemplates.Render("email.match.job-search-footer", language,
                ("jobSearchLink", jobSearchLink),
                ("expiryDays", expiryDays.ToString()));
        }

        return body;
    }

    /// <inheritdoc />
    public string BuildMatchEmailSubject(int score, string? jobLabel, string language) =>
        _emailTemplates.Render("email.match.subject", language,
            ("score", score.ToString()),
            ("jobLabel", jobLabel ?? _emailTemplates.Get("email.match.subject-fallback-label", language)));

    public string GetManualJobLabel(string language) =>
        _emailTemplates.Get("email.match.manual-job-label", language);
}