using System;
using System.Windows.Forms;
using BulkArchiveMailer.Core;
using Outlook = Microsoft.Office.Interop.Outlook;

namespace BulkArchiveMailer.AddIn.UI
{
    /// <summary>
    /// Archive folder, email domain, signature override, test-mode default,
    /// and the two editable mail templates. Saves straight to
    /// %APPDATA%\BulkArchiveMailer\config.json via AppSettings.
    /// </summary>
    public partial class SettingsForm : Form
    {
        private readonly Outlook.Application outlookApplication;

        public SettingsForm(Outlook.Application outlookApplication)
        {
            InitializeComponent();
            this.outlookApplication = outlookApplication;
            Load += SettingsForm_Load;
        }

        private void SettingsForm_Load(object sender, EventArgs e)
        {
            AppSettingsData settings;
            try
            {
                settings = AppSettings.Load();
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "Не удалось прочитать config.json (" + AppSettings.ConfigFilePath + "):\n" + ex.ToString() +
                    "\n\nБудут показаны пустые настройки — сохранение перезапишет файл заново.",
                    "BulkArchiveMailer",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Warning);
                settings = new AppSettingsData();
            }

            PopulateFrom(settings);
        }

        /// <summary>ComboBox item: displays a friendly label but carries the SmtpAddress that actually gets saved to config.json. The first item (SmtpAddress == "") represents "let Outlook pick its default account".</summary>
        private sealed class FromAccountItem
        {
            public string Label { get; set; } = "";
            public string SmtpAddress { get; set; } = "";
            public override string ToString() => Label;
        }

        private const string DefaultAccountLabel = "(по умолчанию Outlook)";

        private void PopulateFrom(AppSettingsData settings)
        {
            txtArchiveFolder.Text = settings.ArchiveFolder ?? "";
            txtDomain.Text = settings.EmailDomain ?? "";
            txtSignaturePath.Text = settings.SignatureHtmlPath ?? "";
            chkTestModeDefault.Checked = settings.TestModeDefault;

            PopulateFromAccountCombo(settings.FromAccountSmtpAddress ?? "");

            var templates = settings.ToTemplateSet();
            txtSshSubject.Text = templates.SshAccess.Subject;
            txtSshBody.Text = templates.SshAccess.BodyHtml;
            txtCfgSubject.Text = templates.ConfigUpdate.Subject;
            txtCfgBody.Text = templates.ConfigUpdate.BodyHtml;
        }

        /// <summary>
        /// Fills cboFromAccount with "(по умолчанию Outlook)" plus one
        /// entry per real Outlook.Account in the current session, then
        /// selects the item matching savedSmtpAddress. If that address no
        /// longer belongs to any account in this session (removed/renamed
        /// since it was configured, or Outlook.Application is unavailable
        /// e.g. under a design-time host), it just falls back to the
        /// default item instead of throwing - never blocks opening the
        /// Settings window over this.
        /// </summary>
        private void PopulateFromAccountCombo(string savedSmtpAddress)
        {
            cboFromAccount.Items.Clear();
            cboFromAccount.Items.Add(new FromAccountItem { Label = DefaultAccountLabel, SmtpAddress = "" });

            if (outlookApplication != null)
            {
                foreach (var account in OutlookAccounts.ListAccounts(outlookApplication))
                {
                    var label = string.IsNullOrEmpty(account.SmtpAddress)
                        ? account.DisplayName
                        : account.DisplayName + " <" + account.SmtpAddress + ">";
                    cboFromAccount.Items.Add(new FromAccountItem { Label = label, SmtpAddress = account.SmtpAddress });
                }
            }

            var selectedIndex = 0;
            if (!string.IsNullOrEmpty(savedSmtpAddress))
            {
                for (var i = 0; i < cboFromAccount.Items.Count; i++)
                {
                    var item = (FromAccountItem)cboFromAccount.Items[i];
                    if (string.Equals(item.SmtpAddress, savedSmtpAddress, StringComparison.OrdinalIgnoreCase))
                    {
                        selectedIndex = i;
                        break;
                    }
                }
            }

            cboFromAccount.SelectedIndex = selectedIndex;
        }

        private void btnBrowseFolder_Click(object sender, EventArgs e)
        {
            using (var dialog = new FolderBrowserDialog())
            {
                dialog.Description = "Папка с архивами, которые ssh-access-tui выкладывает для рассылки";
                if (System.IO.Directory.Exists(txtArchiveFolder.Text))
                {
                    dialog.SelectedPath = txtArchiveFolder.Text;
                }

                if (dialog.ShowDialog(this) == DialogResult.OK)
                {
                    txtArchiveFolder.Text = dialog.SelectedPath;
                }
            }
        }

        private void btnBrowseSignature_Click(object sender, EventArgs e)
        {
            using (var dialog = new OpenFileDialog())
            {
                dialog.Title = "Выберите файл подписи";
                dialog.Filter = "HTML-подпись (*.htm;*.html)|*.htm;*.html|Все файлы (*.*)|*.*";
                if (dialog.ShowDialog(this) == DialogResult.OK)
                {
                    txtSignaturePath.Text = dialog.FileName;
                }
            }
        }

        private void btnAutoDetectSignature_Click(object sender, EventArgs e)
        {
            if (outlookApplication == null)
            {
                MessageBox.Show(this, "Outlook.Application недоступен в этом окне.", "BulkArchiveMailer", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            var path = SignatureReader.TryAutoDetectSignaturePath(outlookApplication);
            if (string.IsNullOrEmpty(path))
            {
                MessageBox.Show(
                    this,
                    "Не удалось определить подпись автоматически (не настроена подпись по умолчанию для новых писем, либо файл не найден). Выберите файл вручную кнопкой \"Обзор...\".",
                    "BulkArchiveMailer",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Information);
                return;
            }

            txtSignaturePath.Text = path;
        }

        private void btnResetDefaults_Click(object sender, EventArgs e)
        {
            var confirm = MessageBox.Show(
                this,
                "Заменить домен и оба шаблона писем значениями по умолчанию? Папка с архивами и файл подписи не изменятся. Несохранённые правки в этом окне будут потеряны.",
                "Подтверждение",
                MessageBoxButtons.YesNo,
                MessageBoxIcon.Question);
            if (confirm != DialogResult.Yes)
            {
                return;
            }

            var defaults = AppSettings.LoadDefaults();
            txtDomain.Text = defaults.EmailDomain;

            var templates = defaults.ToTemplateSet();
            txtSshSubject.Text = templates.SshAccess.Subject;
            txtSshBody.Text = templates.SshAccess.BodyHtml;
            txtCfgSubject.Text = templates.ConfigUpdate.Subject;
            txtCfgBody.Text = templates.ConfigUpdate.BodyHtml;
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrWhiteSpace(txtDomain.Text))
            {
                MessageBox.Show(this, "Домен электронной почты не может быть пустым.", "BulkArchiveMailer", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                tabControl.SelectedTab = tabGeneral;
                txtDomain.Focus();
                return;
            }

            if (!string.IsNullOrWhiteSpace(txtArchiveFolder.Text) && !System.IO.Directory.Exists(txtArchiveFolder.Text))
            {
                var proceed = MessageBox.Show(
                    this,
                    "Указанная папка с архивами не существует:\n" + txtArchiveFolder.Text + "\n\nВсё равно сохранить?",
                    "BulkArchiveMailer",
                    MessageBoxButtons.YesNo,
                    MessageBoxIcon.Warning);
                if (proceed != DialogResult.Yes)
                {
                    tabControl.SelectedTab = tabGeneral;
                    return;
                }
            }

            var selectedAccount = cboFromAccount.SelectedItem as FromAccountItem;

            var data = new AppSettingsData
            {
                ArchiveFolder = txtArchiveFolder.Text.Trim(),
                EmailDomain = txtDomain.Text.Trim(),
                SignatureHtmlPath = txtSignaturePath.Text.Trim(),
                TestModeDefault = chkTestModeDefault.Checked,
                FromAccountSmtpAddress = selectedAccount?.SmtpAddress ?? "",
            };
            data.SetTemplate(ArchiveKind.SshAccess, new MailTemplate { Subject = txtSshSubject.Text, BodyHtml = txtSshBody.Text });
            data.SetTemplate(ArchiveKind.ConfigUpdate, new MailTemplate { Subject = txtCfgSubject.Text, BodyHtml = txtCfgBody.Text });

            try
            {
                AppSettings.Save(data);
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, "Не удалось сохранить настройки: " + ex.ToString(), "BulkArchiveMailer", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            DialogResult = DialogResult.OK;
            Close();
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
            Close();
        }
    }
}