using System.Globalization;
using DevExpress.Office;
using DevExpress.XtraRichEdit;
using DevExpress.XtraRichEdit.API.Native;

namespace ROLAC.API.Services.Disbursement;

/// <summary>
/// Renders a check on 8.5"x11" stock using the DevExpress Office (RichEdit) API:
/// a check block on top followed by two identical ledger detail stubs. The layout is
/// built programmatically (no external .docx template) and exported to PDF.
/// </summary>
public class CheckPrintService : ICheckPrintService
{
    public Task<Stream> RenderPdfAsync(CheckPrintModel model)
    {
        using var server = new RichEditDocumentServer();
        var doc = server.Document;
        doc.BeginUpdate();
        try
        {
            doc.Unit = DocumentUnit.Inch;
            var section = doc.Sections[0];
            section.Page.Width  = 8.5f;
            section.Page.Height = 11f;
            section.Margins.Left = section.Margins.Right = 0.6f;
            section.Margins.Top = section.Margins.Bottom = 0.5f;

            BuildCheckBlock(doc, model);
            BuildStub(doc, model, "PAYMENT ADVICE — DETAIL");
            BuildStub(doc, model, "PAYMENT ADVICE — RECORD COPY");
        }
        finally
        {
            doc.EndUpdate();
        }

        var ms = new MemoryStream();
        server.ExportToPdf(ms);
        ms.Position = 0;
        return Task.FromResult<Stream>(ms);
    }

    public Task<Stream> RenderReceiptPdfAsync(CheckPrintModel model)
    {
        using var server = new RichEditDocumentServer();
        var document = server.Document;
        document.BeginUpdate();
        try
        {
            document.Unit = DocumentUnit.Inch;
            var section = document.Sections[0];
            section.Page.Width = 8.5f;
            section.Page.Height = 11f;
            section.Margins.Left = section.Margins.Right = 0.8f;
            section.Margins.Top = section.Margins.Bottom = 0.8f;

            document.AppendHtmlText(BuildReceiptHtml(model));
        }
        finally
        {
            document.EndUpdate();
        }

        var stream = new MemoryStream();
        server.ExportToPdf(stream);
        stream.Position = 0;
        return Task.FromResult<Stream>(stream);
    }

    private static string BuildReceiptHtml(CheckPrintModel model)
    {
        var issuer = model.Issuer;
        var check = model.Check;

        var issuerAddress = Encode(JoinAddress(issuer.Address, issuer.City, issuer.State, issuer.ZipCode));
        var payeeAddress = Encode(JoinAddress(check.PayeeAddress, check.PayeeCity, check.PayeeState, check.PayeeZip));

        var detailRows = new System.Text.StringBuilder();
        foreach (var line in model.Lines)
        {
            var date = line.Expense?.ExpenseDate.ToString("MM/dd/yyyy") ?? "";
            detailRows.Append(
                "<tr>" +
                $"<td>{Encode(date)}</td>" +
                $"<td>{Encode(line.Description)}</td>" +
                $"<td align=\"right\">{Encode(FormatCurrency(line.Amount))}</td>" +
                "</tr>");
        }

        var signedOn = check.ReceiptSignedAt.HasValue
            ? check.ReceiptSignedAt.Value.ToLocalTime().ToString("MM/dd/yyyy HH:mm")
            : "";

        var signatureBlock = "";
        if (model.SignatureImage is { Length: > 0 })
        {
            var base64 = Convert.ToBase64String(model.SignatureImage);
            signatureBlock =
                $"<p><img src=\"data:{model.SignatureContentType};base64,{base64}\" width=\"260\" /></p>";
        }

        return
            "<div style=\"font-family:Arial;font-size:11pt;color:#111;\">" +
            "<h2 style=\"text-align:center;margin:0;\">Disbursement Receipt / 簽收收據</h2>" +
            $"<p style=\"text-align:center;margin:4px 0 16px 0;\"><b>{Encode(issuer.Name)}</b><br/>{issuerAddress}</p>" +

            "<h3 style=\"margin:8px 0;\">Check Information / 支票資訊</h3>" +
            "<table border=\"1\" cellspacing=\"0\" cellpadding=\"5\" width=\"100%\" style=\"border-collapse:collapse;\">" +
            $"<tr><td width=\"22%\"><b>Check No. / 支票號碼</b></td><td width=\"28%\">{Encode(check.CheckNumber)}</td>" +
            $"<td width=\"22%\"><b>Date / 日期</b></td><td width=\"28%\">{check.CheckDate:MM/dd/yyyy}</td></tr>" +
            $"<tr><td><b>Payee / 收款人</b></td><td colspan=\"3\">{Encode(check.PayeeName)} {payeeAddress}</td></tr>" +
            $"<tr><td><b>Amount / 金額</b></td><td colspan=\"3\">{Encode(FormatCurrency(check.Amount))} &mdash; {Encode(model.AmountInWords)}</td></tr>" +
            $"<tr><td><b>Memo / 摘要</b></td><td colspan=\"3\">{Encode(check.Memo ?? "")}</td></tr>" +
            "</table>" +

            "<h3 style=\"margin:16px 0 8px 0;\">Disbursement Detail / 撥款明細</h3>" +
            "<table border=\"1\" cellspacing=\"0\" cellpadding=\"5\" width=\"100%\" style=\"border-collapse:collapse;\">" +
            "<tr><th align=\"left\">Date / 日期</th><th align=\"left\">Description / 說明</th><th align=\"right\">Amount / 金額</th></tr>" +
            detailRows +
            $"<tr><td></td><td align=\"right\"><b>TOTAL / 合計</b></td><td align=\"right\"><b>{Encode(FormatCurrency(check.Amount))}</b></td></tr>" +
            "</table>" +

            "<h3 style=\"margin:16px 0 8px 0;\">Acknowledgement of Receipt / 收款簽收</h3>" +
            "<p>I acknowledge receipt of the above payment in full. / 本人確認已如數收到上述款項。</p>" +
            $"<p><b>Received by / 簽收人:</b> {Encode(check.ReceiptSignedName ?? "")}<br/>" +
            $"<b>Date / 簽收日期:</b> {Encode(signedOn)}</p>" +
            signatureBlock +
            "</div>";
    }

    private static string Encode(string? text) => System.Net.WebUtility.HtmlEncode(text ?? "");

    private static void BuildCheckBlock(Document doc, CheckPrintModel m)
    {
        var issuer = m.Issuer;
        var check  = m.Check;

        AppendLine(doc, issuer.Name, bold: true, size: 13);
        var issuerAddr = JoinAddress(issuer.Address, issuer.City, issuer.State, issuer.ZipCode);
        if (!string.IsNullOrWhiteSpace(issuerAddr)) AppendLine(doc, issuerAddr, size: 9);
        if (!string.IsNullOrWhiteSpace(issuer.BankName)) AppendLine(doc, issuer.BankName, size: 9);

        AppendLine(doc, "");
        AppendLine(doc, $"Check No: {check.CheckNumber}        Date: {check.CheckDate:MM/dd/yyyy}", bold: true, size: 10);
        AppendLine(doc, "");

        AppendLine(doc, $"PAY TO THE ORDER OF:  {check.PayeeName}", bold: true, size: 11);
        var payeeAddr = JoinAddress(check.PayeeAddress, check.PayeeCity, check.PayeeState, check.PayeeZip);
        if (!string.IsNullOrWhiteSpace(payeeAddr)) AppendLine(doc, payeeAddr, size: 9);

        AppendLine(doc, "");
        AppendLine(doc, $"AMOUNT:  {FormatCurrency(check.Amount)}", bold: true, size: 12);
        AppendLine(doc, m.AmountInWords, size: 10);

        if (!string.IsNullOrWhiteSpace(check.Memo)) { AppendLine(doc, ""); AppendLine(doc, $"Memo: {check.Memo}", size: 9); }

        AppendLine(doc, "");
        AppendLine(doc, "____________________________________", size: 10);
        AppendLine(doc, "Authorized Signature", size: 8);
        AppendSeparator(doc);
    }

    private static void BuildStub(Document doc, CheckPrintModel m, string title)
    {
        var check = m.Check;
        AppendLine(doc, title, bold: true, size: 10);
        AppendLine(doc, $"Check No: {check.CheckNumber}    Date: {check.CheckDate:MM/dd/yyyy}    Payee: {check.PayeeName}", size: 9);
        AppendLine(doc, "");

        var rows = m.Lines.Count + 2; // header + lines + total
        var table = doc.Tables.Create(doc.Range.End, rows, 3, AutoFitBehaviorType.AutoFitToWindow);
        table.Borders.InsideHorizontalBorder.LineStyle = TableBorderLineStyle.Single;
        table.Borders.Top.LineStyle = table.Borders.Bottom.LineStyle = TableBorderLineStyle.Single;

        SetCell(doc, table[0, 0], "Date", bold: true);
        SetCell(doc, table[0, 1], "Description", bold: true);
        SetCell(doc, table[0, 2], "Amount", bold: true, right: true);

        for (var i = 0; i < m.Lines.Count; i++)
        {
            var line = m.Lines[i];
            var r = i + 1;
            // CheckLine snapshots description; date comes from the source expense if loaded.
            var date = line.Expense?.ExpenseDate.ToString("MM/dd/yyyy") ?? "";
            SetCell(doc, table[r, 0], date);
            SetCell(doc, table[r, 1], line.Description);
            SetCell(doc, table[r, 2], FormatCurrency(line.Amount), right: true);
        }

        var totalRow = rows - 1;
        SetCell(doc, table[totalRow, 0], "");
        SetCell(doc, table[totalRow, 1], "TOTAL", bold: true, right: true);
        SetCell(doc, table[totalRow, 2], FormatCurrency(check.Amount), bold: true, right: true);

        AppendLine(doc, "");
        if (check.ReceiptSignedAt is { } signedAt)
            AppendLine(doc, $"Received by: {check.ReceiptSignedName}    on {signedAt:MM/dd/yyyy HH:mm}", size: 9);
        AppendSeparator(doc);
    }

    // ── low-level helpers ──────────────────────────────────────────────────────

    private static void AppendLine(Document doc, string text, bool bold = false, float size = 10)
    {
        var range = doc.AppendText(text + "\r\n");
        var cp = doc.BeginUpdateCharacters(range);
        cp.Bold = bold;
        cp.FontSize = size;
        doc.EndUpdateCharacters(cp);
    }

    private static void AppendSeparator(Document doc)
    {
        AppendLine(doc, "");
        AppendLine(doc, "------------------------------------------------------------------------------------------", size: 8);
        AppendLine(doc, "");
    }

    private static void SetCell(Document doc, TableCell cell, string text, bool bold = false, bool right = false)
    {
        var range = doc.InsertText(cell.ContentRange.Start, text);
        var cp = doc.BeginUpdateCharacters(range);
        cp.Bold = bold;
        cp.FontSize = 9;
        doc.EndUpdateCharacters(cp);
        if (right)
        {
            var pp = doc.BeginUpdateParagraphs(range);
            pp.Alignment = ParagraphAlignment.Right;
            doc.EndUpdateParagraphs(pp);
        }
    }

    private static string FormatCurrency(decimal amount) =>
        amount.ToString("C2", CultureInfo.GetCultureInfo("en-US"));

    private static string JoinAddress(string? addr, string? city, string? state, string? zip)
    {
        var cityLine = string.Join(", ",
            new[] { city, string.Join(" ", new[] { state, zip }.Where(s => !string.IsNullOrWhiteSpace(s))) }
            .Where(s => !string.IsNullOrWhiteSpace(s)));
        return string.Join("  ", new[] { addr, cityLine }.Where(s => !string.IsNullOrWhiteSpace(s)));
    }
}