better domain isolation

README.md

@@ -23,6 +23,8 @@ go install github.com/nmoniz/any2anexoj/cmd/any2anexoj-cli@latest
 cat statement.csv | any2anexoj-cli --platform=tranding212
 ```
 
+Pass `--format html` to emit a complete, standalone Bootstrap-styled HTML report (a `<!DOCTYPE html>` document with the Anexo J table embedded and Bootstrap loaded via CDN); the default `--format table` prints the pretty terminal table and `--format csv` writes the Anexo J CSV schema.
+
 ### Incremental Reports
 
 For year over year reporting, pass `--state-file <path>` to keep the FIFO buy-queue between runs. The typical workflow is:
@@ -53,3 +55,40 @@ State is only persisted once the input reaches EOF, so a crash or `Ctrl-C` befor
 All Euro values are rounded to cents (2 decimal places) but internal calculations use the statement values with full precision.
 There are no explicit rules or details about how to round Euro values in Anexo J.
 This application rounds according to `Portaria n.º 1180/2001, art. 2.º, alínea c) e d)` (Ministerial Order / Government Order) examples, which imply we should round to the 2nd decimal place by rounding up (ceiling) or down (floor) depending on whether the third decimal place is ≥ 5 or < 5, respectively.
+
+## Web app
+
+A minimal single-user web frontend is bundled in the `cmd/any2anexoj-web` binary. It reuses the existing `internal/trading212` parser, the `internal.BuildReport` pipeline, and the `internal/prettyprinter` formatter, so the rendered table is byte-for-byte identical to the CLI output.
+
+### Run
+
+```bash
+go run ./cmd/any2anexoj-web
+```
+
+The server listens on `:8080` by default. Override the port with the `PORT` environment variable:
+
+```bash
+PORT=9000 go run ./cmd/any2anexoj-web
+```
+
+Then open <http://localhost:8080> in a browser, pick a Trading212 CSV file, and click **Upload**. The rendered Anexo J table appears below the form along with the row count.
+
+### API
+
+The web app exposes two JSON endpoints. Auth is intentionally stubbed (a no-op middleware), and state is kept in process memory only — single user, no persistence.
+
+| Method | Path           | Description                                                                                       |
+|--------|----------------|---------------------------------------------------------------------------------------------------|
+| POST   | `/api/upload`  | `multipart/form-data` with a `csv` file field. Returns `{"table": "<rendered>", "rows": <int>}`. |
+| GET    | `/api/table`   | Returns the most recently rendered table (`{"table": "", "rows": 0}` if none uploaded yet).       |
+
+Example:
+
+```bash
+curl -F csv=@trading212-small.csv http://localhost:8080/api/upload
+curl http://localhost:8080/api/table
+```
+
+> [!NOTE]
+> The web app is single-user and in-memory. Uploads overwrite the previously stored table, and restarting the server clears all state. Auth is a stub — do not expose this service to the public internet without adding real authentication and per-user state first.

cmd/any2anexoj-cli/main.go

@@ -13,6 +13,10 @@ import (
 	"github.com/nmoniz/any2anexoj/internal"
 	"github.com/nmoniz/any2anexoj/internal/ofigi"
 	"github.com/nmoniz/any2anexoj/internal/trading212"
+	"github.com/nmoniz/any2anexoj/internal/writing"
+	"github.com/nmoniz/any2anexoj/internal/writing/csv"
+	htmlwriter "github.com/nmoniz/any2anexoj/internal/writing/html"
+	"github.com/nmoniz/any2anexoj/internal/writing/table"
 	"github.com/spf13/pflag"
 	"golang.org/x/text/language"
 )
@@ -23,7 +27,7 @@ var (
 	platform  = pflag.StringP("platform", "p", "trading212", "One of the supported platforms")
 	lang      = pflag.StringP("language", "l", language.Portuguese.String(), "The 2 letter language code")
 	debug     = pflag.BoolP("debug", "d", false, "Activate to log debug messages")
-	format    = pflag.StringP("format", "f", "table", "Output format: table or csv")
+	format    = pflag.StringP("format", "f", "table", "Output format: table, csv or html")
 	ofAPIKey  = pflag.String("open-figi-api-key", "", "An OpenFIGI API key for faster report generation (better rate api rate limits)")
 	selectors = pflag.StringSlice("selectors", nil, "Only process entries that conform to all the selectors: code, assetCountry")
 	stateFile = pflag.String("state-file", "", "Path to a state file for incremental processing")
@@ -98,16 +102,22 @@ func runWithIO(ctx context.Context, stdin io.Reader, stdout io.Writer) error {
 
 	switch *format {
 	case "csv":
-		return NewCSVWriter(stdout).Render(writer)
+		return csv.NewWriter(stdout).Render(writer)
 	case "table":
-		loc, err := NewLocalizer(*lang)
+		loc, err := writing.NewLocalizer(*lang)
 		if err != nil {
 			return fmt.Errorf("create localizer: %w", err)
 		}
-		NewPrettyPrinter(stdout, loc).Render(writer)
+		table.NewPrinter(stdout, loc).Render(writer)
 		return nil
+	case "html":
+		loc, err := writing.NewLocalizer(*lang)
+		if err != nil {
+			return fmt.Errorf("create localizer: %w", err)
+		}
+		return htmlwriter.NewWriter(stdout, loc, *lang).Render(writer)
 	default:
-		return fmt.Errorf("unsupported format %q: must be table or csv", *format)
+		return fmt.Errorf("unsupported format %q: must be table, csv or html", *format)
 	}
 }
 

cmd/any2anexoj-cli/main_test.go

@@ -139,6 +139,40 @@ func TestRunWithIO_NoStateFileByDefault(t *testing.T) {
 	}
 }
 
+// TestRunWithIO_HTMLFormat verifies that --format html produces a complete
+// HTML document on stdout starting with the DOCTYPE declaration.
+func TestRunWithIO_HTMLFormat(t *testing.T) {
+	resetFlags(t)
+	t.Cleanup(func() { resetFlags(t) })
+
+	if err := pflag.Set("format", "html"); err != nil {
+		t.Fatalf("set format flag: %v", err)
+	}
+
+	var stdout bytes.Buffer
+	if err := runWithStdin(t, trading212SampleCSV, &stdout); err != nil {
+		t.Fatalf("runWithIO returned an error: %v\nstdout: %s", err, stdout.String())
+	}
+
+	got := stdout.String()
+	if !strings.HasPrefix(got, "<!DOCTYPE html>") {
+		t.Errorf("expected HTML output to start with <!DOCTYPE html>; got prefix: %q",
+			got[:min(len(got), 64)])
+	}
+	if !strings.Contains(got, "<h1>Tax report</h1>") {
+		t.Errorf("expected output to contain the translated report title")
+	}
+	if !strings.Contains(got, "table-responsive") {
+		t.Errorf("expected output to contain Bootstrap table-responsive wrapper")
+	}
+	if !strings.Contains(got, "table-striped") {
+		t.Errorf("expected output to contain Bootstrap table-striped class")
+	}
+	if !strings.Contains(got, "</html>") {
+		t.Errorf("expected output to end with </html>")
+	}
+}
+
 // TestRunWithIO_UnsupportedPlatformForPersistence verifies that using
 // --state-file with an unknown platform surfaces a clear error rather than
 // silently falling back to EphemeralStore.

cmd/any2anexoj-cli/pretty_printer.go

@@ -1,122 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"io"
-
-	"github.com/biter777/countries"
-	"github.com/jedib0t/go-pretty/v6/table"
-	"github.com/jedib0t/go-pretty/v6/text"
-	"github.com/nmoniz/any2anexoj/internal"
-)
-
-// PrettyPrinter writes a simple, human readable, table row to the provided io.Writer for each
-// ReportItem received.
-type PrettyPrinter struct {
-	table      table.Writer
-	output     io.Writer
-	translator Translator
-}
-
-type Translator interface {
-	Translate(key string, count int, values map[string]any) string
-}
-
-func NewPrettyPrinter(w io.Writer, tr Translator) *PrettyPrinter {
-	tw := table.NewWriter()
-	tw.SetOutputMirror(w)
-	tw.SetAutoIndex(true)
-	tw.SetStyle(table.StyleLight)
-	tw.SetColumnConfigs([]table.ColumnConfig{
-		colCountry(1),
-		colOther(2),
-		colOther(3),
-		colOther(4),
-		colOther(5),
-		colEuros(6),
-		colOther(7),
-		colOther(8),
-		colOther(9),
-		colEuros(10),
-		colEuros(11),
-		colEuros(12),
-		colCountry(13),
-	})
-
-	return &PrettyPrinter{
-		table:      tw,
-		output:     w,
-		translator: tr,
-	}
-}
-
-func (pp *PrettyPrinter) Render(aw *internal.AggregatorWriter) {
-	realizationTxt := pp.translator.Translate("realization", 1, nil)
-	acquisitionTxt := pp.translator.Translate("acquisition", 1, nil)
-	yearTxt := pp.translator.Translate("year", 1, nil)
-	monthTxt := pp.translator.Translate("month", 1, nil)
-	dayTxt := pp.translator.Translate("day", 1, nil)
-	valorTxt := pp.translator.Translate("value", 1, nil)
-
-	pp.table.AppendHeader(table.Row{"", "", realizationTxt, realizationTxt, realizationTxt, realizationTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, "", "", ""}, table.RowConfig{AutoMerge: true})
-	pp.table.AppendHeader(table.Row{
-		pp.translator.Translate("source_country", 1, nil), pp.translator.Translate("code", 1, nil),
-		yearTxt, monthTxt, dayTxt, valorTxt,
-		yearTxt, monthTxt, dayTxt, valorTxt,
-		pp.translator.Translate("expenses", 2, nil), pp.translator.Translate("foreign_tax_paid", 1, nil), pp.translator.Translate("counter_country", 1, nil),
-	})
-
-	for ri := range aw.Iter() {
-		pp.table.AppendRow(table.Row{
-			ri.AssetCountry, ri.Nature,
-			ri.SellTimestamp.Year(), int(ri.SellTimestamp.Month()), ri.SellTimestamp.Day(), ri.SellValue.StringFixed(2),
-			ri.BuyTimestamp.Year(), int(ri.BuyTimestamp.Month()), ri.BuyTimestamp.Day(), ri.BuyValue.StringFixed(2),
-			ri.Fees.StringFixed(2), ri.Taxes.StringFixed(2), ri.BrokerCountry,
-		})
-	}
-
-	pp.table.AppendFooter(table.Row{"SUM", "SUM", "SUM", "SUM", "SUM", aw.TotalEarned(), "", "", "", aw.TotalSpent(), aw.TotalFees(), aw.TotalTaxes()}, table.RowConfig{AutoMerge: true, AutoMergeAlign: text.AlignRight})
-	pp.table.Render()
-}
-
-func colEuros(n int) table.ColumnConfig {
-	return table.ColumnConfig{
-		Number:      n,
-		Align:       text.AlignRight,
-		AlignFooter: text.AlignRight,
-		AlignHeader: text.AlignRight,
-		WidthMin:    12,
-		WidthMax:    15,
-		Transformer: func(val any) string {
-			return fmt.Sprintf("%v €", val)
-		},
-		TransformerFooter: func(val any) string {
-			return fmt.Sprintf("%v €", val)
-		},
-	}
-}
-
-func colOther(n int) table.ColumnConfig {
-	return table.ColumnConfig{
-		Number:      n,
-		Align:       text.AlignLeft,
-		AlignFooter: text.AlignLeft,
-		AlignHeader: text.AlignLeft,
-		WidthMax:    12,
-	}
-}
-
-func colCountry(n int) table.ColumnConfig {
-	return table.ColumnConfig{
-		Number:           n,
-		Align:            text.AlignLeft,
-		AlignFooter:      text.AlignLeft,
-		AlignHeader:      text.AlignLeft,
-		WidthMax:         24,
-		WidthMaxEnforcer: text.Trim,
-		Transformer: func(val any) string {
-			countryCode := val.(int64)
-			return fmt.Sprintf("%v - %s", val, countries.ByNumeric(int(countryCode)).Info().Name)
-		},
-	}
-}

cmd/any2anexoj-web/main.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"embed"
+	"errors"
+	"io/fs"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/nmoniz/any2anexoj/internal/web"
+	"golang.org/x/sync/errgroup"
+)
+
+//go:embed all:static
+var staticFS embed.FS
+
+func main() {
+	if err := run(); err != nil {
+		slog.Error("any2anexoj-web: fatal error", slog.Any("err", err))
+		os.Exit(1)
+	}
+	slog.Info("shutdown gracefully")
+}
+
+// run wires up the server, installs signal-driven cancellation, and blocks on
+// the HTTP server until it stops. It is split out from main so tests can drive
+// the same code paths if needed.
+func run() error {
+	addr := os.Getenv("PORT")
+	if addr == "" {
+		addr = ":8080"
+	}
+	// A bare "8080" value is friendlier than the net.Listen-style ":8080".
+	if addr[0] != ':' {
+		addr = ":" + addr
+	}
+
+	// Sub-mount the embedded FS so the static subtree is rooted at "" inside
+	// the web package (matches /static/...).
+	staticSub, err := fs.Sub(staticFS, "static")
+	if err != nil {
+		return err
+	}
+
+	state := web.NewState()
+	srv, err := web.NewServer(state, staticSub)
+	if err != nil {
+		return err
+	}
+
+	httpServer := &http.Server{
+		Addr:              addr,
+		Handler:           srv.Handler(),
+		ReadHeaderTimeout: 10 * time.Second,
+	}
+
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Kill, os.Interrupt, syscall.SIGTERM)
+	defer cancel()
+
+	eg, ctx := errgroup.WithContext(ctx)
+
+	eg.Go(func() error {
+		slog.Info("listening for http", slog.Any("port", addr))
+		err := httpServer.ListenAndServe()
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			return err
+		}
+		return nil
+	})
+
+	eg.Go(func() error {
+		<-ctx.Done()
+
+		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer shutdownCancel()
+
+		if err := httpServer.Shutdown(shutdownCtx); err != nil {
+			return err
+		}
+		return nil
+	})
+
+	return eg.Wait()
+}

cmd/any2anexoj-web/static/app.js

@@ -0,0 +1,108 @@
+(function () {
+  "use strict";
+
+  var UPLOAD_URL = "/api/upload";
+
+  function $(id) {
+    return document.getElementById(id);
+  }
+
+  function setStatus(message) {
+    var status = $("status");
+    status.textContent = message || "";
+  }
+
+  function setError(message) {
+    var error = $("error");
+    error.textContent = message || "";
+  }
+
+  function clearResult() {
+    var result = $("result");
+    var rowsInfo = $("rows-info");
+    var tableOutput = $("table-output");
+    rowsInfo.textContent = "";
+    tableOutput.textContent = "";
+    result.hidden = true;
+  }
+
+  function showResult(rows, table) {
+    var result = $("result");
+    var rowsInfo = $("rows-info");
+    var tableOutput = $("table-output");
+    rowsInfo.textContent = "Rows: " + rows;
+    tableOutput.textContent = table || "";
+    result.hidden = false;
+  }
+
+  function uploadFile(file) {
+    var formData = new FormData();
+    formData.append("csv", file);
+
+    return fetch(UPLOAD_URL, {
+      method: "POST",
+      body: formData
+    }).then(function (response) {
+      return response.json().then(function (data) {
+        return { ok: response.ok, status: response.status, data: data };
+      });
+    });
+  }
+
+  function handleSubmit(event) {
+    event.preventDefault();
+
+    setError("");
+    clearResult();
+
+    var fileInput = $("csv");
+    if (!fileInput.files || fileInput.files.length === 0) {
+      setError("Please choose a CSV file before uploading.");
+      return;
+    }
+
+    var file = fileInput.files[0];
+    var button = $("upload-button");
+    button.disabled = true;
+    setStatus("Uploading " + file.name + "...");
+
+    uploadFile(file).then(function (result) {
+      button.disabled = false;
+
+      if (!result.ok) {
+        setStatus("");
+        var serverMsg = result.data && result.data.error ? result.data.error : "";
+        var msg = "Upload failed (HTTP " + result.status + ").";
+        if (serverMsg) {
+          msg += " " + serverMsg;
+        }
+        setError(msg);
+        return;
+      }
+
+      if (result.data && typeof result.data.error === "string" && result.data.error.length > 0) {
+        setStatus("");
+        setError(result.data.error);
+        return;
+      }
+
+      var table = result.data && typeof result.data.table === "string" ? result.data.table : "";
+      var rows = result.data && typeof result.data.rows === "number" ? result.data.rows : 0;
+
+      setStatus("Upload complete.");
+      showResult(rows, table);
+    }).catch(function (err) {
+      button.disabled = false;
+      setStatus("");
+      var msg = err && err.message ? err.message : String(err);
+      setError("Network error while uploading: " + msg);
+    });
+  }
+
+  document.addEventListener("DOMContentLoaded", function () {
+    var form = $("upload-form");
+    if (form) {
+      form.addEventListener("submit", handleSubmit);
+    }
+  });
+})();

cmd/any2anexoj-web/static/index.html

@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>any2anexoj web</title>
+  <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+  <main class="container">
+    <h1>any2anexoj web</h1>
+    <p class="lede">Upload a Trading212-style CSV and view the rendered tax report.</p>
+
+    <form id="upload-form" class="upload-form" novalidate>
+      <label class="file-label" for="csv">Choose CSV file</label>
+      <input type="file" id="csv" name="csv" accept=".csv,text/csv">
+
+      <button type="submit" id="upload-button">Upload</button>
+    </form>
+
+    <div id="status" class="status" role="status" aria-live="polite"></div>
+    <div id="error" class="error" role="alert" aria-live="assertive"></div>
+
+    <section id="result" class="result" hidden>
+      <h2 id="result-heading">Result</h2>
+      <p id="rows-info" class="rows-info"></p>
+      <pre id="table-output" class="table-output"></pre>
+    </section>
+  </main>
+
+  <script src="/static/app.js" defer></script>
+</body>
+</html>

cmd/any2anexoj-web/static/style.css

@@ -0,0 +1,168 @@
+:root {
+  --bg: #fafafa;
+  --fg: #1f2328;
+  --muted: #57606a;
+  --accent: #0969da;
+  --accent-hover: #0860c7;
+  --border: #d0d7de;
+  --error-bg: #ffebe9;
+  --error-fg: #82071e;
+  --status-fg: #1f2328;
+  --code-bg: #f6f8fa;
+  --code-fg: #1f2328;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+html,
+body {
+  margin: 0;
+  padding: 0;
+  background-color: var(--bg);
+  color: var(--fg);
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+    "Helvetica Neue", Arial, sans-serif;
+  font-size: 16px;
+  line-height: 1.5;
+}
+
+.container {
+  max-width: 960px;
+  margin: 0 auto;
+  padding: 2rem 1.5rem 4rem;
+}
+
+h1 {
+  margin: 0 0 0.5rem;
+  font-size: 2rem;
+  font-weight: 600;
+}
+
+h2 {
+  margin: 0 0 0.75rem;
+  font-size: 1.25rem;
+  font-weight: 600;
+}
+
+.lede {
+  margin: 0 0 2rem;
+  color: var(--muted);
+}
+
+.upload-form {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.75rem;
+  padding: 1rem;
+  background-color: #ffffff;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  margin-bottom: 1rem;
+}
+
+.file-label {
+  font-weight: 500;
+}
+
+input[type="file"] {
+  font: inherit;
+  flex: 1 1 240px;
+  min-width: 0;
+}
+
+button {
+  font: inherit;
+  font-weight: 500;
+  padding: 0.5rem 1rem;
+  background-color: var(--accent);
+  color: #ffffff;
+  border: 1px solid var(--accent);
+  border-radius: 6px;
+  cursor: pointer;
+}
+
+button:hover:not(:disabled) {
+  background-color: var(--accent-hover);
+  border-color: var(--accent-hover);
+}
+
+button:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+.status {
+  margin: 0.5rem 0 0;
+  color: var(--status-fg);
+  min-height: 1.25rem;
+  font-size: 0.95rem;
+}
+
+.error {
+  margin: 0.5rem 0 1rem;
+  padding: 0.75rem 1rem;
+  background-color: var(--error-bg);
+  color: var(--error-fg);
+  border: 1px solid #ffcecb;
+  border-radius: 6px;
+  font-size: 0.95rem;
+  display: none;
+  white-space: pre-wrap;
+}
+
+.error:not(:empty) {
+  display: block;
+}
+
+.result {
+  margin-top: 1.5rem;
+}
+
+.result[hidden] {
+  display: none;
+}
+
+.rows-info {
+  margin: 0 0 0.75rem;
+  color: var(--muted);
+  font-size: 0.95rem;
+}
+
+.table-output {
+  margin: 0;
+  padding: 1rem;
+  background-color: var(--code-bg);
+  color: var(--code-fg);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
+    "Liberation Mono", monospace;
+  font-size: 0.85rem;
+  line-height: 1.4;
+  overflow-x: auto;
+  overflow-y: visible;
+  white-space: pre;
+  max-width: 100%;
+}
+
+@media (max-width: 600px) {
+  .container {
+    padding: 1.25rem 1rem 3rem;
+  }
+
+  h1 {
+    font-size: 1.5rem;
+  }
+
+  .upload-form {
+    flex-direction: column;
+    align-items: stretch;
+  }
+
+  button {
+    width: 100%;
+  }
+}

internal/writing/csv/writer.go

@@ -1,4 +1,6 @@
-package main
+// Package csv renders an internal.AggregatorWriter as the CSV schema
+// expected by Modelo 3 do Anexo J.
+package csv
 
 import (
 	"encoding/csv"
@@ -8,15 +10,15 @@ import (
 	"github.com/nmoniz/any2anexoj/internal"
 )
 
-type CSVWriter struct {
+type Writer struct {
 	w *csv.Writer
 }
 
-func NewCSVWriter(w io.Writer) *CSVWriter {
-	return &CSVWriter{w: csv.NewWriter(w)}
+func NewWriter(w io.Writer) *Writer {
+	return &Writer{w: csv.NewWriter(w)}
 }
 
-func (cw *CSVWriter) Render(aw *internal.AggregatorWriter) error {
+func (cw *Writer) Render(aw *internal.AggregatorWriter) error {
 	err := cw.w.Write([]string{
 		"source_country", "code",
 		"realization_year", "realization_month", "realization_day", "realization_value",

internal/writing/csv/writer_test.go

@@ -0,0 +1,78 @@
+package csv_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing/csv"
+	"github.com/shopspring/decimal"
+)
+
+func TestWriter_Render(t *testing.T) {
+	aw := internal.NewAggregatorWriter()
+	ctx := t.Context()
+
+	items := []internal.ReportItem{
+		{
+			Symbol:        "AAPL",
+			Nature:        internal.NatureG01,
+			BrokerCountry: 826, // United Kingdom
+			AssetCountry:  840, // United States
+			BuyValue:      decimal.NewFromFloat(100.50),
+			BuyTimestamp:  time.Date(2023, 1, 15, 0, 0, 0, 0, time.UTC),
+			SellValue:     decimal.NewFromFloat(150.75),
+			SellTimestamp: time.Date(2023, 6, 20, 0, 0, 0, 0, time.UTC),
+			Fees:          decimal.NewFromFloat(2.50),
+			Taxes:         decimal.NewFromFloat(5.00),
+		},
+		{
+			Symbol:        "VWRL",
+			Nature:        internal.NatureG20,
+			BrokerCountry: 196, // Portugal equivalent demo
+			AssetCountry:  372, // Ireland
+			BuyValue:      decimal.NewFromFloat(200.00),
+			BuyTimestamp:  time.Date(2024, 2, 1, 0, 0, 0, 0, time.UTC),
+			SellValue:     decimal.NewFromFloat(250.25),
+			SellTimestamp: time.Date(2024, 7, 10, 0, 0, 0, 0, time.UTC),
+			Fees:          decimal.NewFromFloat(1.00),
+			Taxes:         decimal.NewFromFloat(0.00),
+		},
+	}
+
+	for _, ri := range items {
+		if err := aw.Write(ctx, ri); err != nil {
+			t.Fatalf("write report item: %v", err)
+		}
+	}
+
+	var buf bytes.Buffer
+	if err := csv.NewWriter(&buf).Render(aw); err != nil {
+		t.Fatalf("render: %v", err)
+	}
+
+	out := buf.String()
+
+	wantHeader := "source_country,code,realization_year,realization_month,realization_day,realization_value,acquisition_year,acquisition_month,acquisition_day,acquisition_value,expenses,foreign_tax_paid,counter_country"
+	if !strings.HasPrefix(out, wantHeader+"\n") {
+		t.Errorf("expected header row %q, got output:\n%s", wantHeader, out)
+	}
+
+	wantRow1 := "840,G01,2023,6,20,150.75,2023,1,15,100.50,2.50,5.00,826"
+	if !strings.Contains(out, wantRow1+"\n") {
+		t.Errorf("expected row 1 %q in output:\n%s", wantRow1, out)
+	}
+
+	wantRow2 := "372,G20,2024,7,10,250.25,2024,2,1,200.00,1.00,0.00,196"
+	if !strings.Contains(out, wantRow2+"\n") {
+		t.Errorf("expected row 2 %q in output:\n%s", wantRow2, out)
+	}
+
+	// Make sure the header only appears once and we have exactly 1 header + 2 data rows.
+	lines := strings.Split(strings.TrimRight(out, "\n"), "\n")
+	if got, want := len(lines), 3; got != want {
+		t.Errorf("expected %d lines (1 header + 2 rows), got %d:\n%s", want, got, out)
+	}
+}

internal/writing/html/document.tmpl

@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="{{.Lang}}">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<title>{{.Title}}</title>
+<link rel="stylesheet" href="{{.CSSURL}}" integrity="{{.Integrity}}" crossorigin="anonymous">
+</head>
+<body>
+<main class="container-fluid py-4">
+<h1>{{.Title}}</h1>
+<div class="table-responsive">
+{{.TableFragment}}
+</div>
+<p class="text-muted small">Generated at {{.GeneratedAt}}</p>
+</main>
+</body>
+</html>

internal/writing/html/fragment.go

@@ -0,0 +1,69 @@
+package html
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/jedib0t/go-pretty/v6/table"
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing/internal/tabledef"
+)
+
+// htmlCSSClass is the CSS class list put on the rendered report table.
+const htmlCSSClass = "table table-striped table-hover table-bordered"
+
+// widthIndex is the weight of the auto-index (row number) column; the other
+// column weights come from tabledef's width budgets.
+const widthIndex = 6
+
+// htmlColumnWeights lists one weight per rendered column, starting with the
+// auto-index column, mirroring the column order of tabledef.Build so the
+// HTML table keeps columns in the same strict proportion to each other as
+// the terminal layout.
+var htmlColumnWeights = []int{
+	widthIndex,
+	tabledef.WidthCountry, tabledef.WidthOther, tabledef.WidthOther, tabledef.WidthOther, tabledef.WidthOther, tabledef.WidthEuros,
+	tabledef.WidthOther, tabledef.WidthOther, tabledef.WidthOther, tabledef.WidthEuros,
+	tabledef.WidthEuros, tabledef.WidthEuros, tabledef.WidthCountry,
+}
+
+// renderTableFragment renders aw as the Bootstrap-styled HTML <table>
+// fragment embedded in the document. The table gets a fixed layout with
+// strictly proportional column widths, so the browser — not this package —
+// decides when a header or cell wraps: on wide screens everything fits on
+// one line, on narrow ones it wraps automatically.
+func (hw *Writer) renderTableFragment(aw *internal.AggregatorWriter) string {
+	t := tabledef.Build(hw.translator, aw)
+	t.Style().HTML = table.HTMLOptions{
+		CSSClass:    htmlCSSClass,
+		EscapeText:  true,
+		Newline:     "<br/>",
+		EmptyColumn: "&nbsp;",
+	}
+	html := t.RenderHTML()
+
+	// go-pretty cannot emit table-level attributes or a <colgroup>, so splice
+	// them into its output: the fixed layout makes the colgroup's relative
+	// widths authoritative instead of content-driven column sizing.
+	openTag := `<table class="` + htmlCSSClass + `">`
+	fixedTag := `<table class="` + htmlCSSClass + `" style="table-layout: fixed">` + "\n" + colgroupHTML()
+	return strings.Replace(html, openTag, fixedTag, 1)
+}
+
+// colgroupHTML returns a <colgroup> with one <col> per rendered column, each
+// sized strictly in proportion to its weight. With the fixed table layout
+// applied in renderTableFragment these widths are authoritative: wide
+// viewports fit headers on a single line, narrow ones wrap automatically.
+func colgroupHTML() string {
+	var total int
+	for _, w := range htmlColumnWeights {
+		total += w
+	}
+	var sb strings.Builder
+	sb.WriteString("<colgroup>")
+	for _, w := range htmlColumnWeights {
+		fmt.Fprintf(&sb, `<col style="width: %.2f%%">`, float64(w)/float64(total)*100)
+	}
+	sb.WriteString("</colgroup>")
+	return sb.String()
+}

internal/writing/html/fragment_test.go

@@ -0,0 +1,60 @@
+package html_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/nmoniz/any2anexoj/internal/writing"
+	htmlwriter "github.com/nmoniz/any2anexoj/internal/writing/html"
+)
+
+// TestWriter_RenderTableFragment renders a Portuguese document and asserts
+// the embedded report table fragment carries the shared structure: the
+// translated headers, the totals footer, and the strictly proportional
+// colgroup that keeps HTML columns in the same relation to each other as
+// the terminal layout.
+func TestWriter_RenderTableFragment(t *testing.T) {
+	aw := buildTestAggregator(t)
+
+	localizer, err := writing.NewLocalizer("pt")
+	if err != nil {
+		t.Fatalf("failed to create localizer: %v", err)
+	}
+
+	var buf bytes.Buffer
+	hw := htmlwriter.NewWriter(&buf, localizer, "pt")
+
+	if err := hw.Render(aw); err != nil {
+		t.Fatalf("Render returned an error: %v", err)
+	}
+	got := buf.String()
+
+	wantSubstrings := []string{
+		`<table class="table table-striped table-hover table-bordered" style="table-layout: fixed">`,
+		`<colgroup>`,
+		`</colgroup>`,
+		`<col style="width: 3.03%">`,
+		`<col style="width: 12.12%">`,
+		`</table>`,
+		`<thead>`,
+		`</thead>`,
+		`<tbody>`,
+		`</tbody>`,
+		`<tfoot>`,
+		`</tfoot>`,
+		"Realização",
+		"Aquisição",
+		"Soma",
+	}
+	for _, s := range wantSubstrings {
+		if !strings.Contains(got, s) {
+			t.Errorf("rendered document missing expected substring %q\nGot:\n%s", s, got)
+		}
+	}
+
+	// The fragment must be embedded raw, not HTML-escaped.
+	if strings.Contains(got, "&lt;table") {
+		t.Errorf("table fragment appears to be HTML-escaped; expected raw <table> markup\nGot:\n%s", got)
+	}
+}

internal/writing/html/writer.go

@@ -0,0 +1,78 @@
+// Package html renders an internal.AggregatorWriter as a complete,
+// standalone HTML document: the report table fragment (built from the
+// shared table definition in internal/writing/internal/tabledef, so it can
+// never drift from the terminal layout) embedded in a Bootstrap-styled page
+// with a translated title and generation timestamp.
+package html
+
+import (
+	_ "embed"
+	"fmt"
+	"html/template"
+	"io"
+	"time"
+
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing/internal/tabledef"
+)
+
+// bootstrapCSSURL is the jsDelivr CDN URL for Bootstrap 5.3.3.
+const bootstrapCSSURL = "https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
+
+// bootstrapIntegrity is the official SRI hash for Bootstrap 5.3.3 css.
+const bootstrapIntegrity = "sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH"
+
+// Writer writes a complete HTML document for an AggregatorWriter.
+type Writer struct {
+	output     io.Writer
+	translator tabledef.Translator
+	lang       string
+}
+
+// NewWriter builds a Writer that writes a complete HTML document to w. The
+// report table is rendered from the shared table definition via tr, and the
+// document title is looked up from the "report_title" translation via tr,
+// so callers never pass a pre-baked title.
+func NewWriter(w io.Writer, tr tabledef.Translator, lang string) *Writer {
+	return &Writer{
+		output:     w,
+		translator: tr,
+		lang:       lang,
+	}
+}
+
+//go:embed document.tmpl
+var documentTemplateBody string
+
+// documentTemplate renders the full HTML page from document.tmpl. The table
+// fragment is typed as template.HTML so the template engine emits it
+// verbatim without escaping the angle brackets in the <table> markup.
+var documentTemplate = template.Must(template.New("html").Parse(documentTemplateBody))
+
+// Render writes a complete standalone HTML document for aw to the configured
+// output. The same Writer may be reused; each call rebuilds the table
+// fragment from aw so the rendered <tr> count reflects aw's current items and
+// no rows are duplicated across invocations.
+func (hw *Writer) Render(aw *internal.AggregatorWriter) error {
+	fragment := hw.renderTableFragment(aw)
+	title := hw.translator.Translate("report_title", 1, nil)
+	data := struct {
+		Lang          string
+		Title         string
+		CSSURL        string
+		Integrity     string
+		TableFragment template.HTML
+		GeneratedAt   string
+	}{
+		Lang:          hw.lang,
+		Title:         title,
+		CSSURL:        bootstrapCSSURL,
+		Integrity:     bootstrapIntegrity,
+		TableFragment: template.HTML(fragment),
+		GeneratedAt:   time.Now().UTC().Format(time.RFC3339),
+	}
+	if err := documentTemplate.Execute(hw.output, data); err != nil {
+		return fmt.Errorf("render html document: %w", err)
+	}
+	return nil
+}

internal/writing/html/writer_test.go

@@ -0,0 +1,180 @@
+package html_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing"
+	htmlwriter "github.com/nmoniz/any2anexoj/internal/writing/html"
+	"github.com/shopspring/decimal"
+)
+
+// buildTestAggregator returns an AggregatorWriter seeded with two
+// deterministic ReportItems so every test can assert on a stable document
+// shape. Mirrors the fixture pattern used in
+// internal/writing/table/printer_test.go.
+func buildTestAggregator(t *testing.T) *internal.AggregatorWriter {
+	t.Helper()
+	aw := internal.NewAggregatorWriter()
+	ctx := t.Context()
+
+	err := aw.Write(ctx, internal.ReportItem{
+		Symbol:        "AAPL",
+		Nature:        internal.NatureG01,
+		BrokerCountry: 826,
+		AssetCountry:  840,
+		BuyValue:      decimal.NewFromFloat(100.50),
+		BuyTimestamp:  time.Date(2023, 1, 15, 0, 0, 0, 0, time.UTC),
+		SellValue:     decimal.NewFromFloat(150.75),
+		SellTimestamp: time.Date(2023, 6, 20, 0, 0, 0, 0, time.UTC),
+		Fees:          decimal.NewFromFloat(2.50),
+		Taxes:         decimal.NewFromFloat(5.00),
+	})
+	if err != nil {
+		t.Fatalf("failed to write first report item: %v", err)
+	}
+
+	err = aw.Write(ctx, internal.ReportItem{
+		Symbol:        "GOOGL",
+		Nature:        internal.NatureG20,
+		BrokerCountry: 826,
+		AssetCountry:  840,
+		BuyValue:      decimal.NewFromFloat(200.00),
+		BuyTimestamp:  time.Date(2023, 3, 10, 0, 0, 0, 0, time.UTC),
+		SellValue:     decimal.NewFromFloat(225.50),
+		SellTimestamp: time.Date(2023, 9, 5, 0, 0, 0, 0, time.UTC),
+		Fees:          decimal.NewFromFloat(3.00),
+		Taxes:         decimal.NewFromFloat(7.50),
+	})
+	if err != nil {
+		t.Fatalf("failed to write second report item: %v", err)
+	}
+
+	return aw
+}
+
+func TestWriter_Render(t *testing.T) {
+	loc, err := writing.NewLocalizer("en")
+	if err != nil {
+		t.Fatalf("create localizer: %v", err)
+	}
+
+	var buf bytes.Buffer
+	hw := htmlwriter.NewWriter(&buf, loc, "en")
+
+	if err := hw.Render(buildTestAggregator(t)); err != nil {
+		t.Fatalf("Render returned an error: %v", err)
+	}
+
+	got := buf.String()
+
+	wantSubstrings := []string{
+		"<!DOCTYPE html>",
+		`<html lang="en">`,
+		`<meta charset="utf-8">`,
+		`<meta name="viewport" content="width=device-width, initial-scale=1">`,
+		`<title>Tax report</title>`,
+		`https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css`,
+		`integrity="`,
+		`crossorigin="anonymous"`,
+		`<main class="container-fluid py-4">`,
+		`<h1>Tax report</h1>`,
+		`<div class="table-responsive">`,
+		`<table class="table table-striped table-hover table-bordered" style="table-layout: fixed">`,
+		`<colgroup>`,
+		`</table>`,
+		`<tfoot>`,
+		`</tfoot>`,
+		`</html>`,
+		`<p class="text-muted small">Generated at `,
+	}
+	for _, s := range wantSubstrings {
+		if !strings.Contains(got, s) {
+			t.Errorf("rendered HTML missing expected substring %q\nGot:\n%s", s, got)
+		}
+	}
+
+	// The table fragment must be embedded as raw HTML, not escaped.
+	if strings.Contains(got, "&lt;table") {
+		t.Errorf("table fragment appears to be HTML-escaped; expected raw <table> markup\nGot:\n%s", got)
+	}
+	if !strings.Contains(got, "<table") {
+		t.Errorf("expected raw <table> tag in output\nGot:\n%s", got)
+	}
+
+	// Generated timestamp must be valid RFC3339 UTC.
+	startIdx := strings.Index(got, "Generated at ")
+	if startIdx == -1 {
+		t.Fatalf("missing 'Generated at' prefix in output")
+	}
+	timestampLine := got[startIdx:]
+	endIdx := strings.Index(timestampLine, "</p>")
+	if endIdx == -1 {
+		t.Fatalf("missing </p> closing tag after 'Generated at' line")
+	}
+	timestampStr := strings.TrimPrefix(strings.SplitN(timestampLine, "</p>", 2)[0], "Generated at ")
+	if _, err := time.Parse(time.RFC3339, timestampStr); err != nil {
+		t.Errorf("generation timestamp is not valid RFC3339: %q (err: %v)", timestampStr, err)
+	}
+}
+
+// TestWriter_NoRowDuplication verifies that calling Render twice on the
+// same writer produces documents with the same number of <tr> rows, just
+// like table.Printer's no-duplication guarantee.
+func TestWriter_NoRowDuplication(t *testing.T) {
+	loc, err := writing.NewLocalizer("en")
+	if err != nil {
+		t.Fatalf("create localizer: %v", err)
+	}
+
+	var buf bytes.Buffer
+	hw := htmlwriter.NewWriter(&buf, loc, "en")
+
+	aw := buildTestAggregator(t)
+
+	if err := hw.Render(aw); err != nil {
+		t.Fatalf("first Render returned an error: %v", err)
+	}
+	first := buf.String()
+	buf.Reset()
+
+	if err := hw.Render(aw); err != nil {
+		t.Fatalf("second Render returned an error: %v", err)
+	}
+	second := buf.String()
+
+	firstRows := strings.Count(first, "<tr")
+	secondRows := strings.Count(second, "<tr")
+	if firstRows == 0 {
+		t.Fatalf("expected at least one <tr> row in the first render; got:\n%s", first)
+	}
+	if firstRows != secondRows {
+		t.Errorf("expected second Render to produce the same number of <tr> rows as the first (no duplication)\nfirst rows=%d, second rows=%d\nFirst:\n%s\nSecond:\n%s",
+			firstRows, secondRows, first, second)
+	}
+}
+
+func TestWriter_LangAttribute(t *testing.T) {
+	loc, err := writing.NewLocalizer("pt")
+	if err != nil {
+		t.Fatalf("create localizer: %v", err)
+	}
+
+	var buf bytes.Buffer
+	hw := htmlwriter.NewWriter(&buf, loc, "pt")
+
+	if err := hw.Render(buildTestAggregator(t)); err != nil {
+		t.Fatalf("Render returned an error: %v", err)
+	}
+
+	got := buf.String()
+	if !strings.Contains(got, `<html lang="pt">`) {
+		t.Errorf("expected <html lang=\"pt\"> attribute; got:\n%s", got)
+	}
+	if !strings.Contains(got, `<h1>Relatório fiscal</h1>`) {
+		t.Errorf("expected Portuguese title in <h1>; got:\n%s", got)
+	}
+}

internal/writing/internal/tabledef/table.go

@@ -0,0 +1,154 @@
+// Package tabledef holds the single definition of the Anexo J report table
+// — column configuration, translated headers, data rows and the totals
+// footer — shared by every renderer under internal/writing. Living in a
+// writing-internal package lets the table and html packages project the
+// same structure into their own formats without any of them exposing
+// go-pretty types in their public API.
+package tabledef
+
+import (
+	"fmt"
+
+	"github.com/biter777/countries"
+	"github.com/jedib0t/go-pretty/v6/table"
+	"github.com/jedib0t/go-pretty/v6/text"
+	"github.com/nmoniz/any2anexoj/internal"
+)
+
+// Translator is the contract the report table renderers rely on for
+// human-readable column labels. *writing.Localizer satisfies it.
+type Translator interface {
+	Translate(key string, count int, values map[string]any) string
+}
+
+// Column width budgets enforced by the terminal renderer. The html package
+// derives its proportional column widths from the same values, keeping both
+// renderings in the same strict proportion to each other.
+const (
+	// WidthCountry is the width budget of a country column ("code - name").
+	WidthCountry = 24
+	// WidthOther is the width budget of a plain column (code, year, ...).
+	WidthOther = 12
+	// WidthEuros is the width budget of a money column ("123.45 €").
+	WidthEuros = 15
+)
+
+// Build constructs a fully configured go-pretty table.Writer from the items
+// in aw: one column per report field, translated headers, data rows and the
+// totals footer. Each call returns a fresh table so callers can render the
+// same data multiple times without duplicating rows, and the returned table
+// is not wired to any output.
+//
+// Change columns, headers or footers here so every renderer stays in sync.
+func Build(tr Translator, aw *internal.AggregatorWriter) table.Writer {
+	tw := table.NewWriter()
+	tw.SetAutoIndex(true)
+	tw.SetStyle(table.StyleLight)
+	tw.SetColumnConfigs([]table.ColumnConfig{
+		colCountry(1),
+		colOther(2),
+		colOther(3),
+		colOther(4),
+		colOther(5),
+		colEuros(6),
+		colOther(7),
+		colOther(8),
+		colOther(9),
+		colEuros(10),
+		colEuros(11),
+		colEuros(12),
+		colCountry(13),
+	})
+
+	realizationTxt := tr.Translate("realization", 1, nil)
+	acquisitionTxt := tr.Translate("acquisition", 1, nil)
+	yearTxt := tr.Translate("year", 1, nil)
+	monthTxt := tr.Translate("month", 1, nil)
+	dayTxt := tr.Translate("day", 1, nil)
+	valorTxt := tr.Translate("value", 1, nil)
+
+	tw.AppendHeader(table.Row{"", "", realizationTxt, realizationTxt, realizationTxt, realizationTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, "", "", ""}, table.RowConfig{AutoMerge: true})
+	tw.AppendHeader(table.Row{
+		tr.Translate("source_country", 1, nil), tr.Translate("code", 1, nil),
+		yearTxt, monthTxt, dayTxt, valorTxt,
+		yearTxt, monthTxt, dayTxt, valorTxt,
+		tr.Translate("expenses", 2, nil), tr.Translate("foreign_tax_paid", 1, nil), tr.Translate("counter_country", 1, nil),
+	})
+
+	for ri := range aw.Iter() {
+		tw.AppendRow(table.Row{
+			ri.AssetCountry, ri.Nature,
+			ri.SellTimestamp.Year(), int(ri.SellTimestamp.Month()), ri.SellTimestamp.Day(), ri.SellValue.StringFixed(2),
+			ri.BuyTimestamp.Year(), int(ri.BuyTimestamp.Month()), ri.BuyTimestamp.Day(), ri.BuyValue.StringFixed(2),
+			ri.Fees.StringFixed(2), ri.Taxes.StringFixed(2), ri.BrokerCountry,
+		})
+	}
+
+	sumTxt := tr.Translate("sum", 1, nil)
+	// The footer lists one cell per column (13) so it never relies on
+	// go-pretty's implicit short-row padding; the trailing empty cell is the
+	// counter-country column, which has no total. Totals are formatted with
+	// StringFixed(2) so they match the two-decimal data rows.
+	tw.AppendFooter(table.Row{sumTxt, sumTxt, sumTxt, sumTxt, sumTxt, aw.TotalEarned().StringFixed(2), "", "", "", aw.TotalSpent().StringFixed(2), aw.TotalFees().StringFixed(2), aw.TotalTaxes().StringFixed(2), ""}, table.RowConfig{AutoMerge: true, AutoMergeAlign: text.AlignRight})
+
+	return tw
+}
+
+func colEuros(n int) table.ColumnConfig {
+	return table.ColumnConfig{
+		Number:           n,
+		Align:            text.AlignRight,
+		AlignFooter:      text.AlignRight,
+		AlignHeader:      text.AlignRight,
+		WidthMin:         WidthOther,
+		WidthMax:         WidthEuros,
+		WidthMaxEnforcer: truncateHeader,
+		Transformer: func(val any) string {
+			return fmt.Sprintf("%v €", val)
+		},
+		TransformerFooter: func(val any) string {
+			return fmt.Sprintf("%v €", val)
+		},
+	}
+}
+
+func colOther(n int) table.ColumnConfig {
+	return table.ColumnConfig{
+		Number:           n,
+		Align:            text.AlignLeft,
+		AlignFooter:      text.AlignLeft,
+		AlignHeader:      text.AlignLeft,
+		WidthMax:         WidthOther,
+		WidthMaxEnforcer: truncateHeader,
+	}
+}
+
+func colCountry(n int) table.ColumnConfig {
+	return table.ColumnConfig{
+		Number:           n,
+		Align:            text.AlignLeft,
+		AlignFooter:      text.AlignLeft,
+		AlignHeader:      text.AlignLeft,
+		WidthMax:         WidthCountry,
+		WidthMaxEnforcer: text.Trim,
+		Transformer: func(val any) string {
+			countryCode := val.(int64)
+			return fmt.Sprintf("%v - %s", val, countries.ByNumeric(int(countryCode)).Info().Name)
+		},
+	}
+}
+
+// truncateHeader enforces a column's WidthMax on terminal output by cutting
+// the text exactly at the width limit — mid-word if that is where it lands —
+// and marking the cut with an ellipsis: keeping as many leading runes
+// readable beats a tidy word boundary. All indexing is rune-based so
+// multibyte labels (e.g. Portuguese) truncate correctly.
+func truncateHeader(val string, width int) string {
+	runes := []rune(val)
+	if len(runes) <= width {
+		return val
+	}
+	// leave room for the ellipsis
+	limit := max(width-1, 1)
+	return string(runes[:limit]) + "…"
+}

internal/writing/internal/tabledef/table_test.go

@@ -0,0 +1,24 @@
+package tabledef
+
+import "testing"
+
+func TestTruncateHeader(t *testing.T) {
+	tests := []struct {
+		name  string
+		val   string
+		width int
+		want  string
+	}{
+		{name: "fits unchanged", val: "TAX PAID ABROAD", width: 15, want: "TAX PAID ABROAD"},
+		{name: "cut mid-word keeps the most runes", val: "EXPENSES AND CHARGES", width: 15, want: "EXPENSES AND C…"},
+		{name: "single overlong word is hard cut", val: "ESTRANGEIRO", width: 8, want: "ESTRANG…"},
+		{name: "cut ignores word boundaries", val: "IMPOSTO PAGO NO ESTRANGEIRO", width: 15, want: "IMPOSTO PAGO N…"},
+		{name: "multibyte runes count as one", val: "PAÍS DA CONTRAPARTE", width: 12, want: "PAÍS DA CON…"},
+		{name: "narrow width", val: "ABCD", width: 2, want: "A…"},
+	}
+	for _, tt := range tests {
+		if got := truncateHeader(tt.val, tt.width); got != tt.want {
+			t.Errorf("%s: truncateHeader(%q, %d) = %q, want %q", tt.name, tt.val, tt.width, got, tt.want)
+		}
+	}
+}

internal/writing/localizer.go

@@ -1,4 +1,4 @@
-package main
+package writing
 
 import (
 	"embed"

internal/writing/localizer_test.go

@@ -1,6 +1,10 @@
-package main
+package writing_test
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/nmoniz/any2anexoj/internal/writing"
+)
 
 func TestNewLocalizer(t *testing.T) {
 	tests := []struct {
@@ -15,7 +19,7 @@ func TestNewLocalizer(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			_, err := NewLocalizer(tt.lang)
+			_, err := writing.NewLocalizer(tt.lang)
 			if err != nil {
 				t.Fatalf("want success call but failed: %v", err)
 			}

internal/writing/table/printer.go

@@ -0,0 +1,34 @@
+// Package table renders an internal.AggregatorWriter as the human-readable
+// Anexo J report table for the terminal. The shared table definition it (and
+// the html package) renders from lives in internal/writing/internal/tabledef.
+package table
+
+import (
+	"io"
+
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing/internal/tabledef"
+)
+
+// Printer writes a simple, human readable, table to the provided io.Writer
+// for the report items in an AggregatorWriter. Each Render call builds a
+// fresh table from the aggregator, so invoking it repeatedly on the same
+// instance never duplicates rows.
+type Printer struct {
+	output     io.Writer
+	translator tabledef.Translator
+}
+
+func NewPrinter(w io.Writer, tr tabledef.Translator) *Printer {
+	return &Printer{
+		output:     w,
+		translator: tr,
+	}
+}
+
+// Render writes the terminal table for aw to the configured output.
+func (pp *Printer) Render(aw *internal.AggregatorWriter) {
+	t := tabledef.Build(pp.translator, aw)
+	t.SetOutputMirror(pp.output)
+	t.Render()
+}

internal/writing/table/printer_test.go

@@ -1,4 +1,4 @@
-package main
+package table_test
 
 import (
 	"bytes"
@@ -6,10 +6,12 @@ import (
 	"time"
 
 	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing"
+	"github.com/nmoniz/any2anexoj/internal/writing/table"
 	"github.com/shopspring/decimal"
 )
 
-func TestPrettyPrinter_Render(t *testing.T) {
+func TestPrinter_Render(t *testing.T) {
 	// Create test data
 	aw := internal.NewAggregatorWriter()
 	ctx := t.Context()
@@ -48,14 +50,14 @@ func TestPrettyPrinter_Render(t *testing.T) {
 	}
 
 	// Create English localizer
-	localizer, err := NewLocalizer("en")
+	localizer, err := writing.NewLocalizer("en")
 	if err != nil {
 		t.Fatalf("failed to create localizer: %v", err)
 	}
 
-	// Create pretty printer with buffer
+	// Create writing printer with buffer
 	var buf bytes.Buffer
-	pp := NewPrettyPrinter(&buf, localizer)
+	pp := table.NewPrinter(&buf, localizer)
 
 	// Render the table
 	pp.Render(aw)
@@ -66,18 +68,17 @@ func TestPrettyPrinter_Render(t *testing.T) {
 	// Expected output
 	want := `┌───┬────────────────────────────┬───────────────────────────────────┬───────────────────────────────────┬──────────────────────────────────────────────────────────┐
 │   │                            │            REALIZATION            │            ACQUISITION            │                                                          │
-│   │ SOURCE COUNTRY      │ CODE │ YEAR │ MONTH │ DAY │        VALUE │ YEAR │ MONTH │ DAY │        VALUE │ EXPENSES AND CH │ TAX PAID ABROAD │ COUNTER COUNTRY      │
-│   │                     │      │      │       │     │              │      │       │     │              │           ARGES │                 │                      │
+│   │ SOURCE COUNTRY      │ CODE │ YEAR │ MONTH │ DAY │        VALUE │ YEAR │ MONTH │ DAY │        VALUE │ EXPENSES AND C… │ TAX PAID ABROAD │ COUNTER COUNTRY      │
 ├───┼─────────────────────┼──────┼──────┼───────┼─────┼──────────────┼──────┼───────┼─────┼──────────────┼─────────────────┼─────────────────┼──────────────────────┤
 │ 1 │ 840 - United States │ G01  │ 2023 │ 6     │ 20  │     150.75 € │ 2023 │ 1     │ 15  │     100.50 € │          2.50 € │          5.00 € │ 826 - United Kingdom │
 │ 2 │ 840 - United States │ G20  │ 2023 │ 9     │ 5   │     225.50 € │ 2023 │ 3     │ 10  │     200.00 € │          3.00 € │          7.50 € │ 826 - United Kingdom │
 ├───┼─────────────────────┴──────┴──────┴───────┴─────┼──────────────┼──────┴───────┴─────┼──────────────┼─────────────────┼─────────────────┼──────────────────────┤
-│   │                                             SUM │     376.25 € │                    │      300.5 € │           5.5 € │          12.5 € │                      │
+│   │                                             SUM │     376.25 € │                    │     300.50 € │          5.50 € │         12.50 € │                      │
 └───┴─────────────────────────────────────────────────┴──────────────┴────────────────────┴──────────────┴─────────────────┴─────────────────┴──────────────────────┘
 `
 
 	// Compare output
 	if got != want {
-		t.Errorf("PrettyPrinter.Render() output doesn't match expected.\n\nGot:\n%s\n\nWant:\n%s", got, want)
+		t.Errorf("Printer.Render() output doesn't match expected.\n\nGot:\n%s\n\nWant:\n%s", got, want)
 	}
 }

internal/writing/translations/en.json

@@ -42,5 +42,13 @@
   "foreign_tax_paid": {
     "one": "Tax paid abroad",
     "other": "Taxes paid abroad"
+  },
+  "sum": {
+    "one": "Sum",
+    "other": "Sums"
+  },
+  "report_title": {
+    "one": "Tax report",
+    "other": "Tax reports"
   }
 }

internal/writing/translations/pt.json

@@ -42,5 +42,13 @@
   "foreign_tax_paid": {
     "one": "Imposto pago no estrangeiro",
     "other": "Impostos pagos no estrangeiro"
+  },
+  "sum": {
+    "one": "Soma",
+    "other": "Somas"
+  },
+  "report_title": {
+    "one": "Relatório fiscal",
+    "other": "Relatórios fiscais"
   }
 }