better domain isolation

README.md

@@ -55,3 +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-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/localizer.go

@@ -1,8 +1,4 @@
-<<<<<<<< HEAD:cmd/any2anexoj-cli/localizer.go
-package main
-========
 package writing
->>>>>>>> 6ba3d78 (writers in writing package):internal/writing/localizer.go
 
 import (
 	"embed"

internal/writing/localizer_test.go

@@ -1,8 +1,3 @@
-<<<<<<<< HEAD:cmd/any2anexoj-cli/localizer_test.go
-package main
-
-import "testing"
-========
 package writing_test
 
 import (
@@ -10,7 +5,6 @@ import (
 
 	"github.com/nmoniz/any2anexoj/internal/writing"
 )
->>>>>>>> 6ba3d78 (writers in writing package):internal/writing/localizer_test.go
 
 func TestNewLocalizer(t *testing.T) {
 	tests := []struct {
@@ -25,11 +19,7 @@ func TestNewLocalizer(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-<<<<<<<< HEAD:cmd/any2anexoj-cli/localizer_test.go
-			_, err := NewLocalizer(tt.lang)
-========
 			_, err := writing.NewLocalizer(tt.lang)
->>>>>>>> 6ba3d78 (writers in writing package):internal/writing/localizer_test.go
 			if err != nil {
 				t.Fatalf("want success call but failed: %v", err)
 			}

internal/writing/table/printer_test.go

@@ -6,8 +6,6 @@ import (
 	"time"
 
 	"github.com/nmoniz/any2anexoj/internal"
-<<<<<<<< HEAD:cmd/any2anexoj-cli/pretty_printer_test.go
-========
 	"github.com/nmoniz/any2anexoj/internal/writing"
 	"github.com/nmoniz/any2anexoj/internal/writing/table"
 	"github.com/shopspring/decimal"
@@ -52,11 +50,7 @@ func TestPrinter_Render(t *testing.T) {
 	}
 
 	// Create English localizer
-<<<<<<<< HEAD:cmd/any2anexoj-cli/pretty_printer_test.go
-	localizer, err := NewLocalizer("en")
-========
 	localizer, err := writing.NewLocalizer("en")
->>>>>>>> 6ba3d78 (writers in writing package):internal/writing/pretty/printer_test.go
 	if err != nil {
 		t.Fatalf("failed to create localizer: %v", err)
 	}