writers in writing package

internal/web/auth.go

@@ -1,11 +0,0 @@
-package web
-
-import "net/http"
-
-// AuthMiddleware is a placeholder seam for future authentication. For now it
-// is a pass-through that invokes the wrapped handler unchanged.
-func AuthMiddleware(next http.Handler) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		next.ServeHTTP(w, r)
-	})
-}

internal/web/handlers.go

@@ -1,167 +0,0 @@
-package web
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"net/http"
-
-	"github.com/nmoniz/any2anexoj/internal"
-	"github.com/nmoniz/any2anexoj/internal/prettyprinter"
-	"github.com/nmoniz/any2anexoj/internal/trading212"
-)
-
-// MaxUploadSize caps the size of the multipart upload. Trading212 CSV exports
-// for an active account tend to be a few MB; 32 MiB is generous while still
-// preventing abuse.
-const MaxUploadSize = 32 << 20
-
-// tableResponse is the JSON shape returned by both the upload and table
-// endpoints.
-type tableResponse struct {
-	Table string `json:"table"`
-	Rows  int    `json:"rows"`
-}
-
-// errorResponse is the JSON shape returned for all 4xx/5xx responses.
-type errorResponse struct {
-	Error string `json:"error"`
-}
-
-// writeJSON marshals v as JSON and writes it with the given status code. Any
-// encoding error is returned so the caller can decide how to surface it.
-func writeJSON(w http.ResponseWriter, status int, v any) error {
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	w.WriteHeader(status)
-	return json.NewEncoder(w).Encode(v)
-}
-
-// writeError writes a JSON {"error": "..."} response.
-func writeError(w http.ResponseWriter, status int, msg string) error {
-	return writeJSON(w, status, errorResponse{Error: msg})
-}
-
-// ClientError tags an error that originates from the uploaded CSV (bad
-// formatting, missing fields, malformed values, etc.). The upload handler
-// uses it to map these to HTTP 400 instead of HTTP 500: a malformed CSV is a
-// client mistake, not a server problem.
-type ClientError struct {
-	Err error
-}
-
-func (e *ClientError) Error() string { return e.Err.Error() }
-func (e *ClientError) Unwrap() error { return e.Err }
-
-// csvRecordReader wraps a trading212 RecordReader so every error from
-// ReadRecord is tagged as a *ClientError. This lets the handler distinguish
-// "the CSV is bad" from "the server is broken" via errors.As. The Unwrap
-// method on *ClientError preserves errors.Is(err, io.EOF) for BuildReport's
-// end-of-stream detection.
-type csvRecordReader struct {
-	inner internal.RecordReader
-}
-
-func (w *csvRecordReader) ReadRecord(ctx context.Context) (internal.Record, error) {
-	rec, err := w.inner.ReadRecord(ctx)
-	if err != nil {
-		return nil, &ClientError{Err: err}
-	}
-	return rec, nil
-}
-
-// handleUpload parses a multipart form upload, runs the report pipeline, and
-// stores the rendered table for retrieval via GET /api/table.
-func (s *Server) handleUpload(w http.ResponseWriter, r *http.Request) {
-	if err := r.ParseMultipartForm(MaxUploadSize); err != nil {
-		// Malformed multipart bodies (wrong Content-Type, truncated body,
-		// missing boundary, etc.) all land here.
-		if writeErr := writeError(w, http.StatusBadRequest, fmt.Sprintf("failed to parse multipart form: %v", err)); writeErr != nil {
-			http.Error(w, writeErr.Error(), http.StatusInternalServerError)
-		}
-		return
-	}
-
-	file, _, err := r.FormFile("csv")
-	if err != nil {
-		if errors.Is(err, http.ErrMissingFile) {
-			if writeErr := writeError(w, http.StatusBadRequest, "missing csv file"); writeErr != nil {
-				http.Error(w, writeErr.Error(), http.StatusInternalServerError)
-			}
-			return
-		}
-		if writeErr := writeError(w, http.StatusBadRequest, fmt.Sprintf("failed to read csv file: %v", err)); writeErr != nil {
-			http.Error(w, writeErr.Error(), http.StatusInternalServerError)
-		}
-		return
-	}
-	defer file.Close()
-
-	table, rows, buildErr := s.buildRenderedTable(r.Context(), file)
-	if buildErr != nil {
-		// CSV parse failures (tagged as *ClientError by csvRecordReader) are
-		// user mistakes and should surface as HTTP 400. Anything else -
-		// internal.BuildReport failures, localizer creation failures, etc. -
-		// is a server problem and gets HTTP 500.
-		var clientErr *ClientError
-		if errors.As(buildErr, &clientErr) {
-			if writeErr := writeError(w, http.StatusBadRequest, clientErr.Error()); writeErr != nil {
-				http.Error(w, writeErr.Error(), http.StatusInternalServerError)
-			}
-			return
-		}
-		if writeErr := writeError(w, http.StatusInternalServerError, buildErr.Error()); writeErr != nil {
-			http.Error(w, writeErr.Error(), http.StatusInternalServerError)
-		}
-		return
-	}
-
-	s.state.Set(table, rows)
-
-	if err := writeJSON(w, http.StatusOK, tableResponse{Table: table, Rows: rows}); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-}
-
-// handleGetTable returns the most recently rendered table. When no upload has
-// happened yet the response contains an empty table string and zero rows.
-func (s *Server) handleGetTable(w http.ResponseWriter, _ *http.Request) {
-	table, rows := s.state.Get()
-	if err := writeJSON(w, http.StatusOK, tableResponse{Table: table, Rows: rows}); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-}
-
-// buildRenderedTable wires the CSV reader, the aggregator, BuildReport, and the
-// pretty-printer into a single pipeline. It returns the rendered table string
-// and the row count.
-func (s *Server) buildRenderedTable(ctx context.Context, r io.Reader) (string, int, error) {
-	innerReader := trading212.NewRecordReader(r, s.figiClient)
-	reader := &csvRecordReader{inner: innerReader}
-	writer := internal.NewAggregatorWriter()
-
-	if err := internal.BuildReport(ctx, reader, writer, internal.WithSelector(internal.Any())); err != nil {
-		return "", 0, fmt.Errorf("failed to build report: %w", err)
-	}
-
-	loc, err := prettyprinter.NewLocalizer("pt")
-	if err != nil {
-		return "", 0, fmt.Errorf("failed to create localizer: %w", err)
-	}
-
-	var buf bytes.Buffer
-	prettyprinter.NewPrettyPrinter(&buf, loc).Render(writer)
-
-	// Row count is the number of report items the aggregator ended up with,
-	// since each item becomes a row in the rendered table.
-	rows := 0
-	for range writer.Iter() {
-		rows++
-	}
-
-	return buf.String(), rows, nil
-}

internal/web/server.go

@@ -1,82 +0,0 @@
-package web
-
-import (
-	"fmt"
-	"io/fs"
-	"net/http"
-	"time"
-
-	"github.com/nmoniz/any2anexoj/internal/ofigi"
-)
-
-// Server wires the HTTP handlers, embedded static assets, and shared state
-// behind a single http.Handler. Use NewServer to construct one.
-type Server struct {
-	state       *State
-	router      *http.ServeMux
-	staticFS    fs.FS
-	indexHTML   []byte
-	figiClient  *ofigi.Client
-}
-
-// Option mutates a Server during construction. Use WithFigiClient (mainly in
-// tests) to inject a custom OpenFIGI client so tests can run offline against
-// a stub while production uses a real network client.
-type Option func(*Server)
-
-// WithFigiClient overrides the OpenFIGI client used by the report pipeline.
-// Production should leave this unset so NewServer constructs a real client
-// (no API key, 5 s timeout) that gracefully falls back to NatureUnknown
-// when OpenFIGI calls fail. Tests pass a stub backed by an httptest-style
-// transport to keep the test suite offline and deterministic.
-func WithFigiClient(c *ofigi.Client) Option {
-	return func(s *Server) {
-		s.figiClient = c
-	}
-}
-
-// NewServer constructs a Server with all routes registered. The staticFS is
-// the embedded subtree rooted at the directory that should be served under
-// /static/* (i.e. it must contain an "index.html" file). The returned
-// Server's Handler() method exposes the configured http.Handler.
-func NewServer(state *State, staticFS fs.FS, opts ...Option) (*Server, error) {
-	indexBytes, err := fs.ReadFile(staticFS, "index.html")
-	if err != nil {
-		return nil, fmt.Errorf("web: missing index.html in static FS: %w", err)
-	}
-
-	s := &Server{
-		state:     state,
-		router:    http.NewServeMux(),
-		staticFS:  staticFS,
-		indexHTML: indexBytes,
-		figiClient: ofigi.NewOpenFIGI(&http.Client{Timeout: 5 * time.Second}, ""),
-	}
-	for _, opt := range opts {
-		opt(s)
-	}
-	s.routes()
-	return s, nil
-}
-
-// Handler returns the configured HTTP handler, wrapped in the auth middleware
-// stub so future auth wiring only has to change auth.go.
-func (s *Server) Handler() http.Handler {
-	return AuthMiddleware(s.router)
-}
-
-// routes registers the HTTP routes handled by this server.
-func (s *Server) routes() {
-	// API routes.
-	s.router.HandleFunc("POST /api/upload", s.handleUpload)
-	s.router.HandleFunc("GET /api/table", s.handleGetTable)
-
-	// Serve the embedded static assets under /static/*.
-	s.router.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.FS(s.staticFS))))
-
-	// Serve the embedded index page at "/".
-	s.router.HandleFunc("GET /{$}", func(w http.ResponseWriter, _ *http.Request) {
-		w.Header().Set("Content-Type", "text/html; charset=utf-8")
-		_, _ = w.Write(s.indexHTML)
-	})
-}

internal/web/server_test.go

@@ -1,395 +0,0 @@
-package web_test
-
-import (
-	"bytes"
-	"embed"
-	"encoding/json"
-	"io"
-	"io/fs"
-	"mime/multipart"
-	"net/http"
-	"net/http/httptest"
-	"os"
-	"strings"
-	"testing"
-
-	"github.com/nmoniz/any2anexoj/internal/ofigi"
-	"github.com/nmoniz/any2anexoj/internal/web"
-)
-
-//go:embed testdata
-var testdataFS embed.FS
-
-// stubFigiClient returns a real *ofigi.Client backed by a transport that
-// replies with a deterministic security type. Tests use it so the upload
-// pipeline does not hit the public OpenFIGI API. The default stub reports
-// "ETP" (ETF/ETP) because that matches the majority of rows in
-// trading212-small.csv; tests that need a different value build their own.
-func stubFigiClient(t *testing.T, securityType string) *ofigi.Client {
-	t.Helper()
-	return ofigi.NewOpenFIGI(&http.Client{
-		Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
-			body := `[{"data":[{"securityType":"` + securityType + `"}]}]`
-			return &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(strings.NewReader(body)),
-				Header:     make(http.Header),
-			}, nil
-		}),
-	}, "")
-}
-
-// newTestServer builds a Server backed by the embedded testdata FS and a
-// stubbed OpenFIGI client so handlers stay offline.
-func newTestServer(t *testing.T, opts ...web.Option) http.Handler {
-	t.Helper()
-
-	sub, err := fs.Sub(testdataFS, "testdata")
-	if err != nil {
-		t.Fatalf("failed to sub testdata: %v", err)
-	}
-
-	state := web.NewState()
-	opts = append([]web.Option{web.WithFigiClient(stubFigiClient(t, "ETP"))}, opts...)
-	srv, err := web.NewServer(state, sub, opts...)
-	if err != nil {
-		t.Fatalf("failed to construct server: %v", err)
-	}
-	return srv.Handler()
-}
-
-// roundTripFunc adapts a plain function to http.RoundTripper.
-type roundTripFunc func(*http.Request) (*http.Response, error)
-
-func (f roundTripFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }
-
-// multipartUpload builds a multipart/form-data request body with a single
-// "csv" file part from the given file path.
-func multipartUpload(t *testing.T, filePath string) (*bytes.Buffer, string, func()) {
-	t.Helper()
-
-	body := &bytes.Buffer{}
-	w := multipart.NewWriter(body)
-
-	f, err := os.Open(filePath)
-	if err != nil {
-		t.Fatalf("failed to open fixture %q: %v", filePath, err)
-	}
-	defer f.Close()
-
-	fw, err := w.CreateFormFile("csv", "upload.csv")
-	if err != nil {
-		t.Fatalf("failed to create form file: %v", err)
-	}
-	if _, err := io.Copy(fw, f); err != nil {
-		t.Fatalf("failed to copy file into form: %v", err)
-	}
-	if err := w.Close(); err != nil {
-		t.Fatalf("failed to close multipart writer: %v", err)
-	}
-
-	return body, w.FormDataContentType(), func() {}
-}
-
-func TestUploadValidCSV(t *testing.T) {
-	handler := newTestServer(t)
-
-	body, ct, _ := multipartUpload(t, "../../trading212-small.csv")
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	req.Header.Set("Content-Type", ct)
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusOK {
-		t.Fatalf("expected status 200, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal response: %v, body=%q", err, rec.Body.String())
-	}
-
-	if resp.Table == "" {
-		t.Errorf("expected non-empty table in response")
-	}
-	if resp.Rows <= 0 {
-		t.Errorf("expected rows > 0, got %d", resp.Rows)
-	}
-	// The pretty-printer always emits a box-drawing top border.
-	if !strings.Contains(resp.Table, "┌") {
-		t.Errorf("expected rendered table to contain box-drawing border; got:\n%s", resp.Table)
-	}
-}
-
-func TestUploadMissingFile(t *testing.T) {
-	handler := newTestServer(t)
-
-	body := &bytes.Buffer{}
-	mw := multipart.NewWriter(body)
-	// Intentionally do not add a "csv" part.
-	if err := mw.Close(); err != nil {
-		t.Fatalf("close multipart: %v", err)
-	}
-
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	req.Header.Set("Content-Type", mw.FormDataContentType())
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusBadRequest {
-		t.Fatalf("expected status 400, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Error string `json:"error"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal error response: %v, body=%q", err, rec.Body.String())
-	}
-	if resp.Error == "" {
-		t.Errorf("expected non-empty error message, got %q", resp.Error)
-	}
-	if ct := rec.Header().Get("Content-Type"); !strings.HasPrefix(ct, "application/json") {
-		t.Errorf("expected JSON content-type, got %q", ct)
-	}
-}
-
-func TestUploadMalformedRequest(t *testing.T) {
-	handler := newTestServer(t)
-
-	// A plain string body with no Content-Type is not a valid multipart form.
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", strings.NewReader("not a multipart body"))
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusBadRequest {
-		t.Fatalf("expected status 400, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Error string `json:"error"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal error response: %v, body=%q", err, rec.Body.String())
-	}
-	if resp.Error == "" {
-		t.Errorf("expected non-empty error message, got %q", resp.Error)
-	}
-}
-
-// TestUploadMalformedCSV asserts that a syntactically valid multipart upload
-// whose CSV body is parseable by encoding/csv but rejected by the trading212
-// reader (e.g. an unknown action type) returns HTTP 400 (client error), not
-// 500. This exercises the csvRecordReader -> *ClientError tagging path.
-func TestUploadMalformedCSV(t *testing.T) {
-	handler := newTestServer(t)
-
-	// A CSV with the correct header row but a bogus action value triggers
-	// trading212's "parse record type" error, which the handler must map to
-	// 400 via the *ClientError tagging.
-	brokenCSV := "Action,Time,ISIN,Ticker,Name,ID,No. of shares,Price / share,Currency (Price / share),Exchange rate,Result,Currency (Result),Total,Currency (Total),Stamp duty reserve tax,Currency (Stamp duty reserve tax),Currency conversion fee,Currency (Currency conversion fee),French transaction tax,Currency (French transaction tax)\n" +
-		"bogus,2025-06-02 12:33:05,GB00B63H8491,RR,\"Rolls-Royce\",EOF33553786215,0.3847870000,871.0000000000,GBX,84.42052317,,\"EUR\",4.00,\"EUR\",0.02,\"EUR\",0.01,\"EUR\",,\n"
-
-	body := &bytes.Buffer{}
-	w := multipart.NewWriter(body)
-	fw, err := w.CreateFormFile("csv", "broken.csv")
-	if err != nil {
-		t.Fatalf("create form file: %v", err)
-	}
-	if _, err := fw.Write([]byte(brokenCSV)); err != nil {
-		t.Fatalf("write body: %v", err)
-	}
-	if err := w.Close(); err != nil {
-		t.Fatalf("close multipart: %v", err)
-	}
-
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	req.Header.Set("Content-Type", w.FormDataContentType())
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusBadRequest {
-		t.Fatalf("expected status 400 for malformed CSV, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Error string `json:"error"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal error response: %v, body=%q", err, rec.Body.String())
-	}
-	if !strings.Contains(resp.Error, "parse record type") {
-		t.Errorf("expected error message to surface the trading212 parse failure, got %q", resp.Error)
-	}
-}
-
-func TestGetTableReturnsLastUpload(t *testing.T) {
-	handler := newTestServer(t)
-
-	// Initial state: empty table, zero rows.
-	getReq := httptest.NewRequest(http.MethodGet, "/api/table", nil)
-	getRec := httptest.NewRecorder()
-	handler.ServeHTTP(getRec, getReq)
-	if getRec.Code != http.StatusOK {
-		t.Fatalf("initial GET /api/table: expected 200, got %d", getRec.Code)
-	}
-	var initial struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(getRec.Body.Bytes(), &initial); err != nil {
-		t.Fatalf("unmarshal initial: %v", err)
-	}
-	if initial.Table != "" || initial.Rows != 0 {
-		t.Fatalf("expected initial state to be empty, got table=%q rows=%d", initial.Table, initial.Rows)
-	}
-
-	// Upload a CSV.
-	body, ct, _ := multipartUpload(t, "../../trading212-small.csv")
-	upReq := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	upReq.Header.Set("Content-Type", ct)
-	upRec := httptest.NewRecorder()
-	handler.ServeHTTP(upRec, upReq)
-	if upRec.Code != http.StatusOK {
-		t.Fatalf("upload: expected 200, got %d, body=%q", upRec.Code, upRec.Body.String())
-	}
-	var uploaded struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(upRec.Body.Bytes(), &uploaded); err != nil {
-		t.Fatalf("unmarshal upload: %v", err)
-	}
-	if uploaded.Table == "" || uploaded.Rows <= 0 {
-		t.Fatalf("upload returned empty table or zero rows: %+v", uploaded)
-	}
-
-	// Now GET /api/table should return the same table.
-	getReq2 := httptest.NewRequest(http.MethodGet, "/api/table", nil)
-	getRec2 := httptest.NewRecorder()
-	handler.ServeHTTP(getRec2, getReq2)
-	if getRec2.Code != http.StatusOK {
-		t.Fatalf("follow-up GET /api/table: expected 200, got %d", getRec2.Code)
-	}
-	var got struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(getRec2.Body.Bytes(), &got); err != nil {
-		t.Fatalf("unmarshal follow-up: %v", err)
-	}
-	if got.Table != uploaded.Table {
-		t.Errorf("GET /api/table table mismatch with upload response:\n upload=%q\n get=%q", uploaded.Table, got.Table)
-	}
-	if got.Rows != uploaded.Rows {
-		t.Errorf("GET /api/table rows=%d, expected %d", got.Rows, uploaded.Rows)
-	}
-}
-
-// TestUploadRendersPortugueseHeaders is the end-to-end integration check for
-// Chunk 4 of the webapp plan: upload trading212-small.csv through the live
-// HTTP handler and confirm the rendered table contains the Portuguese
-// header text emitted by the backend's pt localizer. The header text is
-// uppercased by go-pretty's StyleLight, so the asserted substring is
-// "REALIZAÇÃO" (with the diacritic preserved).
-func TestUploadRendersPortugueseHeaders(t *testing.T) {
-	handler := newTestServer(t)
-
-	body, ct, _ := multipartUpload(t, "../../trading212-small.csv")
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	req.Header.Set("Content-Type", ct)
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusOK {
-		t.Fatalf("expected status 200, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal response: %v, body=%q", err, rec.Body.String())
-	}
-
-	if resp.Table == "" {
-		t.Fatalf("expected non-empty rendered table")
-	}
-	if resp.Rows <= 0 {
-		t.Fatalf("expected rows > 0, got %d", resp.Rows)
-	}
-
-	// The pt localizer supplies these labels and go-pretty uppercases the
-	// header cells, so we assert the uppercased Portuguese form.
-	for _, want := range []string{"REALIZAÇÃO", "AQUISIÇÃO", "PAÍS DA FONTE"} {
-		if !strings.Contains(resp.Table, want) {
-			t.Errorf("expected rendered table to contain header %q; got:\n%s", want, resp.Table)
-		}
-	}
-}
-
-// TestNatureG20ForETFStub confirms that when the stub returns securityType
-// "ETP", sell rows in the rendered table carry the G20 nature code, not
-// G01. This pins down the OpenFIGI stub misclassification fix: production
-// uses a real OpenFIGI client (which returns "ETP" for ETFs like IDVY),
-// while this test uses a stub that hard-codes "ETP" so the same mapping
-// is exercised without network calls.
-func TestNatureG20ForETFStub(t *testing.T) {
-	handler := newTestServer(t)
-
-	body, ct, _ := multipartUpload(t, "../../trading212-small.csv")
-	req := httptest.NewRequest(http.MethodPost, "/api/upload", body)
-	req.Header.Set("Content-Type", ct)
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusOK {
-		t.Fatalf("expected status 200, got %d, body=%q", rec.Code, rec.Body.String())
-	}
-
-	var resp struct {
-		Table string `json:"table"`
-		Rows  int    `json:"rows"`
-	}
-	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-		t.Fatalf("failed to unmarshal response: %v, body=%q", err, rec.Body.String())
-	}
-
-	if resp.Rows <= 0 {
-		t.Fatalf("expected rows > 0, got %d", resp.Rows)
-	}
-	// The stub returns "ETP" -> G20, so the rendered table must contain
-	// "G20". It must NOT contain "G01" for any sell row of an ETF symbol.
-	if !strings.Contains(resp.Table, "G20") {
-		t.Errorf("expected rendered table to contain nature code G20 (ETP); got:\n%s", resp.Table)
-	}
-}
-
-func TestGetServesIndex(t *testing.T) {
-	handler := newTestServer(t)
-
-	req := httptest.NewRequest(http.MethodGet, "/", nil)
-	rec := httptest.NewRecorder()
-
-	handler.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusOK {
-		t.Fatalf("GET /: expected 200, got %d", rec.Code)
-	}
-	if ct := rec.Header().Get("Content-Type"); !strings.HasPrefix(ct, "text/html") {
-		t.Errorf("GET /: expected text/html content-type, got %q", ct)
-	}
-	if !strings.Contains(rec.Body.String(), "<html") {
-		t.Errorf("GET /: expected HTML body, got %q", rec.Body.String())
-	}
-}

internal/web/state.go

@@ -1,33 +0,0 @@
-package web
-
-import "sync"
-
-// State holds the last rendered report table and row count produced by the
-// upload handler. The web app is single-user and in-memory, but net/http runs
-// handlers concurrently, so reads and writes are guarded by an RWMutex.
-type State struct {
-	mu    sync.RWMutex
-	table string
-	rows  int
-}
-
-// NewState returns an empty State with no rendered table.
-func NewState() *State {
-	return &State{}
-}
-
-// Set replaces the stored rendered table string and row count.
-func (s *State) Set(table string, rows int) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	s.table = table
-	s.rows = rows
-}
-
-// Get returns the current rendered table string and row count. The returned
-// values are zero-valued when no upload has happened yet.
-func (s *State) Get() (string, int) {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	return s.table, s.rows
-}

internal/web/testdata/index.html

@@ -1,2 +0,0 @@
-<!DOCTYPE html>
-<html><body>test fixture</body></html>

internal/writing/csv/writer.go

@@ -0,0 +1,59 @@
+// Package csv renders an internal.AggregatorWriter as the CSV schema
+// expected by Modelo 3 do Anexo J.
+package csv
+
+import (
+	"encoding/csv"
+	"fmt"
+	"io"
+
+	"github.com/nmoniz/any2anexoj/internal"
+)
+
+type CSVWriter struct {
+	w *csv.Writer
+}
+
+func NewCSVWriter(w io.Writer) *CSVWriter {
+	return &CSVWriter{w: csv.NewWriter(w)}
+}
+
+func (cw *CSVWriter) Render(aw *internal.AggregatorWriter) error {
+	err := cw.w.Write([]string{
+		"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 err != nil {
+		return fmt.Errorf("write csv header: %w", err)
+	}
+
+	for ri := range aw.Iter() {
+		err := cw.w.Write(reportItemToRow(ri))
+		if err != nil {
+			return fmt.Errorf("write csv row: %w", err)
+		}
+	}
+
+	cw.w.Flush()
+	return cw.w.Error()
+}
+
+func reportItemToRow(ri internal.ReportItem) []string {
+	return []string{
+		fmt.Sprintf("%d", ri.AssetCountry),
+		string(ri.Nature),
+		fmt.Sprintf("%d", ri.SellTimestamp.Year()),
+		fmt.Sprintf("%d", int(ri.SellTimestamp.Month())),
+		fmt.Sprintf("%d", ri.SellTimestamp.Day()),
+		ri.SellValue.StringFixed(2),
+		fmt.Sprintf("%d", ri.BuyTimestamp.Year()),
+		fmt.Sprintf("%d", int(ri.BuyTimestamp.Month())),
+		fmt.Sprintf("%d", ri.BuyTimestamp.Day()),
+		ri.BuyValue.StringFixed(2),
+		ri.Fees.StringFixed(2),
+		ri.Taxes.StringFixed(2),
+		fmt.Sprintf("%d", ri.BrokerCountry),
+	}
+}

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 TestCSVWriter_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.NewCSVWriter(&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/localizer.go

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

internal/writing/localizer_test.go

@@ -1,9 +1,9 @@
-package prettyprinter_test
+package writing_test
 
 import (
 	"testing"
 
-	"github.com/nmoniz/any2anexoj/internal/prettyprinter"
+	"github.com/nmoniz/any2anexoj/internal/writing"
 )
 
 func TestNewLocalizer(t *testing.T) {
@@ -19,7 +19,7 @@ func TestNewLocalizer(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			_, err := prettyprinter.NewLocalizer(tt.lang)
+			_, err := writing.NewLocalizer(tt.lang)
 			if err != nil {
 				t.Fatalf("want success call but failed: %v", err)
 			}

internal/writing/pretty/printer.go

@@ -1,4 +1,4 @@
-package prettyprinter
+package pretty
 
 import (
 	"fmt"
@@ -17,16 +17,27 @@ type translator interface {
 }
 
 // PrettyPrinter writes a simple, human readable, table row to the provided io.Writer for each
-// ReportItem received.
+// ReportItem received. Render and RenderHTML each build a fresh table.Writer so that
+// invoking them (in any order or repeatedly) on the same instance never duplicates rows.
 type PrettyPrinter struct {
-	table      table.Writer
 	output     io.Writer
 	translator translator
 }
 
 func NewPrettyPrinter(w io.Writer, tr translator) *PrettyPrinter {
+	return &PrettyPrinter{
+		output:     w,
+		translator: tr,
+	}
+}
+
+// buildTable constructs a fully configured table.Writer from the items in aw.
+// Each call returns a new table.Writer so callers can render the same data
+// multiple times without duplicating rows. The returned table is not wired to
+// pp.output via an output mirror; callers that want the rendered output
+// written to pp.output must set the mirror themselves before calling .Render().
+func (pp *PrettyPrinter) buildTable(aw *internal.AggregatorWriter) table.Writer {
 	tw := table.NewWriter()
-	tw.SetOutputMirror(w)
 	tw.SetAutoIndex(true)
 	tw.SetStyle(table.StyleLight)
 	tw.SetColumnConfigs([]table.ColumnConfig{
@@ -45,14 +56,6 @@ func NewPrettyPrinter(w io.Writer, tr translator) *PrettyPrinter {
 		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)
@@ -60,8 +63,8 @@ func (pp *PrettyPrinter) Render(aw *internal.AggregatorWriter) {
 	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{
+	tw.AppendHeader(table.Row{"", "", realizationTxt, realizationTxt, realizationTxt, realizationTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, acquisitionTxt, "", "", ""}, table.RowConfig{AutoMerge: true})
+	tw.AppendHeader(table.Row{
 		pp.translator.Translate("source_country", 1, nil), pp.translator.Translate("code", 1, nil),
 		yearTxt, monthTxt, dayTxt, valorTxt,
 		yearTxt, monthTxt, dayTxt, valorTxt,
@@ -69,7 +72,7 @@ func (pp *PrettyPrinter) Render(aw *internal.AggregatorWriter) {
 	})
 
 	for ri := range aw.Iter() {
-		pp.table.AppendRow(table.Row{
+		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),
@@ -77,8 +80,29 @@ func (pp *PrettyPrinter) Render(aw *internal.AggregatorWriter) {
 		})
 	}
 
-	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()
+	sumTxt := pp.translator.Translate("sum", 1, nil)
+	tw.AppendFooter(table.Row{sumTxt, sumTxt, sumTxt, sumTxt, sumTxt, aw.TotalEarned(), "", "", "", aw.TotalSpent(), aw.TotalFees(), aw.TotalTaxes()}, table.RowConfig{AutoMerge: true, AutoMergeAlign: text.AlignRight})
+
+	return tw
+}
+
+func (pp *PrettyPrinter) Render(aw *internal.AggregatorWriter) {
+	t := pp.buildTable(aw)
+	t.SetOutputMirror(pp.output)
+	t.Render()
+}
+
+// RenderHTML builds a fresh table from aw and renders it as an HTML string
+// using go-pretty's HTMLOptions.
+func (pp *PrettyPrinter) RenderHTML(aw *internal.AggregatorWriter) string {
+	t := pp.buildTable(aw)
+	t.Style().HTML = table.HTMLOptions{
+		CSSClass:    "table table-striped table-hover table-bordered",
+		EscapeText:  true,
+		Newline:     "<br/>",
+		EmptyColumn: "&nbsp;",
+	}
+	return t.RenderHTML()
 }
 
 func colEuros(n int) table.ColumnConfig {

internal/writing/pretty/printer_test.go

@@ -1,12 +1,14 @@
-package prettyprinter_test
+package pretty_test
 
 import (
 	"bytes"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/nmoniz/any2anexoj/internal"
-	"github.com/nmoniz/any2anexoj/internal/prettyprinter"
+	"github.com/nmoniz/any2anexoj/internal/writing"
+	"github.com/nmoniz/any2anexoj/internal/writing/pretty"
 	"github.com/shopspring/decimal"
 )
 
@@ -49,14 +51,14 @@ func TestPrettyPrinter_Render(t *testing.T) {
 	}
 
 	// Create English localizer
-	localizer, err := prettyprinter.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 := prettyprinter.NewPrettyPrinter(&buf, localizer)
+	pp := pretty.NewPrettyPrinter(&buf, localizer)
 
 	// Render the table
 	pp.Render(aw)
@@ -82,3 +84,71 @@ func TestPrettyPrinter_Render(t *testing.T) {
 		t.Errorf("PrettyPrinter.Render() output doesn't match expected.\n\nGot:\n%s\n\nWant:\n%s", got, want)
 	}
 }
+
+func TestRenderHTML(t *testing.T) {
+	// Create test data
+	aw := internal.NewAggregatorWriter()
+	ctx := t.Context()
+
+	err := aw.Write(ctx, 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),
+	})
+	if err != nil {
+		t.Fatalf("failed to write report item: %v", err)
+	}
+
+	// Create Portuguese localizer so the header text is in pt
+	localizer, err := writing.NewLocalizer("pt")
+	if err != nil {
+		t.Fatalf("failed to create localizer: %v", err)
+	}
+
+	// Output buffer used only to satisfy the constructor contract; RenderHTML
+	// must not write to it.
+	var buf bytes.Buffer
+	pp := pretty.NewPrettyPrinter(&buf, localizer)
+
+	html := pp.RenderHTML(aw)
+
+	// RenderHTML must not side-write to pp.output.
+	if buf.Len() != 0 {
+		t.Errorf("RenderHTML should not write to pp.output, but got %d bytes: %q", buf.Len(), buf.String())
+	}
+
+	// Structural assertions.
+	wantSubstrings := []string{
+		`<table class="table table-striped table-hover table-bordered">`,
+		`</table>`,
+		`<thead>`,
+		`</thead>`,
+		`<tbody>`,
+		`</tbody>`,
+		`<tfoot>`,
+		`</tfoot>`,
+		"Realização",
+		"Aquisição",
+		"Soma",
+	}
+	for _, s := range wantSubstrings {
+		if !strings.Contains(html, s) {
+			t.Errorf("RenderHTML output missing expected substring %q\nGot:\n%s", s, html)
+		}
+	}
+
+	// Calling RenderHTML twice on the same instance must not duplicate rows.
+	html2 := pp.RenderHTML(aw)
+	if strings.Count(html2, "<tr") != strings.Count(html, "<tr") {
+		t.Errorf("expected second RenderHTML call to produce the same number of rows as the first\nFirst (%d <tr>):\n%s\nSecond (%d <tr>):\n%s",
+			strings.Count(html, "<tr"), html,
+			strings.Count(html2, "<tr"), html2)
+	}
+}

internal/writing/translations/en.json

@@ -42,5 +42,9 @@
   "foreign_tax_paid": {
     "one": "Tax paid abroad",
     "other": "Taxes paid abroad"
+  },
+  "sum": {
+    "one": "Sum",
+    "other": "Sums"
   }
 }

internal/writing/translations/pt.json

@@ -42,5 +42,9 @@
   "foreign_tax_paid": {
     "one": "Imposto pago no estrangeiro",
     "other": "Impostos pagos no estrangeiro"
+  },
+  "sum": {
+    "one": "Soma",
+    "other": "Somas"
   }
 }