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())
	}
}