package wshub

import (
	"bytes"
	"net/http/httptest"
	"testing"

	"github.com/parquet-go/parquet-go"
)

func TestHandleExportParquetFullResolution(t *testing.T) {
	h := NewHub()
	// Two signals with different lengths and offset time bases: the export must
	// keep every sample of each, on its own timestamps (no holes, no
	// resampling, no decimation).
	sig1 := newSigRing(10000)
	sig2 := newSigRing(10000)
	t1, v1 := make([]float64, 1000), make([]float64, 1000)
	for i := range t1 {
		t1[i] = float64(i) * 0.001
		v1[i] = float64(i) * 2
	}
	sig1.write(t1, v1)
	t2, v2 := make([]float64, 500), make([]float64, 500)
	for i := range t2 {
		t2[i] = 0.1 + float64(i)*0.002
		v2[i] = -float64(i)
	}
	sig2.write(t2, v2)
	h.rings["s1:Ch1"] = sig1
	h.rings["s1:Ch2"] = sig2

	req := httptest.NewRequest("GET", "/api/export?t0=0&t1=2&signals=s1:Ch1,s1:Ch2", nil)
	rec := httptest.NewRecorder()
	h.HandleExport(rec, req)
	if rec.Code != 200 {
		t.Fatalf("status = %d, want 200 (body: %s)", rec.Code, rec.Body.String())
	}

	reader := parquet.NewGenericReader[ExportSample](bytes.NewReader(rec.Body.Bytes()))
	defer reader.Close()

	var got []ExportSample
	buf := make([]ExportSample, 1000)
	for {
		n, err := reader.Read(buf)
		got = append(got, buf[:n]...)
		if err != nil {
			break
		}
	}
	if len(got) != 1500 {
		t.Fatalf("rows = %d, want 1500 (every sample of both signals)", len(got))
	}
	ch1 := filterExportSamples(got, "s1", "Ch1")
	ch2 := filterExportSamples(got, "s1", "Ch2")
	if len(ch1) != 1000 || len(ch2) != 500 {
		t.Fatalf("ch1=%d ch2=%d rows, want 1000/500 (no holes, no resampling)", len(ch1), len(ch2))
	}
	if ch1[0].Time != 0 || ch1[0].Value != 0 || ch1[999].Time != 0.999 || ch1[999].Value != 1998 {
		t.Fatalf("ch1 endpoints wrong: first=%+v last=%+v", ch1[0], ch1[999])
	}
	if ch2[0].Time != 0.1 || ch2[499].Time != 0.1+499*0.002 || ch2[499].Value != -499 {
		t.Fatalf("ch2 endpoints wrong: first=%+v last=%+v", ch2[0], ch2[499])
	}
}

func filterExportSamples(rows []ExportSample, source, signal string) []ExportSample {
	out := make([]ExportSample, 0, len(rows))
	for _, r := range rows {
		if r.Source == source && r.Signal == signal {
			out = append(out, r)
		}
	}
	return out
}

func TestHandleExportParquetBadRange(t *testing.T) {
	h := NewHub()
	h.rings["s1:Ch1"] = newSigRing(10)
	req := httptest.NewRequest("GET", "/api/export?t0=2&t1=1", nil)
	rec := httptest.NewRecorder()
	h.HandleExport(rec, req)
	if rec.Code != 400 {
		t.Fatalf("status = %d, want 400 for inverted range", rec.Code)
	}
}