package handlers

import (
	"context"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/go-chi/chi/v5"

	"sneak.berlin/go/pixa/internal/encurl"
	"sneak.berlin/go/pixa/internal/imgcache"
)

// newEncTestServer builds a router serving the encrypted-URL route with a
// generator seeded by the shared test signing key. The image service is left
// nil: these tests exercise validation that rejects a token before any image
// is fetched, so the handler must never reach the service.
func newEncTestServer(t *testing.T) (*encurl.Generator, http.Handler) {
	t.Helper()

	encGen, err := encurl.NewGenerator(testSigningKey)
	if err != nil {
		t.Fatalf("encurl.NewGenerator() error = %v", err)
	}

	h := &Handlers{
		log:    slog.New(slog.DiscardHandler),
		encGen: encGen,
	}

	r := chi.NewRouter()
	r.Get("/v1/e/{token}/*", h.HandleImageEnc())

	return encGen, r
}

// getEncToken issues a GET for the given token and returns the recorder.
func getEncToken(srv http.Handler, token string) *httptest.ResponseRecorder {
	req := httptest.NewRequestWithContext(
		context.Background(), http.MethodGet, "/v1/e/"+token+"/img.jpg", nil)
	rec := httptest.NewRecorder()
	srv.ServeHTTP(rec, req)

	return rec
}

// TestHandleImageEnc_OverLimitDimension_Returns400 verifies that a decrypted
// token requesting a dimension beyond MaxDimension is rejected with 400
// instead of reaching the image processor and libvips.
func TestHandleImageEnc_OverLimitDimension_Returns400(t *testing.T) {
	t.Parallel()

	encGen, srv := newEncTestServer(t)

	token, err := encGen.Generate(&encurl.Payload{
		SourceHost: "cdn.example.com",
		SourcePath: "/photo.jpg",
		Width:      100000,
		Height:     100000,
	})
	if err != nil {
		t.Fatalf("Generate() error = %v", err)
	}

	rec := getEncToken(srv, token)

	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
}

// TestHandleImageEnc_InvalidFitMode_Returns400 verifies that a decrypted token
// carrying an unrecognized fit mode is rejected with 400 rather than surfacing
// as a 500 from the image processor's default branch.
func TestHandleImageEnc_InvalidFitMode_Returns400(t *testing.T) {
	t.Parallel()

	encGen, srv := newEncTestServer(t)

	token, err := encGen.Generate(&encurl.Payload{
		SourceHost: "cdn.example.com",
		SourcePath: "/photo.jpg",
		Width:      800,
		Height:     600,
		FitMode:    imgcache.FitMode("bogus"),
	})
	if err != nil {
		t.Fatalf("Generate() error = %v", err)
	}

	rec := getEncToken(srv, token)

	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusBadRequest)
	}
}