// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0

package web

import (
	"io"
	"io/fs"
	"net/http"
	"net/http/httptest"
	"regexp"
	"strings"
	"testing"
)

func TestAssetHandlerServesThePackagedFiles(t *testing.T) {
	cases := map[string]string{
		"/admin/assets/admin.css":                           "text/css",
		"/admin/assets/fonts.css":                           "text/css",
		"/admin/assets/graphis.svg":                         "image/svg+xml",
		"/admin/assets/fonts/ubuntu-normal-400-latin.woff2": "font/woff2",
	}
	for path, wantType := range cases {
		rec := httptest.NewRecorder()
		AssetHandler(rec, httptest.NewRequest(http.MethodGet, path, nil))
		response := rec.Result()
		if response.StatusCode != http.StatusOK {
			t.Fatalf("%s: status %d", path, response.StatusCode)
		}
		if got := response.Header.Get("Content-Type"); !strings.HasPrefix(got, wantType) {
			t.Errorf("%s: content type %q, want %q", path, got, wantType)
		}
		body, err := io.ReadAll(response.Body)
		if err != nil || len(body) == 0 {
			t.Fatalf("%s: empty body: %v", path, err)
		}
	}
}

func TestAssetHandlerRejectsUnknownAndTraversal(t *testing.T) {
	for _, path := range []string{
		"/admin/assets/",
		"/admin/assets/nope.css",
		"/admin/assets/../etc/passwd",
		"/admin/assets/fonts/../admin.css",
	} {
		rec := httptest.NewRecorder()
		AssetHandler(rec, httptest.NewRequest(http.MethodGet, path, nil))
		if code := rec.Result().StatusCode; code != http.StatusOK && code != http.StatusNotFound {
			t.Fatalf("%s: status %d", path, code)
		}
		// Only the packaged files are a 200; a re-served parent is a hit
		// only if the tail resolves inside the set after Clean.
		if path == "/admin/assets/" || path == "/admin/assets/nope.css" {
			if rec.Result().StatusCode != http.StatusNotFound {
				t.Errorf("%s: want 404, got %d", path, rec.Result().StatusCode)
			}
		}
	}
}

func TestAssetHandlerRevalidatesWithTheETag(t *testing.T) {
	rec := httptest.NewRecorder()
	AssetHandler(rec, httptest.NewRequest(http.MethodGet, "/admin/assets/admin.css", nil))
	etag := rec.Result().Header.Get("ETag")
	if etag == "" {
		t.Fatal("no ETag on the asset")
	}
	if got := rec.Result().Header.Get("Cache-Control"); !strings.Contains(got, "must-revalidate") {
		t.Errorf("cache-control %q, want revalidation", got)
	}

	second := httptest.NewRecorder()
	request := httptest.NewRequest(http.MethodGet, "/admin/assets/admin.css", nil)
	request.Header.Set("If-None-Match", etag)
	AssetHandler(second, request)
	if code := second.Result().StatusCode; code != http.StatusNotModified {
		t.Fatalf("revalidation status %d, want 304", code)
	}
}

func TestEveryTemplateGlyphReferenceResolves(t *testing.T) {
	sprite := assets["graphis.svg"]
	if sprite == nil {
		t.Fatal("the sprite is not packaged")
	}
	symbol := regexp.MustCompile(`<symbol id="([^"]+)"`)
	defined := map[string]bool{}
	for _, m := range symbol.FindAllStringSubmatch(string(sprite.body), -1) {
		defined[m[1]] = true
	}

	ref := regexp.MustCompile(`icons\.svg#([a-z0-9-]+)"`)
	// The date-picker builds its glyphs in JavaScript, so its ids are not
	// literal in the template; they are named here to keep them covered.
	jsRefs := []string{"chevron-left", "chevron-right", "calendar"}

	tpls, err := fs.ReadDir(TemplateFS(), "templates")
	if err != nil {
		t.Fatalf("templates unreadable: %v", err)
	}
	for _, entry := range tpls {
		body, err := TemplateFS().ReadFile("templates/" + entry.Name())
		if err != nil {
			t.Fatalf("%s: %v", entry.Name(), err)
		}
		for _, m := range ref.FindAllStringSubmatch(string(body), -1) {
			if !defined[m[1]] {
				t.Errorf("%s: references the glyph %q, which the sprite does not define", entry.Name(), m[1])
			}
		}
	}
	for _, name := range jsRefs {
		if !defined[name] {
			t.Errorf("the date picker references the glyph %q, which the sprite does not define", name)
		}
	}
}

func TestSecurityHeadersLetAssetsBeCached(t *testing.T) {
	handler := SecurityHeaders(false)(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		_, _ = io.WriteString(w, "ok")
	}))

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/admin/assets/admin.css", nil))
	if got := rec.Result().Header.Get("Cache-Control"); got != "" {
		t.Errorf("asset cache-control = %q, want the handler to own it", got)
	}
	if strings.Contains(rec.Result().Header.Get("Content-Security-Policy"), "nonce-") {
		t.Error("asset response carries a page CSP with a nonce")
	}

	rec = httptest.NewRecorder()
	handler.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/admin/", nil))
	if got := rec.Result().Header.Get("Cache-Control"); got != "no-store" {
		t.Errorf("admin page cache-control = %q, want no-store", got)
	}
	if !strings.Contains(rec.Result().Header.Get("Content-Security-Policy"), "nonce-") {
		t.Error("admin page CSP lost its nonce")
	}
}