//go:build browser

package gallery

import (
	"context"
	"fmt"
	"testing"
	"time"

	"github.com/chromedp/cdproto/runtime"
	"github.com/chromedp/chromedp"
	"github.com/chromedp/chromedp/kb"

	"amadan.net/rastrillo/fiesta"
	"amadan.net/rastrillo/fiesta/internal/harness"
)

// TestEveryLanguageIsReachableFromThePhoneIndex: every language in the
// phone index's display settings menu can be reached by Tab, with
// scripts, and by scrolling the way a finger would, with scripts and
// without, at 390px and 320px, left to right and right to left, with
// anchor positioning and without. The menu is at the top of the index
// and drops down, and the language list opens in place inside its
// card, so the long list is the card's to scroll. Then every link is
// followed once, since reaching a link is not using it.
//
// "On screen" is inside documentElement's client box, on a rig that
// draws its scrollbars: see requireDrawnScrollbar.
func TestEveryLanguageIsReachableFromThePhoneIndex(t *testing.T) {
	rig := phoneRig(t, harness.WithScrollbars())
	ctx, cancel := context.WithTimeout(rig.Context(), 300*time.Second)
	defer cancel()
	theme := fiesta.ThemeNames()[0]
	open := `document.getElementById("ds-prefs").open = true; document.querySelector("#ds-prefs [rst-locale]").open = true; true`
	for _, scripts := range []bool{true, false} {
		tab := ctx
		if !scripts {
			tab = noScripts(t, ctx)
		}
		for _, w := range []int64{390, 320} {
			for _, locale := range []string{"en", "ar"} {
				for _, anchored := range []bool{true, false} {
					where := fmt.Sprintf("%s/%s index at %dpx, scripts %v, anchor positioning %v", theme, locale, w, scripts, anchored)
					mustRun(t, tab, chromedp.EmulateViewport(w, 700),
						chromedp.Navigate(rig.Origin+pageAt(theme, locale, "index.html")),
						chromedp.WaitVisible(`#ds-prefs`, chromedp.ByQuery))
					if !scripts {
						requireScriptsOff(t, tab, where)
					}
					if !anchored {
						mustRun(t, tab, chromedp.Evaluate(withoutAnchorPositioning, nil,
							func(p *runtime.EvaluateParams) *runtime.EvaluateParams { return p.WithAwaitPromise(true) }))
					}
					requireAnchorPositioning(t, tab, where, "#ds-prefs > [rst-dropdown-menu]", anchored)
					requireCoarse(t, tab)
					requireDrawnScrollbar(t, tab, where)
					mustRun(t, tab, chromedp.Evaluate(`document.getElementById("ds-prefs").open = true;
					  const d = document.querySelector("#ds-prefs [rst-locale]"); d.open = true; d.querySelector("summary").focus(); true`, nil))
					for i, code := range Locales {
						if scripts {
							var got string
							// 0.5px slack: layout at a fractional rem size lands a few
							// hundredths of a pixel past the edge, which no eye and no
							// finger can tell from on screen.
							mustRun(t, tab, chromedp.KeyEvent(kb.Tab), chromedp.Evaluate(`(() => { const a = document.activeElement, r = a.getBoundingClientRect();
							  const de = document.documentElement;
							  return r.top >= -0.5 && r.bottom <= de.clientHeight + 0.5 && r.left >= -0.5 && r.right <= de.clientWidth + 0.5 ? a.lang : "off screen: " + a.outerHTML.slice(0, 60); })()`, &got))
							if got != code {
								t.Errorf("%s: tab %d is %s, want the %s link on screen", where, i+1, got, code)
							}
						}
						var hit bool
						mustRun(t, tab, chromedp.Evaluate(fmt.Sprintf(`(() => {
						  const a = document.querySelector('#ds-prefs [rst-dropdown-menu] a[lang=%q]');
						  a.scrollIntoView({block: "nearest", inline: "nearest"});
						  const r = a.getBoundingClientRect();
						  return document.elementFromPoint((r.left + r.right) / 2, (r.top + r.bottom) / 2) === a;
						})()`, code), &hit))
						if !hit {
							t.Errorf("%s: scrolled into view, the %s link is not what a finger at its centre touches", where, code)
						}
					}
				}
			}
		}
	}

	// Each link followed once, at 390px with scripts: a plain
	// navigation, so the leg polls with until.
	where := theme + "/en index at 390px, scripts on"
	for _, code := range Locales {
		mustRun(t, ctx, chromedp.EmulateViewport(390, 700),
			chromedp.Navigate(rig.Origin+pageAt(theme, "en", "index.html")),
			chromedp.WaitVisible(`#ds-prefs`, chromedp.ByQuery),
			chromedp.Evaluate(open, nil),
			chromedp.Evaluate(fmt.Sprintf(`document.querySelector('#ds-prefs [rst-dropdown-menu] a[lang=%q]').click(); true`, code), nil))
		until(t, ctx, where+", landed on "+code, fmt.Sprintf(`document.documentElement.lang === %q && location.pathname === %q`, code, pageAt(theme, code, "index.html")))
	}

	// With scripts off the link is nothing but its href: one activation
	// through a real navigation.
	offWhere := theme + "/en index at 390px, scripts off"
	off := noScripts(t, ctx)
	mustRun(t, off, chromedp.EmulateViewport(390, 700),
		chromedp.Navigate(rig.Origin+pageAt(theme, "en", "index.html")),
		chromedp.WaitVisible(`#ds-prefs`, chromedp.ByQuery))
	requireScriptsOff(t, off, offWhere)
	mustRun(t, off, chromedp.Evaluate(open, nil),
		chromedp.Evaluate(`document.querySelector('#ds-prefs [rst-dropdown-menu] a[lang="ar"]').click(); true`, nil))
	until(t, off, offWhere+", landed on ar", fmt.Sprintf(`document.documentElement.lang === "ar" && location.pathname === %q`, pageAt(theme, "ar", "index.html")))
	requireScriptsOff(t, off, offWhere+", on the ar index")
}