//go:build browser

package gallery

import (
	"context"
	"net/http"
	"testing"
	"time"

	"github.com/chromedp/chromedp"

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

// A section that moved pages. A fragment that names nothing on this
// page is looked up in the rail, which links every section on every
// page, and followed by location.replace to the page that has it. Two
// lookups: a rail link whose fragment is the one asked for (an icon
// asked of the Tokens page), and, Fiesta's own, a rail link whose page
// stem is the fragment (#button on a page that is not button.html,
// which is where part 3 kept the button).

// TestAMovedSectionsOldLinkReachesIt: index.html#button lands on
// button.html and tokens.html#icon-check on icons.html#icon-check with
// the icon on screen, each replacing rather than pushing the address.
// A fragment that is on the page, one the rail does not know, and the
// skip link's target are left alone.
func TestAMovedSectionsOldLinkReachesIt(t *testing.T) {
	rig := harness.New(t, func(string) http.Handler { return treeHandler(t) })
	ctx, cancel := context.WithTimeout(rig.Context(), 60*time.Second)
	defer cancel()
	theme := fiesta.ThemeNames()[0]
	index := rig.Origin + pageAt(theme, "en", "index.html")
	tokens := rig.Origin + pageAt(theme, "en", "tokens.html")

	start := time.Now()
	where := "index.html#button"
	mustRun(t, ctx, chromedp.EmulateViewport(1280, 900), chromedp.Navigate(index+"#button"), chromedp.WaitReady("body"))
	present(t, ctx, where, "#ds-nav")
	until(t, ctx, where, `location.pathname.endsWith("/button.html") && location.hash === "" && document.readyState === "complete"`)
	var depth int
	mustRun(t, ctx, chromedp.Evaluate(`history.length`, &depth))
	if depth != 2 {
		t.Errorf("%s: history is %d deep after the redirect, want 2 (about:blank, then the page); the old address was pushed rather than replaced", where, depth)
	}
	settle := 2*time.Since(start) + time.Second

	where = "tokens.html#icon-check"
	mustRun(t, ctx, chromedp.Navigate(tokens+"#icon-check"))
	until(t, ctx, where, `location.pathname.endsWith("/icons.html") && location.hash === "#icon-check" && document.readyState === "complete" && (() => { const r = document.getElementById("icon-check").getBoundingClientRect(); return r.top >= 0 && r.top < innerHeight; })()`)

	for _, c := range []struct{ hash, want string }{
		{"#tokens-accent", "a group that is on Tokens"},
		{"#nope", "a fragment the rail does not know"},
		{"#main", "the skip link's target, which is not a section"},
	} {
		where := "tokens.html" + c.hash + ", " + c.want
		mustRun(t, ctx, chromedp.Navigate(tokens+c.hash))
		until(t, ctx, where, `document.readyState === "complete"`)
		time.Sleep(settle)
		var href string
		mustRun(t, ctx, chromedp.Evaluate(`location.href`, &href))
		if href != tokens+c.hash {
			t.Errorf("%s: the page moved to %s; %s is left alone", where, href, c.want)
		}
	}
}

// TestAMovedSectionsOldLinkReachesItFromAnOpenPage: the same old link
// followed with the page already open. Only the fragment changes, so
// nothing is loaded and readiness never fires again; the lookup has to
// run on hashchange too.
func TestAMovedSectionsOldLinkReachesItFromAnOpenPage(t *testing.T) {
	rig := harness.New(t, func(string) http.Handler { return treeHandler(t) })
	ctx, cancel := context.WithTimeout(rig.Context(), 60*time.Second)
	defer cancel()
	theme := fiesta.ThemeNames()[0]
	where := "tokens.html open, then #icon-check"
	mustRun(t, ctx, chromedp.EmulateViewport(1280, 900), chromedp.Navigate(rig.Origin+pageAt(theme, "en", "tokens.html")), chromedp.WaitReady("body"))
	present(t, ctx, where, "#ds-nav")
	until(t, ctx, where+", Tokens loaded", `document.readyState === "complete"`)
	mustRun(t, ctx, chromedp.Evaluate(`location.hash = "#icon-check"; true`, nil))
	until(t, ctx, where, `location.pathname.endsWith("/icons.html") && location.hash === "#icon-check" && document.readyState === "complete" && (() => { const r = document.getElementById("icon-check").getBoundingClientRect(); return r.top >= 0 && r.top < innerHeight; })()`)
}