package e2e

import (
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"testing"
	"time"

	"github.com/go-rod/rod"
	"github.com/go-rod/rod/lib/launcher"
	"github.com/go-rod/rod/lib/proto"
)

// The browser suite covers what needs JavaScript or a real layout engine:
// auto-submitting selects, details popups, the theme script, and the
// responsive layout. Everything else runs without a browser.

// chromePath finds a Chromium binary: HEARTHFORGE_BROWSER, then PATH, then
// a Playwright download. It returns "" when none is installed.
func chromePath() string {
	if p := os.Getenv("HEARTHFORGE_BROWSER"); p != "" {
		return p
	}
	if p, ok := launcher.LookPath(); ok {
		return p
	}
	home, _ := os.UserHomeDir()
	matches, _ := filepath.Glob(filepath.Join(home, ".cache", "ms-playwright", "chromium-*", "chrome-linux*", "chrome"))
	sort.Strings(matches)
	if len(matches) > 0 {
		return matches[len(matches)-1]
	}
	return ""
}

// browser launches headless Chromium for one test.
func browser(t *testing.T) *rod.Browser {
	t.Helper()
	bin := chromePath()
	if bin == "" {
		t.Skip("no Chromium found; set HEARTHFORGE_BROWSER")
	}
	l := launcher.New().Bin(bin).Headless(true).NoSandbox(true)
	u, err := l.Launch()
	if err != nil {
		t.Skipf("launch %s: %v", bin, err)
	}
	b := rod.New().ControlURL(u)
	if err := b.Connect(); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		b.MustClose()
		l.Cleanup()
	})
	return b
}

// pageAs opens a page that carries the session's cookies, so the browser is
// signed in as that user without going through the login form.
func pageAs(t *testing.T, b *rod.Browser, s *session, width int) *rod.Page {
	t.Helper()
	p := b.MustIncognito().MustPage()
	p.MustSetViewport(width, 900, 1, false)
	if c := s.cookie("session"); c != nil {
		p.MustSetCookies(&proto.NetworkCookieParam{Name: c.Name, Value: c.Value, URL: s.env.Base})
	}
	for _, name := range []string{"repo_sort", "theme"} {
		if c := s.cookie(name); c != nil {
			p.MustSetCookies(&proto.NetworkCookieParam{Name: c.Name, Value: c.Value, URL: s.env.Base})
		}
	}
	return p
}

func goTo(p *rod.Page, base, path string) *rod.Page {
	p.Timeout(15 * time.Second).MustNavigate(base + path).MustWaitLoad()
	return p
}

func pathOf(p *rod.Page) string {
	u, _ := url.Parse(p.MustInfo().URL)
	return u.Path
}

func TestBrowser(t *testing.T) {
	e := newEnv(t)
	admin := e.admin()
	e.createRepo(admin, "js-repo")
	e.seedRepo("js-repo", nil)
	admin.post("/js-repo/settings/labels", url.Values{"name": {"bug"}, "color": {"#d73a4a"}})
	admin.post("/js-repo/settings/labels", url.Values{"name": {"docs"}, "color": {"#0075ca"}})
	issue := admin.post("/js-repo/issues", url.Values{
		"title": {"Picker issue"}, "body": {"Body **bold**."},
	}).mustRedirect("/js-repo/issues/")
	admin.post(issue+"/comments", url.Values{"body": {"A comment."}})
	b := browser(t)

	t.Run("sort select auto-submits and sets the cookie", func(t *testing.T) {
		s := e.admin()
		p := pageAs(t, b, s, 1280)
		goTo(p, e.Base, "/")
		wait := p.MustWaitNavigation()
		p.MustElement(".repo-sort-select").MustSelect("Name")
		wait()
		p.MustWaitLoad()
		if got := p.MustElement(".repo-sort-select").MustProperty("value").Str(); got != "name" {
			t.Errorf("sort value after auto-submit = %q", got)
		}
		cookies := p.MustCookies()
		found := false
		for _, c := range cookies {
			if c.Name == "repo_sort" && c.Value == "name" {
				found = true
			}
		}
		if !found {
			t.Error("repo_sort cookie not set to name")
		}
	})

	t.Run("Go button is a noscript fallback", func(t *testing.T) {
		// Rod drives the page with injected JS, so it cannot run with scripts
		// off. The no-JS path is covered by TestSorting posting /sort
		// directly. Here: the fallback is in the HTML, and hidden with JS.
		if !e.admin().get("/").Has(`form[action="/sort"] noscript`) {
			t.Fatal("noscript Go button missing from the HTML")
		}
		p := pageAs(t, b, e.admin(), 1280)
		goTo(p, e.Base, "/")
		if p.MustHas(`form[action="/sort"] button[type=submit]`) {
			t.Error("noscript Go button rendered with JS enabled")
		}
	})

	t.Run("theme cookie applies data-theme before paint", func(t *testing.T) {
		s := e.admin()
		s.post("/settings/theme", url.Values{"theme": {"dark"}})
		p := pageAs(t, b, s, 1280)
		goTo(p, e.Base, "/")
		if got := p.MustEval(`() => document.documentElement.getAttribute("data-theme")`).Str(); got != "dark" {
			t.Errorf("data-theme = %q", got)
		}
	})

	t.Run("reaction picker opens and posts a reaction", func(t *testing.T) {
		p := pageAs(t, b, e.admin(), 1280)
		goTo(p, e.Base, issue)
		p.MustElement(".reaction-picker > summary").MustClick()
		btn := p.MustElement(".reaction-picker-dropdown .reaction-picker-btn")
		if !btn.MustVisible() {
			t.Fatal("picker button not visible after opening")
		}
		wait := p.MustWaitNavigation()
		btn.MustClick()
		wait()
		p.MustWaitLoad()
		if !p.MustHas(".reaction-btn") {
			t.Error("no reaction shown after clicking the picker")
		}
	})

	t.Run("label filter popup applies the filter", func(t *testing.T) {
		p := pageAs(t, b, e.admin(), 1280)
		goTo(p, e.Base, "/js-repo/issues")
		p.MustElement("details.label-filter > summary").MustClick()
		p.MustElement(`.label-filter-popup input[type=checkbox]`).MustClick()
		wait := p.MustWaitNavigation()
		p.MustElement(`.label-filter-popup button[type=submit]`).MustClick()
		wait()
		p.MustWaitLoad()
		u, _ := url.Parse(p.MustInfo().URL)
		if u.Query().Get("labels") == "" {
			t.Errorf("filter did not add labels param: %s", u)
		}
	})

	t.Run("create-tag checkbox reveals the tag fields", func(t *testing.T) {
		p := pageAs(t, b, e.admin(), 1280)
		goTo(p, e.Base, "/js-repo/releases/new")
		group := p.MustElement("#tag-fields-group")
		if group.MustVisible() {
			t.Fatal("tag fields visible before the checkbox is ticked")
		}
		p.MustElement("#create_tag").MustClick()
		if !group.MustVisible() {
			t.Error("tag fields hidden after the checkbox is ticked")
		}
	})

	t.Run("login form works in a browser", func(t *testing.T) {
		p := b.MustIncognito().MustPage()
		goTo(p, e.Base, "/login")
		p.MustElement("[name=username]").MustInput("admin")
		p.MustElement("[name=password]").MustInput(adminPass)
		wait := p.MustWaitNavigation()
		p.MustElement("button[type=submit]").MustClick()
		wait()
		p.MustWaitLoad()
		if pathOf(p) != "/" || !p.MustHas(".nav-user") {
			t.Errorf("after login: path %s, nav-user %v", pathOf(p), p.MustHas(".nav-user"))
		}
	})

	t.Run("no horizontal overflow at 360 and 1280", func(t *testing.T) {
		sha := e.headCommit("js-repo")
		pages := []string{
			"/", "/js-repo", "/js-repo/issues", issue, "/js-repo/commits/main",
			"/js-repo/commit/" + sha, "/js-repo/blob/main/index.js", "/js-repo/settings",
			"/settings", "/login",
		}
		// 360, not 320: a classic 15px scrollbar plus the 320px body floor
		// would always scroll at exactly 320.
		for _, width := range []int{360, 1280} {
			p := pageAs(t, b, e.admin(), width)
			for _, path := range pages {
				goTo(p, e.Base, path)
				sw := p.MustEval(`() => document.documentElement.scrollWidth`).Int()
				cw := p.MustEval(`() => document.documentElement.clientWidth`).Int()
				if sw > cw {
					t.Errorf("%s at %dpx: scrollWidth %d > clientWidth %d", path, width, sw, cw)
				}
			}
		}
	})

	t.Run("raw svg document cannot read cookies", func(t *testing.T) {
		p := pageAs(t, b, e.admin(), 1280)
		goTo(p, e.Base, "/js-repo/raw/main/logo.svg")
		res := p.MustEval(`() => { try { return "ok:" + document.cookie } catch (e) { return "err:" + e.name } }`).Str()
		if !strings.HasPrefix(res, "err:") {
			t.Errorf("raw svg could read document.cookie: %s", res)
		}
	})
}

// TestBrowserConsoleClean loads the main pages and fails on any console
// error, which catches broken asset paths and script errors.
func TestBrowserConsoleClean(t *testing.T) {
	e := newEnv(t)
	admin := e.admin()
	e.createRepo(admin, "console-repo")
	e.seedRepo("console-repo", nil)
	b := browser(t)
	p := pageAs(t, b, e.admin(), 1280)

	var errs []string
	go p.EachEvent(func(ev *proto.RuntimeExceptionThrown) {
		errs = append(errs, ev.ExceptionDetails.Text)
	}, func(ev *proto.LogEntryAdded) {
		if ev.Entry.Level == proto.LogLogEntryLevelError {
			errs = append(errs, fmt.Sprintf("%s %s", ev.Entry.Source, ev.Entry.Text))
		}
	})()
	for _, path := range []string{"/", "/console-repo", "/console-repo/issues", "/settings", "/login", "/register"} {
		goTo(p, e.Base, path)
	}
	time.Sleep(200 * time.Millisecond)
	if len(errs) > 0 {
		t.Errorf("console errors:\n%s", strings.Join(errs, "\n"))
	}
}