package e2e

import (
	"net/url"
	"slices"
	"strings"
	"testing"

	"github.com/PuerkitoBio/goquery"
)

// goquerySel shortens the selection type used in the Each callbacks below.
type goquerySel = goquery.Selection

// navSwitchBranch submits the branch selector of the given page the way a
// browser without JavaScript would: a plain GET of the form action with the
// form's hidden fields plus the chosen revision.
func navSwitchBranch(t *testing.T, s *session, page, rev string) *response {
	t.Helper()
	r := s.get(page)
	form := r.Find("form.branch-selector").First()
	action, ok := form.Attr("action")
	if !ok {
		t.Fatalf("no branch selector form on %s", page)
	}
	q := url.Values{"rev": {rev}}
	form.Find(`input[type="hidden"]`).Each(func(_ int, in *goquerySel) {
		name, _ := in.Attr("name")
		value, _ := in.Attr("value")
		if name != "" {
			q.Set(name, value)
		}
	})
	return s.get(action + "?" + q.Encode())
}

func TestNavigation(t *testing.T) {
	e := newEnv(t)
	admin := e.admin()
	e.createRepo(admin, "my-repo")
	e.seedRepo("my-repo", nil)

	// ─── Branch selector ───────────────────────────────────────────────────
	// A second branch makes the selector meaningful.
	e.seedBranch("my-repo", "dev", nil)

	t.Run("branch selector appears on repo home", func(t *testing.T) {
		r := admin.get("/my-repo")
		if !r.Has(".branch-selector") {
			t.Fatal("branch-selector missing")
		}
		if got := r.Value(".branch-select"); got != "main" {
			t.Errorf("selected branch = %q", got)
		}
	})

	t.Run("branch selector shows all branches on repo home", func(t *testing.T) {
		opts := admin.get("/my-repo").Texts(".branch-select option")
		if !slices.Contains(opts, "main") || !slices.Contains(opts, "dev") {
			t.Errorf("options = %v", opts)
		}
	})

	t.Run("branch selector appears on file tree with current ref selected", func(t *testing.T) {
		r := admin.get("/my-repo/tree/main")
		if !r.Has(".branch-selector") {
			t.Fatal("branch-selector missing")
		}
		if got := r.Value(".branch-select"); got != "main" {
			t.Errorf("selected branch = %q", got)
		}
	})

	t.Run("branch selector appears on commit log with current ref selected", func(t *testing.T) {
		r := admin.get("/my-repo/commits/main")
		if !r.Has(".branch-selector") {
			t.Fatal("branch-selector missing")
		}
		if got := r.Value(".branch-select"); got != "main" {
			t.Errorf("selected branch = %q", got)
		}
	})

	t.Run("branch selector appears on file blob", func(t *testing.T) {
		r := admin.get("/my-repo/blob/main/README.md")
		if !r.Has(".branch-selector") {
			t.Fatal("branch-selector missing")
		}
		if got := r.Value(".branch-select"); got != "main" {
			t.Errorf("selected branch = %q", got)
		}
	})

	t.Run("switching branch on commit log navigates to the selected branch", func(t *testing.T) {
		loc := navSwitchBranch(t, admin, "/my-repo/commits/main", "dev").mustRedirect("/my-repo")
		if !strings.Contains(loc, "/commits/dev") {
			t.Errorf("location = %q", loc)
		}
	})

	t.Run("switching branch on file tree navigates to the selected branch", func(t *testing.T) {
		loc := navSwitchBranch(t, admin, "/my-repo/tree/main", "dev").mustRedirect("/my-repo")
		if !strings.Contains(loc, "/tree/dev") {
			t.Errorf("location = %q", loc)
		}
	})

	t.Run("branch-switch route preserves subpath when switching tree", func(t *testing.T) {
		loc := admin.get("/my-repo/branch-switch?view=tree&rev=dev&path=src/foo").Location()
		if !strings.Contains(loc, "/tree/dev/src/foo") {
			t.Errorf("location = %q", loc)
		}
	})

	t.Run("branch-switch route redirects commits view correctly", func(t *testing.T) {
		loc := admin.get("/my-repo/branch-switch?view=commits&rev=dev").Location()
		if !strings.Contains(loc, "/commits/dev") {
			t.Errorf("location = %q", loc)
		}
	})

	t.Run("branch-switch route redirects blob view correctly", func(t *testing.T) {
		loc := admin.get("/my-repo/branch-switch?view=blob&rev=dev&path=README.md").Location()
		if !strings.Contains(loc, "/blob/dev/README.md") {
			t.Errorf("location = %q", loc)
		}
	})

	// ─── Default branch settings ───────────────────────────────────────────

	t.Run("settings page shows default branch select", func(t *testing.T) {
		r := admin.get("/my-repo/settings")
		if !r.Has("#default_branch") {
			t.Fatal("#default_branch missing")
		}
		opts := r.Texts("#default_branch option")
		if !slices.Contains(opts, "main") || !slices.Contains(opts, "dev") {
			t.Errorf("options = %v", opts)
		}
	})

	t.Run("current default branch is pre-selected", func(t *testing.T) {
		if got := admin.get("/my-repo/settings").Value("#default_branch"); got != "main" {
			t.Errorf("default branch = %q", got)
		}
	})

	t.Run("changing default branch saves and is reflected in the repo home", func(t *testing.T) {
		r := admin.follow(admin.post("/my-repo/settings", url.Values{"default_branch": {"dev"}}))
		if !r.Has(".form-success") {
			t.Fatal("form-success missing")
		}
		if got := r.Value("#default_branch"); got != "dev" {
			t.Errorf("default branch = %q", got)
		}
		if got := admin.get("/my-repo").Value(".branch-select"); got != "dev" {
			t.Errorf("repo home branch = %q", got)
		}
	})

	t.Run("commit log link in repo nav uses the new default branch", func(t *testing.T) {
		href := admin.get("/my-repo").Attr(`.repo-tab[href*="/commits/"]`, "href")
		if !strings.Contains(href, "/commits/dev") {
			t.Errorf("commits href = %q", href)
		}
	})

	t.Run("changing default branch back to main restores original state", func(t *testing.T) {
		r := admin.follow(admin.post("/my-repo/settings", url.Values{"default_branch": {"main"}}))
		if !r.Has(".form-success") {
			t.Fatal("form-success missing")
		}
		if got := r.Value("#default_branch"); got != "main" {
			t.Errorf("default branch = %q", got)
		}
	})

	t.Run("settings page shows hint instead of select when repo has no branches", func(t *testing.T) {
		e.createRepo(admin, "empty-for-branch-test")
		r := admin.get("/empty-for-branch-test/settings")
		if n := r.Count("#default_branch"); n != 0 {
			t.Errorf("#default_branch count = %d", n)
		}
		if !r.Has(".form-hint") {
			t.Error("form-hint missing")
		}
	})

	// ─── File browser ──────────────────────────────────────────────────────
	// A subdirectory makes directory navigation testable.
	e.seedRepo("my-repo", map[string]string{
		"src/app.ts":    "export {};\n",
		"src/README.md": "# src readme\n",
	}, "Add src")

	t.Run("repo home shows file tree instead of recent commits", func(t *testing.T) {
		r := admin.get("/my-repo")
		if !r.Has(".file-tree") {
			t.Error("file-tree missing")
		}
		if n := r.Count(".repo-commits-section"); n != 0 {
			t.Errorf("repo-commits-section count = %d", n)
		}
	})

	t.Run("repo home file tree lists files and directories", func(t *testing.T) {
		names := admin.get("/my-repo").Texts(".file-name a")
		for _, want := range []string{"README.md", "index.js", "src"} {
			if !slices.Contains(names, want) {
				t.Errorf("names %v missing %q", names, want)
			}
		}
	})

	t.Run("directories appear before files in file tree", func(t *testing.T) {
		names := admin.get("/my-repo").Texts(".file-name a")
		srcIdx := slices.Index(names, "src")
		readmeIdx := slices.Index(names, "README.md")
		if srcIdx < 0 || readmeIdx < 0 || srcIdx >= readmeIdx {
			t.Errorf("src at %d, README.md at %d in %v", srcIdx, readmeIdx, names)
		}
	})

	t.Run("no .. entry at repository root", func(t *testing.T) {
		if names := admin.get("/my-repo").Texts(".file-name a"); slices.Contains(names, "..") {
			t.Errorf("names = %v", names)
		}
	})

	t.Run("clicking directory navigates into it", func(t *testing.T) {
		href := ""
		admin.get("/my-repo").Find(".file-name a").Each(func(_ int, s *goquerySel) {
			if strings.TrimSpace(s.Text()) == "src" {
				href, _ = s.Attr("href")
			}
		})
		if href != "/my-repo/tree/main/src" {
			t.Fatalf("src href = %q", href)
		}
		admin.get(href).mustStatus(200)
	})

	t.Run(".. entry appears in subdirectory", func(t *testing.T) {
		names := admin.get("/my-repo/tree/main/src").Texts(".file-name a")
		if !slices.Contains(names, "..") {
			t.Errorf("names = %v", names)
		}
	})

	t.Run(".. at one level deep links to tree root", func(t *testing.T) {
		up := ""
		admin.get("/my-repo/tree/main/src").Find(".file-name a").Each(func(_ int, s *goquerySel) {
			if strings.TrimSpace(s.Text()) == ".." {
				up, _ = s.Attr("href")
			}
		})
		if up != "/my-repo/tree/main" {
			t.Errorf("up href = %q", up)
		}
	})

	t.Run("files in subdirectory show plain names, not full paths", func(t *testing.T) {
		names := admin.get("/my-repo/tree/main/src").Texts(".file-name a")
		if !slices.Contains(names, "app.ts") {
			t.Errorf("names = %v", names)
		}
		for _, bad := range []string{"src/app.ts", "src/README.md"} {
			if slices.Contains(names, bad) {
				t.Errorf("names %v contains full path %q", names, bad)
			}
		}
	})

	t.Run("readme is shown below file tree on repo home", func(t *testing.T) {
		// Geometry needs a browser; document order carries the same intent.
		body := admin.get("/my-repo").BodyString()
		tree := strings.Index(body, `class="file-tree"`)
		readme := strings.Index(body, `class="readme-section"`)
		if tree < 0 || readme < 0 || readme < tree {
			t.Errorf("file-tree at %d, readme-section at %d", tree, readme)
		}
	})

	t.Run("readme in subdirectory is shown when present", func(t *testing.T) {
		r := admin.get("/my-repo/tree/main/src")
		if !r.Has(".readme-section") {
			t.Fatal("readme-section missing")
		}
		html, _ := r.Find(".readme-section .markdown-body").Html()
		if !strings.Contains(html, "src readme") {
			t.Errorf("readme html = %q", html)
		}
	})

	t.Run("file tree on /tree/:ref also shows readme", func(t *testing.T) {
		r := admin.get("/my-repo/tree/main")
		if !r.Has(".file-tree") {
			t.Error("file-tree missing")
		}
		if !r.Has(".readme-section") {
			t.Error("readme-section missing")
		}
	})
}