package e2e

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

	"github.com/PuerkitoBio/goquery"
)

// labelsPatch is a minimal but complete format-patch file.
func labelsPatch(file string) string {
	return strings.Join([]string{
		"From a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2 Mon Sep 17 00:00:00 2001",
		"From: Test User <test@example.com>",
		"Date: Mon, 01 Jan 2024 12:00:00 +0000",
		"Subject: [PATCH] Add " + file,
		"",
		"---",
		"diff --git a/" + file + " b/" + file,
		"new file mode 100644",
		"index 0000000..9daeafb",
		"--- /dev/null",
		"+++ b/" + file,
		"@@ -0,0 +1 @@",
		"+x",
		"",
	}, "\n")
}

// labelsCreate posts the label form on the repo settings page.
func labelsCreate(s *session, repo, name, color string) *response {
	return s.post("/"+repo+"/settings/labels", url.Values{"name": {name}, "color": {color}})
}

// labelsSettingsID returns the id of the named label, read from its delete
// form on the settings page.
func labelsSettingsID(t *testing.T, s *session, repo, name string) string {
	t.Helper()
	id := ""
	s.get("/" + repo + "/settings").Find(".label-settings-item").Each(func(_ int, sel *goquery.Selection) {
		if id == "" && strings.TrimSpace(sel.Find(".label-settings-name").Text()) == name {
			id, _ = sel.Find("input[name=id]").Attr("value")
		}
	})
	if id == "" {
		t.Fatalf("label %q not found in settings", name)
	}
	return id
}

// labelsFilterID returns the label id of the named filter checkbox on a list
// page such as /repo/issues.
func labelsFilterID(t *testing.T, s *session, path, name string) string {
	t.Helper()
	id := ""
	s.get(path).Find(".label-filter-item").Each(func(_ int, sel *goquery.Selection) {
		if id == "" && strings.Contains(sel.Text(), name) {
			id, _ = sel.Find("input[name=labels]").Attr("value")
		}
	})
	if id == "" {
		t.Fatalf("label %q not found in filter popup of %s", name, path)
	}
	return id
}

// labelsItemWith returns the list item whose text contains want.
func labelsItemWith(t *testing.T, r *response, want string) *goquery.Selection {
	t.Helper()
	var found *goquery.Selection
	r.Find(".issue-item").Each(func(_ int, s *goquery.Selection) {
		if found == nil && strings.Contains(s.Text(), want) {
			found = s
		}
	})
	if found == nil {
		t.Fatalf("no list item containing %q", want)
	}
	return found
}

// labelsTexts returns the trimmed text of every match inside a selection.
func labelsTexts(sel *goquery.Selection, css string) []string {
	var out []string
	sel.Find(css).Each(func(_ int, s *goquery.Selection) {
		out = append(out, strings.TrimSpace(s.Text()))
	})
	return out
}

func labelsHas(list []string, want string) bool {
	for _, s := range list {
		if s == want {
			return true
		}
	}
	return false
}

func TestLabels(t *testing.T) {
	e := newEnv(t)
	e.register("alice", "password123")
	admin := e.admin()

	e.createRepo(admin, "label-repo")
	issuePath := issuesCreate(admin, "label-repo", "Labelled issue", "")
	patchPath := admin.postMultipart("/label-repo/patches",
		url.Values{"title": {"Labelled patch"}},
		file{Field: "patch_file", Name: "label-test.patch", Content: []byte(labelsPatch("label-test.txt"))},
	).mustRedirect("/label-repo/patches/")

	t.Run("create label in repo settings", func(t *testing.T) {
		r := admin.follow(labelsCreate(admin, "label-repo", "bug", "#ff0000"))
		if !contains(r.Texts(".label-settings-name"), "bug") {
			t.Error("label not listed")
		}
	})

	t.Run("create a second label", func(t *testing.T) {
		r := admin.follow(labelsCreate(admin, "label-repo", "enhancement", "#00aa00"))
		names := r.Texts(".label-settings-name")
		if !labelsHas(names, "bug") || !labelsHas(names, "enhancement") {
			t.Errorf("labels = %q", names)
		}
	})

	t.Run("duplicate label name is rejected", func(t *testing.T) {
		if !admin.follow(labelsCreate(admin, "label-repo", "bug", "#0000ff")).Has(".form-error") {
			t.Error("no error message")
		}
	})

	t.Run("non-admin cannot create labels", func(t *testing.T) {
		r := e.anon().post("/label-repo/settings/labels",
			url.Values{"name": {"nope"}, "color": {"#123456"}})
		r.mustStatus(http.StatusFound)
		if !strings.Contains(r.Location(), "/login") {
			t.Errorf("location = %q", r.Location())
		}
	})

	t.Run("assign label to issue", func(t *testing.T) {
		bug := labelsSettingsID(t, admin, "label-repo", "bug")
		admin.post(issuePath+"/labels/add", url.Values{"label_id": {bug}}).mustRedirect(issuePath)
		if !labelsHas(admin.get(issuePath).Texts(".label-badge"), "bug") {
			t.Error("label badge missing")
		}
	})

	t.Run("label appears on issue list", func(t *testing.T) {
		item := labelsItemWith(t, admin.get("/label-repo/issues"), "Labelled issue")
		if !labelsHas(labelsTexts(item, ".label-badge"), "bug") {
			t.Error("label badge missing on list")
		}
	})

	t.Run("filter issues by label shows only matching issues", func(t *testing.T) {
		issuesCreate(admin, "label-repo", "Unlabelled issue", "")
		id := labelsFilterID(t, admin, "/label-repo/issues", "bug")
		titles := admin.get("/label-repo/issues?labels=" + id).Texts(".issue-title")
		if !contains(titles, "Labelled issue") || contains(titles, "Unlabelled issue") {
			t.Errorf("titles = %q", titles)
		}
	})

	t.Run("filter popup is visible without JS", func(t *testing.T) {
		r := admin.get("/label-repo/issues")
		if !r.Has("details.label-filter") || !r.Has("details.label-filter summary") {
			t.Error("filter popup not rendered")
		}
	})

	t.Run("remove label from issue", func(t *testing.T) {
		id := admin.get(issuePath).Attr(".issue-labels-row .label-remove-form input[name=label_id]", "value")
		admin.post(issuePath+"/labels/remove", url.Values{"label_id": {id}}).mustRedirect(issuePath)
		if labelsHas(admin.get(issuePath).Texts(".issue-labels-row .label-badge"), "bug") {
			t.Error("label still attached")
		}
	})

	t.Run("assign label to patch", func(t *testing.T) {
		enh := labelsSettingsID(t, admin, "label-repo", "enhancement")
		admin.post(patchPath+"/labels/add", url.Values{"label_id": {enh}}).mustRedirect(patchPath)
		if !labelsHas(admin.get(patchPath).Texts(".label-badge"), "enhancement") {
			t.Error("label badge missing")
		}
	})

	t.Run("label appears on patch list", func(t *testing.T) {
		item := labelsItemWith(t, admin.get("/label-repo/patches"), "Labelled patch")
		if !labelsHas(labelsTexts(item, ".label-badge"), "enhancement") {
			t.Error("label badge missing on list")
		}
	})

	t.Run("filter patches by label", func(t *testing.T) {
		id := labelsFilterID(t, admin, "/label-repo/patches", "enhancement")
		titles := admin.get("/label-repo/patches?labels=" + id).Texts(".issue-title")
		if !contains(titles, "Labelled patch") {
			t.Errorf("titles = %q", titles)
		}
	})

	t.Run("remove label from patch", func(t *testing.T) {
		id := admin.get(patchPath).Attr(".issue-labels-row .label-remove-form input[name=label_id]", "value")
		admin.post(patchPath+"/labels/remove", url.Values{"label_id": {id}}).mustRedirect(patchPath)
		if labelsHas(admin.get(patchPath).Texts(".issue-labels-row .label-badge"), "enhancement") {
			t.Error("label still attached")
		}
	})

	t.Run("delete label removes it from settings list", func(t *testing.T) {
		bug := labelsSettingsID(t, admin, "label-repo", "bug")
		r := admin.follow(admin.post("/label-repo/settings/labels/delete", url.Values{"id": {bug}}))
		if labelsHas(r.Texts(".label-settings-name"), "bug") {
			t.Error("label still listed")
		}
	})

	t.Run("deleted label no longer appears in filter popup", func(t *testing.T) {
		if contains(admin.get("/label-repo/issues").Texts(".label-filter-item"), "bug") {
			t.Error("deleted label still in filter popup")
		}
	})
}

func TestUserLabelManagement(t *testing.T) {
	e := newEnv(t)
	alice := e.register("alice", "password123")
	admin := e.admin()

	e.createRepo(admin, "ulm-repo")
	for _, name := range []string{"bug", "feature"} {
		labelsCreate(admin, "ulm-repo", name, "#808080").mustRedirect("/ulm-repo/settings")
	}
	adminIssuePath := issuesCreate(admin, "ulm-repo", "Admin's issue", "")
	aliceIssuePath := issuesCreate(alice, "ulm-repo", "Alice's issue", "")
	bugLabelID := labelsFilterID(t, admin, "/ulm-repo/issues", "bug")

	checked := "input[name=allow_user_labels][checked]"

	t.Run("allow_user_labels checkbox is present in repo settings", func(t *testing.T) {
		if n := admin.get("/ulm-repo/settings").Count("input[name=allow_user_labels]"); n != 1 {
			t.Errorf("checkbox count = %d", n)
		}
	})

	t.Run("allow_user_labels is off by default", func(t *testing.T) {
		if admin.get("/ulm-repo/settings").Has(checked) {
			t.Error("checkbox is checked")
		}
	})

	t.Run("label checkboxes not shown to non-admin on new issue form when allow_user_labels is off", func(t *testing.T) {
		if n := alice.get("/ulm-repo/issues/new").Count(".label-checkbox-list"); n != 0 {
			t.Errorf("label lists = %d", n)
		}
	})

	t.Run("label checkboxes not shown to non-admin on new patch form when allow_user_labels is off", func(t *testing.T) {
		if n := alice.get("/ulm-repo/patches/new").Count(".label-checkbox-list"); n != 0 {
			t.Errorf("label lists = %d", n)
		}
	})

	t.Run("label checkboxes shown to admin on new issue form regardless of setting", func(t *testing.T) {
		if !admin.get("/ulm-repo/issues/new").Has(".label-checkbox-list") {
			t.Error("label list missing")
		}
	})

	t.Run("admin can enable allow_user_labels", func(t *testing.T) {
		issuesSaveSettings(admin, "ulm-repo", url.Values{"allow_user_labels": {"1"}}).
			mustRedirect("/ulm-repo/settings")
		if !admin.get("/ulm-repo/settings").Has(checked) {
			t.Error("setting did not persist")
		}
	})

	t.Run("label checkboxes shown to non-admin on new issue form when allow_user_labels is on", func(t *testing.T) {
		r := alice.get("/ulm-repo/issues/new")
		if !r.Has(".label-checkbox-list") {
			t.Fatal("label list missing")
		}
		labels := r.Texts(".label-checkbox-list .label-badge")
		if !labelsHas(labels, "bug") || !labelsHas(labels, "feature") {
			t.Errorf("labels = %q", labels)
		}
	})

	t.Run("label checkboxes shown to non-admin on new patch form when allow_user_labels is on", func(t *testing.T) {
		if !alice.get("/ulm-repo/patches/new").Has(".label-checkbox-list") {
			t.Error("label list missing")
		}
	})

	t.Run("non-admin can create issue with label selected", func(t *testing.T) {
		p := alice.post("/ulm-repo/issues", url.Values{
			"title": {"Issue with label"}, "label_ids": {bugLabelID},
		}).mustRedirect("/ulm-repo/issues/")
		if !labelsHas(alice.get(p).Texts(".label-badge"), "bug") {
			t.Error("label not applied")
		}
	})

	t.Run("non-admin can create patch with label selected", func(t *testing.T) {
		featureID := labelsFilterID(t, admin, "/ulm-repo/issues", "feature")
		p := alice.postMultipart("/ulm-repo/patches",
			url.Values{"title": {"Patch with label"}, "label_ids": {featureID}},
			file{Field: "patch_file", Name: "ulm-test.patch", Content: []byte(labelsPatch("ulm-test.txt"))},
		).mustRedirect("/ulm-repo/patches/")
		if !labelsHas(alice.get(p).Texts(".label-badge"), "feature") {
			t.Error("label not applied")
		}
	})

	t.Run("label_ids in POST are ignored for non-admin when allow_user_labels is off (no label applied)", func(t *testing.T) {
		// Post the settings form without allow_user_labels to switch it off.
		admin.post("/ulm-repo/settings", url.Values{"description": {""}, "default_branch": {"main"}})

		p := alice.post("/ulm-repo/issues", url.Values{
			"title": {"Issue sneaking labels"}, "label_ids": {bugLabelID},
		}).mustRedirect("/ulm-repo/issues/")
		if labelsHas(alice.get(p).Texts(".label-badge"), "bug") {
			t.Error("label was applied")
		}

		admin.post("/ulm-repo/settings", url.Values{
			"description": {""}, "default_branch": {"main"}, "allow_user_labels": {"1"},
		})
	})

	t.Run("non-admin can add label to their own issue", func(t *testing.T) {
		alice.post(aliceIssuePath+"/labels/add", url.Values{"label_id": {bugLabelID}}).
			mustRedirect(aliceIssuePath)
		if !labelsHas(alice.get(aliceIssuePath).Texts(".label-badge"), "bug") {
			t.Error("label not applied")
		}
	})

	t.Run("non-admin can remove label from their own issue", func(t *testing.T) {
		alice.post(aliceIssuePath+"/labels/remove", url.Values{"label_id": {bugLabelID}}).
			mustRedirect(aliceIssuePath)
		if labelsHas(alice.get(aliceIssuePath).Texts(".issue-labels-row .label-badge"), "bug") {
			t.Error("label still attached")
		}
	})

	t.Run("non-admin cannot add label to another user's issue", func(t *testing.T) {
		alice.post(adminIssuePath+"/labels/add", url.Values{"label_id": {bugLabelID}}).
			mustStatus(http.StatusForbidden)
	})

	t.Run("unauthenticated user gets 401 adding a label", func(t *testing.T) {
		e.anon().post(aliceIssuePath+"/labels/add", url.Values{"label_id": {bugLabelID}}).
			mustStatus(http.StatusUnauthorized)
	})

	t.Run("admin can disable allow_user_labels", func(t *testing.T) {
		issuesSaveSettings(admin, "ulm-repo", url.Values{"allow_user_labels": nil}).
			mustRedirect("/ulm-repo/settings")
		if admin.get("/ulm-repo/settings").Has(checked) {
			t.Error("setting still on")
		}
	})

	t.Run("non-admin gets 403 adding label to own issue when allow_user_labels is off", func(t *testing.T) {
		alice.post(aliceIssuePath+"/labels/add", url.Values{"label_id": {bugLabelID}}).
			mustStatus(http.StatusForbidden)
	})

	t.Run("label checkboxes hidden on new issue form after allow_user_labels disabled", func(t *testing.T) {
		if n := alice.get("/ulm-repo/issues/new").Count(".label-checkbox-list"); n != 0 {
			t.Errorf("label lists = %d", n)
		}
	})
}