package main

import (
	"net/url"
	"os"
	"strings"
	"testing"
	"time"

	"golang.org/x/net/html"
)

func TestInferAssignmentDate(t *testing.T) {
	now := time.Date(2026, 3, 28, 10, 0, 0, 0, time.UTC)
	got := inferAssignmentDate("Jan 20", now)
	want := time.Date(2026, 1, 20, 0, 0, 0, 0, time.UTC)
	if !got.Equal(want) {
		t.Fatalf("got %s want %s", got, want)
	}
}

func TestInferAssignmentDateRollsBackYear(t *testing.T) {
	now := time.Date(2026, 3, 28, 10, 0, 0, 0, time.UTC)
	got := inferAssignmentDate("Dec 15", now)
	want := time.Date(2025, 12, 15, 0, 0, 0, 0, time.UTC)
	if !got.Equal(want) {
		t.Fatalf("got %s want %s", got, want)
	}
}

func TestInferUpcomingDateRollsForwardYear(t *testing.T) {
	now := time.Date(2026, 12, 28, 10, 0, 0, 0, time.UTC)
	got := inferUpcomingDate("Jan 03", now)
	want := time.Date(2027, 1, 3, 0, 0, 0, 0, time.UTC)
	if !got.Equal(want) {
		t.Fatalf("got %s want %s", got, want)
	}
}

func TestFilterUpcomingAssignments(t *testing.T) {
	now := time.Date(2026, 3, 28, 10, 0, 0, 0, time.UTC)
	assignments := []Assignment{
		{DueDate: time.Date(2026, 3, 29, 0, 0, 0, 0, time.UTC), Title: "Soon"},
		{DueDate: time.Date(2026, 4, 20, 0, 0, 0, 0, time.UTC), Title: "Later"},
		{DueDate: time.Date(2026, 3, 30, 0, 0, 0, 0, time.UTC), Title: "Preparedness", Category: "Preparedness"},
		{DueDate: time.Date(2026, 3, 31, 0, 0, 0, 0, time.UTC), Title: "Weekly assessment", Category: "R.I.C.E. (weekly assessment)"},
	}
	got := filterUpcomingAssignments(assignments, now, 14)
	if len(got) != 1 || got[0].Title != "Soon" {
		t.Fatalf("unexpected filtered assignments: %#v", got)
	}
}

func TestFilterMissingAssignmentsHidesRevisionForCurrentA(t *testing.T) {
	start := time.Date(2026, 1, 20, 0, 0, 0, 0, time.UTC)
	assignments := []Assignment{
		{
			DueDate: time.Date(2026, 3, 20, 0, 0, 0, 0, time.UTC),
			Course:  "Geometry Lab",
			Title:   "Revise me",
			Status:  "Revision Needed",
		},
		{
			DueDate: time.Date(2026, 3, 21, 0, 0, 0, 0, time.UTC),
			Course:  "Geometry Lab",
			Title:   "Still missing",
			Status:  "Missing",
		},
	}
	got := filterMissingAssignments(assignments, start, map[string]struct{}{"geometry lab": {}})
	if len(got) != 1 || got[0].Title != "Still missing" {
		t.Fatalf("unexpected filtered assignments: %#v", got)
	}
}

func TestDedupeAssignments(t *testing.T) {
	assignment := Assignment{
		DueDate: time.Date(2026, 4, 1, 0, 0, 0, 0, time.UTC),
		Title:   "Preparedness",
		Link:    "https://example.invalid/a",
	}
	got := dedupeAssignments([]Assignment{assignment, assignment})
	if len(got) != 1 {
		t.Fatalf("got %d items", len(got))
	}
}

func TestExtractLikeLiveMissingTable(t *testing.T) {
	doc := mustParseHTML(`
<table class="pure-table pure-table-horizontal missing-assignments">
  <tbody>
    <tr>
      <td>Mar<br>25</td>
      <td>
        <small><a href="/class/1">US History</a></small>
        <a data-alma-modal="StudentAssignmentDetailsModal" href="/assignment/1">HW: Timeline Events</a>
      </td>
      <td><i title="Missing"></i></td>
    </tr>
  </tbody>
</table>`)

	table := findNode(doc, func(n *html.Node) bool {
		return n.Type == html.ElementNode && n.Data == "table" && hasClass(n, "missing-assignments")
	})
	if table == nil {
		t.Fatal("missing table not found")
	}
	row := findNode(table, func(n *html.Node) bool { return n.Type == html.ElementNode && n.Data == "tr" })
	cells := directChildrenByTag(row, "td")
	if got := nodeText(cells[0]); got != "Mar 25" {
		t.Fatalf("got %q", got)
	}
	link := findNode(cells[1], func(n *html.Node) bool {
		return n.Type == html.ElementNode && n.Data == "a" && attr(n, "data-alma-modal") != ""
	})
	if got := nodeText(link); got != "HW: Timeline Events" {
		t.Fatalf("got %q", got)
	}
}

func TestLoadAlmaCredsFromEnv(t *testing.T) {
	t.Setenv("ALMA_USERNAME", "student")
	t.Setenv("ALMA_PASSWORD", "secret")

	got, err := loadAlmaCreds("")
	if err != nil {
		t.Fatalf("loadAlmaCreds returned error: %v", err)
	}
	if got["username"] != "student" || got["password"] != "secret" {
		t.Fatalf("unexpected creds: %#v", got)
	}
}

func TestLoadAlmaCredsRequiresPasswordWithEnvUsername(t *testing.T) {
	t.Setenv("ALMA_USERNAME", "student")
	t.Setenv("ALMA_PASSWORD", "")

	if _, err := loadAlmaCreds(""); err == nil {
		t.Fatal("expected error when ALMA_PASSWORD is missing")
	}
}

func TestLoadAlmaCredsFromFile(t *testing.T) {
	dir := t.TempDir()
	path := dir + "/alma.creds"
	if err := os.WriteFile(path, []byte("username: student\npassword: secret\n"), 0o600); err != nil {
		t.Fatalf("write creds file: %v", err)
	}

	got, err := loadAlmaCreds(path)
	if err != nil {
		t.Fatalf("loadAlmaCreds returned error: %v", err)
	}
	if got["username"] != "student" || got["password"] != "secret" {
		t.Fatalf("unexpected creds: %#v", got)
	}
}

func TestNormalizeSMTPHeloName(t *testing.T) {
	if got := normalizeSMTPHeloName("mail.example.invalid"); got != "mail.example.invalid" {
		t.Fatalf("got %q", got)
	}
	if got := normalizeSMTPHeloName("mailer"); got != "mailer.localdomain" {
		t.Fatalf("got %q", got)
	}
}

func TestClassesWithCurrentA(t *testing.T) {
	got := classesWithCurrentA([]ClassInfo{
		{Name: "Geometry Lab", Grade: "A"},
		{Name: "Civics", Grade: "B"},
		{Name: "Intro. Spanish 1", Grade: "A-"},
	})
	if !hasCurrentA(got, "Geometry Lab") {
		t.Fatal("expected Geometry Lab to have current A")
	}
	if !hasCurrentA(got, "Intro. Spanish 1") {
		t.Fatal("expected Intro. Spanish 1 to have current A")
	}
	if hasCurrentA(got, "Civics") {
		t.Fatal("did not expect Civics to have current A")
	}
}

func TestFetchScheduleClasses(t *testing.T) {
	doc := mustParseHTML(`
<table class="student-classes current-classes pure-table pure-table-horizontal">
  <tbody>
    <tr>
      <td><a data-track="Class Home Page" href="/class/1?back=/schedule">Geometry Lab</a></td>
      <td>S1, S2</td>
      <td>-</td>
      <td>Teacher</td>
      <td>A</td>
      <td>Aug 25, 2025</td>
      <td>-</td>
    </tr>
    <tr>
      <td><a data-track="Class Home Page" href="/class/2?back=/schedule">Civics</a></td>
      <td>S2</td>
      <td>-</td>
      <td>Teacher</td>
      <td>B</td>
      <td>Jan 20, 2026</td>
      <td>-</td>
    </tr>
  </tbody>
</table>`)
	base, err := url.Parse("https://example.invalid/children/student/schedule")
	if err != nil {
		t.Fatalf("parse base URL: %v", err)
	}
	got, err := extractScheduleClasses(doc, base)
	if err != nil {
		t.Fatalf("extractScheduleClasses returned error: %v", err)
	}
	if len(got) != 2 {
		t.Fatalf("got %d classes", len(got))
	}
	if got[1].Grade != "A" || got[1].Name != "Geometry Lab" {
		t.Fatalf("unexpected classes: %#v", got)
	}
}

func TestBuildBodyIncludesWeekday(t *testing.T) {
	now := time.Date(2026, 3, 30, 10, 0, 0, 0, time.UTC)
	start := time.Date(2026, 1, 20, 0, 0, 0, 0, time.UTC)
	body := buildBody([]Assignment{{
		DueDate: time.Date(2026, 3, 30, 0, 0, 0, 0, time.UTC),
		Course:  "Civics",
		Title:   "Essay",
		Status:  "Missing",
	}}, nil, start, "https://example.invalid/assignments", "https://example.invalid/schedule", now, 14)
	if !strings.Contains(body, "Monday 2026-03-30") {
		t.Fatalf("body missing weekday date: %s", body)
	}
}

func mustParseHTML(text string) *html.Node {
	doc, err := html.Parse(strings.NewReader(text))
	if err != nil {
		panic(err)
	}
	return doc
}