package hub

import (
	"context"
	"strings"
	"testing"
	"time"

	"gitea.lab.audasmedia.com.au/sam/compass_teams_nhs/internal/store"
)

// fakeReader is the read-only Reader backed by fixed data. It has no write
// method, which is how the "read only" contract is enforced on /ask.
type fakeReader struct {
	children []store.Child
	items    map[int64][]store.Item
	scans    map[int64]store.ScanStatus
}

func (f *fakeReader) ListChildren(context.Context) ([]store.Child, error) {
	return f.children, nil
}

func (f *fakeReader) ItemsForChild(_ context.Context, childID int64) ([]store.Item, error) {
	return f.items[childID], nil
}

func (f *fakeReader) ScanSummaryForChild(_ context.Context, childID int64) (store.ScanStatus, error) {
	return f.scans[childID], nil
}

// testNow is a fixed Wednesday afternoon in the family timezone.
var testNow = time.Date(2026, 10, 15, 12, 0, 0, 0, mustSydney())

func mustSydney() *time.Location {
	loc, err := time.LoadLocation("Australia/Sydney")
	if err != nil {
		panic(err)
	}
	return loc
}

func at(y int, mo time.Month, d, h, mi int) *time.Time {
	t := time.Date(y, mo, d, h, mi, 0, 0, mustSydney())
	return &t
}

func okScan(t time.Time) store.ScanStatus {
	return store.ScanStatus{EverRun: true, Total: 3, Last: &store.Scan{ID: 3, StartedAt: t, OK: true}}
}

func testAnswerer(r Reader) *Answerer {
	a := NewAnswerer(r, mustSydney())
	a.Now = func() time.Time { return testNow }
	return a
}

// harryData is one realistic day: eight lessons, one task due today, two
// overdue SACs, one task this week and one notice.
func harryData() *fakeReader {
	return &fakeReader{
		children: []store.Child{{ID: 1, Name: "Harry"}, {ID: 2, Name: "Finn"}},
		items: map[int64][]store.Item{1: {
			{ID: 1, ChildID: 1, Type: "event", Title: "8:55: 11XMUSA6 - A1 - JBR", DueAt: at(2026, 10, 15, 8, 55)},
			{ID: 2, ChildID: 1, Type: "event", Title: "9:50: 11AACPA4 - C1 - BDR", DueAt: at(2026, 10, 15, 9, 50)},
			{ID: 3, ChildID: 1, Type: "event", Title: "11:00: 11SBIOA1 - M4 - AFR", DueAt: at(2026, 10, 15, 11, 0)},
			{ID: 4, ChildID: 1, Type: "event", Title: "14:00: 11EENGB3 - H3 - CHA", DueAt: at(2026, 10, 15, 14, 0)},
			{ID: 5, ChildID: 1, Type: "event", Title: "18:00: Senior Music Concert - HALL", DueAt: at(2026, 10, 15, 18, 0)},
			{ID: 6, ChildID: 1, Type: "task", Subject: "11EENG ENGLISH", Title: "SAC 3: Responding to Texts",
				Body: "Status: Pending\nDue: 2026-10-15 16:00", DueAt: at(2026, 10, 15, 16, 0)},
			{ID: 7, ChildID: 1, Type: "task", Subject: "11HLEG LEGAL STUDIES", Title: "SAC 6: Human Rights",
				Body: "Status: Overdue", DueAt: at(2026, 10, 9, 16, 0)},
			{ID: 8, ChildID: 1, Type: "task", Subject: "11XMUS MUSIC", Title: "SAC 1: Performing",
				Body: "Status: Overdue", DueAt: at(2026, 10, 5, 16, 0)},
			{ID: 9, ChildID: 1, Type: "task", Subject: "11MGMA MATHS", Title: "SAC 4: Networks",
				Body: "Status: Pending", DueAt: at(2026, 10, 19, 16, 0)},
			{ID: 10, ChildID: 1, Type: "message", Title: "Health Information", DueAt: at(2026, 10, 13, 9, 0)},
		}},
		scans: map[int64]store.ScanStatus{1: okScan(testNow.Add(-4 * time.Hour))},
	}
}

func answerOf(t *testing.T, a *Answerer, req AskRequest) string {
	t.Helper()
	resp := a.Answer(context.Background(), req)
	if resp.Answer == nil {
		t.Fatalf("answer = nil, reason = %q", resp.Reason)
	}
	return *resp.Answer
}

func TestTodayQuestion(t *testing.T) {
	a := testAnswerer(harryData())
	got := answerOf(t, a, AskRequest{
		Question: "what does Harry have on today at school?",
		Asker:    "sam",
		Person:   "harry",
		Source:   "esp32",
	})
	// 5 lessons, 1 task due today, 2 overdue.
	if !strings.Contains(got, "5 school events today from 8:55am to 6:00pm") {
		t.Errorf("answer = %q, want the lesson count and span", got)
	}
	if !strings.Contains(got, "1 task due today") {
		t.Errorf("answer = %q, want 1 task due today", got)
	}
	if !strings.Contains(got, "2 overdue tasks") {
		t.Errorf("answer = %q, want 2 overdue tasks", got)
	}
	if strings.Count(got, ".") != 1 {
		t.Errorf("answer = %q, want one sentence", got)
	}
}

func TestTodayQuestionIsCorrectForRealShape(t *testing.T) {
	// The Hub lower-cases the person, and the status line uses the HTML grid
	// prefix. Both must resolve the same way.
	a := testAnswerer(harryData())
	resp := a.Answer(context.Background(), AskRequest{Question: "what has harry got on today?", Asker: "sam", Person: "Harry"})
	if resp.Answer == nil {
		t.Fatalf("answer = nil, reason = %q", resp.Reason)
	}
	if resp.Data["child"] != "Harry" {
		t.Errorf("data.child = %v, want Harry", resp.Data["child"])
	}
	if resp.Expires == "" {
		t.Error("expires is empty, want end of day")
	}
}

func TestOverdueFocus(t *testing.T) {
	a := testAnswerer(harryData())
	got := answerOf(t, a, AskRequest{Question: "does Harry have any overdue work?", Asker: "sam", Person: "harry"})
	if got != "Harry has 2 overdue tasks." {
		t.Errorf("answer = %q, want the overdue count only", got)
	}
}

func TestMessagesFocus(t *testing.T) {
	a := testAnswerer(harryData())
	got := answerOf(t, a, AskRequest{Question: "any school notices for Harry?", Asker: "sam", Person: "harry"})
	if got != "Harry has 1 school notice." {
		t.Errorf("answer = %q, want one notice", got)
	}
}

func TestWeekFocus(t *testing.T) {
	a := testAnswerer(harryData())
	got := answerOf(t, a, AskRequest{Question: "what is due this week for Harry?", Asker: "sam", Person: "harry"})
	if !strings.Contains(got, "1 task due this week") {
		t.Errorf("answer = %q, want the week count", got)
	}
}

// TestFailedScanIsLoud is the FR-12 promise: a failed scan is never an empty
// day. The answer says due work is unknown.
func TestFailedScanIsLoud(t *testing.T) {
	r := harryData()
	r.scans[1] = store.ScanStatus{EverRun: true, Total: 4, Failed: 1,
		Last: &store.Scan{ID: 4, StartedAt: testNow.Add(-2 * time.Hour), OK: false, Error: "cloudflare challenge"}}
	a := testAnswerer(r)
	resp := a.Answer(context.Background(), AskRequest{Question: "what does Harry have on today?", Asker: "sam", Person: "harry"})
	if resp.Answer == nil {
		t.Fatal("answer = nil, want a loud answer")
	}
	got := *resp.Answer
	if !strings.Contains(got, "failed") || !strings.Contains(got, "unknown") {
		t.Errorf("answer = %q, want the failed scan stated", got)
	}
	if strings.Contains(got, "nothing due") {
		t.Errorf("answer = %q, must not read as nothing due", got)
	}
	if resp.Data["scan_ok"] != false {
		t.Errorf("data.scan_ok = %v, want false", resp.Data["scan_ok"])
	}
}

func TestNeverScannedIsLoud(t *testing.T) {
	r := harryData()
	r.scans[1] = store.ScanStatus{}
	a := testAnswerer(r)
	got := answerOf(t, a, AskRequest{Question: "what does Harry have on today?", Asker: "sam", Person: "harry"})
	if !strings.Contains(got, "has not run") {
		t.Errorf("answer = %q, want the missing scan stated", got)
	}
}

func TestStaleScanIsQualified(t *testing.T) {
	r := harryData()
	r.scans[1] = okScan(testNow.Add(-50 * time.Hour))
	a := testAnswerer(r)
	got := answerOf(t, a, AskRequest{Question: "what does Harry have on today?", Asker: "sam", Person: "harry"})
	if !strings.Contains(got, "may be out of date") {
		t.Errorf("answer = %q, want a stale warning", got)
	}
}

func TestUnknownPersonCannotAnswer(t *testing.T) {
	a := testAnswerer(harryData())
	resp := a.Answer(context.Background(), AskRequest{Question: "what does Hogwarts have on today?", Asker: "sam"})
	if resp.Answer != nil {
		t.Fatalf("answer = %q, want nil", *resp.Answer)
	}
	if resp.Reason == "" {
		t.Error("reason is empty, want an explanation")
	}
}

func TestChildCannotAskAboutSibling(t *testing.T) {
	a := testAnswerer(harryData())
	resp := a.Answer(context.Background(), AskRequest{Question: "what does Finn have on today?", Asker: "harry", Person: "finn"})
	if resp.Answer != nil {
		t.Fatalf("answer = %q, want nil", *resp.Answer)
	}
	if !strings.Contains(resp.Reason, "not allowed") {
		t.Errorf("reason = %q, want a permission refusal", resp.Reason)
	}
}

func TestChildMayAskAboutThemselves(t *testing.T) {
	a := testAnswerer(harryData())
	resp := a.Answer(context.Background(), AskRequest{Question: "what do I have on today?", Asker: "harry", Person: "harry"})
	if resp.Answer == nil {
		t.Fatalf("answer = nil, reason = %q", resp.Reason)
	}
}

func TestEmptyQuestionCannotAnswer(t *testing.T) {
	a := testAnswerer(harryData())
	resp := a.Answer(context.Background(), AskRequest{Asker: "sam"})
	if resp.Answer != nil || resp.Reason == "" {
		t.Errorf("resp = %+v, want cannot-answer", resp)
	}
}

func TestCapabilitiesNameMatchesRouting(t *testing.T) {
	caps := DefaultCapabilities()
	if caps.Project != "compass_nhs" {
		t.Errorf("project = %q, want compass_nhs (the Hub routing.md row)", caps.Project)
	}
	if len(caps.Topics) == 0 || len(caps.People) == 0 {
		t.Error("capabilities must name topics and people")
	}
}