package hub

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

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

// fakeReader is a read-only Reader backed by fixed data.
type fakeReader struct {
	devices []store.Device
	eff     map[int64]store.EffectiveState
	usage   map[string][]store.DeviceDayUsage
}

func (f *fakeReader) ListDevices(context.Context) ([]store.Device, error) {
	return f.devices, nil
}

func (f *fakeReader) EffectiveState(_ context.Context, dev store.Device, _ time.Time) (store.EffectiveState, error) {
	return f.eff[dev.ID], nil
}

func (f *fakeReader) UsageByDeviceForDay(_ context.Context, day string) ([]store.DeviceDayUsage, error) {
	return f.usage[day], nil
}

func testAnswerer(r Reader, now time.Time) *Answerer {
	loc := time.UTC
	a := NewAnswerer(r, loc)
	a.Now = func() time.Time { return now.In(loc) }
	return a
}

func mustAnswer(t *testing.T, a *Answerer, req AskRequest) AskResponse {
	t.Helper()
	return a.Answer(context.Background(), req)
}

func answerTextOf(t *testing.T, resp AskResponse) string {
	t.Helper()
	if resp.Answer == nil {
		t.Fatalf("answer = nil, reason = %q", resp.Reason)
	}
	return *resp.Answer
}

func TestScreenTimeToday(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{
			{ID: 1, Name: "Harry's phone", Child: "Harry"},
			{ID: 2, Name: "Finn's computer", Child: "Finn"},
		},
		usage: map[string][]store.DeviceDayUsage{
			"2026-10-13": {
				{DeviceID: 1, Name: "Harry's phone", Child: "Harry", AppSeconds: 3600, DomainSeconds: 900},
				// app and domain for the same session must not be summed.
				{DeviceID: 2, Name: "Finn's computer", Child: "Finn", AppSeconds: 1800, DomainSeconds: 2000},
			},
		},
	}
	a := testAnswerer(r, now)

	resp := mustAnswer(t, a, AskRequest{
		Question: "how long have the kids been on screens today?",
		Asker:    "sam",
	})
	got := answerTextOf(t, resp)
	if !strings.Contains(got, "1h 30m") {
		t.Errorf("answer = %q, want 1h 30m", got)
	}
	if total, _ := resp.Data["total_seconds"].(int); total != 5400 {
		t.Errorf("total_seconds = %v, want 5400 (app totals, no double count)", resp.Data["total_seconds"])
	}
}

func TestScreenTimeOneChild(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{
			{ID: 1, Name: "Harry's phone", Child: "Harry"},
			{ID: 2, Name: "Finn's computer", Child: "Finn"},
		},
		usage: map[string][]store.DeviceDayUsage{
			"2026-10-13": {
				{DeviceID: 1, Name: "Harry's phone", Child: "Harry", AppSeconds: 2700},
				{DeviceID: 2, Name: "Finn's computer", Child: "Finn", AppSeconds: 900},
			},
		},
	}
	a := testAnswerer(r, now)
	resp := mustAnswer(t, a, AskRequest{Question: "how long has Harry been on screens?", Asker: "sam"})
	if got := answerTextOf(t, resp); !strings.Contains(got, "45m") || !strings.Contains(got, "Harry") {
		t.Errorf("answer = %q, want Harry 45m", got)
	}
}

func TestScreenTimeYesterday(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{{ID: 1, Name: "Harry's phone", Child: "Harry"}},
		usage: map[string][]store.DeviceDayUsage{
			"2026-10-12": {{DeviceID: 1, Name: "Harry's phone", Child: "Harry", AppSeconds: 120}},
		},
	}
	a := testAnswerer(r, now)
	resp := mustAnswer(t, a, AskRequest{Question: "how long were the kids on screens yesterday?", Asker: "sam"})
	if got := answerTextOf(t, resp); !strings.Contains(got, "yesterday") {
		t.Errorf("answer = %q, want yesterday", got)
	}
}

func TestScreenTimeNoneRecorded(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{{ID: 1, Name: "Harry's phone", Child: "Harry"}},
		usage:   map[string][]store.DeviceDayUsage{},
	}
	a := testAnswerer(r, now)
	resp := mustAnswer(t, a, AskRequest{Question: "how long have the kids been on screens today?", Asker: "sam"})
	if got := answerTextOf(t, resp); !strings.Contains(got, "no recorded screen time") {
		t.Errorf("answer = %q", got)
	}
}

func TestBlockedAnswer(t *testing.T) {
	now := time.Date(2026, 10, 13, 20, 30, 0, 0, time.UTC)
	until := time.Date(2026, 10, 13, 21, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{{ID: 1, Name: "Harry's phone", Child: "Harry"}},
		eff: map[int64]store.EffectiveState{
			1: {DeviceID: 1, Locked: true, Reason: "schedule", Until: &until},
		},
	}
	a := testAnswerer(r, now)
	resp := mustAnswer(t, a, AskRequest{Question: "what is blocked right now?", Asker: "sam"})
	if got := answerTextOf(t, resp); !strings.Contains(got, "Harry's phone") || !strings.Contains(got, "21:00") {
		t.Errorf("answer = %q", got)
	}
}

func TestPresenceAnswer(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	lastSeen := now.Add(-2*time.Hour - 10*time.Minute)
	r := &fakeReader{
		devices: []store.Device{
			{ID: 1, Name: "Harry's phone", Child: "Harry", Online: true},
			{ID: 2, Name: "Finn's computer", Child: "Finn", Online: false, LastSeen: &lastSeen},
		},
	}
	a := testAnswerer(r, now)
	resp := mustAnswer(t, a, AskRequest{Question: "are the devices online?", Asker: "sam"})
	if got := answerTextOf(t, resp); !strings.Contains(got, "Finn's computer") || !strings.Contains(got, "2h 10m") {
		t.Errorf("answer = %q", got)
	}
}

func TestPermissionsAndUnknowns(t *testing.T) {
	now := time.Date(2026, 10, 13, 15, 0, 0, 0, time.UTC)
	r := &fakeReader{
		devices: []store.Device{{ID: 1, Name: "Harry's phone", Child: "Harry"}},
	}
	a := testAnswerer(r, now)

	cases := []struct {
		name string
		req  AskRequest
		want string
	}{
		{"no asker", AskRequest{Question: "screen time?"}, "no asker"},
		{"not sam", AskRequest{Question: "screen time?", Asker: "harry"}, "only answer for Sam"},
		{"unknown person", AskRequest{Question: "screen time?", Asker: "sam", Person: "jo"}, "no data for that person"},
		{"unknown intent", AskRequest{Question: "what is the weather?", Asker: "sam"}, "I can answer"},
	}
	for _, tc := range cases {
		resp := mustAnswer(t, a, tc.req)
		if resp.Answer != nil {
			t.Errorf("%s: answer = %q, want nil", tc.name, *resp.Answer)
			continue
		}
		if !strings.Contains(resp.Reason, tc.want) {
			t.Errorf("%s: reason = %q, want to contain %q", tc.name, resp.Reason, tc.want)
		}
	}
	if !strings.Contains(mustAnswer(t, a, AskRequest{Question: "", Asker: "sam"}).Reason, "no question") {
		t.Error("empty question should be refused")
	}
}

func TestDefaultCapabilities(t *testing.T) {
	c := DefaultCapabilities()
	if c.Project != "internet_control" {
		t.Errorf("project = %q", c.Project)
	}
	if len(c.Topics) == 0 || len(c.People) == 0 {
		t.Errorf("capabilities = %#v", c)
	}
}

func TestScreenSecondsPrefersApp(t *testing.T) {
	if got := ScreenSeconds(600, 900); got != 600 {
		t.Errorf("screenSeconds(600,900) = %d, want 600", got)
	}
	if got := ScreenSeconds(0, 900); got != 900 {
		t.Errorf("screenSeconds(0,900) = %d, want 900", got)
	}
}