package usecase_test

import (
	"context"
	"testing"

	"apps/backend/internal/module/usage/domain"
	"apps/backend/internal/module/usage/repository"
	"apps/backend/internal/module/usage/usecase"

	"github.com/stretchr/testify/require"
)

func newUsage(uid int64, mode string) *usecase.Service {
	r := repository.NewMemory()
	res := &usecase.StaticResolver{Map: map[string]string{
		"1000001:ai_copy":    mode,
		"1000001:web_search": mode,
	}}
	// also allow mixed tests
	if mode == "mixed" {
		res.Map = map[string]string{
			"1000001:ai_copy":    domain.KeyModeByok,
			"1000001:web_search": domain.KeyModePlatform,
		}
	}
	return usecase.New(r, res)
}

func TestUSG_01_NewMemberSummarySplit(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	sum, err := svc.GetSummary(context.Background(), 1_000_001, "")
	require.NoError(t, err)
	require.Equal(t, domain.PlanFree, sum.PlanID)
	require.Equal(t, 0, sum.Platform.CreditsUsed)
	require.Equal(t, 0, sum.Byok.CallCount)
	require.Greater(t, sum.Platform.CreditsRemaining, 0)
}

func TestUSG_02_PlatformOnly(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	_, err := svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModePlatform, "copy", "test")
	require.NoError(t, err)
	sum, err := svc.GetSummary(context.Background(), 1_000_001, domain.CurrentMonthKey())
	require.NoError(t, err)
	require.Equal(t, 1, sum.Platform.CreditsUsed)
	require.Equal(t, 0, sum.Byok.CallCount)
}

func TestUSG_03_ByokOnly(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModeByok)
	before, _ := svc.GetSummary(context.Background(), 1_000_001, "")
	_, err := svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "copy", "test")
	require.NoError(t, err)
	sum, err := svc.GetSummary(context.Background(), 1_000_001, domain.CurrentMonthKey())
	require.NoError(t, err)
	require.Equal(t, before.Platform.CreditsRemaining, sum.Platform.CreditsRemaining)
	require.Equal(t, 1, sum.Byok.CallCount)
	require.Equal(t, 0, sum.Platform.CreditsUsed)
}

func TestUSG_04_MixedAIByokSearchPlatform(t *testing.T) {
	svc := newUsage(1_000_001, "mixed")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "ai", "t")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterWebSearch, domain.KeyModePlatform, "search", "t")
	sum, err := svc.GetSummary(context.Background(), 1_000_001, domain.CurrentMonthKey())
	require.NoError(t, err)
	require.Equal(t, 1, sum.Platform.CreditsUsed) // search only
	require.Equal(t, 1, sum.Byok.CallCount)       // ai only
}

func TestUSG_05_ListEventsHasKeyMode(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModePlatform, "x", "t")
	list, err := svc.ListEvents(context.Background(), 1_000_001, "", "all", 10)
	require.NoError(t, err)
	require.NotEmpty(t, list)
	require.Equal(t, domain.KeyModePlatform, list[0].KeyMode)
	require.NotEmpty(t, list[0].Meter)
}

func TestUSG_06_FilterByok(t *testing.T) {
	svc := newUsage(1_000_001, "mixed")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "a", "t")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterWebSearch, domain.KeyModePlatform, "s", "t")
	list, err := svc.ListEvents(context.Background(), 1_000_001, "", domain.KeyModeByok, 50)
	require.NoError(t, err)
	require.Len(t, list, 1)
	require.Equal(t, domain.KeyModeByok, list[0].KeyMode)
}

func TestUSG_07_FilterPlatform(t *testing.T) {
	svc := newUsage(1_000_001, "mixed")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "a", "t")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterWebSearch, domain.KeyModePlatform, "s", "t")
	list, err := svc.ListEvents(context.Background(), 1_000_001, "", domain.KeyModePlatform, 50)
	require.NoError(t, err)
	require.Len(t, list, 1)
	require.Equal(t, domain.KeyModePlatform, list[0].KeyMode)
}

func TestUSG_08_NoMergedTotalOnly(t *testing.T) {
	svc := newUsage(1_000_001, "mixed")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "a", "t")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterWebSearch, domain.KeyModePlatform, "s", "t")
	sum, err := svc.GetSummary(context.Background(), 1_000_001, domain.CurrentMonthKey())
	require.NoError(t, err)
	// Must have separate blocks; platform remaining is not reduced by byok
	require.NotNil(t, sum.Platform)
	require.NotNil(t, sum.Byok)
	require.Equal(t, 1, sum.Platform.CallCount)
	require.Equal(t, 1, sum.Byok.CallCount)
	// total_credits is plan allotment (platform), not call merge
	require.Equal(t, sum.Platform.CreditsTotal, sum.TotalCredits)
}

func TestST_07_ByokNoCreditCharge(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModeByok)
	before, _ := svc.GetSummary(context.Background(), 1_000_001, "")
	mode, err := svc.PrepareCall(context.Background(), 1_000_001, domain.MeterAICopy)
	require.NoError(t, err)
	require.Equal(t, domain.KeyModeByok, mode)
	_, err = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, mode, "byok", "ai")
	require.NoError(t, err)
	after, _ := svc.GetSummary(context.Background(), 1_000_001, domain.CurrentMonthKey())
	require.Equal(t, before.Platform.CreditsRemaining, after.Platform.CreditsRemaining)
	require.Equal(t, 1, after.Byok.CallCount)
}

func TestST_09_NoKeyFails(t *testing.T) {
	r := repository.NewMemory()
	svc := usecase.New(r, &usecase.StaticResolver{Map: map[string]string{}})
	_, err := svc.PrepareCall(context.Background(), 1_000_001, domain.MeterAICopy)
	require.ErrorIs(t, err, domain.ErrNoKey)
}

func TestST_13_PlatformQuota(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	// burn free plan
	for i := 0; i < 80; i++ {
		_, err := svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModePlatform, "x", "t")
		require.NoError(t, err)
	}
	_, err := svc.PrepareCall(context.Background(), 1_000_001, domain.MeterAICopy)
	require.ErrorIs(t, err, domain.ErrQuotaExceeded)
}

func TestUSG_11_PurchasePlan(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	p, err := svc.PurchasePlan(context.Background(), 1_000_001, domain.PlanStarter, "mock-pay-1")
	require.NoError(t, err)
	require.Equal(t, domain.PlanStarter, p.PlanID)
	prefs, _ := svc.GetPrefs(context.Background(), 1_000_001)
	require.Equal(t, domain.PlanStarter, prefs.PlanID)
	list, err := svc.ListMyPurchases(context.Background(), 1_000_001, 10)
	require.NoError(t, err)
	require.NotEmpty(t, list)
}

func TestUSG_10_TenantAnalyticsSplit(t *testing.T) {
	svc := newUsage(1_000_001, "mixed")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterAICopy, domain.KeyModeByok, "a", "t")
	_, _ = svc.RecordCall(context.Background(), 1_000_001, domain.MeterWebSearch, domain.KeyModePlatform, "s", "t")
	ten, err := svc.TenantSummary(context.Background(), domain.CurrentMonthKey())
	require.NoError(t, err)
	require.Equal(t, 1, ten.PlatformCreditsUsed)
	require.Equal(t, 1, ten.ByokCallCount)
}

func TestUSG_14_MemberCannotSetOthersPrefs(t *testing.T) {
	svc := newUsage(1_000_001, domain.KeyModePlatform)
	_, err := svc.SetPrefs(context.Background(), 1_000_001, 1_000_002, false, domain.PlanPro, nil)
	require.ErrorIs(t, err, domain.ErrForbidden)
}