package billing

import (
	"context"
	"errors"
	"testing"
	"time"
)

func TestValidatePriceInput(t *testing.T) {
	input := CreatePriceBookInput{
		TenantID: "10000000-0000-0000-0000-000000000010", Provider: "mock", Currency: "CNY",
		SourceRef: "contract://mock/2026-v1", ChangeSummary: "本地回归单价", EffectiveFrom: time.Now().UTC(),
		Rates: []RateInput{{UsageCategory: "LLM", MetricCode: "input_tokens", Unit: "token", UnitPriceMicros: 2}},
	}
	if err := validatePriceInput(input); err != nil {
		t.Fatalf("valid price input rejected: %v", err)
	}
	input.Rates = append(input.Rates, input.Rates[0])
	if err := validatePriceInput(input); !errors.Is(err, ErrInvalid) {
		t.Fatalf("duplicate rate error = %v, want ErrInvalid", err)
	}
}

func TestValidateQuotaInput(t *testing.T) {
	valid := QuotaInput{ScopeType: "TENANT", BillingTimezone: "Asia/Shanghai", Currency: "CNY", DailyLimitMicros: 10_000_000, MonthlyLimitMicros: 100_000_000, MaxConcurrentCalls: 10, MaxCallDurationSec: 3600, InProgressAction: "COMPLETE_CURRENT_TURN", ChangeSummary: "家庭试点额度"}
	if err := validateQuotaInput(valid); err != nil {
		t.Fatalf("valid quota rejected: %v", err)
	}
	for name, mutate := range map[string]func(*QuotaInput){
		"tenant scope id":     func(item *QuotaInput) { item.ScopeID = "10000000-0000-0000-0000-000000000511" },
		"monthly below daily": func(item *QuotaInput) { item.MonthlyLimitMicros = item.DailyLimitMicros - 1 },
		"invalid timezone":    func(item *QuotaInput) { item.BillingTimezone = "China/Unknown" },
		"short duration":      func(item *QuotaInput) { item.MaxCallDurationSec = 59 },
	} {
		t.Run(name, func(t *testing.T) {
			item := valid
			mutate(&item)
			if err := validateQuotaInput(item); !errors.Is(err, ErrInvalid) {
				t.Fatalf("error = %v, want ErrInvalid", err)
			}
		})
	}
}

func TestUsageQuantityPrecision(t *testing.T) {
	for _, value := range []string{"0", "1", "1000", "0.000001", "999999999999999999.999999"} {
		if !quantityPattern.MatchString(value) {
			t.Fatalf("valid quantity %q rejected", value)
		}
	}
	for _, value := range []string{"-1", "01", "1.0000001", "1e3", "9999999999999999999"} {
		if quantityPattern.MatchString(value) {
			t.Fatalf("invalid quantity %q accepted", value)
		}
	}
}

func TestRecordProviderUsageValidation(t *testing.T) {
	ctx := context.Background()
	if _, err := RecordProviderUsageTx(ctx, nil, "", "", "", "", "", time.Time{}, nil); !errors.Is(err, ErrInvalid) {
		t.Fatalf("empty usage error=%v", err)
	}
	metrics := []UsageMetricInput{
		{UsageCategory: " llm ", MetricCode: " INPUT_TOKENS ", Quantity: "12", Unit: " TOKEN "},
		{UsageCategory: "LLM", MetricCode: "input_tokens", Quantity: "13", Unit: "token"},
	}
	if _, err := RecordProviderUsageTx(ctx, nil,
		"10000000-0000-0000-0000-000000000001", "10000000-0000-0000-0000-000000000901",
		"10000000-0000-0000-0000-000000000902", "mock", "usage-validation", time.Now().UTC(), metrics,
	); !errors.Is(err, ErrInvalid) {
		t.Fatalf("duplicate metric error=%v", err)
	}
	metrics = []UsageMetricInput{{UsageCategory: "UNKNOWN", MetricCode: "input_tokens", Quantity: "1", Unit: "token"}}
	if _, err := RecordProviderUsageTx(ctx, nil,
		"10000000-0000-0000-0000-000000000001", "10000000-0000-0000-0000-000000000901",
		"10000000-0000-0000-0000-000000000902", "mock", "usage-validation", time.Now().UTC(), metrics,
	); !errors.Is(err, ErrInvalid) {
		t.Fatalf("invalid category error=%v", err)
	}
	if _, err := NewService(nil, nil); err == nil {
		t.Fatal("invalid billing service dependencies were accepted")
	}
}