package distribution

import "testing"

func TestDefaultRules(t *testing.T) {
	cases := []struct {
		mode  string
		check func(Rule) bool
	}{
		{ModeTwoPartyDistributorReceive, func(r Rule) bool { return r.DistributorReceiveRatio == 3.5 && r.PlatformSellRatio == 4 }},
		{ModeTwoPartyPlatformReceive, func(r Rule) bool { return r.PlatformReceiveRatio == 3.5 && r.DistributorSellRatio == 4 }},
		{ModeThreeParty, func(r Rule) bool { return r.DistributorARatio == 3.5 && r.DistributorBRatio == 4 }},
	}
	for _, item := range cases {
		rule, err := DefaultRule(item.mode)
		if err != nil || !item.check(rule) || rule.ServiceFeeValue != 2.5 || rule.PaymentFeeBPS != 50 {
			t.Fatalf("default rule %s = %#v, err=%v", item.mode, rule, err)
		}
	}
	if _, err := DefaultRule(ModeSiteSelfSell); err != ErrUnsupportedMode {
		t.Fatalf("site self-sell must not have a default split, err=%v", err)
	}
}

func TestCalculateSettlementDeductsFeeBeforeSplit(t *testing.T) {
	rule := Rule{ServiceFeeValue: 0, ServiceFeeUnit: ServiceFeeUnitFixedAmount, PaymentFeeBPS: 50}
	got, err := CalculateSettlement(rule, SettlementInput{GrossPaidAmountCent: 10001, RefundAmountCent: 1000, MarkupAmountCent: 300})
	if err != nil {
		t.Fatal(err)
	}
	if got.NetPaidAmountCent != 9001 || got.PaymentFeeCent != 45 || got.SplitBaseAmountCent != 8956 {
		t.Fatalf("unexpected settlement: %#v", got)
	}
}

func TestCalculateSettlementTaxesEachPositivePartyProfit(t *testing.T) {
	rule := Rule{ServiceFeeUnit: ServiceFeeUnitFixedAmount, PaymentFeeBPS: 0, TaxEnabled: true, TaxRateBPS: 100}
	got, err := CalculateSettlement(rule, SettlementInput{
		GrossPaidAmountCent: 10000,
		GrossProfitByParty: []PartyProfitInput{
			{PartyRole: "distributor_a", IncomeAmountCent: 1000, CostAmountCent: 400},
			{PartyRole: "distributor_b", IncomeAmountCent: 500, CostAmountCent: 700},
		},
	})
	if err != nil {
		t.Fatal(err)
	}
	if got.TaxAmountCent != 6 || len(got.TaxByParty) != 2 || got.TaxByParty[0].TaxAmountCent != 6 || got.TaxByParty[1].TaxAmountCent != 0 {
		t.Fatalf("unexpected tax result: %#v", got)
	}
}

func TestCalculateSettlementRejectsRefundOverPayment(t *testing.T) {
	_, err := CalculateSettlement(Rule{ServiceFeeUnit: ServiceFeeUnitFixedAmount}, SettlementInput{GrossPaidAmountCent: 1, RefundAmountCent: 2})
	if err != ErrInvalidAmount {
		t.Fatalf("err = %v", err)
	}
}

func TestSplitSettlementTwoPartyDistributorReceive(t *testing.T) {
	rule := Rule{Mode: ModeTwoPartyDistributorReceive, DistributorReceiveRatio: 3.5, PlatformSellRatio: 4}
	splits := SplitSettlement(rule, 10000, 0)
	if len(splits) != 2 {
		t.Fatalf("splits = %#v", splits)
	}
	if splits[0].PartyRole != "distributor_receive" || splits[0].AmountCent != 350 {
		t.Fatalf("distributor split = %#v", splits[0])
	}
	if splits[1].PartyRole != "platform_sell" || splits[1].AmountCent != 400 {
		t.Fatalf("platform split = %#v", splits[1])
	}
	if got := SplitRemainderCent(10000, splits); got != 9250 {
		t.Fatalf("remainder = %d, want 9250", got)
	}
}

func TestSplitSettlementMarkupGoesToSeller(t *testing.T) {
	// 两方-分销收号模式：卖出方是主站（platform_sell）。
	rule := Rule{Mode: ModeTwoPartyDistributorReceive, DistributorReceiveRatio: 3.5, PlatformSellRatio: 4}
	splits := SplitSettlement(rule, 10000, 300)
	if splits[1].AmountCent != 700 {
		t.Fatalf("platform split with markup = %d, want 700", splits[1].AmountCent)
	}
	// 两方-分销卖出模式：卖出方是分销网（distributor_sell）。
	ruleSell := Rule{Mode: ModeTwoPartyPlatformReceive, DistributorSellRatio: 4, PlatformReceiveRatio: 3.5}
	splitsSell := SplitSettlement(ruleSell, 10000, 300)
	if splitsSell[0].PartyRole != "distributor_sell" || splitsSell[0].AmountCent != 700 {
		t.Fatalf("distributor sell split with markup = %#v", splitsSell[0])
	}
	if got := SplitRemainderCent(10000, splitsSell); got != 8950 {
		t.Fatalf("remainder = %d, want 8950", got)
	}
}

func TestSplitSettlementThreeParty(t *testing.T) {
	rule := Rule{Mode: ModeThreeParty, DistributorARatio: 3.5, DistributorBRatio: 4}
	splits := SplitSettlement(rule, 10001, 0)
	if len(splits) != 2 || splits[0].AmountCent != 350 || splits[1].AmountCent != 400 {
		t.Fatalf("splits = %#v", splits)
	}
	// 尾差归平台：10001 - 750 = 9251。
	if got := SplitRemainderCent(10001, splits); got != 9251 {
		t.Fatalf("remainder = %d, want 9251", got)
	}
}