package store

import (
	"errors"
	"math"
	"testing"
)

func TestChargeFormulaVersionAndOverflow_HP_STORE_04(t *testing.T) {
	t.Parallel()

	if ChargeFormulaVersion != 1 {
		t.Fatalf("charge formula version = %d", ChargeFormulaVersion)
	}
	charge, err := EstimateCharge(ChargeInput{EncodedBytes: 100, SQLiteRows: 2, IndexEntries: 3})
	want := uint64(100 + 2*ChargeSQLiteRowBytes + 3*ChargeIndexEntryBytes)
	if err != nil || charge != want {
		t.Fatalf("EstimateCharge = (%d, %v), want %d", charge, err, want)
	}
	for _, input := range []ChargeInput{
		{SQLiteRows: math.MaxUint64},
		{IndexEntries: math.MaxUint64},
		{EncodedBytes: math.MaxUint64, SQLiteRows: 1},
	} {
		if _, err := EstimateCharge(input); !errors.Is(err, ErrCapacityExhausted) {
			t.Errorf("EstimateCharge(%+v) error = %v", input, err)
		}
	}
}

func TestTieredReservationOrderAndBoundaries_HP_STORE_05(t *testing.T) {
	t.Parallel()

	limits := quotaTestLimits()
	base := ReservationState{
		CommandOutputCharged: 10, CommandTotalCharged: 20, ClientTotalCharged: 30,
		ServerTotalCharged: 40, CloseoutRemaining: 20, FilesystemFreeBytes: 1000,
	}
	decision, err := CheckReservation(limits, base, ReservationRequest{ChargedBytes: 10, PhysicalBytes: 5, Output: true})
	if err != nil {
		t.Fatal(err)
	}
	if decision.CommandOutputCharged != 20 || decision.CommandTotalCharged != 30 || decision.ClientTotalCharged != 40 || decision.ServerTotalCharged != 50 || decision.CloseoutRemaining != 20 {
		t.Fatalf("decision = %+v", decision)
	}

	cases := []struct {
		name    string
		state   ReservationState
		request ReservationRequest
		tier    CapacityTier
	}{
		{"hard maximum first", base, ReservationRequest{ChargedBytes: 101, PhysicalBytes: 1, Output: true}, CapacityTierHardMaximum},
		{"output", withState(base, 95, 20, 30, 40, 20, 1000), ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1, Output: true}, CapacityTierCommandOut},
		{"command reserve", withState(base, 10, 175, 175, 175, 20, 1000), ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1}, CapacityTierCommand},
		{"client", withState(base, 10, 20, 295, 295, 20, 1000), ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1}, CapacityTierClient},
		{"server", withState(base, 10, 20, 30, 395, 20, 1000), ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1}, CapacityTierServer},
		{"filesystem", withState(base, 10, 20, 30, 40, 20, 54), ReservationRequest{ChargedBytes: 10, PhysicalBytes: 5}, CapacityTierFilesystem},
	}
	for _, test := range cases {
		t.Run(test.name, func(t *testing.T) {
			_, err := CheckReservation(limits, test.state, test.request)
			var capacity *CapacityError
			if !errors.As(err, &capacity) || capacity.Tier != test.tier {
				t.Fatalf("error = %v, want tier %s", err, test.tier)
			}
		})
	}
}

func TestCloseoutReservationCanBeConsumed_BH_STORE_06(t *testing.T) {
	t.Parallel()

	limits := quotaTestLimits()
	state := ReservationState{
		CommandOutputCharged: 90, CommandTotalCharged: 190, ClientTotalCharged: 200,
		ServerTotalCharged: 200, CloseoutRemaining: 10, FilesystemFreeBytes: 1000,
	}
	if _, err := CheckReservation(limits, state, ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1}); err == nil {
		t.Fatal("normal allocation consumed closeout headroom")
	}
	decision, err := CheckReservation(limits, state, ReservationRequest{ChargedBytes: 10, PhysicalBytes: 1, UseCloseout: true})
	if err != nil {
		t.Fatal(err)
	}
	if decision.CommandTotalCharged != 200 || decision.CloseoutRemaining != 0 {
		t.Fatalf("closeout decision = %+v", decision)
	}
	if _, err := CheckReservation(limits, state, ReservationRequest{ChargedBytes: math.MaxUint64, PhysicalBytes: 1, UseCloseout: true}); !errors.Is(err, ErrCapacityExhausted) {
		t.Fatalf("overflow error = %v", err)
	}
}

func quotaTestLimits() QuotaLimits {
	return QuotaLimits{
		HardAllocationBytes: 100, CommandOutputBytes: 100, CommandTotalBytes: 200,
		ClientTotalBytes: 300, ServerTotalBytes: 400, CloseoutReserveBytes: 20, FilesystemFloorBytes: 50,
	}
}

func withState(base ReservationState, output, command, client, server, closeout, free uint64) ReservationState {
	base.CommandOutputCharged = output
	base.CommandTotalCharged = command
	base.ClientTotalCharged = client
	base.ServerTotalCharged = server
	base.CloseoutRemaining = closeout
	base.FilesystemFreeBytes = free
	return base
}