package processor

import (
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"

	"apskel-pos-be/internal/entities"
)

func gameEvent(multiplier *float64, bonus *int64) entities.GameEvent {
	return entities.GameEvent{ID: uuid.New(), BudgetID: uuid.New(), Multiplier: multiplier, Bonus: bonus}
}

func amounts(parts []gameRewardComponent) []int64 {
	out := make([]int64, 0, len(parts))
	for _, p := range parts {
		out = append(out, p.Amount)
	}
	return out
}

// PRD §7, §14, §16 with the default stacking rules.
func TestRewardComponents(t *testing.T) {
	ramadan := gameEvent(ptr(2.0), nil)
	parts, capped := rewardComponents(10, 0, []entities.GameEvent{ramadan})
	assert.False(t, capped)
	assert.Equal(t, []int64{10, 10}, amounts(parts), "10 Coin + Ramadan 2x: 10 from the global budget, 10 from the event's")
	assert.Equal(t, gameRewardKindBase, parts[0].Kind)
	assert.Equal(t, gameRewardKindEvent, parts[1].Kind)
	assert.Equal(t, ramadan.BudgetID, parts[1].BudgetID)
	assert.Equal(t, ramadan.ID, *parts[1].EventID)

	// Each event works on the base: 2x and 1.5x add 10 and 5, they do not compound.
	// Bonuses are counted on their own.
	parts, _ = rewardComponents(10, 0, []entities.GameEvent{gameEvent(ptr(2.0), nil), gameEvent(ptr(1.5), ptr(int64(3))), gameEvent(nil, ptr(int64(5)))})
	assert.Equal(t, []int64{10, 10, 8, 5}, amounts(parts))

	// Rounded down to whole EnakCoin.
	parts, _ = rewardComponents(3, 0, []entities.GameEvent{gameEvent(ptr(1.5), nil), gameEvent(ptr(1.33), nil)})
	assert.Equal(t, []int64{3, 1}, amounts(parts), "1.5 adds 1.5 → 1; 1.33 adds 0.99 → 0 and is left out")

	// The cap holds for the total, cutting the lowest priority event first.
	parts, capped = rewardComponents(10, 22, []entities.GameEvent{gameEvent(ptr(2.0), nil), gameEvent(nil, ptr(int64(5)))})
	assert.True(t, capped)
	assert.Equal(t, []int64{10, 10, 2}, amounts(parts))
	assert.Equal(t, []int64{10, 10, 5}, []int64{parts[0].Earned, parts[1].Earned, parts[2].Earned})
	parts, _ = rewardComponents(30, 20, []entities.GameEvent{gameEvent(ptr(2.0), nil)})
	assert.Equal(t, []int64{20, 0}, amounts(parts), "a base at the cap leaves events nothing")

	// Nothing earned, nothing added: a bonus needs a play that earned.
	parts, _ = rewardComponents(0, 0, []entities.GameEvent{gameEvent(nil, ptr(int64(5)))})
	assert.Empty(t, parts)

	// Events paid by the same budget pay one ledger row.
	shared := uuid.New()
	a, b := gameEvent(nil, ptr(int64(2))), gameEvent(nil, ptr(int64(3)))
	a.BudgetID, b.BudgetID = shared, shared
	parts, _ = rewardComponents(10, 0, []entities.GameEvent{a, b})
	parts[0].BudgetID = uuid.New()
	payments := paymentsByBudget(parts)
	assert.Len(t, payments, 2)
	assert.EqualValues(t, 5, payments[1].Amount)
}