package learn

import (
	"reflect"
	"testing"
)

func TestBuildDatasetMapsWinAndLoss(t *testing.T) {
	rows := []LabeledRow{
		{Result: ResultWin, Features: map[string]float64{"a": 1}},
		{Result: ResultLoss, Features: map[string]float64{"a": 2}},
	}
	x, y, names := BuildDataset(rows)
	if !reflect.DeepEqual(names, []string{"a"}) {
		t.Fatalf("feature names must be [a], got %v", names)
	}
	if !reflect.DeepEqual(y, []int{1, 0}) {
		t.Fatalf("win must map to 1 and loss to 0, got %v", y)
	}
	if len(x) != 2 || x[0][0] != 1 || x[1][0] != 2 {
		t.Fatalf("feature matrix wrong: %v", x)
	}
}

func TestBuildDatasetDropsUndecided(t *testing.T) {
	rows := []LabeledRow{
		{Result: ResultWin, Features: map[string]float64{"a": 1}},
		{Result: ResultPending, Features: map[string]float64{"a": 9}},
		{Result: ResultNoBid, Features: map[string]float64{"a": 9}},
		{Result: ResultLoss, Features: map[string]float64{"a": 2}},
		{Result: "garbage", Features: map[string]float64{"a": 9}},
	}
	x, y, _ := BuildDataset(rows)
	if len(x) != 2 || len(y) != 2 {
		t.Fatalf("only the two decided rows must survive, got %d rows", len(x))
	}
	if y[0] != 1 || y[1] != 0 {
		t.Fatalf("the surviving rows must be the win then the loss, got %v", y)
	}
}

func TestBuildDatasetStableColumnOrdering(t *testing.T) {
	// feature keys arrive in different orders across rows; the column layout must be the sorted union.
	rows := []LabeledRow{
		{Result: ResultWin, Features: map[string]float64{"zeta": 1, "alpha": 2, "mid": 3}},
		{Result: ResultLoss, Features: map[string]float64{"mid": 4, "alpha": 5, "zeta": 6}},
	}
	x, _, names := BuildDataset(rows)
	if !reflect.DeepEqual(names, []string{"alpha", "mid", "zeta"}) {
		t.Fatalf("columns must be the sorted union, got %v", names)
	}
	// row 0 values must line up with the sorted names: alpha=2, mid=3, zeta=1
	if !reflect.DeepEqual(x[0], []float64{2, 3, 1}) {
		t.Fatalf("row 0 must align to sorted columns, got %v", x[0])
	}
	if !reflect.DeepEqual(x[1], []float64{5, 4, 6}) {
		t.Fatalf("row 1 must align to sorted columns, got %v", x[1])
	}
}

func TestBuildDatasetMissingFeatureIsZero(t *testing.T) {
	// row 1 lacks feature b; the union has a and b, so row 1's b column defaults to 0.
	rows := []LabeledRow{
		{Result: ResultWin, Features: map[string]float64{"a": 1, "b": 7}},
		{Result: ResultLoss, Features: map[string]float64{"a": 2}},
	}
	x, _, names := BuildDataset(rows)
	if !reflect.DeepEqual(names, []string{"a", "b"}) {
		t.Fatalf("columns must be [a b], got %v", names)
	}
	if !reflect.DeepEqual(x[1], []float64{2, 0}) {
		t.Fatalf("a missing feature must default to 0, got %v", x[1])
	}
}

func TestBuildDatasetEmptyInput(t *testing.T) {
	x, y, names := BuildDataset(nil)
	if len(x) != 0 || len(y) != 0 || len(names) != 0 {
		t.Fatalf("an empty input must yield empty outputs, got x=%v y=%v names=%v", x, y, names)
	}
}

func TestIsDecided(t *testing.T) {
	if !IsDecided(ResultWin) || !IsDecided(ResultLoss) {
		t.Fatal("win and loss must be decided")
	}
	if IsDecided(ResultPending) || IsDecided(ResultNoBid) || IsDecided("") {
		t.Fatal("pending, no_bid, and unknown must not be decided")
	}
}